Liquid Crystalline Polymer Compositions, Process and Products

This application claims priority of PCT Application No. PCT/US83/01437 filed 15 Sept. 1983.

The present invention relates broadly to novel anisotropic (liquid crystalline) extended chain polymer-polyphosphoric acid compositions, to the preparation of such compositions by polycondensation of selected monomers in certain polyphosphoric acids under conditions to exercise control of molecular weight (characterized by intrinsic viscosity), and especially to the preparation of highly concentrated polymer compositions from which industrially useful polymeric articles such as fibers, fibrids, films and the like are readily produced.

Among some of the most serious difficulties encountered in the production of thermally stable articles such as fibers and film from extended chain polymers are described in the Background Art below.

Reference is made to other co-pending PCT International and U.S. patent applications all assigned to SRI International and having as one of their inventors, James F. Wolfe. Said other PCT applications are entitled: "Liquid Crystalline Poly(2,6-benzothiazole) Compositions, Process, and Products", No. PCT/US82/01286; "Liquid Crystalline Polymer Compositions, Process, and Products", No. PCT/US82/01285 both having a filling date of 17 Sept. 1982 and "Liquid Crystalline Polymer Compositions, Process, and Products", No. PCT/US83/01437 having a filing date of 15 Sept. 1983. These co-pending International and corresponding U.S. patent applications are herein incorporated by reference.

In general, the class of aromatic heterocyclic extended chain polymers are well known for their outstanding thermal, physical, and chemical properties. Unfortunately, these polymers are essentially non-melting and have proven very difficult to economically process into articles. In order to fashion such polymers into desired articles of commerce, for example fibers, films, fibrids, and the like, it is necessary that they be in solution or dope form. Although such polymers can be dissolved in various acidic solvents, such as sulfuric acid, methanesulfonic acid, chlorosulfonic acid, polyphosphoric acid, and the like, difficulty is often experienced in preparing and using the polymer-acid compositions or dopes because of poor polymer-acid solubility.

Normally, a precipitated or dried particulate form of the polymer is dissolved in a strong acid solvent by mixing the (isolated) polymer particles at elevated temperatures and/or under high pressures for a period from several hours to several days. If the polymer is insoluble in the particular solvent, other solvents or various solvent mixtures are employed. Usually, heating and cooling cycles are applied and repeated to obtain a useful dope.

The resulting dopes often contain undissolved polymer and must be filtered before further processing into articles.

Although spinning dopes of polybenzobisoxazole, polybenzimidazole and polybenzobisthiazole in sulfuric acid and/or methanesulfonic acid and/or chlorosulfonic acid with polymer concentrations above about 10 percent are known in the art, the intrinsic viscosity of these polymers is for the most part below 5 dL/g and oftentimes less than 3 dL/g. The cohesive strength of such dopes is inherently weak and economically less desirable for use in dry-jet wet spinning. In the case of polybenzobisoxazole, numerous attempts of dry-jet wet spinning an approximately 10% polybenzobisoxazole/methane sulfonic acid-dope into fibers were not successful (E. W. Choe, et al., in Macromolecules 1981, 14, pp 920-924).

In the case of polybenzimidazole, prior art dopes of this polymer lack adequate strength to maintain filament integrity while dropping through the air-gap. In order to overcome this problem U.S. Pat. No. 4,263,245 teaches dissolving a high concentration (up to 30%) of this polymer into suitable solvents such as concentrated sulfuric acid. At such high polymer concentrations lithium chloride is required to prevent the polybenzimidazole from phasing out of solution.

In the case of polybenzobisthiazole, U.S. Pat. No. 4,225,700 teaches the formation of a liquid crystalline composition of this polymer at concentrations near 10% in methanesulfonic acid and chlorosulfonic acid and at about 6% in polyphosphoric acid. Concentrations of polybenzobisthiazole in polyphosphoric acid above about 10% by weight are difficult, if indeed possible to achieve. One difficulty encountered is that the solution of the 2,5-diamino-1,4-benzenedithiol monomer in polyphosphoric acid with the P.sub.2 O.sub.5 content described in U.S. Pat. No. 4,225,700 is very viscous and dehydrohalogenation is difficult. Also considerable foaming results. Although solutions of precipitated polymer in solvents such as methanesulfonic acid and chlorosulfonic acid can be prepared, high concentrations of polymer are difficult or impossible to achieve. S. R. Allen, et al., in Macromolecules 1981, 14, pp. 1135-1139 describes attempts at spinning polybenzobisthiazole directly from the polymerization medium (polyphosphoric acid) containing 5-6% polymer.

Insofar as polybenzobisthiazole is concerned it is possible to obtain compositions near to 10% of the polymer in polyphosphoric acid with intrinsic viscosity equal to 26 dL/g (J. F. Wolfe, et al., Macromolecules 1981, 14, pp. 915-920). Attempts to increase the intrinsic viscosity of the polymer can only be achieved at a major sacrifice (decrease) in polymer concentration. Liquid crystalline compositions of 10% polybenzobisthiazole in polyphosphoric acid are heretofore unknown in the art. Liquid crystalline compositions of polybenzobisthiazole having intrinsic viscosities greater than about 30.3 dL/g in polyphosphoric acid are heretofore unknown in the art.

In general, liquid crystalline extended chain polymer compositions (with the exception of polybenzobisthiazole as mentioned above) in polyphosphoric acid are heretofore unknown in the art; and moreover, liquid crystalline extended chain copolymer and block polymer compositions are heretofore unknown in the art. Furthermore, the preparation of anisotropic extended chain polymer-polyphosphoric acid compositions having high polymer content and under conditions to exercise control of molecular weight is heretofore unknown in the art.

In practical terms this means that prior art dopes are severely limited in their potential usefulness for the production of highly ordered high molecular weight polymer articles. The prior art dopes may be less desirable for making articles of uniform quality and reproducibility which must require polymers with the highest molecular weight attainable or a selected lower molecular weight for maintaining dope processability or other difficult to control parameters.

Accordingly, it is an object of the present invention to provide compositions substantially free of one or more of the disadvantages of prior art compositions.

Another object is to provide a process for preparing liquid crystalline extended chain polymer compositions.

A further object is to provide liquid crystalline extended chain polymer compositions having excellent cohesive strength.

Another object is to provide liquid crystalline extended chain polymer compositions having excellent spin stretchability.

Another object is to provide liquid crystalline extended chain polymer compositions capable of being drawn through long air gap distances.

Yet another object is to provide liquid crystalline extended chain polymer compositions capable of being drawn at high spin draw ratios.

A further object of the invention is to prepare a liquid crystalline spinning composition having a high extended chain polymer content.

A still further object is to provide liquid crystalline extended chain homopolymer compositions.

Another object is to provide liquid crystalline extended chain copolymer compositions.

Yet another object is to provide liquid crystalline extended chain block polymer compositions.

Another object of the invention is to provide a method of preparing a liquid crystalline polymer composition having a high polymer content of an extended chain homopolymer.

Another object of the invention is to provide a method of preparing a liquid crystalline polymer composition having a high polymer content of an extended chain copolymer.

Another object of the invention is to provide a method of preparing a liquid crystalline polymer composition having a high polymer content of an extended chain block polymer.

Another object of the invention is to provide a method of preparing liquid crystalline extended chain polymer compositions from selected monomers.

Another object is to provide a process for preparing liquid crystalline high molecular weight extended chain polymer compositions.

A further object of the invention is to provide a method for synthesizing high molecular weight extended chain homopolymers.

A further object of the invention is to provide a method for synthesizing high molecular weight extended chain copolymers.

A further object of the invention is to provide a method for synthesizing high molecular weight extended chain block polymers.

A still further object is to provide a method whereby the dehydrohalogenation of certain hydrohalide monomers may be carried out more easily and rapidly.

Yet another object is to provide a method whereby a substantially higher concentration of monomeric reactants can be employed which results in liquid crystalline extended chain polymer compositions of considerably higher polymer concentration than has been possible heretofore.

Another object is to alleviate the foaming problem referred to above.

Another object is to provide articles prepared from liquid crystalline extended chain polymer compositions.

A further object of the invention is to prepare articles such as fibers and films from a liquid crystalline polymer composition comprising selected extended chain homopolymers.

A further object of the invention is to prepare articles such as fibers and films from a liquid crystalline polymer composition comprising selected extended chain copolymers.

A further object of the invention is to prepare articles such as fibers and films from a liquid crystalline polymer composition comprising selected extended chain block polymers.

Yet another object is to provide a process for preparing liquid crystalline extended chain polymers compositions under conditions to exercise control of molecular weight (characterized by intrinsic viscosity) so as to obtain a molecular weight less than the maximum attainable.

Another object is to provide a process for preparing liquid crystalline extended chain homopolymer, copolymer, or block polymer compositions under conditions to exercise control of molecular weight (characterized by intrinsic viscosity) so as to obtain a molecular weight less than the maximum attainable.

A still further object is to provide a process for preparing a liquid crystalline polymer composition having a high polymer content of an extended chain homopolymer, copolymer, or block polymer under conditions to exercise control of molecular weight (characterized by intrinsic viscosity) so as to obtain a molecular weight less than the maximum attainable.

Another object of the invention is to provide a process for the continuous production of extended chain homopolymer, copolymer, and block polymer articles such as fibers and films starting with selected monomers.

The above and other objects of the invention will be apparent from the ensuing description and the appended claims.

In accordance with our discovery, the present invention broadly encompasses novel polymer compositions which are useful as dopes in the production of high strength shaped articles comprising blends of certain polyphosphoric acids, as described hereinafter, and a high concentration of one or more substantially high molecular weight chain polymers having one or more mesogenic group or groups. The extended chain polymers can be homopolymers, copolymers, or block polymers, as exemplified hereinafter. The extended chain polymer is present in the blend at a sufficient concentration so as to be capable of exhibiting an anisotropic polymer phase alone or in combination with one or more different polymers with or without mesogenic group or groups. The blends according to the invention are polycondensation products obtained by reaction of selected monomers in an appropriate solution of phosphoric acid under conditions to exercise control of molecular weight (characterized by intrinsic viscosity). Suitable control of molecular weight is accomplished by discontinuing the condensation at a desired degree of polymerization; the extended chain polymer molecular weight of such blends can be further adjusted on heating. Alternatively, molecular weight control or "stabilization" can be accomplished by off balancing the stoichiometric proportion of monomers (i.e., adding a selected excess amount of one bifunctional reactant AA or BB) at a selected stage of condensation. Most preferably, molecular weight control (i.e., molecular weight "stabilization") can be accomplished by the addition of one or more suitable monofunctional reactants in selected amounts and at a selected stage of condensation. These methods of achieving molecular weight control are further described hereinafter. The blends of the invention exhibit special properties which make them very useful as dopes in the production of fibers, films, fibrids, and the like. In addition to being anisotropic (liquid-crystalline), the blends have a novel combination of properties including unexpectedly high spin-stretchability and excellent cohesive strength, as well as having the capability of being drawn through short, as well as extremely long, air-gap distances, and spun at low, as well as exceptionally high, draw ratios. It is believed that these properties can be attributed to the combination of high polymer concentration, substantially high polymer molecular weight, and a high phosphorus pentoxide content comprising the blends of the present invention.

Our discovery further broadly encompasses a process for preparing novel liquid crystalline extended chain polymer compositions which are useful as dopes in the production of fibers, fibrids, films, and the like. This process comprises:

(a) mixing at least one of a selected first monomer (as described hereinafter) with or without oxidation protecting atoms or groups with a preliminary solvent of phosphoric acid having a relatively low phosphorus pentoxide content.

(b) heating and optionally placing the resulting mixture under reduced pressure to remove any volatilized protecting atoms or groups present and provide a first mixture of the first monomer in the preliminary solvent,

(c) adding at least one of a selected second monomer (as described hereinafter) in the resulting mixture of step (b) to provide a first mixture of the first and second monomer in the preliminary solvent,

(d) then increasing the phosphorus pentoxide content of the mixture resulting from step (b) or (c) to provide a first or a first and second monomer reaction medium of greater phosphorus pentoxide content suitable for polymerization.

(e) causing polymerization of the first or the first and second monomer at a temperature sufficient to effect reaction at a rate to form a first homo-oligomeric product or a first co-oligomeric product having a preselected intrinsic viscosity, or

(f) causing polymerization of the first or the first and second monomer at a temperature sufficient to effect reaction at a rate to form a first homopolymeric product or a first copolymeric product,

(g) mixing a selected amount of the first homo-oligomeric product with a selected amount of at least one of a selected second homo-oligomeric product so as to form a first poly-oligomeric product, the second homo-oligomeric product being formed by like steps (a) and (b) followed by:

(1g) adding at least one of a selected second monomer in the resulting mixture of step (b) to provide a mixture of a first and second monomer in the preliminary solvent,

(2g) then increasing the phosphorus pentoxide content of the mixture resulting from step (b) or (1g) to provide a first and second monomer reaction medium of greater phosphorus pentoxide content suitable for polymerization.

(3g) causing polymerization of the first or first and second monomer at a temperature sufficient to effect reaction at a rate to form the second homo-oligomeric product having a preselected intrinsic viscosity.

with the overall proviso that at least one of the selected monomers of step (a) or (1g) which forms the second homo-oligomeric product be different from at least one of the selected monomers of step (a) or (c) which forms the first homo-oligomeric product, or

(h) mixing a selected amount of the first homo-oligomeric product with a selected amount of a second mixture of at least one of a selected first monomers of a first and second monomer in the preliminary solvent so as to form a monomer-oligomer mixture, and then increasing the phosphorus pentoxide content of the monomer-oligomer mixture to provide a monomer-oligomer reaction medium of greater phosphorus pentoxide content suitable for polymerization, the first monomer of the second mixture being formed by like steps (a) and (b) and the first and second monomer of the second mixture being formed by like steps (a), (b) and (c), with the overall proviso that at least one of the selected monomers of step (a) or (c) which forms the first or first and second monomer of the second mixture, be different from at least one of the selected monomers of step (a) or (c) which forms the first homo-oligomeric product,

(i) causing polymerization of the poly-oligomeric product resulting from step (g) or the monomer-oligomer resulting from step (h) at a temperature sufficient to effect reaction at a rate to form a first block-oligomeric product having a preselected intrinsic viscosity or a first block-polymeric product,

(j) spinning, drawing, extruding, or casting an article from said first homo-oligomeric product, said first co-oligomeric product, said first homopolymeric product, said first copolymer product, said first poly-oligomeric product, said second homo-oligomeric product, said first block-oligomeric product, said first block-polymeric product, or mixtures thereof.

In another embodiment of the invention, the molecular weight (characterized by intrinsic viscosity) of said first homo-oligomeric product, said first co-oligomeric product, said first homopolymeric product, said first copolymeric product, said first poly-oligomeric product, said second homo-oligomeric product, said first block-oligomeric product, and said first block-polymeric product is controlled by discontinuing steps (e), (f) (3g), and (i) (which forms said respective products) at an early stage of reaction so as to achieve a preselected low intrinsic viscosity or said steps are continued at a temperature sufficient to effect further reaction to obtain a preselected higher intrinsic viscosity or further heating said products to achieve an intrinsic viscosity closer to the maximum attainable.

In yet a further embodiment of the invention, the molecular weight (characterized by intrinsic viscosity) of those said first homo-oligomeric product, said first co-oligomeric product, said first homopolymeric product, said first copolymeric product, said first poly-oligomeric product, said second homo-oligomeric product, said first block-oligomeric product, and said first block-polymeric product which are formed by the respective reaction steps (e), (f), (3g), and (i) involving the reaction of a selected first and second monomer is controlled by adding a selected excess molar amount of said selected second monomer or more preferably a selected excess molar amount of said selected first monomer or allowing the loss of a smal proportion of said selected first or said selected second monomer during said polymerization steps thereby off-balancing the stoichiometry of the monomers to obtain a desired intrinsic viscosity value less than the maximum attainable.

In still another embodiment of the invention, the molecular weight (characterized by intrinsic viscosity) of said first homo-oligomeric product, said first co-oligomeric product, said first homopolymeric product, said first copolymeric product, said first poly-oligomeric product, said second homo-oligomeric product, said first block-oligomeric product, and said first block-polymeric product is controlled by adding of one or more selected monofunctional reactants (as described hereinafter) having a single functional group in steps (a), (b), (c), and (1g) to achieve an intrinsic viscosity less than the maximum attainable.

The invention will be more fully explained with reference to the Figures wherein:

FIG. 1 graphically illustrates the weight stability of as spun polymer fibers of --BI--.sub.n (Example 13) and --AI--.sub.n (Example 12) with time during isothermal aging in circulating air at 371.degree. C.;

FIG. 2 graphically illustrates the weight stability of as spun polymer fibers of --V--.sub.n (Example 120) and --T--.sub.n (Example 27) with time during isothermal aging in circulating air at 371.degree. C.;

FIG. 2a graphically illustrates the weight stability by TGA of block copolymers AI-AN" (Example 74) and AI-AG" (Example 73) with temperature in air at a heating rate of 5.degree. C. per minute;

FIG. 3 graphically illustrates the weight stability by TGA of polymers --T--.sub.n (Example 27) and --V--.sub.n (Example 120) with temperature in helium at a heating rate of 5.degree. C. per minute;

FIG. 4 graphically illustrates the weight stability by TGA of polymers --BI--.sub.n (Example 13 and --AI--.sub.n (Example 12) with temperature in helium at a heating rate of 5.degree. C. per minute;

FIG. 5 graphically illustrates the weight stability by TGA of polymers --T--.sub.n (Example 27) and --V--.sub.n (Example 120) with temperature in air at a heating rate of 5.degree. C. per minutes;

FIG. 6 graphically illustrates the weight stability by TGA of polymers --BI--.sub.n (Example 13) and --AI--.sub.n (Example 12) with temperature in air at a heating rate of 5.degree. C. per minute;

FIG. 7 graphically illustrates the relationship of amount of useable PPA and %P.sub.2 O.sub.5 content required to achieve f of 0.822 for selected polymer concentrations, P.sub.c, (plot of equation a*) showing a region of (shaded dash area) of poor solubility for monomer 1a;

FIG. 8 graphically illustrates the %P.sub.2 O.sub.5 content profile for a 14.8 wt% --AI--.sub.n (Example 2) polymerization showing the limits of achievable molecular weight when starting with a high P.sub.2 O.sub.2 content preliminary solvent;

FIG. 9 graphically illustrates the %P.sub.2 O.sub.5 content profile for a 8.6 wt% --T--.sub.n (Example 3) polymerization showing the limits of achievable degree of (polymer) polymerization when starting with a high P.sub.2 O.sub.5 content preliminary solvent;

FIG. 10 graphically illustrates the %P.sub.2 O.sub.5 content profile for a 14.5 wt% --AI--.sub.n (Example 12) polymerization showing the advantages of the invention when starting with a low P.sub.2 O.sub.5 content preliminary solvent followed by an increase of P.sub.2 O.sub.5 content at the start of polymerization;

FIG. 11 graphically illustrates the %P.sub.2 O.sub.5 content profile for a 13.0 wt% --BI--.sub.n (Example 13) polymerization showing the advantages of the invention when starting with a low P.sub.2 O.sub.5 content preliminary solvent and step-wise addition of P.sub.2 O.sub.5 followed by an increase of P.sub.2 O.sub.5 content at the start of polymerization;

FIG. 12 graphically illustrates the %P.sub.2 O.sub.5 content profile for a 20.3 wt% --T--.sub.n (Example 27) polymerization showing the advantages of the invention when starting with a low P.sub.2 O.sub.5 content preliminary solvent followed by an increase of P.sub.2 O.sub.5 content at the start of polymerization;

FIG. 13 graphically illustrates the %P.sub.2 O.sub.5 content profile for a 16.87 wt% --V--.sub.n (Example 122) polymerization showing the advantages of the invention when starting with a low P.sub.2 O.sub.5 content preliminary solvent followed by an increase of P.sub.2 O.sub.5 content at the start of polymerization;

FIG. 14 is a %P.sub.2 O.sub.5 profile diagram giving the profile area bounded by ABCDEFGHI of %P.sub.2 O.sub.5 for achieving the advantages of this invention.

FIG. 15 graphically illustrates the intrinsic viscosity of the end-capped --AI-- component of the reaction product as a function of polymerization time showing the advantage of the invention of obtaining a stabilized molecular weight after short polymerization time.

The extended chain polymers of the compositions of the present invention are a class of polymers that can obtain a substantial degree of shape anisotropy in the liquid state due to restricted rotation of bonds in the polymer backbone and/or appropriate catenation geometry of rigid backbone segments. The degree of shape anisotropy is generally defined by the axial ratio, .rho./d, where .rho. is the persistence length of the chain and d is the diameter of the chain. For extended chain polymers, .rho. may be substantially the same as or greater than the contour length l of the polymer. In the case of a rigid rod polymer, .rho. is essentially infinite and the axial ratio is l/d.

By the method of the present invention, it is possible to prepare liquid crystalline compositions of extended chain homopolymers, copolymers, or block polymers containing 15 percent or more of polymer. As will appear, the invention is applicable to the preparation of liquid crystalline extended chain polymer compositions of lower polymer concentration but there are special advantages to preparing compositions of high concentration.

Extended chain polymer-polyphosphoric acid compositions of such higher polymer concentration are advantageous. For example, if the polymer is one, such as polybenzobisthiazole, polybenzobisoxazole, and polybenzobisimidazole, capable of forming liquid crystalline compositions at low concentration (e.g., 5-10%), that is, if the critical concentration necessary for formation of the anisotropic phase is low, compositions of even higher polymer concentration can be spun to produce a better quality, higher strength fiber. We believe this results, in part at least, from a more fully anisotropic composition and improved composition integrity. These improvements allow greater drawing in the air-gap, improve the coagulation characteristics, which leads to fewer flaws, and increase polymer throughput when a liquid crystalline composition is spun by a dry-jet-wet spinning techniques into a polyphosphoric acid-solvent/polymer-nonsolvent such as methanol, water, or dilute aqueous acid(s).

If the polymer is one, such as poly(2,6-benzothiazole) that is less rodlike in structure than polybenzobisthiazole or polybenzobisoxazole and thus possesses a critical concentration for anisotropic phase formation greater than 10% and in the region of concentrations of this invention, extruding of these heretofore unattainable solutions produces a dramatic increase in strength and modulus because of the ordering of the polymer during this fabrication.

These advantages result in a more highly ordered, lower-defect fiber than results from spinning a less concentrated composition of polymers.

Another advantage of preparation of these polymers in the anisotropic phase is a considerable increase in the molecular weight of the polymer obtained.

In instances where extended chain polymers having a preselected low molecular weight, intermediate molecular weight, or ultra-high molecular weight (up to the maximum attainable) are desired, the present invention is most advantageous. Extended chain polymers of essentially any desired molecular weight (characterized by intrinsic viscosity) up to the maximum attainable may be prepared in the anisotropic phase without substantial difficulty in accordance with the practice of the invention.

In instances where the extended chain polymer molecular weight must be maintained at a level below the maximum attainable, for example, if additional heating is necessary to effect storage and/or transfer of polymer dope from reactor to spinning lines or to carry out procedures such as filtering, degassing, and the like and that such heating will induce further polymerization which may be undesirable, the preparation of such polymers in accordance with the practice of the invention is advantageous.

Preliminarily it is helpful to describe the chemistry of phosphoric acids and strong phosphoric acids or polyphosphoric acids as follows:

As used herein the term "phosphoric acid(s)" means commercial phosphoric acid(s) containing 85-86% H.sub.3 PO.sub.4.

The strong phosphoric acids, or polyphosphoric acids referred to as PPA (polyphosphoric acid) are members of a continuous series of amorphous condensed phosphoric acid mixtures given by the formula

or

where the value of n depends on the molar ratio of water to phosphorus pentoxide present.

Characterization and methods of forming various polyphosphoric acids and examples of such strong acids useful in accordance with the practice of the present invention can be found in the following papers: A. L. Huhti and P. A. Gartaganis "The Composition of the Strong Phosphoric Acids," Can. J. Chem., Vol. 34, 1956 pp. 785-797; and J. E. Such, "Linear Polyphosphoric Acids", Mellar's Comprehensive Treatise on Inorganic and Theoretical Chemistry, Vol VIII, Supplement III, pp. 726-753, Wiley 1971. The subject matter of these articles is specifically incorporated herein by reference.

In its most general definition, polyphosphoric acid composition can range from distributions where the average value of n is less than unity, giving rise to a mobile liquid, to high values of n, where the polyphosphoric acid is a glass at normal temperatures. Because the species of polyphosphoric acid are in a mobile equilibrium, a given equilibrium composition can be prepared in many ways. For instance, the same distribution or polyphosphoric acid composition could be prepared by either starting with concentrated orthophosphoric acid (H.sub.3 PO.sub.4, n=1) and driving off water or by starting with phosphorus pentoxide (P.sub.2 O.sub.5) and adding an appropriate amount of water.

All polyphosphoric acid compositions can be described as a ratio of P.sub.2 O.sub.5 and water by reducing the various species present (on paper) to P.sub.2 O.sub.5 and water. We will then use the convention that polyphosphoric acid composition will be expressed in terms of a P.sub.2 O.sub.5 content (as a percentage) defined as P.sub.2 O.sub.5 content ##EQU1## Thus, the P.sub.2 O.sub.5 content of pure orthophosphoric acid could be derived by reducing one mole of H.sub.3 PO.sub.4 to 0.5 moles P.sub.2 O.sub.5 +1.5 moles H.sub.2 O. Converting to weights gives the P.sub.2 O.sub.5 content as ##EQU2##

Similarly, the P.sub.2 O.sub.5 content of commercial polyphosphoric acid can be derived in the following way. Polyphosphoric acid is available commercially in two grades, 105% and 115%. These percentages refer to H.sub.3 PO.sub.4 content, which means that 100 g of the two grades contain 105 and 115 grams of H.sub.3 P.sub.4. The P.sub.2 O.sub.5 content of 115% polyphosphoric acid can then be calculated knowing the P.sub.2 O.sub.5 content of 100% H.sub.3 PO.sub.4. ##EQU3##

Freshly prepared polyphosphoric acid as described by Wolfe and Loo U.S. Pat. No. 4,225,700 employed 1.52X g of P.sub.2 O.sub.5 to x grams of 85.6% H.sub.3 PO.sub.4, thus the P.sub.2 O.sub.5 content of that mixture is ##EQU4##

Thus, polyphosphoric acid compositions, by our definition, equivalent to these three examples could be prepared in principle by starting with P.sub.2 O.sub.5 and adding 27.6, 16.7, and 15.1% by weight of water.

In accordance with one aspect of the invention, there is provided a liquid-crystalline composition useful in the preparation of fibers and films comprising a polycondensation product consisting essentially of a blend of certain polyphosphoric acids and a high concentration of at least one extended chain homopolymer having a substantially stabilized molecular weight (characterized by intrinsic viscosity) said homopolymer having recurring units of the general formulas: ##STR1## wherein Ar.sup.1 represents an aromatic moiety and is XX as defined below, X.sub.1 and X.sub.2 are the same or different and are sulfur, oxygen, or NR (R being hydrogen or an organic group), the nitrogen atoms and X.sub.1 and X.sub.2 being bonded to aromatic carbon atoms of Ar.sup.1, N and X.sub.1 or X.sub.2 of each hetero ring are disposed ortho to one another and Y.sup.2 is nil or represents a bivalent organic radical and is XXI as defined below, n being a positive integer; ##STR2## wherein Ar.sup.3 represents an aromatic moiety and is XXII as defined below, X.sub.3 is sulfur, oxygen, or NR (R being hydrogen or an organic group), the nitrogen atoms and X.sub.3 being bonded to aromatic carbon atoms of Ar.sup.3, N and X.sub.3 of each hetero ring are disposed ortho to one another, n being a positive integer; ##STR3## wherein Ar.sup.1 represents an aromatic moiety and is XX as defined below, and Ar.sup.4 represents a different aromatic moiety and is XXIII as defined below, the nitrogen atoms being bonded to aromatic carbon atoms of Ar.sup.1 and the carbon atoms being bonded to aromatic carbon atoms of Ar.sup.4, n being a positive integer; ##STR4## ps wherein Ar.sup.5 represents an aromatic moiety and is XXIV as defined below, the nitrogen atoms being bonded to Ar.sup.5, n being a positive integer; wherein Ar.sup.6 represents an aromatic moiety and is XXV as defined below, Ar.sup.1 represents a different aromatic moiety and is XX as defined below, X.sub.1 and X.sub.2 are the same or different and are sulfur, oxygem, or NR (R being hydrogen or an organic group), the NH groups and X.sub.1 and X.sub.2 being bonded to aromatic carbon atoms of Ar.sup.6 and Ar.sup.1, NH and X.sub.1 or X.sub.2 of each hetero ring are disposed ortho to one another, n being a positive integer; ##STR5## wherein Ar.sup.9 represents an aromatic moiety and is XXVI as defined below, X.sub.4 is sulfur, oxygen, or NR (R being hydrogen or an organic group), the NH groups and X.sub.4 being bonded to aromatic carbon atoms of Ar.sup.9, n being a positive integer; ##STR6## wherein Ar.sup.1 represents an aromatic moiety and is XXVII as defined below, Y.sup.7 represents an aromatic or heteroaromatic moiety and is XXVIII as defined below, the nitrogen atoms being bonded to aromatic carbon atoms of Ar.sup.1 and bonded to adjacent carbon atoms of Y.sup.7, n being a positive integer; ##STR7## wherein Ar.sup.1 represents an aromatic moiety and is XX as defined below, Y.sup.8 is XXIX as defined below, X.sub.1 and X.sub.2 are the same or different and are sulfur, oxygen, or NR (R being hydrogen or an organic group), the nitrogen atoms and X.sub.1 and X.sub.2 being bonded to aromatic carbon atoms of Ar.sup.1 and adjacent carbon atoms of Y.sup.8, N and X.sub.1 or X.sub.2 of each hetero ring are disposed ortho to one another, n being a positive integer.

The aromatic moieties Ar.sup.1, Ar.sup.3, Ar.sup.4, Ar.sup.5, Ar.sup.6, Ar.sup.9, and Y.sup.2, Y.sup.7, and Y.sup.8 of the extended chain polymer formulas above are defined as follows: ##STR8##

Any monomeric material or mixture of monomeric materials having the ability to react in polyphosphoric acid to form the extended chain polymers (i.e., the above formulas I-VIII homopolymers, and the various formula IX-XIX copolymers and block polymers herein defined in the specification) of this invention can be utilized.

In general, suitable monomeric materials selected for use in forming liquid-crystalline extended chain polymer compositions of the present invention are of nine types as described below.

Type 1 monomers has the general formula ##STR9## wherein Ar.sup.1 is an aromatic moiety; X.sub.1 and X.sub.2 are the same or different atoms or groups selected from the class O, S, and NR; R is hydrogen or an organic group attached to N; the R's on the two nitrogen atoms where both X.sub.1 and X.sub.2 are NR may be the same or different; NH.sub.2, X.sub.1 H and X.sub.2 H are bonded to aromatic carbon atoms of Ar.sup.1 ; the groups on the left side of Ar.sup.1 are ortho with respect to one another and the groups on the right side of Ar.sup.1 are ortho with respect to one another.

The two sets of NH.sub.2 and XH are positioned on Ar.sup.1 such that they do not both interact partially with the appropriate condensing moiety of another monomer. Monomer 1 is typically isolated as a hydrohalide salt of the monomer.

In general, Ar.sup.1 may be any aromatic moiety (carbocyclic or heterocyclic) and it may be a single ring such as ##STR10## or it may comprise a plurality of aromatic rings connected by valence bonds or by linking atoms or groups such as ##STR11## where .beta. is a valence bond (as in diphenyl) or a divalent atom (--O-- or --S--) or group such as --NR--(R.dbd.H or an organic group), --(CH.sub.2).sub.n -- (n=1 or a higher integer). Specific examples of Ar.sup.1 are as follows: ##STR12##

The aromatic ring or rings of Ar.sup.1, such as those described above and others, may bear one or more substituents. These substituents, which may be organic or inorganic may be or may contain hetero atoms, may be any atom or group which is compatible with the reactant, the solvent, the polycondensation reaction and the resulting oligomer or polymer. Substituents which are chemically reactive with Types 2 thru 9 monomers (see below), with the solvent (PPA) or with the oligomeric or polymeric products are to be avoided. Also, substituents which offer steric hindrance to the polycondensation are to be avoided.

Among permissible hydrocarbon substituents are alkyl (e.g., C.sub.1 to C.sub.10 straight chain and branched chain alkyl, benzyl, etc.), phenyl, chloro substituted alkyl, phenyl and benzyl. Among permissible hetero substituents are chloro, bromo, nitro, alkoxy, aryloxy, SO.sub.3 H, SR, and --NR.sub.1 R.sub.2 (R.sub.1 and R.sub.2 being organic groups).

Formula 1 monomers useful in preparing the extended chain polymers and novel liquid-crystalline compositions of the instant invention may also further be classified into three groups: Class 1 (1,1), Class 2 (1,2), and Class 3 (1,3). The first number of the number pairs denotes the monomer type and the second number of the pairs denotes the monomer class.

The preferred (1,1) monomers are those wherein Ar.sup.1 is a six-membered aromatic ring with the four valence positions being on carbon atoms having a 1, 2, 4, 5 relationship to each other, such as 1, 2, 4, 5-benzene or 2, 3, 5, 6-pyridine; R is H or a monovalent aromatic radical, such as phenyl, or a monovalent heteroaromatic radical, such as 2-pyridyl, or a monovalent aliphatic radical, such as methyl. Monomers (1,1) which when reacted with a diacid or a diacid derivative give two substantially collinear bonds are most preferred.

Specific examples of (1,1) monomers preferred for use in the invention include those monomers (shown as hydrohalides) in Table 1 below.

obtained according to Wolfe, et al., Macromolecules, Vol. 14, Page 915 (1981). ##STR14## obtained from 4,6-dinitro-1,3-benzenediol according to Wolfe, et al., Macromolecules, Vol. 14, Page 909 (1981). ##STR15## obtained from Aldrich Chemical Co. and purified by recrystallization from dilute HCl by heating, adding charcoal, filtering, and adding concentrated HCl. ##STR16## prepared according to Wolfe, et al., J. Polymer Sci., Part A-1, Vol. 6, page 1503 (1968). ##STR17## prepared by the dinitration of 2,6-diamino pyridine, followed by hydrolysis and reduction by the method of A. H. Gerber, J. Polymer Sci., Polymer Chemistry Ed., Vol. 11, page 1703 (1973). ##STR18## prepared by dinitration of 2,6-dimethoxy pyridine according to C. D. Johnson, et al., J. Chem. Soc. (B), 1967, page 1204, followed by reduction and dealkylation. ##STR19## prepared from commercially available 2,5-diamino-pyridine by methods analogous to the preparation of 1a. ##STR20## prepared starting from m-dichlorobenzene according to H. Vogel and C. S. Marvel, J. Polym. Sci., A, Vol. 1, page 1531 (1963) and purified from toluene before use.

The preferred (1,2) monomers are those wherein Ar.sup.1 is two six-membered aromatic rings attached by a covalent carbon-carbon bond each with valences on carbon atoms in the 3 and 4 positions, such as 3,3',4,4'-biphenyl or 4,4',5,5'-(2,2'-bipyridyl), or Ar.sup.1 is two fused six-membered rings with valence positions being on carbon atoms and having a 1,2,5,6 relationship to each other, such as 1,2,5,6-naphthalene.

The four functional groups attached to the valence positions of Ar.sup.1 by covalent bonds comprise two amino groups and the groups --X.sub.1 H and --X.sub.2 H such that one amino group is ortho to --X.sub.1 H and the other amino group is ortho to X.sub.2 H and X.sub.1 H is attached to either the 3 or 4 position in the first case or the 1 or 2 position in the second case and --X.sub.2 H is attached to either the 3' or 4' position in the first case and the 5 or 6 position in the second case. X.sub.1 and X.sub.2 are defined as above.

Specific examples of (1,2) monomers preferred for use in the invention include those monomers (shown as hydrohalides) in Table 2 below.

prepared by the method of Houben-Weyl, Methoden der Organischen Chemie, E. Miller, Ed., Vol IX, page 39 (1955). ##STR22## prepared by the method of C. G. Vogt and F. Marschall, U.S. Pat. No. 2,497,248 (1950) from o-dianisidine and aluminum chloride. ##STR23## prepared by the method of Y. Imai, I. Taoka, K. Uno, and Y. Iwakura, Makromol. Chem. 83, page 167 (1965). ##STR24## prepared according to (same ref. as for 1 h) and the tetrahydrochloride recrystallized from dilute HCl containing stannous chloride by adding concentrated HCl. ##STR25## prepared from dinitration of 4,4'-dichlorobiphenyl, displacement of the chloro groups by aniline, and reduction. ##STR26## by methods analogous to Monomers 1a and 1i. ##STR27## prepared from 2,6-dichloro-1,5-dinitro-naphthalene. ##STR28## prepared by the amination of 2,6-dichloro-1,5-dinitro-naphthalene followed by catalytic reduction according to K. Imai, N. Kurihara, L. Mathias, J. Wittmann, W. B. Alston, and J. K. Stille, Macromolecules, 6, 158 (1973).

The preferred (1,3) monomers are those wherein Ar.sup.1 is any aromatic moiety with two sets of ortho-valences at carbon atoms, such as ##STR29## wherein .beta. is a bivalent aromatic or heteroaromatic moiety, O, S, SO.sub.2, C.dbd.O, --CH.sub.2 CH.sub.2 --, etc.

The four functional groups attached to the valence positions of Ar.sup.1 are divided into two sets (NH.sub.2 and X.sub.1 H) and (NH.sub.2 and X.sub.2 H) with the functional groups within each set being positioned ortho to each other and the two sets positioned on Ar.sup.1 such that they cannot simultaneously react with the same functional group of another monomer. X.sub.1 and X.sub.2 are defined as above.

Specific examples of (1,3) monomers preferred for use in the invention include those monomers (shown as hydrohalides or as monomers) in Table 3 below.

prepared according to the method of V. V. Korshak, E. S. Krongauz, A. P. Travnikova, A. L. Rasanov, and A. D. Katsarava, Dokl. Akad. Nauk. SSSR, 196, 106 (1971). ##STR31## obtained commercially from Pfaltz & Bauer. ##STR32## is prepared according to the method of S. U. Kantor and J. Sonnenberg, U.S. Pat. No. 3,306,876 (1967). ##STR33## prepared according to the method of A. S. Lindsey, S. E. Hunt, and G. K. L. Gibson, U.K. Pat. No. 1,181,531 (1970). ##STR34## prepared from commercially available 4,4'-diaminodiphenyl sulfone by acetylation, dinitration, hydrolysis, and reduction. ##STR35## prepared from commercially available 4,4'-diaminodiphenyl sulfone by methods analogous to the preparation of 1a and 1i. ##STR36## prepared according to the method of G. I. Braz, I. Y. Kardash, and V. S. Yakubovich, Polym. Sci. USSR., 8, page 2013 (1967). ##STR37## prepared from commercially available 4,4'-dihydroxydiphenyl sulfone by acetylation, dinitration, hydrolysis and reduction. ##STR38## available commercially from Polysciences, Inc. ##STR39## prepared by isolation of 2,7-diaminobenzol[1,2-d;6,5-d']bisthiazole from the scheme to prepare 1a followed by hydrolysis.

Type 2 monomers have the general formula

wherein Y.sup.2 is a bivalent organic group and Z.sub.1 and Z.sub.2 are electron-defficient carbon groups and may be the same or different groups selected from the following class:

(R.sub.1 =H or an organic group bonded to N by a carbon atom)

The only requirement of Z.sub.1 and Z.sub.2 is that they react with the X.sub.1 H and X.sub.2 H and with the two hydrogen atoms of the primary amino groups of Type 1 monomers to form suitable leaving entities, such as water, hydrogen sulfide, hydrogen halide, ammonia, etc.

The bivalent group Y.sup.2 may be an aromatic group, an acyclic aliphatic group, or a cycloaliphatic group, and such groups may be substituted by hydrocarbon groups (aliphatic or aromatic) and by hetero atoms and groups. In general any of groups described above as substituents of the aromatic ring or rings of Ar.sup.1 may be used subject to the same restrictions.

Formula 2 monomers useful in preparing the extended chain polymers and novel liquid-crystalline compositions of the instant invention may also further be classified into three groups: Class 1 (2,1), Class 2 (2,2), and Class 3 (2,3). The first number of the number pairs denotes the monomer type and the second number of the pairs denotes the monomer class.

The preferred (2,1) monomers are those wherein Y.sup.2 is nil, or Y.sup.2 comprise at least two carbon atoms to which are attached Z.sub.1 and Z.sub.2 such that the two exocyclic bonds between Y.sup.2 and Z.sub.1 and between Y.sup.2 and Z.sub.2 have a rigid and fixed relationship to each other and are substantially collinear, or Y.sup.2 may also be a cycloaliphatic group that has at least two carbon atoms to which are attached Z.sub.1 and Z.sub.2 such that the two bonds between Y.sup.2 and Z.sub.1 and between Y.sup.2 and Z.sub.2 have a highly preferred relationship to each other that is substantially collinear. Carboxylic acid derivatives of 2j-2q and 2z (as herein described below) such as COOH that decarboxylate at temperatures below that required for polycondensation with Type 1 monomers are less preferred.

Specific examples of (2,1) monomers preferred for use in the invention include those monomers in Table 4 below.

obtained from Amoco Chemicals Co. and micronized and dried before use. ##STR41## obtained from Aldrich and sublimed immediately before use. ##STR42## prepared from 2b or obtained commercially from Pfaltz and Bauer. ##STR43## obtained from Pfaltz and Bauer. ##STR44## obtained from Aldrich and recrystallized from water. ##STR45## prepared from 2e. ##STR46## prepared from 2f. ##STR47## prepared from 2g. ##STR48## obtained from Aldrich Chemical Co. ##STR49## prepared by diazotization of 2,6-diaminobenzobisthiazole (see reference for 1a) followed by treatment with cuprous cyanide. ##STR50## prepared from the condensation of compound 1b with urea followed by diazotization as for compound 2j. ##STR51## prepared as for 2k using compound 1c. ##STR52## prepared as described for 2k using compound 1d. ##STR53## prepared as for 2k using compound 1e. ##STR54## prepared as for 2k using compound 1f. ##STR55## prepared as for 2j, using 2,6-diaminopyridobisthiazole as prepared in the synthesis of 1g. ##STR56## prepared as for 2k using compound 1h. ##STR57## prepared by the condensation of compound 1a with p-toluic acid followed by oxidation. ##STR58## prepared by the condensation of 1b with p-toluic acid followed by oxidation. ##STR59## prepared by a method similar to 2s using 1c. ##STR60## prepared by method similar to 2s using 1d. ##STR61## prepared by a method similar to 2s using 1e. ##STR62## prepared by a method similar to 2s using 1f. ##STR63## prepared by a method similar to 2s using 1g. ##STR64## prepared by a method similar to 2s using 1h. ##STR65## obtained from Aldrich Chemical Co.

The preferred (2,2) monomers are those wherein Y.sup.2 comprise two six-membered rings attached by a covalent carbon-carbon bond each with valences on the 4-position or each with valences on the 3-position, such a 4,4'-biphenyl or 3,3'-biphenyl, or Y.sup.2 comprise two fused six-membered rings with valence positions being on carbon atoms and having a 1,5 relationship to each other, such as 2,6-naphthalene or 2,6-quinoline, or Y.sup.2 is a cycloaliphatic divalent moiety with valences on carbon atoms and in a 1,2-trans configuration, or Y.sup.2 is a variety of condensed aromatic and heteroaromatic ring systems attached only by carbon-carbon bonds and having 2 valences, Z.sub.1 and Z.sub.2 are the same as defined above. Specific examples of (2,2) monomers preferred for use in the invention include those monomers in Table 5 below.

obtained from Aldrich Chemical Co. ##STR67## prepared from 2aa. ##STR68## prepared according to the method of B. Raecke and H. Schirp, Org. Syn. Coll. Vol. V, page 813 (1973) from commercially available 1,8-naphthalenedicarboxylic anhydride. ##STR69## prepared from 2cc by treatment with thionyl chloride. ##STR70## prepared from commercially available (Aldrich) 2,6-dimethyl quinoline by oxidation. ##STR71## prepared from o-nitrobenzoic acid by the method of M. Kurihara and N. Yoda, J. Macromol. Sci. Chem Al(6), page 1069 (1967). ##STR72## was obtained from Aldrich Chemical Co. and recrystallized from methanol before use. ##STR73## prepared by the method of J. Preston, W. De Winter and W. L. Hofferbert, J. Heterocyclic Chem. 5, page 269 (1968). ##STR74## prepared by methods analogous to 2hh. ##STR75## prepared by methods analogous to 2hh.

The preferred (2,3) monomers are those wherein Y.sup.2 may be any aromatic, heteroaromatic and aliphatic divalent species not previously described.

Specific examples of (2,3) monomers preferred for use in the invention include those monomers in Table 6 below.

prepared according to the method of R. C. Evers, F. E. Arnold, and T. E. Helminiak Macromolecules, 14, page 925 (1981). ##STR77## prepared according to method of T. Takekoshi, J. G. Wirth, Dr. Heath, J. E. Kochanowski, J. S. Manello, and M. J. Weber, Polym. Prepr., J. Am. Chem. Soc., 20(1), page 179 (1979). ##STR78## prepared according to method of T. Takekoshi, J. G. Wirth, Dr. Heath, J. E. Kochanowski, J. S. Manello, and M. J. Weber, Polym. Prepr., J. Am. Chem. Soc., 20(1), page 179(1979) ##STR79## from 2 mm according to method of R. C. Evers, F. E. Arnold, and T. E. Helminiak, Macromolecules, 14, page 925(1981). ##STR80## prepared according to the method of R. C. Evers, F. E. Arnold, and T. E. Helminiak Macromolecules, 14, page 925(1981). ##STR81## according to the method of R. C. Evers, F. E. Arnold, and T. E. Helminiak Macromolecules, 14, page 925(1981). ##STR82## prepared according to the method of R. C. Evers. F. E. Arnold, and T. E. Helminiak Macromolecules, 14, page 925(1981). ##STR83## prepared according to the method of R. C. Evers, F. E. Arnold, and T. E. Helminiak Macromolecules, 14, page 925(1981). ##STR84## obtained from Pfaltz and Bauer and recrystallized from 90% ethanol. ##STR85## obtained from Polysciences, Inc. ##STR86## prepared from a coupling of m-cresol and m-bromotoluene followed by oxidation by the method of M. Tomita, J. Pharm. Soc., Japan, 57, page 391(1937). ##STR87## obtained from Aldrich Chemical Co. ##STR88## obtained from Aldrich Chemical Co. ##STR89## obtained from Aldrich Chemical Co. ##STR90## obtained from Aldrich Chemical Co. ##STR91## obtained from Aldrich Chemical Co.

Type 3 monomers have the general formula ##STR92## wherein Ar.sup.3 is a trivalent aromatic or heteroaromatic moiety, and X.sub.3 is O, S, or N--R (R=H or an organic group).

Formula 3 monomers useful in preparing the extended chain polymers and novel liquid-crystalline compositions of the instant invention may also further be classified into two groups: Class 1 (3,1) and Class 2 (3,2). The first number of the number pairs denotes the monomer type and the second number of the pairs denotes the monomer class.

The preferred (3,1) monomers are those wherein Z.sub.3 is the same as defined for Z.sub.1, Ar.sup.3 is a trivalent aromatic or heteroaromatic moiety with the three valence positions being on carbon atoms and having the relationship that the valence bond between Z.sub.3 and Ar.sup.3 is nearly collinear with the same valence bond in subsequently condensed monomers, and X.sub.3 is defined as for X.sub.1 in Table 1. X.sub.3 and NH.sub.2 are positioned ortho to each other on Ar.sup.3.

Specific examples of (3,1) monomers preferred for use in the invention include the monomer in Table 7 below.

prepared according to R. F. Kovar and F. E. Arnold, J. Polym. Sci. Polym. Chem. Ed., 14, page 2807 (1976).

The preferred (3,2) monomers are those wherein Z.sub.3, Ar.sup.3, and X.sub.3 are defined as above. The bonds that are formed in homopolymerization of (3,2) monomers are defined in their spatial relationship having an angle of catenation of less than about 150.degree. to about 180.degree..

Specific examples of (3,2) monomers preferred for use in the invention include those monomers (shown as hydrohalides or as monomers) in Table 8 below.

prepared according to Wolfe, AFOSR Final Technical Report, Dec. 15, 1980. ##STR95## prepared as described in Example 5. ##STR96## prepared as described by Y. Imai, K. Uno, and Y. Iwakura, Makromol. Chem., 83, 179(1965). ##STR97## prepared as described by K. Auwers and H. Rohrig, Chem. Ber., 30, 992(1897). ##STR98## obtained from Aldrich Chemical Co. and recrystallized from deoxygenated water before use. ##STR99## prepared from p-aminobenzoic acid by chlorination, oxidation to 3-chloro-4-nitrobenzoic acid, followed by anilation and reduction. ##STR100## prepared by nitration of commercially available (Aldrich) p-chlorobenzoic acid, followed by anilation and reduction. ##STR101## prepared by nitration of commercially available 4-carboxybiphenyl (ICN/K and K) and reduction to 4-amino-4'-carboxybiphenyl, followed by placement of the o-mercapto group by methods analogous to those described for 3a. ##STR102## prepared by the nitration of commercially available (ICN/K and K) 4-carboxybiphenyl, conversion to 4-carboxy-p-phenol by reduction and diazotization, followed by acetylation, nitration, hydrolysis, and reduction. ##STR103## prepared by acetylation of 4-amino-4'-carboxylbiphenyl (see preparation of 3h) followed by nitration, hydrolysis, and reduction.

Type 4 monomers have the general formula ##STR104## wherein Z.sub.4, Z.sub.5, Z.sub.6, and Z.sub.7 are the same or different and are chosen from the list of carboxylic acid derivatives given for Z.sub.1 in Table 4. Z.sub.4 and Z.sub.5, or Z.sub.6 and Z.sub.7, or both sets can also be carboxylic acid anhydride groups. Ar.sup.4 is an aromatic or aromatic heterocyclic moiety having four valence positions at carbon atoms. Ar.sup.4 can be a six-member ring with the valence positions having 1, 2, 4, 5 relationship, or Ar.sup.4 can be two condensed six-member rings, such as naphthalene. Z.sub.4 and Z.sub.5 as one set and Z.sub.6 and Z.sub.7 as another set must either be ortho-positioned within each set or bear a 1, 4, 5, 8 relationship to each other. An (imaginary) line perpendicular to the bond between the valence carbons attached to Z.sub.4 and Z.sub.5 must be collinear with the corresponding (imaginary) line for Z.sub.6 and Z.sub.7.

Formula 4 monomers useful in preparing the extended chain polymers and novel liquid-crystalline compositions of the instant invention are classified as Class 1 (4,1). The first number of the number pair denotes the monomer type and the second number of the pair denotes the monomer class.

Specific exampls of (4,1) monomers preferred for use in the invention include those monomers in Table 9 below.

obtained from Aldrich Chemical Co. and sublimed or recrystallized (acetic anhydride) before use. ##STR106## obtained from Aldrich Chemical Co.

Type 5 monomers have the general formula ##STR107## wherein Z.sub.8 and Z.sub.9 are defined as for Z.sub.4 and Z.sub.5 in Table 9, Ar.sup.5 is defined as in Table 9, the two amino groups are ortho to each other, and Z.sub.8, Z.sub.9, and the two amino groups are positioned such that two imaginary lines drawn perpendicular to the bonds between their valence carbons are collinear.

Formula 5 monomers useful in preparing the extended chain polymers and novel liquid-crystalline compositions of the instant invention are classified as Class 1 (5,1). The number pair (5,1) has the same significance as above.

Specific examples of (5,1) monomers preferred for use in the invention include the monomer in Table 10 below.

prepared from the dinitroderivative by chemical reduction according to I. Honda and M. Okazaki, J. Soc. Org. Synthetic Chem. (Japan), 7, Page 25(1950).

Type 6 monomers have the general formula ##STR109## wherein Ar.sup.6 represents an aromatic moiety and is a tetrahydroxy fused ring system, Z.sub.10, Z.sub.11, Z.sub.12, Z.sub.13 are the same HO atoms bonded to carbon atoms of Ar.sup.6.

In general, Ar.sup.6 may comprise a single or a plurality of aromatic rings in the center of a completely conjugated fused ring system. The center aromatic ring or rings of the completely conjugated fused ring system can be any of those described above, and others.

Formula 6 monomers useful in preparing the extended chain polymers and novel liquid-crystalline compositions of the instant invention may also be further classified into two groups: Class 1 (6,1), and Class 2 (6,2). The number pairs have the same significance as above.

The preferred (6,1) monomers are those wherein Ar.sup.6 comprises a single center aromatic ring in the center of the fused ring system.

The preferred (6,2) monomers are those wherein Ar.sup.6 comprises at least two center aromatic rings in the center of the fused ring system.

Specific examples of (6,1) and (6,2) preferred for use in the invention include those monomers in Tables 11 and 12 respectively.

prepared from condensation of 1,2,4,5-tetraaminobenzene with oxalic acid according to H. Tadamus, F., DeSchryver, W. DeWinter, and C. S. Marvel, J. Polym. Sci. A-1,4, page 2831(1966).

prepared from condensation of 3,3'-diaminobenzidine with oxalic acid according to method of H. Tadamus, et al., J. Polym. Sci. A-1, 4, page 2831 (1966).

Type 7 monomers have the general formula ##STR112## wherein Y.sup.7 represents an aromatic or heteroaromatic moiety and is a fused ring carbon group, the X.sub.7 's are double bonded to carbon of Y.sup.7.

Formula 7 monomers useful in preparing the extended chain polymers and novel liquid-crystalline compositions of the instant invention can be classified as Class 1 (7,1). The number pair (7,1) has the same significance as above.

A specific example of (7,1) preferred for use in the present invention is 7a in Table 13 below.

M. Corell, and H. Streck, Ann. 531, page 6(1937).

Type 8 monomers have the general formula ##STR114## wherein Y.sup.8 is a single carbon cyclic moiety, X.sub.10 and X.sub.11 are HO and O atoms respectively, bonded to carbon atoms of Y.sup.8.

Formula 8 monomers useful in preparing the extended chain polymers and novel liquid-crystalline compositions of the instant invention can be classified as Class 1 (8,1). The number pair (8,1) has the same significance as above.

A specific example of (8,1) preferred for use in the present invention is 8a in Table 14 below.

obtained from Aldrich Chemical Co.

Type 9 monomer has the general formula ##STR116## wherein Ar.sup.9 represents an aromatic moiety and is a partially fused ring system, Z.sub.14 and Z.sub.15 are OH atoms, X.sub.4 are selected from the class O, S, and NR; R is H or an organic group attached to N; NH.sub.2, X.sub.4 H, Z.sub.14, and Z.sub.15 are bonded to carbon atoms of Ar.sup.9 ; NH.sub.2 and X.sub.4 H are positioned ortho; Z.sub.14 and Z.sub.15 are positioned ortho.

Formula 9 monomers useful in preparing the extended chain polymers and novel liquid-crystalline compositions of the present invention can be classified as Class 1 (9,1). The number pair (9,1) has the same significance as above.

A specific example of (9,1) preferred for use in the present invention is 9a in Table 15 below.

prepared from 1,2-diamino-4,5-dinitrobenzene by condensation with oxalic acid followed by reduction according to R. F. Kovar and F. E. Arnold J. Polym. Sci., Polym. Chem. Ed., 14, page 2807 (1976).

Any monofunctional reactant or mixture of monofunctional reactants having the ability to react in polyphosphoric acid to form the heterocyclic ring structures of this invention can be utilized. Monofunctional reactants may be used in the amounts of 0.025 mole percent or less to about 3 mole percent or more. Amounts substantially greater than 3 mole percent should be avoided in order to prevent formation of low molecular weight polymer and/or the formation of isotropic solutions. Polymers that have chain ends made non-reactive by reaction of a monofunctional reactant are called end-capped or chain-terminated polymers.

In general, suitable monofunctional reactants selected for use in controlling the molecular weight of the extended chain polymers of the present invention are of three types as described below.

Type 10 monofunctional reactants have the general formula ##STR118## wherein Ar.sup.10 is an aromatic moiety; X.sub.1 is selected from the class O, S, and NR; R is hydrogen or an organic group attached to N; NH.sub.2, and X.sub.1 H are bonded to aromatic carbon atoms of Ar.sup.10 ; the groups on Ar.sup.10 are ortho with respect to one another.

Monofunctional reactant 10 is typically isolated as a hydrohalide salt.

In general, Ar.sup.10 may be any aromatic moiety (carbocyclic or heterocyclic) and it may be a single ring such as ##STR119## or it may comprise a plurality of aromatic rings connected by valence bonds or by linking atoms or groups such as ##STR120## where .beta. is a valence bond (as in diphenyl) or a divalent atom (--O-- or --S--) or group such as --NR--(R=H or an organic group), --(CH.sub.2).sub.n -- (n=1 or a higher integer). Specific examples or Ar.sup.10 are as follows: ##STR121##

The aromatic ring or rings of Ar.sup.10, such as those described above and others, may bear one or more substituent. These substituents, which may be organic or inorganic may be or may contain hetero atoms, may be any atom or group which is compatible with the reactant, the solvent, the polycondensation reaction and the resulting oligomer or polymer. Substituents which are chemically reactive with Types 2 thru 9 monomers (see above), with the solvent (PPA) or with the oligomeric or polymeric products are to be avoided.

Among permissible hydrocarbon substituents are alkyl (e.g., C.sub.1 to C.sub.10 straight chain and branched chain alkyl, benzyl, etc.), phenyl, chloro substituted alkyl, phenyl and benzyl. Among permissible hetero substituents are chloro, bromo, nitro, alkoxy, aryloxy, SO.sub.3 H, SR, and --NR.sub.1 R.sub.2 (R.sub.1 and R.sub.2 being organic groups).

Specific examples of Type 10 monofunctional reactants preferred for use in the invention include those compounds (shown as free amines or hydrohalides) in Table 15a below.

obtained from Aldrich Chemical Co. and purified by distilation under reduced pressure. ##STR123## obtained from Aldrich Chemical Co. and purified by distillation under reduced pressure. ##STR124## obtained from Aldrich Chemical Co. and purified by sublimation. ##STR125## obtained Aldrich Chemical Co. and purified by recrystallization from benzene. ##STR126## prepared from 4-aminobiphenyl by methods analogous to Monomers 1a and 1i. ##STR127## was obtained from CTC Organics and used as obtained. ##STR128## prepared by methods analogous to Monomers 1a and 1i. ##STR129## obtained from Aldrich Chemical Co. and purified by recrystallization from dilute HCl containing stannous chloride by adding concentrated HCl. ##STR130## was obtained from Aldrich Chemical Co. and purified by recrystallization from water. ##STR131## obtained from Aldrich Chemical Co. and was purified by recrystallization from dilute HCl containing stannous chloride by adding concentrated HCl.

Type 11 monofunctional reactants have the general formula

wherein Y.sup.9 is a monovalent organic group and Z.sub.1 is an electron-deficient carbon group selected from the following class:

(R.sub.1 =H or an organic group bonded to N by a carbon atom)

The only requirement of Z.sub.1 is that it react with the X.sub.1 H and X.sub.2 H and with two hydrogen atoms of the primary amino groups of Type 1 monomers to form suitable leaving entities, such as water, hydrogen sulfide, hydrogen halide, ammonia, etc.

The monovalent group Y.sup.9 may be an aromatic group, an acyclic aliphatic group, or a cycloaliphatic group, and such groups may be substituted by hydrocarbon groups (aliphatic or aromatic) and by hetero atoms and groups. In general any of groups described above as substituents of the aromatic ring or rings of Ar.sup.1 may be used subject to the same restrictions.

Specific examples of Type 11 monofunctional reactants preferred for use in the invention include those compounds in Table 15b below.

Matheson primary standard grade ##STR133## obtained from Aldrich Chemical Co. and purified by distillation. ##STR134## obtained from Aldrich Chemical Co. and purified by distillation. ##STR135## obtained from Aldrich Chemical Co. and purified by recrystallization from water. ##STR136## obtained from Aldrich Chemical Co. and purified by distillation. ##STR137## obtained from Aldrich Chemical Co. and purified by sublimation. ##STR138## obtained from Aldrich Chemical Co. ##STR139## obtained from Aldrich Chemical Co. ##STR140## obtained from Aldrich Chemical Co. ##STR141## obtained from Aldrich Chemical Co. ##STR142## obtained from Aldrich Chemical Co. ##STR143## obtained from Aldrich Chemical Co. ##STR144## obtained from Aldrich Chemical Co. ##STR145## obtained form Aldrich Chemical Co.

Type 12 monofunctional reactants have the general formula ##STR146## wherein Z.sub.4 and Z.sub.5, are chosen from the list of carboxylic acid derivatives given for Z.sub.1 as defined for monomers of Type 2. Z.sub.4 and Z.sub.5, can also be a carboxylic acid anhydride group. Ar.sup.11 is an aromatic or aromatic heterocyclic moiety having two valence positions at carbon atoms. Ar.sup.11 can be a six-member ring or Ar.sup.11 can be two condensed six-member rings, such as naphthalene. Z.sub.4 and Z.sub.5 must either be ortho-positioned within each set or bear a 1,8-relationship (if Ar.sup.11 is a naphthalene nucleus) to each other.

Specific examples of Type 12 monofunctional reactants preferred for use in the invention include those compounds in Table 15c below.

obtained from Aldrich Chemical Co. ##STR148## obtained from Aldrich Chemical Co.

All of the above-cited patents and/or publications of Tables 1-15 are specifically incorporated herein by reference.

In accordance with the practice of the present invention, the synthesis of the aforementioned formulas I-VIII homopolymers may be illustrated by the following general reaction system:

Formation of formula I homopolymer ##STR149## Formation of formula II homopolymer ##STR150## Formation of formula III homopolymer ##STR151## Formation of formula IV homopolymer ##STR152## Formation of formula V homopolymer ##STR153## Formation of formula VI homopolymer ##STR154## Formation of formula VII homopolymer ##STR155## Formation of formula VIII homopolymer ##STR156##

Representative examples of suitable homopolymers forming liquid crystalline homopolymer compositions in accordance with the practice of the present invention (provided they fall within the above-defined general formulas I-VIII) include the following polymers. For the sake of convenience, polymer formulas are hereinbelow shown in simplified representation. As an example, --AI--.sub.n is ##STR157##

The structure representing --AI-- are defined in the Appendix. --A-- has the structure ##STR158## and --I-- has the structure ##STR159##

Their sequential combination is therefore ##STR160##

All simplified polymer formula representations appearing in the specification may be readily interpreted by reference to the Appendix. ##STR161##

The most preferred extended chain homopolymers in accordance with the practice of the present invention include ##STR162##

The especially preferred extended chain homopolymers in accordance with the practice of the present invention include ##STR163##

The preferred extended chain homopolymers in accordance with the practice of the present invention include ##STR164##

It is helpful to define three P.sub.2 O.sub.5 contents, operative at different stages of polymerization, that must be controlled in order to optimize the synthesis procedure of the present invention. We will define the initial P.sub.2 O.sub.5 content m.sub.o as the P.sub.2 O.sub.5 content of the polyphosphoric acid operative during dehydrohalogenation (in step b above and as explained more fully hereinafter). The initial P.sub.2 O.sub.5 content in accordance with the practice of the instant invention should be below about 83.3%, and may range from between about 83.3% to about 63%; preferably below about 82%, more preferably below about 80%, and most preferably below about 76%.

The intermediate P.sub.2 O.sub.5 content is operative at the initiation of polycondensation and is calculated so as to give the third (or final) P.sub.2 O.sub.5 content f that accounts for polyphosphoric acid hydrolysis by 100% of the theoretical water of polycondensation. The final P.sub.2 O.sub.5 content, f, must be above some minimum value if the solution is to maintain its effectiveness as a reaction medium at the late stages of polymerization. The final P.sub.2 O.sub.5 content should be between about 82% to about 86%, preferrably between about 82% to about 84%, and most preferrably between about 82% to about 83%.

The various important general process steps for preparing liquid crystalline polymer compositions of the present invention may include one or more of the following stages which are considered to be within the process parameters described above, These stages are:

Stage One--One or more of a selected first monomers selected from the group consisting of (amino-group-containing) monomers 1, 3, 5, or 9 is added to a specified initial weight in grams (given by a*) of a polyphosphoric acid with a P.sub.2 O.sub.5 content m.sub.o according to the empirical equation

where P.sub.y is the weight in grams of the theoretical yield of polymer, P.sub.c is the weight fraction of polymer in the total weight of the final liquid crystalline polymer composition (and is chosen to be above the critical concentration of the polymer necessary for liquid crystalline phase formation in the resulting polymer-polyphosphoric acid composition), n.sub.o is an integer giving the number of moles of condensation by-product per mole of polymer repeating unit. The number 18.02 is the molecular weight of the condensation by-product. M.sub.W is molecular weight of the polymer repeating unit, and f is the final P.sub.2 O.sub.5 content that must be above a minimum value as defined by this invention.

Stage Two--Once the first monomer(s) are combined with polyphosphoric acid, and protecting groups, if present, released, (optionally, depending on the particular polymer and reaction mechanism chosen) a stoichiometric amount of one or more of a selected second monomer selected from the group consisting of 2, 4, 6, 7, or 8 is next added and the chosen value of f is achieved by adding b* (an intermediate weight in grams of P.sub.2 O.sub.5) to the mixture according to the equation.

Stage Three--The resulting mixture (containing the first monomer(s) and/or the second monomer(s)) is then heated to a temperature suitable for polycondensation and maintained for a time to achieve the desired molecular weight (characterized by intrinisic viscosity).

Optionally, where the resultant extended chain polymer is formed from a selected first and second monomer, a selected excess molar amount (from 0.025 molar or less to 3 molar or more percent) of said selected second monomer can be added in Stage Two or more preferably a selected excess molar amount of said selected first monomer can be added in Stage One or allowing the loss of a small proportion of said selected first or said selected second monomer during polymerization Stage Three thereby off-balancing the stoichiometry of the monomers to obtain a desired intrinsic viscosity value less than the maximum attainable. Alternatively, one or more monofunctional reactants selected from Tables 15a, 15b, and 15c can be added during Stage One thereby limiting the maximum intrinsic viscosity attainable at Stage Three. The monofunctional reactants described herein are effective when added at the beginning of the polymerization Stage.

The reaction temperature may range from about 100.degree. C. to about 210.degree. C., preferably about 160.degree. C. to about 190.degree. C., and most preferably about 185.degree. C.

The P.sub.2 O.sub.5 content, m.sub.o, should be low enough to:

(1) achieve efficient dehydrohalogenation and/or

(2) achieve sufficient monomer loading to achieve desired P.sub.c without foaming problem or unusually high bulk viscosity. f should be high enough to:

(2a) maintain a polyphosphoric acid composition that is an effective reaction medium at late stages of polycondensation.

(2b) provide an effective phosphorylating medium as described in N. Yoda and M. Kurihara, "New Polymers of Aromatic Heterocycles by Polyphosphoric Acid Solution Methods", J. Polymer Scienc, Macromolecular Reviews, Volume 5, (1971), p. 159 at initial stage of polymerization. The subject matter of the paper by Yoda and et. al., is specifically incorporated herein by reference.

(2c) provide an effective solvent for the polymer at the end of polycondensation.

For purpose of illustration, a plot of equation a* is presented in FIG. 7 showing regions (shaded dash area) of poor monomer 1a solubility. In the case of polymer --AI--.sub.n, the family of P.sub.c curves can be utilized as follows:

1. choose a --AI--.sub.n polymer concentration, P.sub.c, as an example 0.16;

2. select a point on the curve P.sub.c =0.16 above the shaded dash area indicating poor monomer 1a solubility;

3. from that point selected, the weight in grams of PPA (a*) of the corresponding P.sub.2 O.sub.5 content (m.sub.o) that should be added to 92.06 g of monomer is can be determined;

4. after dehydrochlorination is complete, the amount of monomer 2a to be added is 62.38 g; and

5. if the final P.sub.2 O.sub.5 content (f) has been chosen to be 82.2%, then the amount of P.sub.2 O.sub.5 to be added (b*) is the difference between the amount of PPA used in step 3 above and the weight of PPA at the end of the curve for P.sub.c =0.16.

The choice of the optimal m.sub.o is dependent on the desired polymer concentration and the solubiity limits of the first monomer. The region of poor solubility for monomer 1a is shown in FIG. 7. Other monomers exhibit different solubility limits. Solubility rankings of some representative monomers are limited below.

Accordingly, it is possible to dehydrohalogenate the selected hydrohalide (monomers) more rapidly; the foaming problem is alleviated or eliminated; the solution in PPA of lesser P.sub.2 O.sub.5 content than that of U.S. Pat. No. 4,225,700 is much less viscous and dehydrohalogenation can be carried out much more readily. Further, a solution of selected monomers in PPA of considerably higher concentration is possible and a reaction product containing a much higher concentration of polymer is possible.

The above-mentioned formulas I, III, V, VII, and VIII homopolymer compositions may be prepared in accordance with the above process parameters by:

(a) mixing a selected first monomer (for example, a selected first monomer selected from the group consisting of (1,1), (1,2), or (1,3) with or without oxidation protecting atoms or groups with a preliminary solvent of phosphoric acid having a relatively low phosphorus pentoxide content.

(b) heating and optionally placing the resulting mixture under reduced pressure to remove any volatilized protecting atoms or groups present and provide a solution of the first monomer in the preliminary solvent.

(c) adding a selected second monomer (for example, a second monomer selected from the group consisting of (2.1), (2.2), (2.3), (4.1), (6.1), (6.2), (7.1) or (8.1)) in the resulting solution of step (b) to provide a mixture of the first and second monomer in the preliminary solvent.

(d) then increasing the phosphorus pentoxide content of the mixture resulting from step (c) to provide a first and second monomer reaction medium of greater phosphorus pentoxide content suitable for polymerization,

(e) causing polymerization of the first and second monomer at a temperature sufficient to effect reaction at a rate to form a first homo-oligomeric product having a preselected intrinsic viscosity or a first homopolymeric product,

(f) optionally adding a preselected excess molar amount of said selected first monomer in step (a) thereby off-balancing the stoichiometry proportion of said selected first and second monomers in said first and second monomer reaction medium so as to provide a said first homo-oligomeric product or a said first homopolymeric product following polymerization step (e) having a predetermined intrinsic viscosity less than the maximum attainable for a stoichiometric equivalent amount of both said selected first and second monomers,

(g) optionally adding a preselected excess molar amount of said selected second monomer in step (c) thereby off-balancing the stoichiometry proportion of said selected first and second monomers in said first and second monomer reaction medium so as to provide a said first homo-oligomeric product or a said first homopolymeric product following polymerization step (e) having a predetermined intrinsic viscosity less than the maximum attainable for a stoichiometric equivalent amount of both said selected first and second monomers,

(h) optionally adding one or more of a selected monofunctional reactants in step (a) so as to provide a said first homo-oligomeric product or a said first homopolymeric product following polymerization step (e) having a predetermined intrinsic viscosity less than the maximum attainable in the absence of said selected monofunctional reactants.

Formulas II, IV, and VI homopolymer compositions may be prepared by:

(a) mixing a selected first monomer (for example, a selected first monomer selected from the group consisting of (3.1), (3.2), (5.1), or (9.1)) with or without oxidation protecting atoms or groups with a preliminary solvent of phosphoric acid having a relatively low phosphorus pentoxide content,

(b) heating and optionally placing the resulting mixture under reduced pressure to remove any volatilized protecting atoms or groups present and provide a solution of the first monomer in the preliminary solvent,

(c) then increasing the phosphorus pentoxide content of the mixture resulting from step (b) to provide a first monomer reaction medium of greater phosphorus pentoxide content suitable for polymerization,

(d) causing polymerization of the first monomer at a temperature sufficient to effect reaction at a rate to form a first homo-oligomeric product having a preselected intrinsic viscosity or a first homopolymeric product,

(e) optionally adding one or more of a selected monofunctional reactants in step (a) so as to provide a said first homo-oligomeric product or a said first homopolymeric product following polymerization step (d) having a predetermined intrinsic viscosity less than the maximum attainable in the absence of said selected monofunctional reactants.

In accordance with a further aspect of the invention, there is provided a liquid-crystalline composition useful in the preparation of fibers and films comprising a polycondensation product consisting essentially of a blend of certain polyphosphoric acids and a high concentration of at least one high molecular weight extended chain copolymer selected from the group consisting of recurring units of the general formulas: ##STR165## wherein Ar.sup.1 represents an aromatic moiety and is XXX as defined above, X.sub.1 and X.sub.2 are the same or different and are sulfur, oxygen, or NR (R being hydrogen or an organic group), the nitrogen atoms and X.sub.1 and X.sub.2 being bonded to aromatic carbon atoms of Ar.sup.1, N and X.sub.1 or X.sub.2 of each hetero ring are disposed ortho to one another, and Y.sup.2 is nil or represents a bivalent organic radical and is XXXI as defned above, a.sub.i b.sub.j represents the molar proportions of the respective different recurring units present in said copolymer, y.sub.ij represents an average number of the respective different sequential recurring units present in said copolymer, n being a positive integer; ##STR166## wherein Ar.sup.1 represents an aromatic moiety and is XXX as defined above, X.sub.1 and X.sub.2 are the same or different and are sulfur, oxygen, or NR (R being hydrogen or an organic goup), the nitrogen atoms and X.sub.1 and X.sub.2 being bonded to aromatic carbon atoms of Ar.sup.1, N and X.sub.1 or X.sub.2 of each hetero ring are disposed ortho to one another and Y.sup.2 represents a bivalent organic radical and is XXXI as defined above, a.sub.i b.sub.j m/m+m' represents the molar proportions of the respective different recurring units present in said copolymer, y.sub.ij represents an average number of the respective different sequential recurring units present in said copolymer, Ar.sup.3 represents a different aromatic moiety and is XXII as defined above, the nitrogen atom and X.sub.3 being bonded to aromatic carbon atoms of Ar.sup.3, c.sub.k m'/m+m' represents the molar proportions of the respective different recurring units present in said copolymer, y.sub.k represents an average number of the respective different sequential recurring units present in said copolymer, n being a positive integer; ##STR167## wherein Ar.sup.3 represents an aromatic moiety and is XXII as defined above, X.sub.3 is sulfur, oxygen, or NR (R being hydrogen or an organic group), the nitrogen atoms and X.sub.3 being bonded to aromatic carbon atoms of AR.sup.3, N and X.sub.3 of each hetero ring are disposed ortho to one another, c.sub.k represents the molar proportions of the respective different recurring units present in said copolymer, y.sub.k represents an average number of the respective different sequential recurring units present in said copolymer, n being a positive integer; ##STR168## wherein Ar.sup.1 represents an aromatic moiety and is XXXII as defuned above, Ar.sup.4 represents a different aromatic moiety and is XXIII as defined above, the nitrogen atoms being bonded AR.sup.1 and the carbon atoms being bonded to Ar.sup.4, a.sub.i b.sub.j represents the molar proportions of the respective different recurring units present in said copolymer, y.sub.ij represents an average number of the respective different sequential recurring units present in said copolymer, n being a positive integer; ##STR169## wherein Ar.sup.4 represents a different aromatic moiety and is XXIII as defined above. Ar.sup.1 represents an aromatic moiety and is XXXII as defined above, and Ar.sup.5 represents an aromatic moiety different from Ar.sup.4 and Ar.sup.1 and is XXIV as defined above, the carbon atoms being bonded to Ar.sup.4 and Ar.sup.5 and the nitrogen atoms being bonded to Ar.sup.1 and Ar.sup.5, n being a positive integer; c.sub.k m'/m+m' represents the molar proportions of the respective different recurring units present in said copolymer, y.sub.k represents an average number of the respective different sequential recurring units present in said copolymer, a.sub.i b.sub.j m/m+m' represents the molar proportions of the respective different recurring units present in said copolymer, y.sub.ij represents an average number of the respective different sequential recurring units present in said copolymer, n being a positive integer; ##STR170## wherein Ar.sup.1 represents an aromatic moiety and is XXX as defined above. AR.sup.6 represents a different aromatic moiety and is XXV as defined above, X.sub.1 and X.sub.2 are the same or different and are sulfur, oxygen, or NR (R being hydrogen or an organic group), the NH groups and X.sub.4 and X.sub.1 being bonded to aromatic carbon atoms of AR.sup.6 and Ar.sup.1, NH and X.sub.1 or X.sub.2 of each hetero ring are disposed ortho to one another, a.sub.i b.sub.j represents the molar proportions of the respective different recurring units present in said copolymer, y.sub.ij represents an average number of the respective different sequential recurring units present in said copolymer, n being a positive integer; ##STR171## wherein Ar.sup.1 represents an aromatic moiety and is XXX as defined above, Ar.sup.6 represents a different aromatic moiety and is XXV as defined above, X.sub.1 and X.sub.2 are the same or different and are sulfur, oxygen, or NR (R being hydrogen or an organic group), the NH groups and X.sub.1 and X.sub.2 being bonded to aromatic carbon atoms of Ar.sup.6 and Ar.sup.1, NH and X.sub.1 or X.sub.2 of each hetero ring are disposed ortho to one another, a.sub.i b.sub.j m/m+m' represents the molar proportions of the respective different recurring units present in said copolymer, y.sub.ij represents an average number of the respective different sequential recurring units present in said copolymer, Ar.sup.9 represents an aromatic moiety different from Ar.sup.6 and Ar.sup.1 and is XXVI as defined above, X.sub.4 is sulfur, oxygen, or NR (R being hydrogen or an organic group), the NH groups and X.sub.4 being bonded to aromatic carbon atoms of Ar.sup.6 and Ar.sup.9, c.sub.k m'/m+m' represents the molar proportions of the respective different recurring units present in said copolymer, y.sub.k represents an average number of the respective different sequential recurring units present in said copolymer, n being a positive integer; ##STR172## wherein Ar.sup.1 represents an aromatic moiety and is XXXII as defined above, Y.sup.7 represents an aromatic or heteroaromatic moiety and is XXVIII as defined above, the nitrogen atoms being bonded to aromatic carbon atoms of Ar.sup.1 and bonded to adjacent carbon atoms of Y.sup.7, a.sub.i b.sub.j represents the molar proportions of the respective different recurring units present in said copolymer, y.sub.ij represents an average number of the respective different sequential recurring units present in said copolymer, n being a positive integer.

In accordance with the practice of the present invention, the synthesis of the aforementioned formulas IX-XVIII copolymers may be illustrated by the following general reaction system:

Formation of formula IX copolymer ##STR173## Formation of formula X copolymer ##STR174## Formation of formula XI copolymer ##STR175## Formation of formula XII copolymer ##STR176## Formation of formula XV copolymer ##STR177## Formation of formula XVI copolymer ##STR178## Formation of formula XVII copolymer ##STR179## Formation of formula XVIII copolymer ##STR180##

The above-mentioned formulas IX, X, XII, XV, XVI, XVII, and XVIII copolymer compositions can be prepared in accordance with the above process parameters by:

(a) mixing at least two of a selected first monomers (for example, two or more of a monomer selected from the group consisting of (1.1).

(1.2), (1.3), (3.1), (3.2), (5.1), or (9.1)) with or without oxidation protecting atoms or groups with a preliminary solvent of phosphoric acid having a relatively low phosphorus pentoxide content,

(b) heating and optionally placing the resulting mixture under reduced pressure to remove any volatilized protecting atoms or groups present and provide a solution of the first monomer in the preliminary solvent,

(c) adding at least one of a selected second monomers (for example, one or more of a monomer selected from the group consisting of (2.1), (2.2), (2.3), (4.1), (6.1), (6.2), (7.1) or (8.1)) in the resulting solution of step (b) to provide a mixture of the first and second monomer in the preliminary solvent,

(d) then increasing the phosphorus pentoxide content of the mixture resulting from step (c) to provide a first and second monomer reaction medium of greater phosphorus pentoxide content suitable for polymerization,

(e) causing polymerization of the first and second monomer at a temperature sufficient to effect reaction at a rate to form a first co-oligomeric product having a preselected intrinsic viscosity or a first copolymeric product,

(f) optionally adding a preselected excess molar amount of said selected first monomer in step (a) thereby off-balancing the stoichiometry proportion of said selected first and second monomers in said first and second monomer reaction medium so as to provide a said first co-oligomeric product or a said first copolymeric product following polymerization step (e) having a predetermined intrinsic viscosity less than the maximum attainable for a stoichiometric equivalent amount of both said selected first and second monomers,

(g) optionally adding a preselected excess molar amount of said selected second monomer in step (c) thereby off-balancing the stoichiometry proportion of said selected first and second monomers in said first and second monomer reaction medium so as to provide a said first co-oligomeric product or a said first copolymeric product following polymerization step (e) having a predetermined intrinsic viscosity less than the maximum attainable for a stoichiometric equivalent amount of both said selected first and second monomers,

(h) optionally adding one or more of a selected monofunctional reactants in step (a) so as to provide a said first co-oligomeric product or a said first copolymeric product following polymerization step (e) having a predetermined intrinsic viscosity less than the maximum attainable in the absence of said selected monofunctional reactants.

Similarly formulas IX, XII, XVI, and XVIII copolymer compositions can be prepared by:

(a) mixing at least one of a selected first monomers (for example, one or more of a monomer selected from the group consisting of (1.1), (1.2), (1.3), (3.1), (3.2), (5.1), or (9.1))with or without oxidation protecting atoms or groups with a preliminary solvent of phosphoric acid having a relatively low phosphorus pentoxide content,

(b) heating and optionally placing the resulting mixture under reduced pressure to remove any volatilized protecting atoms or groups present and provide a solution of the first monomer in the preliminary solvent,

(c) adding at least two of a selected second monomers (for example, one or more of a monomer selected from the group consisting of (2.1), (2.2), (2.3), (4.1), (6.1), (6.2), (7.1) or (8.1)) in the resulting solution of step (b) to provide a mixture of the first and second monomer in the preliminary solvent,

(d) then increasing the phosphorus pentoxide content of the mixture resulting from step (c) to provide a first and second monomer reaction medium of greater phosphorus pentoxide content suitable for polymerization,

(e) causing polymerization of the first and second monomer at a temperature sufficient to effect reaction at a rate to form a first co-oligomeric product having a preselected intrinsic viscosity or a first copolymeric product,

(f) optionally adding a preselected excess molar amount of said selected first monomer in step (a) thereby off-balancing the stoichiometry proportion of said selected first and second monomers in said first and second monomer reaction medium so as to provide a said first co-oligomeric product or a said first copolymeric product following polymerization step (e) having a predetermined intrinsic viscosity less than the maximum attainable for a stoichiometric equivalent amount of both said selected first and second monomers,

(g) optionally adding one or more of a selected monofunctional reactants in step (a) so as to provide a said first co-oligomeric product or a said first copolymeric product following polymerization step (e) having a predetermined intrinsic viscosity less than the maximum attainable in the absence of said selected monofuntional reactants.

Preferred formulas IX, X, XI, XII, XV, XVI, XVII, and XVIII copolymers forming liquid crystalline copolymer compositions of the instant invention are those wherein a.sub.i is the mole fraction of the ith monomer selected from Type 1, b.sub.j is the mole fraction of the jth monomer selected from Types 2, 4, 6, 7, or 8, c.sub.k is the mole fraction of the kth monomer selected from Types 3, 5, or 9, m and m' are appropriate molar quantities based on desired yield, a.sub.i b.sub.j and a.sub.i b.sub.j m/m+m' are the molar proportions of the recurring units resulting from the condensation of the ith monomer of Type 1 and the jth monomer of Type 2, 4, 6, 7, or 8, c.sub.k and c.sub.k m'/m+m' are the molar proportions of the recurring unit resulting from the condensation of the kth monomer of Type 3, 5, or 9, y.sub.ij is the average block length (i.e., the average number of sequential recurring units unbroken by a different recurring unit) of the recurring unit formed from the ith monomer of Type 1 and the jth monomer of Type 2, 4, 6, 7, or 8, y.sub.k is the average block length of the recurring unit formed by self-condensation of the kth monomer of Type 3, 5, or 9, and n is the average overall length of the copolymer (i.e., the average total number of recurring units independent of structure). The number of recurring units in the copolymer may be the product of the highest i and the highest j or may be the product of the highest i and the highest j plus the highest k. i, j and k can be as high as is practical, but may have certain minimal values if copolymers, rather than homopolymers, are to be obtained.

Selected molar quantities (a.sub.1 m, a.sub.2 m, . . . a.sub.i m) of monomers of Type 1 may be mixed with a phosphoric acid having a phosphorus pentoxide content of from about 63% to about 78%, preferably greater than about 68%, most preferably about 78%, and the protecting groups, such as hydrogen halide, if present, may be substantially removed by heating, and applying reduced pressure if desired. The quantity of the phosphoric acid is most desirably determined in accordance with equation a* above, making the necessary calculations for addition of monomers of possibly different molecular weights and different proportions. A stoichiometric quantity (i.e., b.sub.1 m+b.sub.2 m+ . . . b.sub.j m=m) of monomer selected from Type 2, 4, 6, 7, or 8 may then be added to the resulting solution. The phosphorus pentoxide content of the resulting mixture may then be raised in accordance with equation b* above, so as to raise the final phosphorus pentoxide content of the substantially copolymerized mixture to a value preferably within the range between about 81% to about 84% and most preferably between about 82% to about 83.5%. The resulting mixture may then be heated to a temperature preferably about 100.degree. C. to about 210.degree. C., most preferably to about 170.degree. C. to about 185.degree. C. within a practical time period, from less than about one hour to greater than about 5 hours, preferably within about 1 to about 3 hours. The temperature may be maintained for a sufficient time, which may range from less than about 1 hour to about 48 hours or more, most preferably between from about 1 to about 23 hours, to achieve the desired n value. The practice of the present invention as it relates to the production of novel liquid-crystalline compositions comprising copolymers with the general formulas IX, XII, XVI, and XVIII is illustrated for those compositions including general formula IX wherein the selected monomers of Type 1 are further classified as being of Types (1.1), (1.2) or (1.3) and the selected monomers of Type 2 are of Types (2.1), (2.2), or (2.3).

General formula IX copolymers prepared from type (1.1) and type (2.1) monomers have the advantage that the critical concentration necessary for liquid-crystalline behavior is low. For the copolymers listed below, their critical concentration may be as low as about 5 weight percent in polyphosphoric acid at substantially moderate n values, thus allowing a broad range of operable concentrations. ##STR181##

Since the recurring units of the copolymers are of essentially comparable mesogenicity, a broad range of copolymer compositions may be achieved; for instance, a.sub.1 b.sub.1 can range from nearly zero to nearly one while a.sub.1 b.sub.2 or a.sub.2 b.sub.1 (because it is equal to 1-a.sub.1 b.sub.1) ranges from nearly one to nearly zero, respectively. The average block lengths y.sub.11 and Y.sub.12 or y.sub.21 are governed by the method of monomer addition described above and the molar quantities selected. Thus, for monomer pairs of essentially equal reactivity, y.sub.11, which equals 1/1-a.sub.1 b.sub.1, may range from nearly one to very high values. In a like manner, y.sub.12 or y.sub.21 can range from very high values to nearly one. Monomer purity, control of stoichiometry, and exclusion of side reactions caused by oxidizing impurities must be sufficient to obtain an overall copolymer length, n, greater than about 50 in order to obtain the desired polymeric properties of useful mechanical strength, modulus, etc. The practice of the invention as it relates to copolymers derived from Class 1 monomers is further illustrated in Examples 49-51 and 54-66 below.

General formula IX copolymers may be prepared from type (1.1), (2.1) and (2.2) monomers and from type (1.1), (1.2) and (2.1) monomers. These monomers are classified as Class 2 owing either to a moderately reduced mesogenic character of the recurring unit derived from them or to their tendency to reduce the solubility range of the resulting polymer, which in turn is usually owing to an overall reduction of the heteroatom/hydrocarbon ratio of the resulting polymer. Both of these conditions dictate that incorporation of Class 2 monomers into copolymers of the present invention should be carefully selected. The degree of this selectivity is illustrated by the following copolymers prepared in accordance with the practice of the invention. ##STR182##

The immediately preceding list of copolymers is derived from monomer compositions containing monomers imparting reduced solubility to the copolymer. The preferred values of a.sub.1 b.sub.1 (i.e., the mole fraction of the more soluble recurring unit) are those greater than about 0.8, leading to values of y.sub.11 greater than about 5 and y.sub.12 values of nearly one. Monomer purity, control of stoichiometry, exclusion of oxidizing impurities, and selection of the molar quantity of the less soluble monomer to maintain copolymer solubility must be sufficient to achieve an average n value of greater than about 50. Increased proportion of a less soluble monomer may be achieved by selecting comonomers that impart improved solubility to the copolymer. In general, monomers of Type 1 wherein X is S impart greater solubility than those in which X is O or N. The practice of the invention as it relates to copolymers of partially reduced solubility is further illustrated in Examples 52, 53, 70, 71, and 72 below.

The following list of copolymers is derived from incorporation of monomers of moderately reduced mesogenicity and the practice of the invention is illustrated for them. ##STR183##

The preferred ranges of a.sub.1 b.sub.1 are from nearly zero to nearly one for copolymers in this classification with the overall proviso that the overall copolymer concentration in the polyphosphoric acid be above a critical concentration determined by the least mesogenic recurring unit. Thus, above about 13% the above copolymers may have a.sub.1 b.sub.1 values between about one and zero, y.sub.11 values of nearly one and greater, and y.sub.21 values of nearly one and greater. The preferred concentration with these a.sub.1 b.sub.2 and a.sub.2 b.sub.1 values may be between about 15 and about 22 weight percent. If the molar proportion of the more highly mesogenic recurring unit (i.e., a.sub.1 b.sub.1) is selected to have values of greater than about 0.6, preferably greater than about 0.75, then the range of operable concentrations is increased to include concentrations of the copolymer in greater than about 8 weight percent, preferably above about 10 weight percent. Values of n greater than about 50 are preferable as stated above.

General formula IX copolymer compositions may be prepared from Class 3 monomers.

Monomers characterized as belonging to Class 3 lead to polymer recurring units that have little or no mesogenic character. Their incorporation into copolymers prepared as above are within the scope of the present invention but are less preferred because the random incorporation of a significant molar proportion of these nonmesogenic units leads to insufficient block length of the mesogenic recurring unit or units to impart liquid-crystalline behavior. Incorporation of less than about 3 molar percent of Class 3 monomers is preferred. Increased incorporation of Class 3 polymers are highly preferred by use of a block polymer procedure described below. A less preferred embodiment of the present invention is the preparation of General formulas X, XV, and XVII by the addition of monomers of Types 3, 5, and 9, respectively, to the initial solution of the above copolymer procedure. The unique feature of the geometry of monomers of Types 3 (except for 3k), 5, or 9 is the requirement that the block lengths, y.sub.k, be large or, if small, be an even number. This condition dictates that preferred compositions of formulas X, XV, and XVII are prepared by a block polymer procedure described below.

The general formula XI copolymer composition shown above is prepared according to the following procedure:

(a) mixing at least two of a selected first monomer with or without oxidation protecting atoms or groups with a preliminary solvent of phosphoric acid having a relatively low phosphorus pentoxide content,

(b) heating and optionally placing the resulting mixture under reduced pressure to remove any volatilized protecting atoms or groups present and provide a solution of the first monomer in the preliminary solvent,

(c) then increasing the phosphorus pentoxide content of the mixture resulting from step (b) to provide a first monomer reaction medium of greater phosphorus pentoxide content suitable for polymerization,

(d) causing polymerization of the said two of a selected first monomer at a temperature sufficient to effect reaction at a rate to form a first co-oligomeric product having a reselected intrinsic viscosity or a first copolymeric product,

(e) optionally adding one or more of a selected monofunctional reactants in step (a) so as to provide a said first co-oligomeric product or a said first copolymeric product following polymerization step (d) having a predetermined intrinsic viscosity less than the maximum attainable in the absence of said selected monofunctional reactants.

Selected molar quantities (c.sub.1 m, c.sub.2 m, . . . c.sub.k m) of Type 3 monomers may be mixed with a phosphoric acid having a phosphorus pentoxide content of from about 63% to about 78%, preferably greater than about 68%, most preferably about 78%, and the protecting groups, if present, may be substantially removed by heating, and applying reduced pressure, if desired. The quantity of phosphoric acid is determined in accordance with equation a* above, making the necessary calculations for the addition of monomers of possibly different molecular weights and different proportions. The phosphorus pentoxide content of the resulting mixture may then be raised in accordance with equation b* above, so as to raise the final phosphorus pentoxide of the substantially copolymerized mixture to a value greater than about 81%, most preferably between about 82% to about 83% but less than about 84%. The resulting mixture may then be heated to about 100.degree. C. to about 200.degree. C., most preferably between about 150.degree. C. to about 185.degree. C. within a practical period of time, preferably within a time period of less than about 1 hour to about 5 hours or more, and most preferably within a period of about 1 hour to about 3 hours, and then maintained at the selected temperature for sufficient time to achieve the desired n value.

The practice of the present invention as it relates to the production of novel liquid-crystalline compositions that include copolymers with the general formula XI is further illustrated for those compositions wherein the selected monomers of Type 3 are further classified as being of Type (3.2).

The polymers ##STR184## are prepared according to the above procedure wherein c.sub.1 is the molar proportion of the more soluble recurring unit and selected to be above about 0.5, more preferably above about 0.7, to ensure the solubility of the resulting copolymer to the high concentrations required for liquid-crystalline behavior. A weight percent of the copolymer above about 15 weight percent, more preferably above about 17.5 weight percent, may be selected. Molar proportions selected above and monomer reactivity ratios determine the average block lengths y.sub.1 and y.sub.2. The block length does not bear on whether liquid-crystalline behavior in polyphosphoric acid is obtained with these polymers. The important factor is the maintenance of solubility at high concentration and the preparation of these copolymers in polyphosphoric acid at high concentration from monomers.

In accordance with a still further aspect of the invention, there is provided a liquid-crystalline composition useful in the preparation of fibers and films comprising a polycondensation product consisting essentially of a blend of certain polyphosphoric acids and a high concentration of at least one high molecular weight extended chain block polymer selected from the group consisting of recurring units of the general formulas: ##STR185## wherein Ar.sup.1 represents an aromatic moiety and is XXX as defined above, X.sub.1 and X.sub.2 are the same or different and are sulfur, oxygen, or NR (R being hydrogen or an organic group), the nitrogen atoms and X.sub.1 and X.sub.2 being bonded to aromatic carbon atoms of Ar.sup.1, N and X.sub.1 or X.sub.2 of each hetero ring are disposed ortho to one another and Y.sup.2 is nil or represents a bivalent organic radical and is XXXI as defined above, a.sub.i b.sub.j represents the molar proportions of the respective different recurring units present in said block polymer, y.sub.ij represents an average number of the respective different sequential recurring units present in said block polymer, n being a positive integer; ##STR186## wherein Ar.sup.1 represents an aromatic moiety and is XXX as defined above, X.sub.1 and X.sub.2 are the same or different and are sulfur, oxygen, or NR (R being hydrogen or an organic group), the nitrogen atoms and X.sub.1 and X.sub.2 being bonded to aromatic carbon atoms of Ar.sup.1, N and X.sub.1 or X.sub.2 of each hetero ring are disposed ortho to one another and Y.sup.2 is nil or represents a bivalent organic radical and is XXXI as defined above, a.sub.i b.sub.j m/m+m' represents the molar proportions of the respective different recurring units present in said block polymer, y.sub.ij represents an average number of the respective different sequential recurring units present in said block polymer, Ar.sup.3 represents an aromatic moiety and is XXII as defined above, X.sub.3 is sulfur, oxygen, or NR (R being hydrogen or an organic group), the nitrogen atoms and X.sub.3 being bonded to aromatic carbon atoms of Ar.sup.3, N and X.sub.3 of each hetero ring are disposed ortho to one another, c.sub.k m'/m+m' represents the molar proportions of the respective different recurring units present in said block polymer, y.sub.k represents an average number of the respective different sequential recurring units present in said block polymer, n being a positive integer; ##STR187## wherein Ar.sup.3 represents an aromatic moiety and is XXII as defined above, X.sub.3 is sulfur, oxygen, or NR (R being hydrogen or an organic group), the nitrogen atoms and X.sub.3 being bonded to aromatic carbon atoms of Ar.sup.3, N and X.sub.3 of each hetero ring are disposed ortho to one another, c.sub.k represents the molar proportions of the respective different recurring units present in said block polymer, y.sub.k represents an average number of the respective different sequential recurring units present in said block polymer, n being a positive integer; ##STR188## wherein Ar.sup.1 represents an aromatic moiety and is XXXII as defined above, Ar.sup.4 represents a different aromatic moiety and is XXIII as defined above, the nitrogen atoms being bonded to Ar.sup.1 and the carbon atoms being bonded to Ar.sup.4, a.sub.i b.sub.j represents the molar proportions of the respective different recurring units present in said block polymer, y.sub.ij represents an average number of the respective different sequential recurring units present in said block polymer, n being a positive integer; ##STR189## wherein Ar.sup.1 represents an aromatic moiety and is XXXII or XXX as defined above with the proviso that when Ar.sup.1 is bonded to nitrogen atoms Ar.sup.1 is XXXII and when Ar.sup.1 is bonded to both nitrogen atoms and X.sub.1 and X.sub.2, Ar.sup.1 is XXX as defined above, Ar.sup.4 represents a different aromatic moiety and is XXIII as defined above, the carbon atoms being bonded to Ar.sup.4, m'/m+m' represents the molar proportions of the respective different recurring units present in said block polymer, y' represents an average number of the respective different sequential recurring units present in said block polymer, X.sub.1 and X.sub.2 are the same or different and are sulfur, oxygen, or NR (R being hydrogen or an organic group), the nitrogen atoms and X.sub.1 and X.sub.2 being bonded to aromatic carbon atoms of Ar.sup.1, N and X.sub.1 or X.sub.2 of each hetero ring are disposed ortho to one another and Y.sup.2 is nil or represents a bivalent organic radical and is XXXI as defined above, m/m+m' represents the molar proportions of the respective different recurring units present in said block polymer, y represents an average number of the respective different sequential recurring units present in said block polymer, n being a positive integer; ##STR190## wherein Ar.sup.3 represents an aromatic moiety and is XXII as defined above, X.sub.3 is sulfur, oxygen, or NR (R being hydrogen or an organic group), the nitrogen atoms and X.sub.3 being bonded to aromatic carbon atoms of Ar.sup.3, N and X.sub.3 of each hetero ring are disposed ortho to one another, p represents the molar proportions of the respective different recurring units present in said block polymer, y'/2 represents an average number of the respective different sequential recurring units present in said block polymer. Ar.sup.1 represents an aromatic moiety and is XXXII as defined above, Ar.sup.4 represents a different aromatic moiety and is XXIII as defined above, the nitrogen atoms being bonded to Ar.sup.1 and the carbon atoms being bonded to Ar.sup.4, q represents the molar proportions of the respective different recurring units present in said block polymer, y represents an average number of the respective different sequential recurring units present in said block polymer, n being a positive integer; ##STR191## wherein Ar.sup.4 represents a different aromatic moiety and is XXIII as defined above, Ar.sup.1 represents an aromatic moiety and is XXXII as defined above, and Ar.sup.5 represents an aromatic moiety different from Ar.sup.4 and Ar.sup.1 and is XXIV as defined above, the carbon atoms being bonded to Ar.sup.4 and Ar.sup.5 and the nitrogen atoms being bonded to Ar.sup.1 and Ar.sup.5, n being a positive integer; c.sub.k m'/m+m' represents the molar proportions of the respective different recurring units present in said block polymer, y.sub.k represents an average number of the respective different sequential recurring units present in said block polymer, a.sub.i b.sub.j m/m+m' represents the molar proportions of the respective different recurring units present in said block polymer, y.sub.ij represents an average number of the respective different sequential recurring units present in said block polymer, n being a positive integer; ##STR192## wherein Ar.sup.1 represents an aromatic moiety and is XXX as defined above. Ar.sup.6 represents a different aromatic moiety and is XXV as defined above, X.sub.1 and X.sub.2 are the same or different and are sulfur, oxygen, or NR (R being hydrogen or an organic group), the NH groups and X.sub.1 and X.sub.2 being bonded to aromatic carbon atoms of Ar.sup.6 and Ar.sup.1, NH and X.sub.1 or X.sub.2 of each hetero ring are disposed ortho to one another, a.sub.i b.sub.j represents the molar proportions of the respective different recurring units present in said block polymer, y.sub.ij represents an average number of the respective different sequential recurring units present in said block polymer, n being a positive integer; ##STR193## wherein Ar.sup.1 represents an aromatic moiety and is XXX as defined above, Ar.sup.6 represents a different aromatic moiety and is XXV as defined above, X.sub.1 and X.sub.2 are the same or different and are sulfur, oxygen, or NR (R being hydrogen or an organic group), the NH groups and X.sub.1 and X.sub.2 being bonded to aromatic carbon atoms of Ar.sup.6 and Ar.sup.1, the NH groups and X.sub.4 being bonded to carbon atoms of Ar.sup.1 and Ar.sup.9, NH and X.sub.1 or X.sub.2 of each hetero ring are disposed ortho to one another, a.sub.i b.sub.j m/m+m' represents the molar proportions of the respective different recurring units present in said block polymer, y.sub.ij represents an average number of the respective different sequential recurring units present in said block polymer, Ar.sup.9 represents an aromatic moiety different from Ar.sup.6 and Ar.sup.1 and is XXVI as defined above, X.sub.4 is sulfur, oxygen, or NR (R being hydrogen or an organic group), the NH groups and X.sub.4 being bonded to aromatic carbon atoms of Ar.sup.6 and Ar.sup.9, c.sub.k m'/m+m' represents the molar proportions of the respective different recurring units present in said block polymer, y.sub.k represents an average number of the respective different sequential recurring units present in said block polymer, n being a positive integer; ##STR194## wherein Ar.sup.1 represents an aromatic moiety and is XXXII as defined above, Y.sup.7 represents an aromatic or heteroaromatic moiety and is XXVIII as defined above, the nitrogen atoms being bonded to aromatic carbon atoms of Ar.sup.1 and bonded to adjacent carbon atoms of Y.sup.7, a.sub.i b.sub.j represents the molar proportions of the respective different recurring units present in said block polymer, y.sub.ij represents an average number of the respective different sequential recurring units present in said block polymer, n being a positive integer. In accordance with the practice of the present invention, the synthesis of the aforementioned formulas IX-XIX block polymers can be illustrated by the following general reaction system:

Formation of formula IX block polymer ##STR195## Formation of formula X block polymer ##STR196## Formation of formula XI block polymer ##STR197## Formation of formula XII block polymer ##STR198## Formation of formula XIII block polymer ##STR199## Formation of formula XIV block polymer ##STR200## Formation of formula XV block polymer ##STR201## Formation of formula XVI block polymer ##STR202## Formation of formula XVII block polymer ##STR203## Formation of formula XVIII block polymer ##STR204## Formation of formula XIX block polymer ##STR205##

The above-mentioned formulas IX, XII, XVI, XVIII, and XIX block polymer compositions may be prepared in accordance with the above process parameters by:

(a) mixing at least one of a selected first monomer with or without oxidation protecting atoms or groups with a preliminary solvent of phosphoric acid having a relatively low phosphorus pentoxide content,

(b) heating and optionally placing the resulting mixture under reduced pressure to remove any volatilized protecting atoms or groups present and provide a solution of the first monomer in the preliminary solvent,

(c) adding at least one of a selected second monomer in the resulting solution of step (b) to provide a mixture of the first and second monomer in the preliminary solvent,

(d) then increasing the phosphorus pentoxide content of the mixture resulting from step (c) to provide a first and second monomer reaction medium of greater phosphorus pentoxide content suitable for polymerization,

(e) causing polymerization of the first and second monomer at a temperature sufficient to effect reaction at a rate to form a first homo-oligomeric product having a preselected intrinsic viscosity,

(f) mixing a selected amount of the first homo-oligomeric product with a selected amount of at least one of a selected second homo-oligomeric product so as to form a first poly-oligomeric product, said second homo-oligomeric product being formed by like steps (a), (b), (c), (d), and (e) with the overall proviso that at least one of the selected monomer of step (a) or (c) which forms the second homo-oligomeric product be different from at least one of the selected monomer of step (a) or (c) which forms the first homo-oligomeric product,

(g) causing polymerization of the poly-oligomeric product at a temperature sufficient to effect reaction at a rate to form a first block-oligomeric product having a preselected intrinsic viscosity or a first block-polymeric product,

(h) optionally adding one or more of a selected monofunctional reactants prior to end of polymerization in step (g) so as to provide a said first block-oligomeric product or a said first block-polymeric product having a predetermined intrinsic viscosity less than the maximum attainable in the absence of said selected monofunctional reactants.

Alternatively, formulas IX, XII, XVI, XVIII, and XIX block polymer compositions may be prepared by:

(a) mixing at least one of a selected first monomer with or without oxidation protecting atoms or groups with a preliminary solvent of phosphoric acid having a relatively low phosphorus pentoxide content,

(b) heating and optionally placing the resulting mixture under reduced pressure to remove any volatilized protecting atoms or groups present and provide a solution of the first monomer in the preliminary solvent,

(c) adding at least one of a selected second monomer in the resulting solution of step (b) to provide a first mixture of the first and second monomer in the preliminary solvent,

(d) then increasing the phosphorus pentoxide content of the mixture resulting from step (c) to provide a first and second monomer reaction medium of greater phosphorus pentoxide content suitable for polymerization,

(e) causing polymerization of the first and second monomer at a temperature sufficient to effect reaction at a rate to form a first homo-oligomeric product having a preselected intrinsic viscosity,

(f) mixing a selected amount of the first homo-oligomeric product with a selected amount of a second mixture of a different first and second monomer in the preliminary solvent, said second mixture being formed by like steps (a), (b) and (c) with the overall proviso that at least one of the selected monomer of step (a) or (c) which forms the second mixture be different from at least one of the selected monomer of step (a) or (c) which forms the first homo-oligomeric product,

(g) then increasing the phosphorus pentoxide content of the mixture resulting from step (f) to provide a first oligomer-monomer reaction medium of greater phosphorus pentoxide content suitable for polymerization.

(h) causing polymerization of the mixture resulting from step (g) at a temperature sufficient to effect reaction at a rate to form a first block-oligomeric product having a preselected intrinsic viscosity or a first block-polymeric product,

(i) optionally adding one or more of a selected monofunctional reactants prior to end of polymerization in step (h) so as to provide a said first block-oligomeric product or a said first block-polymeric product having a predetermined intrinsic viscosity less than the maximum attainable in the absence of said selected monofunctional reactants.

The above IX-XIX block polymers forming the liquid crystalline block polymer compositions of the instant invention can be characterized as having more than one recurring unit, the distribution or sequencing of which may be different from that obtained by the random condensation of monomers as in the copolymers described above and is further characterized as having contiguous blocks of the same recurring unit as obtained by the random condensation of oligomers.

The preferred formulas IX, XII, XVI, XVIII, and XIX block polymers are those polymers wherein a.sub.i b.sub.j is the mole fraction of the recurring unit formed by the condensation of a homo-oligomeric reaction product (defined below) derived from the ith monomer of Type 1 with a stoichiometric quantity of jth monomer of Type 2, 4, 6, 7, or 8, respectively, and incorporated by a block-polymeric procedure described below, and y.sub.ij and n have the same meaning as described above for copolymers. The preferred XI block polymers are those wherein c.sub.k is the mole fraction of the recurring unit formed by the condensation of a homo-oligomeric reaction product (defined below) derived from the kth monomer of Type 3 and incorporated by a block polymeric procedure described below, and y.sub.k and n are as defined for copolymers.

The preferred X, XV, and XVII block polymers are those wherein a.sub.i b.sub.j m/m+m' is the mole fraction of the recurring unit formed by the condensation of m moles of recurring units of a homo-oligomeric reaction product derived from the ith monomer of Type 1 and the jth monomer of Type 2, 4, or 6 and combined with m' moles of recurring units of a homo-oligomeric reaction product derived from condensation of the kth monomer of Type 3, 5, or 9, respectively, and y.sub.ij, y.sub.k, and n are as defined for copolymers.

The preferred XIII block polymers are those wherein m' and m are appropriate molar quantities of the monomers that form the reaction products and are selected to give desired yields and molar proportions of the respective recurring units, y' and y are block lengths as defined above, n is the total number of recurring units, and x is a molar quantity substantially less than m' that is selected to give an appropriate block length of the first homo-oligomer end-capped with o-diamine functional groups,

The preferred XIV block polymers are those wherein m', m, x, n, y, y' are as defined above, q is equal to m'/m+m' and p is equal to m/2(m+m').

Selected molar quantity, m, of a monomer of Type 1 may be mixed with a phosphoric acid having a phosphorus pentoxide content of from about 63% to about 78%, preferably greater than about 68%, most preferably about 78%, and the protecting groups, if present, may be removed as described previously. The quantity of the phosphoric acid is most desirably determined in accordance with equation a* as described above. A stoichiometic quantity (i.e, m) of a monomer of Type 2, 4, 6, 7, or 8 may then be added to the resulting solution. The phosphorus pentoxide content of the resulting mixture may then be raised in accordance with equation b* given above, so as to raise the final phosphorus pentoxide content of the substantially polymerized mixture to a value greater than about 81%, most preferably between about 82% to about 83.5%, but less than about 84%. The resulting mixture may then be heated to about 100.degree. C. to about 185.degree. C., most preferably to about 170.degree. C. to about 185.degree. C., within a practical period of time, preferably within a period of from less than about one to about 5 hours, most preferably from about one to about 3 hours. This temperature is maintained for sufficient time to achieve a selected n value, hereinafter referred to as the homo-oligomeric n value, that is above a selected minimum value to be described for specific cases below, is characterized as being equal to 1/2(1-p), where p is the extent of reaction, defined as the mole fraction of either type of functional group present that has undergone condensation, and being preferably below a selected maximum value characteristic of complete polymerization. A selected molar quantity, m.sub.ij, of the homo-oligomeric reaction product thus obtained is diverted into a second vessel containing a selected molar quantity, m.sub.ij, of a similarly obtained but structurally different homo-oligomeric reaction product and the heating at elevated temperatures continued.

The average block lengths, y.sub.ij, of the block polymers may be determined the following way. The ijth oligomeric reaction product is prepared by adding a.sub.i moles of a first monomer to an equimolar amount b.sub.j of the second monomer. The sum of all a.sub.i or b.sub.j is 1. The mixture is polymerized to a selected intermediate extent of reaction, p.sub.ij. The oligomeric n value of the ijth oligomeric reaction product, n.sub.ij, is given by 1/2(1-p.sub.ij). The molar proportions of the recurring units incorporated into the block polymer are given by ##EQU5##

The block lengths y.sub.ij can be calculated by the equation ##EQU6## which assumes that the homo-oligomers condense with equal reactivity. The above equation for y.sub.ij shows that if either of two homo-oligomeric reaction products are polymerized to high conversion, (i.e., allowed to achieve a high n.sub.ij value before mixing) then both block lengths in the resulting block polymer will be high.

The practice of the present invention as it relates to the production of novel liquid-crystalline compositions that include block polymers with the general formulas IX, XII, XVI, XVIII, and XIX is illustrated for those compositions including general formula IX wherein the selected first homo-oligomer may be prepared from monomers of Type 1 and Type 2 that are further classified as belonging to class 1 and the selected second homo-oligomer is further characterized as belonging to either class 1, class 2, or class 3.

General formula IX block polymers may be prepared from homo-oligomers derived exclusively from class 1 monomers. The block polymers, ##STR206## have the same advantage of a broad range of operable concentrations as described for copolymers formed exclusively from Class 1 monomers. The advantage to the block polymer procedure described above for these polymers is the ability to vary y.sub.11 and y.sub.12, or y.sub.21, or y.sub.22 essentially independent of the molar proportion a.sub.1 b.sub.1, or a.sub.2 b.sub.2, or a.sub.2 b.sub.1, or a.sub.1 b.sub.2 by selecting appropriate extents of reaction for the corresponding homo-oligomer. For example, y.sub.11 may be 20 or greater for a broad range of a.sub.1 b.sub.1 values by increasing the extent of reaction, p.sub.11, as the a.sub.1 b.sub.1 value is decreased. y.sub.12, y.sub.21, or y.sub.22 of the above formulas may be obtained with values from about one to about 75, most preferably from about 25 to about 50, by selecting appropriate p.sub.11 and p.sub.12, p.sub.21, or p.sub.22 values. In practice, the members of this selected class of block polymers, because all the recurring units have a high degree of mesogenicity, are liquid-crystalline when an n value of greater than about 40 is obtained at a concentration of greater than about 6 weight percent independent of the block lengths achieved. The practice of the invention as it relates to block polymers of Class 1 is further illustrated in Examples 75-84 below.

General formula IX block polymers may be prepared from a first homo-oligomer of Class 1 and a second homo-oligomer derived from monomer pairs containing Class 2 monomers. The block polymers, ##STR207## are derived from homo-oligomers of different mesogenicity. The selection of a.sub.1 b.sub.1 (the molar proportion of the first and more highly mesogenic recurring unit) and the preferred y.sub.11 (the average block length of the first and more highly mesogenic recurring unit) are governed by the following considerations. The block polymer reaction product in the first case may derive liquid-crystalline behavior by virtue of the sole presence of the first recurring unit when y.sub.11 is greater than about 30, more preferably greater than about 40, at concentrations of the first recurring unit alone (i.e., the weight of the first oligomer added/weight of the final block polymer reaction product) greater than about 7 percent, or the block polymer reaction product in the second case may derive liquid-crystalline behavior by virtue of the combined presence of both recurring units, independent of y.sub.11, at concentrations above which the moderately mesogenic recurring unit derived from the second homo-oligomer is liquid-crystalline alone. The preferred values of a.sub.1 b.sub.1 are from about 0.4 to about one, with y.sub.11 ranging from about 80 to about 20, respectively, as a.sub.1 b.sub.1 is varied from 0.4 to one. The most preferred concentrations of these block polymers is above about 15 weight percent but may be lower as either the a.sub.1 b.sub.1 value or the y.sub.11 value or both values are increased. The preferred n value for these compositions is from about 50 to 150, most preferably greater than 100. Obtaining sufficient n values may be aided by the addition of the second homo-oligomeric reaction product before the phosphorus pentoxide content is raised to the value necessary for polymerization (i.e., when p.sub.12 or p.sub.21 is zero and n.sub.12 or n.sub.21 =1/2) and then adding the appropriate amount of phosphorus pentoxide to raise the mixture to sufficient phosphorus pentoxide content. This procedure aids in mixing and is most preferred when the homo-oligomeric n value of the first homo-oligomer, n.sub.11, is large. The practice of the invention as it relates to the preparation of block polymers of Class 2 is further illustrated in Examples 85-88 below.

General formula IX block polymers may be prepared from a first homo-oligomer of Class 1 and a second homo-oligomer derived from monomer pairs containing Class 3 monomers. The block polymers ##STR208## derive their liquid-crystalline behavior entirely from the presence of the first recurring unit, its average block length y.sub.11, and its concentration alone in the total weight of the final block polymer reaction product. Thus, the values of a.sub.1 b.sub.1, y.sub.11, and concentration must meet the conditions of the first case described for the block polymers containing Class 2 monomers. The method of the invention allows the preparation of such highly concentrated mixtures of mesogenic units, i.e., reaction products substantially higher in polymer concentration than that required for liquid-crystalline behavior, that incorporation of significant amounts of non-mesogenic units is possible if the above conditions are met.

The preferred values of a.sub.1 b.sub.1 are from about 0.6 to about one. The preferred values of y.sub.11 are from at least about 30 to about 100, more preferably between about 50 to 100. The preferred values of y.sub.12 or y.sub.21 are from about one to about 50. The preferred values of n are from about 50 to 200 with the most preferred values being about 100 to 150. The preferred selected concentrations of the block polymer are above about 15 weight percent, especially as the proportion of the non-mesogenic recurring unit is increased. The practice of the invention as it relates to production of block polymers containing Class 3 monomers is further illustrated in Examples 73, 74, 89-94 below.

The practice of the invention as it relates to the production of novel liquid-crystalline compositions that include block polymers with the general formulas X, XV, XVII are illustrated for block polymers of formula X wherein the selected first homo-oligomer is prepared from Type (1,1) or (1,2) and Type (2,1) monomers and the selected second homo-oligomer is prepared from monomers of Type (3,2).

The general formulas X, XV, and XVII liquid crystalline block polymer compositions shown above are prepared according to the following procedure:

(a) mixing at least one of a selected first monomer with or without oxidation protecting atoms or groups with a preliminary solvent of phosphoric acid having a relatively low phosphorus pentoxide content,

(b) heating and optionally placing the resulting mixture under reduced pressure to remove any volatilized protecting atoms or groups present and provide a solution of the first monomer in the preliminary solvent,

(c) then increasing the phosphorus pentoxide content of the mixture resulting from step (b) to provide a first monomer reaction medium of greater phosphorus pentoxide content suitable for polymerization.

(d) causing polymerization of the first monomer at a temperature sufficient to effect reaction at a rate to form a first homo-oligomeric product having a preselected intrinsic viscosity,

(e) mixing a selected amount of the first homo-oligomeric product with a selected amount of at least one of a selected second homo-oligomeric product so as to form a first poly-oligomeric product, said second homo-oligomer product being formed by like steps (a) and (b) followed by:

(1e) adding at least one of a selected second monomer in the resulting solution of step (b) to provide a mixture of a first and second monomer in the preliminary solvent,

(2e) then increasing the phosphorus pentoxide content of the mixture resulting from step (1e) to provide a first and second monomer reaction medium of greater phosphorus pentoxide content suitable for polymerization.

(3e) causing polymerization of the first and second monomer at a temperature sufficient to effect reaction at a rate to form said second homo-oligomeric product having a preselected intrinsic viscosity,

with the overall proviso that at least one of the selected monomer of step (a) or (1e) which forms the second homo-oligomeric product be different from at least one of the selected monomer of step (a) which forms the first homo-oligomeric product,

(f) causing polymerization of the poly-oligomeric product at a temperature sufficient to effect reaction at a rate to form a first block-oligomeric product having a preselected intrinsic viscosity or a first block-polymeric product,

(g) optionally adding one or more of a selected monofunctional reactants prior to end of polymerization in step (f) so as to provide a said first block-oligomeric product or a said first block-polymeric product having a predetermined intrinsic viscosity less than the maximum attainable in the absence of said selected monofunctional reactants.

Alternatively, the general formulas X, XV, and XVII liquid crystalline block polymer compositions shown above may be also prepared by:

(a) mixing at least one of a selected first monomer with or without oxidation protecting atoms or groups with a preliminary solvent of phosphoric acid having a relatively low phosphorus pentoxide content,

(b) heating and optionally placing the resulting mixture under reduced pressure to remove any volatilized protecting atoms or groups present and provide a solution of the first monomer in the preliminary solvent,

(c) mixing a selected amount of the solution of step (b) with a selected amount of at least one of a selected first homo-oligomeric product so as to form a first oligomeric-first monomer reaction medium, said first homo-oligomeric product being formed by like steps (a) and (b) followed by:

(1c) adding at least one of a selected second monomer in the resulting solution of step (b) to provide a mixture of a first and second monomer in the preliminary solvent,

(2c) then increasing the phosphorus pentoxide content of the mixture resulting from step (1) to provide a first and second monomer reaction medium of greater phosphorus pentoxide content suitable for polymerization,

(3c) causing polymerization of the first and second monomer at a temperature sufficient to effect reaction at a rate to form said first homo-oligomeric product having a preselected intrinsic viscosity,

with the overall proviso that at least one of the selected monomer of step (a) or (1c) which forms the first monomer solution, be different from at least one of the selected monomer of step (a) which forms the first homo-oligomeric product,

(d) then increasing the phosphorus pentoxide content of the mixture resulting from step (c) to provide a reaction medium of greater phosphorus pentoxide content suitable for polymerization,

(e) causing polymerization of the first oligomer-monomer at a temperature sufficient to effect reaction at a rate to form a first block-oligomeric product having a preselected intrinsic viscosity or a first block-polymeric product,

(f) optionally adding one or more of a selected monofunctional reactants prior to end of polymerization in step (e) so as to provide a said first block-oligomeric product or a said first block-polymeric product having a predetermined intrinsic viscosity less than the maximum attainable in the absence of said selected monofunctional reactants.

General formula X block polymers may be derived from a first homo-oligomer of Class 1 and a second homo-oligomer of Class (3,2). The block polymers of Type X are prepared by a procedure analogous to the procedure described for Type IX block polymers, except that the second homo-oligomer is prepared from a single monomer.

The polymers ##STR209## have preferred molar proportion of the first recurring unit, a.sub.1 b.sub.1 m/m+m' of from about zero to about 0.5 when the concentration selected to be above about 15 weight percent. When a.sub.1 b.sub.1 m/m+m' is selected to be above about 0.5 but less than one then the operable concentration range is extended to include concentrations of 7%, more preferably 10 weight percent. At concentrations above about 15 weight percent all selected values of y.sub.11 and values of y.sub.1 greater than about 5 give liquid-crystalline products, but n must be greater than about 50, preferably above about 100 to give desirable mechanical properties.

The practice of the invention as it relates to the block polymers of this Class is further illustrated in Examples 102-112 below

General formula X block polymer may be derived from a first homo-oligomer of class 2 and a second homo-oligomer of Class (3,2). The block polymers ##STR210## are prepared from two homo-oligomers of Class 2 which dictates the selection of concentrations greater than about 15 weight percent. The molar proportions of the various recurring units are selected based on desired mechanical properties or the maintenance of solubility in two recurring units of different solubility characteristics. The preferred values of y.sub.1 are those from about 5-50, more preferably greater than 30. The practice of the invention as it relates to block polymers of this class is further illustrated in Examples 113-115 below.

The practice of the invention is illustrated for general formula XI for block polymers prepared from a single monomer of Type (3,2).

The general formula XI liquid crystalline block polymer compositions shown above are prepared according to the following procedure:

(a) mixing at least one of a selected first monomer with or without oxidation protecting atoms or groups with a preliminary solvent of phosphoric acid having a relatively low phosphorus pentoxide content,

(b) heating and optionally placing the resulting mixture under reduced pressure to remove any volatilized protecting atoms or groups present and provide a solution of the first monomer in the preliminary solvent,

(c) then increasing the phosphorus pentoxide content of the mixture resulting from step (b) to provide a first monomer reaction medium of greater phosphorus pentoxide content suitable for polymerization,

(d) causing polymerization of the first monomer at a temperature sufficient to effect reaction at a rate to form a first homo-oligomeric product having a preselected intrinsic viscosity,

(e) mixing a selected amount of the first homo-oligomeric product with a selected amount of at least one of a selected second homo-oligomeric product so as to form a first poly-oligomeric product, said second homo-oligomeric product being formed by like steps (a), (b), (c), and (d) with the overall proviso that at least one of the selected monomer of step (a) which forms the second homo-oligomeric product be different from at least one of the selected monomer of step (a) which forms the first homo-oligomeric product,

(f) causing polymerization of the poly-oligomeric product at a temperature sufficient to effect reaction at a rate to form a first block-oligomeric product having a preselected intrinsic viscosity or a first block-polymeric product,

(g) optionally adding one or more of a selected monofunctional reactants prior to end of polymerization in step (f) so as to provide a said first block-oligomeric product or a said first block-polymeric product having a predetermined intrinsic viscosity less than the maximum attainable in the absence of said selected monofunctional reactants.

The block polymers ##STR211## have preferred values of c.sub.1 between 0.5 and one, owing to the greater solubility and mesogenicity of the first recurring unit and preferred values of y.sub.1 greater than about 25 but less than about 100, owing to the higher mesogenicity. Concentrations greater than about 15%, more preferably greater than about 18%, and most preferably 20%, are selected. Examples 98-101 below further illustrate the method of the present invention.

The method of the invention also relates to the preparation of block polymers by the condensation of co-oligomeric reaction products, instead of the homo-oligomeric reaction products described in the above procedures.

Intrinsic viscositiy is determined by extrapolation of .eta..sub.rel -1/c and ln .eta..sub.rel /c to zero concentration in methanesulfonic acid at 30.degree. C.

The extended chain polymer compositions of this invention are optically anisotropic, i.e., microscopic regions of a given extended chain composition are birefringent; a bulk extended chain composition sample depolarizes plane-polarized light because the light transmission properties of the microscopic areas of the extended chain composition vary with direction. This characteristic is associated with the existence of at least part of the extended chain polymer compositions in the liquid crystalline or mesomorphic state.

The extended chain polymer compositions of this invention that exhibit optical anisotropy do so while the extended chain polymer compositions are in the relaxed state. This is in contrast to conventional polymer solutions which may be caused to depolarize plane-polarized light when subjected to appreciable shear.

The extended chain polymer concentration of the compositions of the instant invention is above the "critical concentration point." The "critical concentration point" is routinely determined using conventional concentration and viscosity measuring techniques (see Kwolek U.S. Pat. No. 3,671,542).

Another qualitative determination of the liquid crystalline character of these extended chain polymer compositions may be made with the naked eye. These extended chain polymer compositions may appear turbid or hazy and yet contain no, or practically no undissolved solid. When the extended chain polymer compositions, seen under reflected ordinary light, is disturbed by shaking or rolling the vessel containing the extended chain polymer compositions or by only slow stirring, there is produced a characteristic, readily observed, satin-like sheen or glow which is observed even after the disturbance ceases, and which decreases in intensity thereafter. This may be described as being a pearly or opalescent quality of the extended chain polymer compositions of this invention. Compositions which are disturbed as described above often give the appearance of having striations and or graininess in the surface. These visual effects are observed in the liquid crystalline extended chain polymer compositions of this invention. This may commonly be referred to as "stir opalescence." Further details on qualitative and quantitative determinations of optical anisotropy are presented in Kwolek U.S. Pat. No. 3,671,542.

The liquid crystalline compositions may be formed into fibers of high quality by spinning them into suitable baths such as by wet and "air gap" spinning techniques, using spinnerets and other apparatus constructed of materials resistant to the strong acids used. In "air-gap" spinning the spinneret is usually located in air or in an inert gaseous medium a short distance (e.g., 1 to 24 cm) above the surface of a coagulating bath.

However, air-gaps suitable for use in the present invention may range from less than about 1 cm to about 150 cm or longer, preferably from about 2 cm to about 300 cm, more preferably from about 10 cm to about 200 cm, and most preferably from about 10 cm to about 100 cm.

In accordance with the practice of the invention, the initial draw ratio is approximately from about 1:1 to about 500:1 or higher. Preferably, the initial draw ratio is from about 20:1 to about 80:1, especially preferably from about 60:1 to about 200:1, and most preferably from about 100:1 to about 300:1.

The term "draw ratio", as is well known, is a measure of the degree of stretching during the orientation of the fibrous material. In the present invention, the initial draw ratio is a measure of the degree of stretching of the filaments which occurs between the extrusion orifices and the exit from the coagulation bath. The initial draw ratio is defined as exit velocity divided by jet speed.

The jet speed is the speed at which the extruded polymer exits an extrusion orifice. It is conveniently determined by dividing the total polymer extrusion velocity by the total surface area of the extrusion orifices.

The exit velocity is the speed at which the filaments leave the coagulation bath. Although any means of measurement may be used, the exit velocity is conveniently determined by the surface speed of the rolls which take up the filaments after their exit from the bath. Thus, the speed of the wash rolls is preferably measured for this purpose.

Spinning of polybenzimidazole fibers by one working of this general technique is described in, e.g., Tan, U.S. Pat. No. 4,263,245. A variety of baths may be used to coagulate the extruded dope into fibers. The baths may be, e.g., water or methanol and the like, or a dilute solution of a mineral acid (for example, phosphoric acid or sulfuric acid and the like). Preferably, the temperature of a coagulation bath is room temperature or below.

It is desirable to completely remove the spinning solvent from fiber samples prepared from the liquid crystalline compositions of this invention. Water alone or aqueous alkaline solutions may be used for removal of the residual acid. A convenient method is to spray the threadline as it leaves the coagulating bath with an aqueous alkaline solution (e.g., saturated sodium bicarbonate), remove the surface liquid from the threadline with a wiping device (e.g., a sponge) or a jet, wash with water and/or aqueous alkaline solutions to reduce the acid content, and wind up the fibers on bobbins. The fibers may be soaked in water for a period sufficient to remove the acid. The thoroughly washed fibers may be dried on the bobbin in the area of temperatures of up to about 110.degree. C. They can also be conveniently dried on heated rolls.

The liquid crystalline compositions are especially suitable for extruding. This and other methods of article fabrication are fully described in J. S. Robinson, "Spinning, Extruding, and Processing of Fibers"; Chemical Technology Review No. 159, Noyes Data Corp., 1980. The above cited patents and/or publications are incorporated herein by reference.

The fibers prepared from the polymers of this invention exhibit high values of tensile properties, especially in the as-extruded state, i.e., without subsequent hot drawing or annealing. The tensile properties of these as-extruded fibers can be enhanced by subjecting the undrawn fibers to a heat treatment.

Filament properties are measured on fibers that are conditioned at 21 degrees C. and 65% relative humidity (R.H.) for at least 16 hours unless otherwise specified. Yarn properties are measured on yarn that are conditioned at 24 degrees C. and 55% R.H. for at least 16 hours. All measurements are made in the fiber conditioning environment.

Tenacity (breaking tenacity) (T), elongation (breaking elongation) (E), and initial modulus (Mi) are obtained from breaking a single filament or a multifilament yarn on an Instron tester (Instron Engineering Corp., Canton, Mass.).

Single filaments are broken with a gauge length (distance between jaws) of 1.0 inch (2.54 cm.). The results on 3 filaments are averaged. Yarns are given 3 turns per inch (2.54 cm.) twist (under 0.1 g.p.d. tension) and broken with a 10 inch (25.4 cm.) gauge length. All samples are elongated at a constant rate of extension (10% elongation/minute for fibers having an E of under 8%, and 60% elongation/minute for fibers with E of 8 to 100%) until the sample breaks.

The denier of a single filament (d.p.f.) is calculated from its functional resonant frequency, determined by vibrating a 7 to 9 cm. length of fiber under tension with changing frequency (ASTM D1577-1973). This filament is then used for 1 break.

The denier of yarn is determined by weighing a known length (at 0.1 g.p.d. tension); 90 cm. length is convenient.

The tenacity (grams/denier), elongation (percent) and initial modulus (gram/denier) as defined in ASTM 3379-75e are obtained from the load-elongation curve and the measured denier. In actual practice, the measured denier of the sample, test conditions and sample identification may be fed to a computer before the start of a test; the computer records the load-elongation curve of the fiber as it is broken and then calculates the fiber properties.

It should be noted that different values maybe obtained from single filaments (filament properties) and from multifilament strands (yarn properties) of the same sample. Unless specified otherwise all properties given herein are filament properties.

It will be understood that the usual additives such as dyes, fillers, antioxidants, and the like can be incorporated into the compositions of the present invention for the purpose intended, before preparation of the shaped article.

Mineral acids that are solvents for the extended chain polymers of the instant compositions such as polyphosphoric acid, methane sulfonic acid, 100% sulfuric acid, chlorosulfonic acid, and the like, may be added to the compositions of the invention in minor amounts (without departing from the scope of the invention) for purposes of modifying conditions for processing into shaped articles. The strong acid additives may contain one or more of the acid-soluble polymers described in Helminiak, et al., U.S. Pat. No. 4,207,407 and P. D. Sybert, "Rigid-Rod Polyquinolines: Synthesis, Structure-Property Relationships and High-Strength Fibers", Colorado State University, Ph.D. Thesis, 1980. The above cited patent and thesis are incorporated herein by reference.

The liquid crystalline extended chain polymer compositions are extremely suitable for spinning into highly ordered and high strength fibers. Such fibers are useful as reinforcement substitutes for other inorganic or organic products. Various examples include glass fibers, asbestos, boron fibers, carbon and graphite fibers, whiskers, quartz and silica fibers, ceramic fibers, metal fibers, natural organic fibers, and synthetic organic fibers. A reinforcement may be defined simply as the material that is added to a resinous matrix to improve the strength and other physical and chemical properties of the material.

Furthermore, the polymers of the instant compositions can be employed in any use typically performed by engineering thermoplastic materials, such as metal replacements and those areas where high performance is necessary. Extended chain polymer compositions may be employed for use in forming high strength films suitable in the production of composites, belts, tires, i.e., as tire cords, and the like. The films are suitable as construction materials for rocket nose cones and various other parts of space craft.

Depending on the extended chain polymer fiber or film selected (i.e., homopolymer, copolymer, block polymer, or mixture thereof) the properties of the article formed may be controlled to suit the desired use. The control of polymer properties is an advantage, since, in the various areas of utility for such polymers, e.g. as laminates, structural materials, adhesives and ablative materials, the needs vary considerably.

By way of comparison, Examples 1-5 below are illustrative of low molecular weight (i.e., low intrinsic viscosity) and/or low polymer concentration compositions.

In a 6-L resin flask were placed 386.76 g (1.5774 mol) of 2,5-diamino-1,4-benzenedithiol dihydrochloride (1a) and 2.98 kg of freshly prepared PPA. The PPA was prepared as described in Wolfe and Arnold, Macromolecules, Vol 14, 909 (1981). The mixture was stirred at room temperature under a flow of argon for 24 h and heated at 60.degree.-70.degree. C. for 34 h. The resulting solution was clear with no evidence of bubbles. Terephthalic acid (262.35 g, 1.5792 mol) was then added and incorporated into the solution by rapid stirring at 110.degree. C. Additional PPA (4.1 kg) was then added. The yellow mixture was heated as follows: 110.degree.-165.degree. in 5 h, 165.degree. C. for 12 h, 180.degree. C. for 12 h, and 195.degree. C. for 12 h. The mixture became stir-opalescent after 6 h at polymerization temperatures. Reduced pressure was applied during the first 6 h of reaction but was alternated with an argon stream such that the mixture did not foam above a predetermined flask wall level. The hazy green product exhibiting yellow-green opalescence was removed from the flask and precipitated into a large volume of water. The copper-colored polymer was washed until the water was no longer acidic and then dried at 80.degree.-100.degree. C. under reduced pressure for 48 h. A portion of the reaction product was bottled for use in fiber-spinning studies: intrinsic viscosity [.eta.]=30.3 dL/g (MSA). Anal. Calcd. for C.sub.14 H.sub.6 N.sub.2 S.sub.2 ; C, 63.13; H, 2.27; N, 10.51; S, 24.08. Found: C, 62.75; H, 2.346; N, 10.24; S, 23.22. The foregoing procedure provided a 5.6 wt% of polymer --AI--.sub.n in PPA. Polymerization mixtures of higher polymer concentration (up to 10%) were prepared. These runs required higher monomer 1a concentration during dehydrochlorination. Intermittent cooling was cycled with argon pressure as required to control foaming at the desired level in the reaction vessel. Similarly, polymer --AI--.sub.n in PPA of lower concentration were prepared and these required less time for complete dehydrochlorination than that described.

In a 6-L resin flask were placed 919.94 g (3.7519 mole) of 1a and approximately 2.7 kg of 115% PPA; the % P.sub.2 O.sub.5 content profile for this Example is illustrated in FIG. 8.

The 115% PPA was obtained from FMC Corporation and heated to 150.degree. C. under an argon atmosphere, heated at 150.degree. C. under reduced pressure for 18 h, and cooled to room temperature immediately before use. The viscous mixture was stirred and an ice bath was applied for 24 h to prevent vigorous foaming. Five additional days of stirring at room temperature were required to remove enough hydrogen chloride to allow heating above room temperature. A clear, viscous solution was obtained after heating for 18 h at 80.degree. C. Finely powdered 2a (622.90 g, 3.7454 mol) and an additional 2,773 g of the above 115% PPA were then added. The mixture was then stirred and heated to 140.degree. C. for 3 h and then heated at 150.degree.-160.degree. C. for 16 h. The mixture gradually darkened, became optically isotropic, and never became noticeably more viscous. Samples that were removed and precipitated in water gave a dark green non-fibrous material. Additional heating failed to increase the viscosity to an extent to yield a fibrous material. The theoretical polymer concentration --AI-- for this experiment was 14.8% in a PPA with an intermediate P.sub.2 O.sub.5 content of 83.8% and a final of 79.8%.

To a 100 mL flask containing 15.8 g of concentrated orthophosphoric acid (85.4% H.sub.3 PO.sub.4) that had been cooled in an ice bath was added 24.2 g of phosphorus pentoxide and the mixture heated at 150.degree. C. for 6 h under an argon atmosphere. The % P.sub.2 O.sub.5 content profile for this Example is illustrated in FIG. 9.

After cooling the PPA (84.9% P.sub.2 O.sub.5) to room temperature, 6.0 g (0.029 mol) of 4-amino-3-mercaptobenzoic acid hydrochloride (3a) (prepared by the method of Wolfe, AFOSR Final Technical Report, Dec. 15, 1980) was added and the viscous mixture stirred at 40.degree. C. for 24 h. The mixture was then placed under reduced pressure and the temperature slowly raised to 70.degree. C. The orange-yellow mixture was then heated to 150.degree. over a 2 h period. The resulting dark red solution was optically isotropic. The solution was then stirred at 150.degree. C. for an additional 24 h. The polymer was isolated from the resulting optically isotropic solution containing 8.6% of the polymer by precipitation with water to give brittle films. The intrinsic viscosity of the isolated polymer --T--.sub.n was 3.0 dL/g in methanesulfonic acid at 30.degree. C.

To a 50 mL round bottom flask containing 48.15 g of PPA that was prepared as described in Wolfe and Arnold, Macromolecules, Vol. 14, 909 (1981) was added 7.436 g (0.03616 mol) of 4-amino-3-mercaptobenzoic acid hydrochloride (3a) that was prepared as described in Wolfe, AFOSR Final Technical Report, Dec. 15, 1980. The mixture was stirred at room temperature under an argon flow for 18 h. After stirring for 2 h under reduced pressure between 50.degree. and 80.degree. C. the solution was a clear orange color. The solution was then heated under reduced pressure as follows: 90.degree. C. for 0.5 h; 100.degree. C. for 0.5 h; 110.degree. C. for 0.5 h; 130.degree. C. for 0.5 h; 140.degree. C. for 0.5 h; 180.degree. C. for 8 h; 150.degree. C. for 5 h; 190.degree. C. for 16 h; 160.degree. C. for 16 h; 200.degree. C. for 200 h and 170.degree. C. for 7 h. The resulting isotropic solution having a concentration of polymer --T--.sub.n of 9.4% by weight gave only brittle amorphous films when precipitated in water. The intrinsic viscosity of the isolated polymer was 3.80 dL/g in methanesulfonic acid at 30.0.degree. C.

To 38 g of PPA that was prepared as described in Wolfe and Arnold, Macromolecules, Vol. 14, 909 (1981) was added 1.421 g (8.41 mmol) of 4-amino-3-mercaptobenzoic acid (3b) that was prepared by neutralization of an aqueous suspension of 4-amino-3-mercaptobenzoic acid hydrochloride (3a) (prepared according to Wolfe, AFOSR Final Technical Report, Dec. 15, 1980) followed by extraction with ethyl acetate, evaporation of the ethyl acetate, and recrystallization of the pale yellow residue from methylene chloride. The viscous mixture was heated to 140.degree. C. under an argon flow in a 0.5 h period. The temperature was raised to 160.degree. C. over a 0.5 h period and then maintained at 160.degree. C. for 18 h under reduced pressure. The optically isotropic, red solution was then heated under reduced pressure for 8 h at 200.degree. C. The isolated polymer --T--.sub.n had an intrinsic viscosity of 4.57 dL/g in MSA at 30.0.degree. C.

The compositions of this invention, their production and their advantages and uses are further illustrated in the following examples. These are intended only to demonstrate the invention and are not to be construed as limiting its scope, which scope is instead defined by the appended claims.

All polyphosphoric acid (PPA) hereinafter referred to as 115% was obtained from FMC Corporation and used as received. Terephthalic acid (2a) was obtained from Amoco Chemicals Company, reduced to an average particle size of 95% <10 um by an air-impact method, and dried before use. All monomers and P.sub.2 O.sub.5 that were added to PPA were deaerated by placing them in a desiccator, applying reduced pressure, filling with an inert gas, and repeating the procedure at least once.

A mixture of 88.2 g of concentrated orthophosphoric acid (85.4% H.sub.3 PO.sub.4) and 205.2 g of 115% PPA was stirred at 100.degree. C. for 2 h under reduced pressure. After allowing the PPA solution to cool to approximately 50.degree. C. a portion of this solution (282.1 g) was added to a 500 mL resin kettle containing 53.01013 g (0.21620 mol) of 1a. After stirring to incorporate the solid monomer into the PPA, the mixture was stirred at room temperature for 2 h under argon and then under reduced pressure at: 25.degree.-30.degree. C. for 24 h; 50.degree. C. for 3 h; and 70.degree. C. for 16 h. Monomer 2a (35.91734 g, 0.216196 mol) was then added to the resulting clear light green solution in four portions. After the addition of each portion, the reaction kettle was placed under reduced pressure before the 2a was incorporated by stirring. The mixture was allowed to cool to approximately 50.degree. C. before 118.3 g of P.sub.2 O.sub.5 was added to increase the effective P.sub.2 O.sub.5 content to 83.9%. The viscous slurry was then heated as follows: 100.degree.-170.degree. C. in 3 h; 170.degree. C. for 17 h; 185.degree. C. for 5 h; and 200.degree. C. for 19 h. The intrinsic viscosities (in dL/g) of the polymer --AI--.sub.n were determined from samples of the polymer solution withdrawn at the polymerization times indicated: 9.2 (8.5 h), 12.6 (25.5 h), 15.8 (44.0 h). Heating this reaction solution at 200.degree. C. for an additional 76 h only increased the intrinsic viscosity of the --AI--.sub.n component to 16.4 dL/g. The reaction product is characterized as having a final P.sub.2 O.sub.5 content of approximately 80.8% with the --AI--.sub.n polymer concentration being approximately 12.6 wt%.

A mixture of 57.3 g of concentrated orthophosphoric acid (85.4% H.sub.3 PO.sub.4) and 133.7 g of 115% PPA was stirred at 100.degree. C. for 4 h under reduced pressure. After allowing the PPA solution to cool to room temperature, a portion of this solution (185.0 g) was added to a 500 mL resin kettle containing 53.61422 g (0.21866 mol) of 1a. (Monomer 1a of small crystal size was prepared without a final recrystallization according to the method of Wolfe, Loo, and Arnold, Macromolecules Vol. 14, 915 (1981) using the final isolation procedure involving the transfer of the dipotassium salt of 1a as an aqueous solution into 6N hydrochloric acid.)

After stirring to incorporate the monomer into the PPA, the mixture was stirred at 55.degree.-65.degree. C. for 5.5 h under reduced pressure, at 25.degree. C. for 15.5 h under an argon flow, and at 65.degree.-72.degree. C. for 4 h under reduced pressure. Monomer 2a (36.3268 g, 0.21866 mol) was added to the resin kettle containing the dehydrochlorinated solution of monomer 1a in PPA. After the addition of each of the six portions, the incorporation of the solid into the solution was aided by placing the kettle under reduced pressure before stirring was initiated. Powdered phosphorus pentoxide (114.4 g) was then added to increase the effective P.sub.2 O.sub.5 content to 86.4% and the mixture was stirred at 100.degree. C. for 27 h. The polymerization mixture was then heated as follows: 100.degree.-170.degree. C. in 1 h; 170.degree. C. for 21.5 h; and 200.degree. C. for 71.5 h. The intrinsic viscosities (in dL/g) of the polymer --AI--.sub.n were determined from samples withdrawn at the polymerization times indicated: 23.1 (22.5 h), 24.8 (29.0 h), 27.0 (94 h). The reaction product is characterized as having a final effective P.sub.2 O.sub.5 content of approximately 82.2% and a polymer --AI--.sub.n concentration being approximately 15.2 wt%.

182.7 g of a PPA solution with an effective P.sub.2 O.sub.5 content of 77.2% (prepared by mixing 30 wt% of H.sub.3 PO.sub.4 and 70 wt% of 115% PPA) was added to a 500 mL resin kettle containing 52.62853 g (0.21460 mol) of 1a. (Monomer 1a of large crystal size was prepared with a final recrystallization according to the method of Wolfe, Loo, and Arnold, Macromolecules, 14, 915 (1981) using the final isolation procedure involving a transfer of the dipotassium salt of monomer 1a as a solid into 6N hydrochloric acid.) After stirring to incorporate the solid monomer into the PPA, the mixture was substantially dehydrochlorinated by heating the mixture at 55.degree.-70.degree. C. under reduced pressure for approximately 31 h. Monomer 2a (35.6522 g, 0.21460 mol) was added to the resin kettle and incorporated as described in the previous Example. Powdered P.sub.2 O.sub.5 (123.35 g) was then added to increase the effective P.sub.2 O.sub.5 content to approximately 86.4% and resulting mixture was stirred at 100.degree. C. for 17 h under an argon flow. The polymerization mixture was then heated with stirring as follows: 100.degree.-170.degree. C. in 1 h, 170.degree. C. for 23 h, and 200.degree. C. for 24 h. The intrinsic viscosities (in dL/g) were determined for the --AI--.sub.n polymer from samples withdrawn at the indicated times: 17.2 (7 h), 22.8 (24 h), and 35.4 (48 h). Heating without stirring for an additional 24 h did not increase the intrinsic viscosity of the --AI--.sub.n polymer. The green reaction product exhibits stir-opalescence and is characterized as having a final effective P.sub.2 O.sub.5 content of 82.2% with --AI--.sub.n polymer concentration being approximately 15.1 wt%.

A mixture of 4,925 g of concentrated orthophosphoric acid (85.4% H.sub.3 PO.sub.4) and 11,491 g of 115% PPA was stirred in a 22 L flask for 5 h at 100.degree. C. under reduced pressure. After allowing the PPA solution to cool to 50.degree. C. under a flow of argon, a portion of this solution (11,321 g) was added to a 40-L glass resin kettle (equipped with a mechanical stirrer consisting of a 3/4 hp variable speed drive and stirring blades made of Hastelloy C-276) containing 2,380.55 g (9.7088 mol) of a 1a prepared as described in Example 7. The mixture was then stirred at: 65.degree. C. for 17 h under a flow of argon; 65.degree. C. for 2 h at 700-400 mm Hg; and 65.degree. C. for 2 h at 40 mm Hg. An additional 2,552.77 g (10.4112 mol) of monomer 1a that had been prepared and deaerated as described in Example 8 was then added under a flow of argon. An additional 4,874 g of the above-mentioned PPA was added and the mixture stirred at: 65.degree. C. for 1 h at 700-300 mm Hg; 65.degree.-70.degree. C. for 3.25 h at 40 mm Hg; 70.degree. C. for 2.5 h at less than 5 mm Hg; 700.degree. C. for 7.5 h under a flow of argon; and 80.degree. C. for 26 h at less than 5 mm Hg. Monomer 2a (3,342.62 g, 20.1205 mol) was then added. The resulting slurry was then cooled to 40.degree. C. and 6,512.1 g of powdered P.sub.2 O.sub.5 was added over a 4.5 period. The resulting viscous mixture was stirred at 80.degree. C. for 17 h under an argon flow. The mixture was then heated to 100.degree. C. and an additional 4,655.4 g of P.sub.2 O.sub.5 was added to increase the effective P.sub.2 O.sub.5 content to 86.5%. After stirring for an additional 48 h at 100.degree.-108.degree. C., the polymerization mixture was heated as follows: 100.degree.-170.degree. C. in 3 h; 170.degree. C. for 20 h; and 200.degree. C. for 1.5 h. The intrinsic viscosities (in dL/g) were determined from samples withdrawn at the indicated reaction times: 17.9 (14 h), 18.5 (16.5 h), 19.0 (23 h), 24.34 (24.5 h). Additional heating at 200.degree. C. only increased the intrinsic viscosity to 24.6 dL/g. The reaction product exhibited stir-opalescence and is characterized as having a final effective P.sub.2 O.sub.5 content of 82.2% with the --AI--.sub.n polymer concentration being approximately 15.6% by weight.

To a 500 mL resin kettle containing a deaerated mixture of 12.06155 g (0.0594092 mol) of terephthaloyl chloride (2b) and 14.5665 g (0.0594081 mol) of 1a was added approximately 140 g of 115% PPA that had been stirred at 100.degree. C. under reduced pressure for 1-2 h, and had cooled to room temperature. The mixture was then stirred under an argon flow at: 40.degree. C. for 23 h; 50.degree. C. for 3 h; 60.degree. C. for 2 h; 70.degree. C. for 19 h; and 80.degree. C. for 3 h. The solution was then stirred at 80.degree. C. under reduced pressure for 1 h. An additional 140 g of deaerated 115% PPA was then incorporated into the solution. The polymerization was stirred under argon at: 100.degree. C. for 30 min; 110.degree. C. for 30 min; 120.degree. C. for 30 min; 130.degree. C. for 30 min; 140.degree. C. for 30 min; 150.degree. C. for 30 min; 160.degree. C. for 45 min; 170.degree. C. for 11 h; 185.degree. C. for 5 h; and 200.degree. C. for 46.5 h. Precipitation in water of a small amount of the anisotropic product provided polymer --AI--.sub.n which possessed an intrinsic viscosity of 17.7 (dL/g) in MSA at 30.degree. C.

A mixture of 74.52 g of 85.7% orthophosphoric acid and 173.88 g of 115% PPA (83.8% P.sub.2 O.sub.5 content) is stirred under reduced pressure for 2 h at 100.degree. C. After cooling to room temperature, 55.23561 g (0.225273 mol) of 1a (prepared as described in Example 8) and 45.73607 g (0.225273 mol) of 2b (freshly sublimed) are added in eight portions. After the addition of each portion of monomer, stirring is initiated to incorporate the monomer. The mixture is then stirred while the temperature is slowly increased and the pressure is slowly decreased until dehydrochlorination is complete. Deaerated phosphorus pentoxide (87.54 g) is then added to the dehydrochlorination mixture at 50.degree. C. The mixture is then stirred at 100.degree. C. for several hours. The polymerization is then stirred under an argon atmosphere at 170.degree. C. for approximately 20 h, at 180.degree. C. for approximately 8 h, and at 200.degree. C. for 3 h. The resulting product contains 15 wt% of --AI--.sub.n PPA (82.2% P.sub.2 O.sub.5).

86.17 g of a PPA solution with an effective P.sub.2 O.sub.5 content of 74.9% (prepared by mixing 40 wt% of 85% H.sub.3 PO.sub.4 and 60 wt% of 115% PPA) was added to a 500 mL resin kettle containing 27.62485 g (0.112665 mol) of 1a. The monomer was incorporated into the PPA solution by stirring and the resulting mixture was then substantially dehydrochlorinated by heating the mixture at 55.degree.-80.degree. C. under reduced pressure for approximately 21 hours. The % P.sub.2 O.sub.5 content profile for this Example is illustrated in FIG. 10. Monomer 2a (18.720 g, 0.112686 mol) was then added to the resin kettle. Powdered P.sub.2 O.sub.5 (83.17 g) was then added to increase the effective P.sub.2 O.sub.5 content to approximately 87.2%. The resulting yellow slurry was stirred at 100.degree. C. for 15 h under an argon flow. This slurry, which had not noticeably increased in bulk viscosity, was then stirred vigorously and heated by increasing the oil bath temperature from 100.degree. C. to 178.degree. C. within 40 minutes, and to 185.degree. C. within 1 h. Polymerization times indicated below begin with time above 100.degree. C. The 185.degree. C. temperature was then maintained for 76.5 h. Intrinsic viscosities in MSA at 30.degree. C. (in dL/g) were determined for the --AI--.sub.n polymer from samples withdrawn at the indicated polymerization times: 16.6 (1.5 h), 21.7 (2.25 h), 24.2 (3.25 h), 35.7 (7.7 h), and 42.1 (76.5 h). The intrinsic viscosity of 42.1 corresponds to an average n value of polymerization of about 140. The polymerization product was stir-opalescent after a polymerization time of 0.75 h and was found to be highly drawable after 1.25 h. Fibers prepared by directly drawing this product and precipitating the strands into water were amber, translucent, birefringent (crossed polars), showed extinction of transmitted light when a single polaroid sheet was placed perpendicular to the fiber direction, and could be fibrillated into microfibrils. Fibers prepared after 1.5 h by the same method were noticeably stronger than the sample at 1.25 h. The bulk viscosity of the product and the relaxation time of opalescence had noticeably increased after 2.25 h. The P.sub.2 O.sub.5 content of the PPA component of the product was approximately 83.2% and the concentration of the --AI--.sub.n polymer was 14.5% by weight based on the total weight of the resulting reaction product.

A mixture of 17.7 g of concentrated orthophosphoric acid (85.7% H.sub.3 PO.sub.4) and 26.6 g of 115% PPA was stirred under reduced pressure at 100.degree. C. for 2 hours. The % P.sub.2 O.sub.5 content profile for this Example is illustrated in FIG. 11. The resulting solution was then poured at approximately 100.degree. C. under a stream of argon into a 200 mL resin kettle containing 11.41145 g (0.054028 mol) of 4,6-diamino-1,3-benzenediol dihydrochloride (1b) that was prepared according to the method of Wolfe and Arnold, Macromolecules, Vol. 14, 909 (1981), recrystallized from aqueous hydrochloric acid containing 3 wt% stannous chloride, and dried for 20 h at 63.degree. C. under reduced pressure immediately before use. The mixture was stirred at 53.degree. C. for 15 h and 62.degree. C. for 4 h under reduced pressure. Upon heating to 70.degree. C., the monomer precipitated. Addition of 16.6 g of P.sub.2 O.sub.5 resulted in redissolution of the monomer. The solution was then heated at 100.degree. C. for 3 h under reduced pressure to complete the dehydrochlorination. Monomer 2a (8.9761 g, 0.05403 mol) was then added under an argon flow. Additional P.sub.2 O.sub.5 (19.0 g) was then added. The solution was then heated as follows: 100.degree. C. for 48 h; 150.degree. C. for 2.5 h; 160.degree. C. for 10 h (the dark green solution became stir-opalescent during this period); and 180.degree. C. for 25 h. The resulting reaction product was deep purple with a metallic luster, exhibited stir-opalescence, depolarized plane-polarized light as evidenced by strong birefringence when viewed between crossed polars, and is further characterized as having a final effective P.sub.2 O.sub.5 content of 82% with the --BI--.sub.n polymer concentration being 13.3% by weight. The intrinsic viscosity of the polymer --BI--.sub.n isolated from the reaction product was 23.9 dL/g in MSA at 30.degree. C., which corresponds to an average number of recurring units, n, of approximately 110.

The reaction product from Example 13 was drawn many times its length to give highly fibrillar fibers. A portion of the solution was removed from the reaction flask and placed in a KBr press equipped with a die with a circular orifice of 0.13 mm in diameter. The solution was extruded into the air and stretched by pulling manually and then the fiber was dipped in water. The fiber thus produced was washed with water and then dried under tension in an air oven overnight at 110.degree. C. The fiber produced was measured to be between 0.0093 mm and 0.012 mm in diameter. High orientation was evident from fibrils which split from the surface of the fiber and by the complete extinction of light transmitted through the fiber when a single polaroid was placed in a perpendicular direction only between the source and the fiber.

The procedure of Example 8 is essentially repeated. Instead of monomers 1a and 2a, 48.9831 g (0.19978 mol) of monomer 1a is dehydrochlorinated in an "initial" solution of 269.68 g PPA having a P.sub.2 O.sub.5 content of 77.2% (prepared by mixing 80.9 g of 85.4% H.sub.3 PO.sub.4 with 188.8 g of 115% PPA). When dehydrochlorination is substantially complete, 79.9805 g (0.19978 mol) of monomer 2s is added followed by the gradual addition of 142.23 g of P.sub.2 O.sub.5. The mixture is then stirred and heated essentially according to Example 8. The amount of P.sub.2 O.sub.5 is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 85.07% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2% subsequent to substantial complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 19%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 20 dL/g in MSA at 30.degree. C. which corresponds to an n value of average polymerization of about 50.

The procedure of Example 8 is essentially repeated. Instead of monomers 1a and 2a, 64.4470 g (0.26284 mol) of monomer 1a is dehydrochlorinated in an "initial" solution of 341.97 g PPA having a P.sub.2 O.sub.5 content of 77.2% (prepared by mixing 102.6 g of 85.4% H.sub.3 PO.sub.4 with 239.4 g of 115% PPA). When dehydrochlorination is substantially complete. 63.6826 g (0.26284 mol) of monomer 2j is added followed by the gradual addition of 137.3 g of P.sub.2 O.sub.5. The mixture is then stirred and heated essentially according to Example 8. The amount of P.sub.2 O.sub.5 is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 83.7% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2% subsequent to substantial complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 17%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 15 dL/g in MSA at 30.degree. C. which corresponds to an n value of average polymerization of about 100.

The procedure of Example 8 is essentially repeated. Instead of monomers 1a and 2a, 61.1619 g (0.28706 mol) of monomer 1b is dehydrochlorinated in an "initial" solution of 338.4 g PPA having a P.sub.2 O.sub.5 content of 77.2% (prepared by mixing 101.5 g of 85.4% H.sub.3 PO.sub.4 with 236.8 g of 115% PPA). When dehydrochlorination is substantially complete, 69.5488 g (0.28706 mol) of monomer 2j is added followed by the gradual addition of 140.1 g of P.sub.2 O.sub.5. The mixture is then stirred and heated essentially according to Example 8. The amount of P.sub.2 O.sub.5 is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 83.8% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2% subsequent to substantial complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 17%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 16 dL/g in MSA at 30.degree. C. which corresponds to an n value of average polymerization of about 60.

The procedure of Example 8 is essentially repeated. Instead of monomers 1a and 2a, 81.9923 g (0.28869 mol) of monomer 1c is dehydrochlorinated in an "initial" solution of 366.8 g PPA having a P.sub.2 O.sub.5 content of 77.2% (prepared by mixing 110 g of 85.4% .sub.3 PO.sub.4 with 256.8 g of 115% PPA). When dehydrochlorination is substantially complete. 69.9438 g (0.28869 mol) of monomer 2j is added followed by the gradual addition of 148.4 g of P.sub.2 O.sub.5. The mixture is then stirred and heated essentially according to Example 8. The amount of P.sub.2 O.sub.5 is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 83.8% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2% subsequent to substantial complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 16%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 16 dL/g in MSA at 30.degree. C. which corresponds to an n value of average polymerization of about 60.

The procedure of Example 8 is essentially repeated. Instead of monomers 1a and 2a, 93.8232 g (0.29202 mol) of monomer 1i is dehydrochlorinated in an "initial" solution of 263.5 g PPA having a P.sub.2 O.sub.5 content of 77.2% (prepared by mixing 79.1 g of 85.4% H.sub.3 PO.sub.4 with 184.4 g of 115% PPA). When dehydrochlorination is substantially complete, 48.5129 g (0.29202 mol) of monomer 2a is added followed by the gradual addition of 171 g of P.sub.2 O.sub.5. The mixture is then stirred and heated essentially according to Example 8. The amount of P.sub.2 O.sub.5 is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 86.2% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2% subsequent to substantially complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 18%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 15 dL/g in MSA at 30.degree. C.

The procedure of Example 8 is essentially repeated. Instead of monomers 1a and 2a, 93.1836 g (0.32225 mol) of monomer 1j is dehydrochlorinated in an "initial" solution of 254.0 g PPA having a P.sub.2 O.sub.5 content of 77.2% (prepared by mixing 76.2 g of 85.4% H.sub.3 PO.sub.4 with 177.8 g of 115% PPA). When dehydrochlorination is substantially complete, 53.5357 g (0.3225 mol) of monomer 2a is added, followed by the gradual addition of 178.4 g of P.sub.2 O.sub.5. The mixture is then stirred and heated essentially according to Example 8. The amount of P.sub.2 O.sub.5 is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 86.6% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2% subsequent to substantially complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 18%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 14 dL/g in MSA at 30.degree. C.

The procedure of Example 8 is essentially repeated. Instead of monomers 1a and 2a, 93.1836 g (0.32225 mol) of monomer 1k is dehydrochlorinated in an "initial" solution of 254.0 g PPA having a P.sub.2 O.sub.5 content of 77.2% (prepared by mixing 76.2 g of 85.4% H.sub.3 PO.sub.4 with 177.8 g of 115% PPA). When dehydrochlorination is substantially complete, 53.5357 g (0.32225 mol) of monomer 2a is added, followed by the gradual addition of 178.4 g of P.sub.2 O.sub.5. The mixture is then stirred and heated essentially according to Example 8. The amount of P.sub.2 O.sub.5 is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 86.6% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2% subsequent to substantially complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 18%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 14 dL/g in MSA at 30.degree. C.

The procedure of Example 8 is essentially repeated. Instead of monomers 1a and 2a, 128.47 g (0.32431 mol) of monomer 11 is dehydrochlorinated in an "initial" solution of 223.5 g PPA having a P.sub.2 O.sub.5 content of 79.4% (prepared by mixing 44.7 g of 85.4% H.sub.3 PO.sub.4 with 178.8 g of 115% PPA). When dehydrochlorination is substantially complete, 53.8778 g (0.32431 mol) of monomer 2a is added, followed by the gradual addition of 197.0 g of P.sub.2 O.sub.5. Inorganic salts, such as lithium salts (e.g., LiCl, LiF, Lithium phosphate, and the like) can be added at this point, if required, to promote polymer solubility. The mixture is then stirred and heated essentially according to Example 8. The amount of P.sub.2 O.sub.5 is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 89.1 % prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2% subsequent to substantially complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 18%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 12 dL/g in MSA at 30.degree. C.

The procedure of Example 8 is essentially repeated. Instead of monomers 1a and 2a, 70.3707 g (0.21902 mol) of monomer 1i is dehydrochlorinated in an "initial" solution of 323.1 g PPA having a P.sub.2 O.sub.5 content of 77.2% (prepared by mixing 96.9 g of 85.4% H.sub.3 PO.sub.4 with 226.2 g of 115% PPA). When dehydrochlorination is substantially complete, 53.0654 g (0.21902 mol) of monomer 2j is added followed by the gradual addition of 125.0 g of P.sub.2 O.sub.5. The mixture is then stirred and heated essentially according to Example 8. The amount of P.sub.2 O.sub.5 is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 83.6% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2% subsequent to substantially complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 18%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 17 dL/g in MSA at 30.degree. C.

The procedure of Example 8 is essentially repeated. Instead of monomers 1a and 2a, 68.1280 g (0.23560 mol) of monomer 1j is dehydrochlorinated in an "initial" solution of 320.7 g PPA having a P.sub.2 O.sub.5 content of 77.2% (prepared by mixing 96.2 g of 85.4% H.sub.3 PO.sub.4 with 224.5 g of 115% PPA). When dehydrochlorination is substantially complete, 57.824 g (0.23560 mol) of monomer 2j is added followed by the gradual addition of 126.9 g of P.sub.2 O.sub.5. The mixture is then stirred and heated essentially according to Example 8. The amount of P.sub.2 O.sub.5 is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 83.7% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2% subsequent to substantially complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 18%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 15 dL/g in MSA at 30.degree. C.

The procedure of Example 8 is essentially repeated. Instead of monomers 1a and 2a, 68.1280 g (0.23560 mol) of monomer 1k is dehydrochlorinated in an "initial" solution of 320.64 g PPA having a P.sub.2 O.sub.5 content of 77.2% (prepared by mixing 96.19 g of 85.4% H.sub.3 PO.sub.4 with 184.4 g of 115% PPA). When dehydrochlorination is substantially complete, 57.0824 g (0.23560 mol) of monomer 2j is added followed by the gradual addition of 126.88 g of P.sub.2 O.sub.5. The mixture is then stirred and heated essentially according to Example 8. The amount of P.sub.2 O.sub.5 is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P205 content of approximately 83.7% prior to the start of polymerization and an effective P205 content of approximately 82.2% subsequent to substantially complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 18%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 14 dL/g in MSA at 30.degree. C.

Analogous to the foregoing Examples 6-25, other Type I extended chain polymers may be synthesized to yield liquid-crystalline compositions having varying proportions of polymer concentration, P.sub.2 O.sub.5 content and polymer intrinsic viscosity in accordance with the present invention.

The synthesis is illustrated by the reaction systems in Tables 16a, 16b, 17a, 17b, and 17c. The m.fwdarw., e.fwdarw., and p.fwdarw. denote most preferred, especially preferred, and preferred selected monomer reactions respectively.

A solution consisting of 63.34 g concentrated phosphoric acid and 147.59 g of 115% PPA was stirred at 100.degree. C. under reduced pressure for 3 h in a 300 ml 3-necked flask. To a 500 mL resin kettle was added 63.49 g (0.3087 mol) of 4-amino-3-mercaptobenzoic acid hydrochloride (3a) (prepared by the method of Wolfe, AFOSR Final Technical Report, Dec. 15, 1980). A portion of the above-prepared PPA having a P.sub.2 O.sub.5 of 77.3% (207.57 g) was poured into the resin kettle containing the monomer while under argon flow. After the monomer had been incorporated, a second portion of monomer (30.71 g, 0.1493 mol) was added. The mixture was heated to 55.degree. C. and the pressure was gradually decreased over 1.5 h. An additional 5.35 g of monomer was added to the kettle under argon flow bringing the total monomer added to 99.65 g (0.4845 mol). The mixture was then stirred under reduced pressure at 50.degree. C. overnight. The temperature was then raised to 70.degree. C. for 8 h. Phosphorus pentoxide (138.62 g) was then added in one portion to increase the effective P.sub.2 O.sub.5 content to 86.4%. After heating at 100.degree. C. with stirring overnight the reaction product was stir-opalescent. After placing the mixture, which still contained undissolved monomer, under reduced pressure for 3 h, a sample was removed and was placed between a microscope slide and a cover glass. The unprecipitated product depolarized plane-polarized light. The reaction mixture was then heated under argon as follows: an additional 2.5 h at 100.degree. C.; 2 h at 120.degree. C.; 16 h at 130.degree. C.; 31 h at 170.degree. C.; 43.5 h at 200.degree. C. A sample of the green, opalescent polymer reaction product yielded gold-orange fibers upon precipitation in water. The sample was extracted in water for 24 h and dried under vacuum at 140.degree. C. for 24 h. The intrinsic viscosity was determined to be 8.2 dL/g in MSA at 30.1.degree. C. The reaction product is characterized as having a final effective P.sub.2 O.sub.5 content of 82.2% with the polymer --T--.sub.n having a concentration of 15.1% by weight.

A mixture of 125.8 g of 115% PPA and 53.9 g of concentrated phosphoric acid (85.7% H.sub.3 PO.sub.4) was heated to 100.degree. C. for 4 h under reduced pressure in a 500 mL 3-necked flask. The % P.sub.2 O.sub.5 content profile for this Example is illustrated in FIG. 12. To a 500 mL resin kettle was added 91.85 g (0.4466 mol) of 3a. The kettle containing the monomer was deaerated. 108.17 g of the PPA prepared above (having a P.sub.2 O.sub.5 content of 77.2%) was then added. The kettle was then heated with an oil bath at 50.degree. C. under a thin stream of argon overnight. The kettle was then placed under reduced pressure again and heated to 70.degree. C. for 23 h. P.sub.2 O.sub.5 (108.32 g) was then added in three portions to increase the effective P.sub.2 O.sub.5 content to 88.5%. Reduced pressure was applied to degas the P.sub.2 O.sub.5 and to cause foaming that aided in mixing. After 3 h of stirring the temperature was raised to 100.degree. C. and maintaining at that temperature under reduced pressure for 21 h. The mixture was stir-opalescent and depolarized plane-polarized light. The mixture was then heated as follows: 115.degree. C. under argon for 3 h; 130.degree. C. under reduced pressure for 2 h; 170.degree. C. for 0.5 h; 190.degree. C. for 17 h. A sample of the green, opalescent reaction product was removed and gave a fibrillar, golden-colored fiber upon drawing followed by precipitation in water. After extracting with water in a Soxhlet apparatus for 24 h the sample was dried for 24 h at 110.degree. C. under reduced pressure. The intrinsic viscosity of this sample was 15.8 dL/g in MSA at 30.0.degree. C. An additional 7.5 h of heating gave a sample with an intrinsic viscosity of 16.7 dL/g. The reaction product thus obtained was 20.3% by weight of polymer --T--.sub.n in PPA with a final P.sub.2 O.sub.5 content of 82.4%.

The procedure of Example 27 is essentially repeated. Instead of monomer 3a, 146.9123 g (0.4305753 mol) of monomer 3k is dehydrochlorinated in an "initial" solution of 265.9 g of PPA having a P.sub.2 O.sub.5 content of 77.3% (prepared by mixing 78.6 g of 85.4% H.sub.3 PO.sub.4 with 187.4 g of 115% PPA). When dehydrochlorination is substantially complete, an additional 144.85 g of P.sub.2 O.sub.5 is gradually added to the mixture and dissolved by stirring and heating essentially according to the schedule given in Example 27. The amount of P.sub.2 O.sub.5 added is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 85.3% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2% subsequent to substantial complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 19%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 15 dL/g in MSA at 30.degree. C. which corresponds to an average n value of polymerization of about 70.

The procedure of Example 27 is essentially repeated. Instead of monomer 3a, 161.90 g (0.85391 mol) of monomer 3c is dehydrochlorinated in an "initial" solution of 198.8 g of PPA having a P.sub.2 O.sub.5 content of 77.3% (prepared by mixing 58.7 g of 85.4% H.sub.3 PO.sub.4 with 140.0 g of 115% PPA). When dehydrochlorination is substantially complete, an additional 196.8 g of P.sub.2 O.sub.5 is gradually added to the mixture and dissolved by stirring and heating essentially according to Example 27. The amount of P.sub.2 O.sub.5 added is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 88.6% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2% subsequent to substantial complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 19%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 12 dL/g in MSA at 30.degree. C.

The procedure of Example 27 is essentially repeated. Instead of monomer 3a, 161.90 g (0.85391 mol) of monomer 3d is dehydrochlorinated in an "initial" solution of 221.7 g of PPA having a P.sub.2 O.sub.5 content of 77.3% (prepared by mixing 65.50 g of 85.4% H.sub.3 PO.sub.4 with 156.2 g of 115% PPA). When dehydrochlorination is substantially complete, an additional 203.1 g of P.sub.2 O.sub.5 is gradually added to the mixture and dissolved by stirring and heating essentially according to Example 27. The amount of P.sub.2 O.sub.5 added is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 88.2% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2% subsequent to substantial complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 18%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 12 dL/g in MSA at 30.degree. C.

Analogous to the foregoing Examples 26-30, other Type II extended chain polymers may be synthesized to yield liquid-crystalline compositions having varying proportions of polymer concentration, P.sub.2 O.sub.5 content and polymer intrinsic viscosity in accordance with the present invention.

The synthesis is illustrated by the reaction systems in Table 19. The e.fwdarw. denotes especially preferred selected monomer reactions.

The procedure of Example 8 is essentially repeated. Instead of monomers 1a and 2a, 99.923 g (0.35182 mol) of monomer 1c is dehydrochlorinated in an "initial" solution of 602.0 g of PPA having a P.sub.2 O.sub.5 content of 77.3% (prepared by mixing 177.9 g of 85.4% H.sub.3 PO.sub.4 with 424.1 g of 115% PPA). When dehydrochlorination is substantially complete, 76.740 g (0.35182 mol) of monomer 4a is added followed by the gradual addition of 272.7 g of P.sub.2 O.sub.5. The mixture is then stirred and heated essentially according to Example 8. The amount of P.sub.2 O.sub.5 added is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 84.4% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.0% subsequent to substantial complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 10%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 10 dL/g in MSA at 30.degree. C.

Analogous to the foregoing Example 31, other Type III extended chain polymers may be synthesized to yield liquid-crystalline compositions having varying proportions of polymer concentration, P.sub.2 O.sub.5 content and polymer intrinsic viscosity in accordance with the present invention.

The synthesis is illustrated by the reaction systems in Table 20. The e.fwdarw. denotes especially preferred selected monomer reactions.

The procedure of Example 8 is essentially repeated. Instead of monomers 1a and 2a, 109.94 g (0.27752 mol) of monomer 1l is dehydrochlorinated in an "initial" solution of 317.2 g of PPA having a P.sub.2 O.sub.5 content of 77.3% (prepared by mixing 93.7 g of 85.4% H.sub.3 PO.sub.4 with 223.5 g of 115% PPA). When dehydrochlorination is substantially complete, 60.533 g (0.27752 mol) of monomer 4a is added followed by the gradual addition of 219.5 g of P.sub.2 O.sub.5. The mixture is then stirred and heated essentially according to Example 8. The amount of P.sub.2 O.sub.5 added is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 86.6% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.0% subsequent to substantial complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 15%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 7 dL/g in MSA at 30.degree. C.

Analogous to the foregoing Example 32, other Type III extended chain polymers may be synthesized to yield liquid-crystalline compositions having varying proportions of polymer concentration, P.sub.2 O.sub.5 content and polymer intrinsic viscosity in accordance with the present invention.

The synthesis is illustrated by the reactions in Table 21. The e.fwdarw. denotes especially preferred selected monomer reactions.

The procedure of Example 27 is essentially repeated. Instead of monomer 3a, 117.5156 g (0.5149463 mol) of monomer 5a is dissolved in an "initial" solution of 623.7 g of PPA having a P.sub.2 O.sub.5 content of 77.0% (prepared by mixing 192.8 g of 85.4% H.sub.3 PO.sub.4 with 430.9 g of 115% PPA). When dissolution is substantially complete, an additional 257.8 g of P.sub.2 O.sub.5 is gradually added to the mixture and dissolved by stirring and heating essentially according to Example 27. The amount of P.sub.2 O.sub.5 added is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 83.7% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.0% subsequent to substantial complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 10%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 10 dL/g in MSA at 30.degree. C.

The procedure of Example 8 is essentially repeated. Instead of monomers 1a and 2a, 70.784 g (0.28869 mol) of monomer 1a is dehydrochlorinated in an "initial" solution of 242.6 g of PPA having a P.sub.2 O.sub.5 content of 77.3% (prepared by mixing 71.7 g of 85.4% H.sub.3 PO.sub.3 with 171.0 g of 115% PPA). When dehydrochlorination is substantially complete, 71.070 g (0.28869 mol) of monomer 6a is added followed by the gradual addition of 162.9 g of P.sub.2 O.sub.5. The mixture is then stirred and heated according to a schedule similar to Example 8. The amount of P.sub.2 O.sub.5 added is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 86.4% prior to start the polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2 % subsequent to substantial complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 19%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 7 dL/g in MSA at 30.degree. C.

The procedure of Example 13 is essentially repeated. Instead of monomers 1b and 2a, 67.798 g (0.31820 mole) of monomer 1b is dehydrochlorinated in an "initial" mixture of 343.3 g of PPA having a P.sub.2 O.sub.5 content of 77.3% (prepared by mixing 101.4 g of 85.4% H.sub.3 PO.sub.4 with 241.9 g of 115% PPA). When dehydrochlorination is substantially complete, 78.336 g (0.31820 mol) of monomer 6a is added followed by the gradual addition of 200.4 g of P.sub.2 O.sub.5. The mixture is then stirred and heated according to a schedule similar to Example 13. The amount of P.sub.2 O.sub.5 added is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 85.7% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2% subsequent to substantial complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 15%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 7 dL/g in MSA at 30.degree. C.

The procedure of Example 8 is essentially repeated. Instead of monomers 1a and 2a, 90.945 g (0.32021 mol) of monomer 1c is dehydrochlorinated in an "initial" solution of 402.5 g of PPA having a P.sub.2 O.sub.5 content of 77.3% (prepared by mixing 192.1 g of 85.4% H.sub.3 PO.sub.4 with 210.4 g of 115% PPA). When dehydrochlorination is substantially complete, 78.830 g (0.32021 mol) of monomer 6a is added followed by the gradual addition of 307.8 g of P.sub.2 O.sub.5. The mixture is then stirred and heated according to a schedule similar to Example 8. The amount of P.sub.2 O.sub.5 added is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 84.9% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2% subsequent to substantial complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 12%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 7 dL/g in MSA at 30.degree. C.

Analogous to the foregoing Examples 34-36, other Type V extended chain polymers may be synthesized to yield liquid-crystalline compositions having varying proportions of polymer concentration. P.sub.2 O.sub.5 content and polymer intrinsic viscosity in accordance with the present invention.

The synthesis is illustrated by the reaction systems in Table 23. The e.fwdarw.denotes especially preferred selected monomer reactions.

The procedure of Example 8 is essentially repeated. Instead of monomers 1a and 2a, 58.035 g (0.23669 mol) of monomer 1a is dehydrochlorinated in an "initial" solution of 307.7 g of PPA having a P.sub.2 O.sub.5 content of 77.3% (prepared by mixing 90.9 g of 85.4% H.sub.3 PO.sub.4 with 216.8 g of 115% PPA). When dehydrochlorination is substantially complete, 76.281 g (0.23669 mol) of monomer 6b is added followed by the gradual addition of 163.5 g of P.sub.2 O.sub.5. The mixture is then stirred and heated according to a schedule similar to Example 8. The amount of P.sub.2 O.sub.5 added is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 85.2% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2 % subsequent to substantial complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 17%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 7 dL/g in MSA at 30.degree. C.

The procedure of Example 13 is essentially repeated. Instead of monomers 1b and 2a, 54.581 g (0.25617 mol) of monomer 1b is dehydrochlorinated in an "initial" solution of 330.4 g of PPA having a P.sub.2 O.sub.5 content of 77.3% (prepared by mixing 97.6 g of 85.4% H.sub.3 PO.sub.4 with 232.7 g of 115% PPA). When dehydrochlorination is substantially complete, 82.559 g (0.25617 mol) of monomer 6b is added followed by the gradual addition of 176.2 g of P.sub.2 O.sub.5. The mixture is then stirred and heated according to a schedule similar to Example 13. The amount of P.sub.2 O.sub.5 added is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 85.2% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2% subsequent to substantial complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 16%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 7 dL/g in MSA at 30.degree. C.

The procedure of Example 8 is essentially repeated. Instead of monomers 1a and 2a, 73.126 g (0.25747 mol) of monomer 1c is dehydrochlorinated in an "initial" solution of 362.6 g of PPA having a P.sub.2 O.sub.5 content of 77.3% (prepared by mixing 107.1 g of 85.4% H.sub.3 PO.sub.4 with 255.5 g of 115% PPA). When dehydrochlorination is substantially complete, 82.978 g (0.25747 mol) of monomer 6b is added followed by the gradual addition of 185.5 g of P.sub.2 O.sub.5. The mixture is then stirred and heated according to a schedule similar to Example 8. The amount of P.sub.2 O.sub.5 added is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 85.0% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2% subsequent to substantial complete polymerization. The reaction product obtaned exhibits stir-opalescence and is further characterized as having a polymer concentration of 15%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 6 dL/g in MSA at 30.degree. C.

Analogous to the foreging Examples 37-39, other Type V extended chain polymers may be synthesized to yield liquid-crystalline compositions having varying proportions of polymer concentration, P.sub.2 O.sub.5 content and polymer intrinsic viscosity in accordance with the present invention.

The synthesis is illustrated by the reaction systems in Table 24a. The e.fwdarw.denotes especially preferred selected monomer reactions.

The procedure of Example 8 is essentially repeated. Instead of monomers 1a and 2a, 76.047 g (0.23369 mol) of monomer 1i is dehydrochlorinated in an "initial" solution of 369.2 g of PPA having a P.sub.2 O.sub.5 content of 77.3% (prepared by mixing 109.1 g of 85.4% H.sub.3 PO.sub.4 with 260.1 g of 115% PPA). When dehydrochlorination is substantially complete, 58.269 g (0.23369 mol) of monomer 6a is added followed by the gradual addition of 180.4 g of P.sub.2 O.sub.5. The mixture is then stirred and heated according to a schedule similar to Example 8. The amount of P.sub.2 O.sub.5 added is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 84.8% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2 % subsequent to substantial complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 15%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 10 dL/g in MSA at 30.degree. C.

The procedure of Example 8 is essentially repeated. Instead of monomers 1a and 2a, 74.075 g (0.25617 mol) of monomer 1j is dehydrochlorinated in an "initial" solution of 493.7 g of PPA having a P.sub.2 O.sub.5 content of 77.3% (prepared by mixing 145.9 g of 85.4% H.sub.3 PO.sub.4 with 347.8 g of 115% PPA). When dehydrochlorination is substantially complete, 63.065 g (0.25617 mol) of monomer 6a is added followed by the gradual addition of 221.2 g of P.sub.2 O.sub.5. The mixture is then stirred and heated according to a schedule similar to Example 8. The amount of P.sub.2 O.sub.5 added is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 84.3% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2% subsequent to substantial complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 12%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 6 dL/g in MSA at 30.degree. C.

The procedure of Example 8 is essentially repeated. Instead of monomers 1a and 2a, 74.075 g (0.25617 mol) of monomer 1k is dehydrochlorinated in an "initial" solution of 493.7 g of PPA having a P.sub.2 O.sub.5 content of 77.3% (prepared by mixing 145.9 g of 85.4% H.sub.3 PO.sub.4 with 347.8 g of 115% PPA). When dehydrochlorination is substantially complete, 63.065 g (0.25617 mol) of monomer 6a is added followed by the gradual addition of 221.2 g of P.sub.2 O.sub.5. The mixture is then stirred and heated according to a schedule similar to Example 8. The amount of P.sub.2 O.sub.5 added is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 84.3% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2% subsequent to substantial complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 12%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 6 dL/g in MSA at 30.degree. C.

The procedure of Example 8 is essentially repeated. Instead of monomers 1a and 2a, 101.996 g (0.25747 mol) of monomer 1l is dehydrochlorinated in an "initial" solution of 493.3 g of PPA having a P.sub.2 O.sub.5 content of 77.3% (prepared by mixing 145.7 g of 85.4% H.sub.3 PO.sub.4 with 347.6 g of 115% PPA). When dehydrochlorination is substantially complete, 63.385 g (0.25747 mol) of monomer 6a is added followed by the gradual addition of 221.5 g of P.sub.2 O.sub.5. The mixture is then stirred and heated according to a schedule similar to Example 8. The amount of P.sub.2 O.sub.5 added is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 84.3% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2% subsequent to substantial complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 12%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 7 dL/g in MSA at 30.degree. C.

Analogous to the foregoing Examples 40-43, other Type V extended chain polymers may be synthesized to yield liquid-crystalline compositions having varying proportions of polymer concentration, P.sub.2 O.sub.5 content and polymer intrinsic viscosity in accordance with the present invention.

The synthesis is illustrated by the reaction systems in Tables 24b and 24c. The e.fwdarw.and p.fwdarw.denote especially preferred and preferred selected monomer reactions respectively.

The procedure of Example 27 is essentially repeated. Instead of monomer 3a, 123.074 g (0.64042 mol) of monomer 9a is dissolved in an "initial" solution of 423.1 g of PPA having a P.sub.2 O.sub.5 content of 77.3% (prepared by mixing 125.0 g of 85.4% H.sub.3 PO.sub.4 with 298.1 g of 115% PPA). When dissolution is substantially complete, an additional 223.0 g of P.sub.2 O.sub.5 is gradually added to the mixture and dissolved by stirring and heating essentially according to Example 27. The amount of P.sub.2 O.sub.5 added is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 85.1% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2% subsequent to substantial complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 13%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 10 dL/g in MSA at 30.degree. C.

The procedure of Example 8 is essentially repeated. Instead of monomers 1a and 2a, 86.502 g (0.30457 mol) of monomer 1c is dehydrochlorinated in an "initial" solution of 478.4 g of PPA having a P.sub.2 O.sub.5 content of 77.3% (prepared by mixing 141.3 g of 85.4% H.sub.3 PO.sub.4 with 337.0 g of 115% PPA). When dehydrochlorination is substantially complete, 79.864 g (0.30457 mol) of monomer 7a is added followed by the general addition of 233.0 g of P.sub.2 O.sub.5. The mixture is then stirred and heated according to a schedule similar to Example 8. The amount of P.sub.2 O.sub.5 added is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 84.7% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2% subsequent to substantial complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 12%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 10 dL/g in MSA at 30.degree. C.

Analogous to the following Example 45, other Type VII extended chain polymers may be synthesized to yield liquid-crystalline compositions having varying proportions of polymer concentration, P.sub.2 O.sub.5 content and polymer intrinsic viscosity in accordance with the present invention.

The synthesis is illustrated by the reaction systems in Tables 26 and 27. The e.fwdarw. denotes especially preferred selected monomer reactions.

The procedure of Example 8 is essentially repeated. Instead of monomers 1a and 2a, 102.35 g (0.48036 mol) of monomer 1b is dehydrochlorinated in an "initial" solution of 329.2 g of PPA having a P.sub.2 O.sub.5 content of 77.3% (prepared by mixing 97.3 g of 85.4% H.sub.3 PO.sub.4 with 231.9 g of 115% PPA). When dehydrochlorination is subsequently complete, 67.296 g (0.48036 mol) of monomer 8a is added followed by the gradual addition of 250.5 g of P.sub.2 O.sub.5. The mixture is then stirred and heated according to a schedule similar to Example 8. The amount of P.sub.2 O.sub.5 added is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 87.1% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2% subsequent to substantial complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 14%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 7 dL/g in MSA at 30.degree. C.

The procedure of Example 8 is essentially repeated. Instead of monomers 1a and 2a, 137.73 g (0.48494 mol) of monomer 1c is dehydrochlorinated in an "initial" solution of 370.8 g of PPA having a P.sub.2 O.sub.5 content of 77.3% (prepared by mixing 109.6 g of 85.4% H.sub.3 PO.sub.4 with 261.3 g of 115% PPA). When dehydrochlorination is substantially complete, 67.939 g (0.48494 mol) of monomer 8a is added followed by the gradual addition of 263.5 g of P.sub.2 O.sub.5. The mixture is then stirred and heated according to a schedule similar to Example 8. The amount of P.sub.2 O.sub.5 added is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 86.7% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2% subsequent to substantial complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 13%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 7 dL/g in MSA at 30.degree. C.

Analogous to the foregoing Examples 46 and 47, other Type VIII extended chain polymers may be synthesized to yield liquid-crystalline compositions having varying proportions of polymer concentration, P.sub.2 O.sub.5 content and polymer intrinsic viscosity in accordance with the present invention.

The synthesis is illustrated by the reaction systems in Table 28. The e.fwdarw. and p.fwdarw. denote especially preferred and preferred selected monomer reactions respectively.

The procedure of Example 8 is essentially repeated. Instead of monomers 1a and 2a, 140.33 (0.35423 mol) of monomer 1l is dehydrochlorinated in an "initial" solution of 313.01 g of PPA having a P.sub.2 O.sub.5 content of 77.3% (prepared by mixing 92.5 g of 85.4% H.sub.3 PO.sub.4 with 220.5 g of 115% PPA). When dehydrochlorination is substantially complete, 49.627 g (0.35423 mol) of monomer 8a is added followed by the gradual addition of 263.0 of P.sub.2 O.sub.5. The mixture is then stirred and heated according to a schedule similar to Example 8. The amount of P.sub.2 O.sub.5 added is preselected (as determined in accord with the aforementioned formulae a* and b*) to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 85.8% prior to the start of polymerization and an effective P.sub.2 O.sub.5 content of approximately 82.2% subsequent to substantial complete polymerization. The reaction product obtained exhibits stir-opalescence and is further characterized as having a polymer concentration of 14%; fibers are readily formed by direct spinning, or drawing from the reaction product. The polymer obtained is of the following structure:

characterized by an intrinsic viscosity of 6 dL/g in MSA at 30.degree. C.

A mixture of 123.38 g of 115% PPA and 52.63 g of concentrated orthophosphoric acid (85.7% H.sub.3 PO.sub.4) was stirred at 100.degree. C. for 2 h under reduced pressure. After allowing the solution to cool to 50.degree. C. under a flow of argon, a portion (168.18 g) of the PPA (77.3% P.sub.2 O.sub.5) was added under a flow of argon to a resin kettle containing 57.61082 g (0.23496 mol, a.sub.1 =0.95) of 1a that had been prepared as described in Example 8 and 2.6358 g (0.012371 mol, a.sub.2 =0.05) of 1b that had been prepared by the method of Wolfe and Arnold, Macromolecules, Vol. 14, 909 (1981) and recrystallized from hydrochloric acid containing 3 wt% of stannous chloride. The mixture was then stirred at 50.degree. C. for 33 h under reduced pressure and 90.degree. C. for 4 h under reduced pressure. Monomer 2a (41.0899 g, 0.24733 mol=m, b.sub.1 =1) was then added. The mixture was cooled to approximately 40.degree. C. and 139.18 g of P.sub.2 O.sub.5 was added to increase the effective P.sub.2 O.sub.5 content before polymerization to 87.6%. The mixture was then stirred at the specified temperatures for the specified times under a flow of argon: 100.degree. C. for 24 h; 150.degree. C. for 1 h; 160.degree. C. for 1 h; 170.degree. C. for 5.5 h; and 200.degree. C. for 64 h. The final concentration of the resulting random copolymer was 16.8% in a PPA with an approximate P.sub.2 O.sub.5 content of 82.5%. Fibers of the copolymer were isolated by drawing the resulting green, opalescent product and precipitating into water. The intrinsic viscosity of the copolymer isolated after heating to 200.degree. C. for 1.5 h was shown to be 25.4 dL/g and actually decreased to 24.4 dL/g after completing the above heating schedule. The copolymer obtained apparently is of the following structure: ##STR738## where the mole fraction of AI units (a.sub.1 b.sub.1) is believed to be 0.95, the mole fraction of BI units (a.sub.2 b.sub.1) is believed to be 0.05, the average block lengths y.sub.11 and y.sub.21 are believed to be 20 and 1, respectively, and the average total number of recurring units of both types (n) is believed to be approximately 100.

To a deaerated mixture of 16.09147 g (0.0656275 mol, a.sub.1 =0.75) of 1a and 4.66149 g (0.0218778 mol, a.sub.2 =0.25) of 1b was added 220 g of freshly prepared and deaerated PPA (The PPA was prepared from 173.81 g of 86.8% orthophosphoric acid and 267.64 g of phosphorus pentoxide, equilibrated, and deaerated). The mixture was stirred under an argon flow at: room temperature overnight; 50.degree. C. for 3.5 h; and 72.degree. C. for 21 h. The mixture was stirred under reduced pressure at 72.degree. C. overnight to substantially complete dehydrochlorination. Terephthalic acid (2a) (14.53762 g, 0.0875059 mol) was added to the solution and the mixture was deaerated before stirring was initiated. The PPA prepared above was then added to this mixture to give a total of 394.5 g of PPA. The slurry was then stirred under reduced pressure for 0.5 h at 110.degree. C. and under an argon atmosphere at: 120.degree. C. for 1 h; 130.degree. C. for 0.5 h; 140.degree. C. for 0.5 h; 150.degree. C. for 0.5 h; 160.degree. C. for 1.0 h; 170.degree. C. for 15.5 h; 185.degree. C. for 6.5 h; and 200.degree. C. for 19 h. The optically anisotropic product contained 5.3 wt% polymer in PPA (84.0% P.sub.2 O.sub.5 content). Precipitation of a small amount of the polymeric product provided the random copolymer, believed to have the structure: ##STR739## where a.sub.1 b.sub.1 =0.75, y.sub.11 =4, a.sub.2 b.sub.1 =0.25, and y.sub.21 =1.33, with an intrinsic viscosity of 26.59 dL/g in MSA at 30.degree. C., which corresponds to an n value of approximately 110.

To a deaerated mixture of 22.36319 g (0.0912061 mol, a.sub.1 =0.9) of 1a and 2.15918 g (0.0101340 mol, a.sub.2 =0.10) of 1b was added approximately 230 g of freshly prepared deaerated PPA. (The PPA was prepared by stirring a mixture of 135.87 g of 85.4% orthophosphoric acid and 207.36 g of phosphorus pentoxide at 150.degree. C. overnight under a argon atmosphere, followed by deaeration by stirring under reduced pressure at 150.degree. C. for 5.5 h. The solution was allowed to cool to room temperature under argon before use). The mixture was stirred under an argon flow at: room temperature overnight; 50.degree. C. for 3 h, and at 70.degree. C. overnight. The solution was then stirred under reduced pressure for 2.5 h at 70.degree. C. Terephthalic acid (2a) (16.83595 g, 0.101340 mol); was added to the solution and, after placing the kettle under reduced pressure, stirring was initiated. The remaining above-mentioned PPA was then added to the mixture (total PPA added=317.6 g) under an argon atmosphere. The polymerization mixture was then stirred under an argon atmosphere at 110.degree. C. for 30 min; 120.degree. C. for 30 min; 130.degree. C. for 30 min; 140.degree. C. for 30 min; 150.degree. C. for 30 min; 160.degree. C. for 30 min; and 170.degree. C. for 14.5 h. The polymerization mixture was heated under an argon atmosphere without stirring at 185.degree. C. for 5 h and at 193.degree.-200.degree. C. for 28 h. The final polymer concentration was 7.6 wt% in PPA (83.0% P.sub.2 O.sub.5). Precipitation of a small amount of the anistropic polymer product provided the random copolymer of Type IX, Class 1 with the structure: ##STR740## where a.sub.1 b.sub.1 =0.9, a.sub.2 b.sub.1 =0.10, and the average block lengths y.sub.11 and y.sub.21 are believed to be 10 and 1.11, respectively. The isolated copolymer possessed an intrinsic viscosity of 26.36 dL/g in MSA at 30.degree. C., which corresponds to an n value of approximately 110.

A solution of 135.51 g of 115% PPA and 59.10 g of 85.7% H.sub.3 PO.sub.4 was stirred at 100.degree. C. for 2 h under reduced pressure. The solution was allowed to cool to room temperature under reduced pressure, and 180.16 g of the mixture was added to 30.20054 g of 1a under an argon atmosphere. After a homogeneous mixture was obtained 28.29941 g (58.49995 g total, 0.23859 mol total=m, a.sub.1 =1) of deaerated 1a was added. The mixture was stirred under reduced pressure at: 50.degree. C. for 18.5 h; 70.degree. C. for 10 min; 80.degree. C. for 25 min; and 90.degree. C. for 5.5 h. Deaerated 2a (35.6892 g, 0.21482 mol, b.sub.1 =0.9) and 5.79905 g (0.02394 mol, b.sub.2 =0.10 ) of deaerated 4,4'-biphenyldicarboxylic acid (2aa) were added under an inert atmosphere. After the monomer were incorporated into the mixture, the reaction mixture was cooled to 40.degree. C. and 136.11 g of dearated P.sub.2 O.sub.5 was added to give an effective P.sub.2 O.sub.5 content before polymerization of 87.01%. After stirring at 100.degree. C. for 63 h, the polymerization was stirred at: 160.degree. C. for 2.5 h; 170.degree. C. for 5.5 h, and 200.degree. C. for 64 h. The concentration of the resulting copolymer was 15.9% in PPA with a P.sub.2 O.sub.5 content of approximately 82.5%. The reaction product was stir-opalescent and was drawn into oriented fibers. The copolymer possessed an intrinsic viscosity of 7.9 dL/g in MSA at 30.degree. C. The structure of the resulting polymer is believed to be: ##STR741## where a.sub.1 b.sub.1 is 0.9, a.sub.1 b.sub.2 is 0.1, y.sub.11 is 10, y.sub.12 is 1.1, and n is approximately 40.

A mixture of 20.10 g of concentrated orthophosphoric acid (85.7% H.sub.3 PO.sub.4) and 46.74 g of 115% PPA was stirred at 100.degree. C. for 2 h under reduced pressure in a 100 mL 3-necked flask. After allowing this PPA solution, having a P.sub.2 O.sub.5 content of 77.3%, to cool to 50.degree. C. under reduced pressure, a portion (62.45 g) was added under a flow of argon to a 200 mL resin kettle containing 20.2783 g (0.082703 mol=m, a.sub.1 =1) of 1a that had been prepared and deaerated as described in Example 7. The mixture was then stirred at the specified temperatures for the specified times under either reduced pressure (vac) or argon flow (Ar): 50.degree. C., 4 h, vac; 50.degree. C., 15 h, Ar; 60.degree. C., 3 h, vac; 80.degree. C., 1 h, vac; 90.degree. C., 3 h, vac; 60.degree. C., 15 h, Ar; 80.degree. C., 7 h, vac. Trans-1,2-cyclohexanedicarboxylic acid (2gg) (0.6781 g, 0.004132 mol, b.sub.2 =0.05) that was obtained from Aldrich Chemical Company and was recrystallized from methanol before use was added to the kettle and then terephthalic acid (2a) (13.05455 g, 0.078579 mol, b.sub.1 =0.95) was added. Powdered P.sub.2 O.sub.5 (45.00 g) was then added to the mixture that had been cooled to 50.degree. C. to increase the effective P.sub.2 O.sub.5 content before polymerization to 86.8%. The mixture was then stirred for 17 h at 100.degree. C. under an argon flow. The yellow mixture was then heated with stirring under argon as follows: 120.degree. C. for 1 h; 130.degree.-140.degree. C. for 1 h; 150.degree. C. for 2 h; 160.degree. C. for 0.5 h; 170.degree. C. for 4 h (stir-opalescence was apparent during this time); 185.degree. C. for 15.5 h; and 200.degree. C. for 75 h. The final concentration of the resulting random copolymer was 16.4% in PPA, with a P.sub.2 O.sub.5 content of approximately of 82.2%. The polymer obtained apparently is of the following structure: ##STR742## characterized as having an intrinsic viscosity in methanesulfonic acid at 30.degree. C. of 10.0 dL/g, which corresponds to an average n value of about 50, a mole fraction of --AI--.sub.n units (a.sub.1 b.sub.1) of 0.95, and a mole fraction of --AA"--.sub.n units (a.sub.1 b.sub.2) of 0.05. The average block lengths, y.sub.11 and y.sub.12, are believed to be 20 and 1, respectively.

The procedure of Example 49 is essentially repeated. Instead of using 95 mol% of monomer 1a, 5 mol% of monomer 1b, and 100 mol% of monomer 2a, a mixture of 50 mol% of monomer 1a and 50 mol% of monomer 1c is substantially dehydrochlorinated in a comparable weight percent of PPA with essentially similar P.sub.2 O.sub.5 content. After the addition of a stoichiometric amount of monomer 2a and an appropriate amount of P.sub.2 O.sub.5 (thereby raising the final P.sub.2 O.sub.5 content to substantially above about 82%), the resultant mixture is then heated in essentially the same manner in accordance with Example 12 to provide a copolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning, or drawing. The copolymer obtained is of the following structure: ##STR743##

The procedure of Example 49 is essentially repeated. Instead of using 95 mol% of monomer 1a, 5 mol% of monomer 1b, and 100 mol% of monomer 2a, a mixture of 50 mol% of monomer 1b and 50 mol% of monomer 1c is substantially dehydrochlorinated in a comparable weight percent of PPA with essentially similar P.sub.2 O.sub.5 content. After the addition of a stoichiometric amount of monomer 2a and an appropriate amount of P.sub.2 O.sub.5 (thereby raising the final P.sub.2 O.sub.5 content to substantially above about 82%), the resultant mixture is then heated in essentially the same manner in accordance with Example 12 to provide a copolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning, or drawing. The copolymer obtained is of the following structure: ##STR744##

The procedure of Example 53 is essentially repeated. Instead of using 100 mol% of monomer 1a, 95 mol% of monomer 2a, and 5 mol% of monomer 2gg, 100 mol% of monomer 1a is substantially dehydrochlorinated in a comparable weight percent of PPA with essentially similar P.sub.2 O.sub.5 content. After the addition of 50 mol% of monomer 2a and 50 mol% of monomer 2j and an appropriate amount of P.sub.2 O.sub.5 (thereby raising the final P.sub.2 O.sub.5 content to substantially above about 82%), the resultant mixture is then heated in essentially the same manner in accordance with Example 12 to provide a copolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning, or drawing. The copolymer obtained is of the following structure: ##STR745##

The procedure of Example 53 is essentially repeated. Instead of using 100 mol% of monomer 1a, 95 mol% of monomer 2a, and 5 mol% of monomer 2gg, 100 mol% of monomer 1a is substantially dehydrochlorinated in a comparable weight percent of PPA with essentially similar P.sub.2 O.sub.5 content. After the addition of 50 mol% of monomer 2a and 50 mol% of monomer 2k and an appropriate amount of P.sub.2 O.sub.5 (thereby raising the final P.sub.2 O.sub.5 content to substantially above about 82%), the resultant mixture is then heated in essentially the same manner in accordance with Example 12 to provide a copolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning, or drawing. The copolymer obtained is of the following structure: ##STR746##

The procedure of Example 53 is essentially repeated. Instead of using 100 mol% of monomer 1a, 95 mol% of monomer 2a, and 5 mol% of monomer 2gg, 100 mol% of monomer 1a is substantially dehydrochlorinated in a comparable weight percent of PPA with essentially similar P.sub.2 O.sub.5 content. After the addition of 50 mol% of monomer 2a and 50 mol% of monomer 21 and an appropriate amount of P.sub.2 O.sub.5 (thereby raising the final P.sub.2 O.sub.5 content to substantially above about 82%), the resultant mixture is then heated in essentially the same manner in accordance with Example 12 to provide a copolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning, or drawing. The copolymer obtained is of the following structure: ##STR747##

The procedure of Example 53 is essentially repeated. Instead of using 100 mol% of monomer 1a, 95 mol% of monomer 2a, and 5 mol% of monomer 2gg, 100 mol% of monomer 1b is substantially dehydrochlorinated in a comparable weight percent of PPA with essentially similar P.sub.2 O.sub.5 content. After the addition of 50 mol% of monomer 2a and 50 mol% of monomer 2j and an appropriate amount of P.sub.2 O.sub.5 (thereby raising the final P.sub.2 O.sub.5 content to substantially above about 82%), the resultant mixture is then heated in essentially the same manner in accordance with Example 12 to provide a copolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning, or drawing. The copolymer obtained is of the following structure: ##STR748##

The procedure of Example 53 is essentially repeated. Instead of using 100 mol% of monomer 1a, 95 mol% of monomer 2a, and 5 mol% of monomer 2gg, 100 mol% of monomer 1b is substantially dehydrochlorinated in a comparable weight percent of PPA with essentially similar P.sub.2 O.sub.5 content. After the addition of 50 mol% of monomer 2a and 50 mol% of monomer 2k and an appropriate amount of P.sub.2 O.sub.5 (thereby raising the final P.sub.2 O.sub.5 content to substantially above about 82%), the resultant mixture is then heated in essentially the same manner in accordance with Example 12 to provide a copolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning, or drawing. The copolymer obtained is of the following structure: ##STR749##

The procedure of Example 53 is essentially repeated. Instead of using 100 mol% of monomer 1a, 95 mol% of monomer 2a, and 5 mol% of monomer 2gg, 100 mol% of monomer 1b is substantially dehydrochlorinated in a comparable weight percent of PPA with essentially similar P.sub.2 O.sub.5 content. After the addition of 50 mol% of monomer 2a and 50 mol% of monomer 21 and an appropriate amount of P.sub.2 O.sub.5 (thereby raising the final P.sub.2 O.sub.5 content to substantially above about 82%), the resultant mixture is then heated in essentially the same manner in accordance with Example 12 to provide a copolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning, or drawing. The copolymer obtained is of the following structure: ##STR750##

The procedure of Example 53 is essentially repeated. Instead of using 100 mol% of monomer 1a, 95 mol% of monomer 2a, and 5 mol% of monomer 2gg, 100 mol% of monomer 1a is substantially dehydrochlorinated in a comparable weight percent of PPA with essentially similar P.sub.2 O.sub.5 content. After the addition of 75 mol% of monomer 2a and 25 mol% of monomer 2i and an appropriate amount of P.sub.2 O.sub.5 (thereby raising the final P.sub.2 O.sub.5 content to substantially above about 82%), the resultant mixture is then heated in essentially the same manner in accordance with Example 12 to provide a copolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning, or drawing. The copolymer obtained is of the following structure: ##STR751##

The procedure of Example 53 is essentially repeated. Instead of using 100 mol% of monomer 1a, 95 mol% of monomer 2a, and 5 mol% of monomer 2gg, 100 mol% of monomer 1b is substantially dehydrochlorinated in a comparable weight percent of PPA with essentially similar P.sub.2 O.sub.5 content. After the addition of 75 mol% of monomer 2a and 25 mol% of monomer 2i and an appropriate amount of P.sub.2 O.sub.5 (thereby raising the final P.sub.2 O.sub.5 content to substantially above about 82%), the resultant mixture is then heated in essentially the same manner in accordance with Example 12 to provide a copolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning, or drawing. The copolymer obtained is of the folowing structure: ##STR752##

The procedure of Example 53 is essentially repeated. Instead of using 100 mol% of monomer 1a, 95 mol% of monomer 2a, and 5 mol% of monomer 2gg, 100 mol% of monomer 1c is substantially dehydrochlorinated in a comparable weight percent of PPA with essentially similar P.sub.2 O.sub.5 content. After the addition of 75 mol% of monomer 2a and 25 mol% of monomer 2i and an appropriate amount of P.sub.2 O.sub.5 (thereby raising the final P.sub.2 O.sub.5 content to substantially above about 82%), the resultant mixture is then heated in essentially the same manner in accordance with Example 12 to provide a copolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning, or drawing. The copolymer obtained is of the following structure: ##STR753##

The procedure of Example 53 is essentially repeated. Instead of using 100 mol% of monomer 1a, 95 mol% of monomer 2a, and 5 mol% of monomer 2gg, 100 mol% of monomer 1a is substantially dehydrochlorinated in a comparable weight percent of PPA with essentially similar P.sub.2 O.sub.5 content. After the addition of 75 mol% of monomer 2a and 25 mol% of monomer 2e and an appropriate amount of P.sub.2 O.sub.5 (thereby raising the final P.sub.2 O.sub.5 content to substantially above about 82%), the resultant mixture is then heated in essentially the same manner in accordance with Example 12 to provide a copolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning, or drawing. The copolymer obtained is of the following structure: ##STR754##

The procedure of Example 53 is essentially repeated. Instead of using 100 mol% of monomer 1a, 95 mol% of monomer 2a, and 5 mol% of monomer 2gg, 100 mol% of monomer 1b is substantially dehydrochlorinated in a comparable weight percent of PPA with essentially similar P.sub.2 O.sub.5 content. After the addition of 75 mol% of monomer 2a and 25 mol% of monomer 2e and an appropriate amount of P.sub.2 O.sub.5 (thereby raising the final P.sub.2 O.sub.5 content to substantially above about 82%), the resultant mixture is then heated in essentially the same manner in accordance with Example 12 to provide a copolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning, or drawing. The copolymer obtained is of the following structure: ##STR755##

The procedure of Example 49 is essentially repeated. Instead of using 95 mol% of monomer 1a, 5 mol% of monomer 1b, and 100 mol% of monomer 2a, a mixture of 60 mol% of monomer 1a and 40 mol% of monomer 1i is substantially dehydrochlorinated in a comparable weight percent of PPA with essentially similar P.sub.2 O.sub.5 content. After the addition of a stoichiometric amount of monomer 2a and an appropriate amount of P.sub.2 O.sub.5 (thereby raising the final P.sub.2 O.sub.5 content to substantially above about 82%), the resultant mixture is then heated in essentially the same manner in accordance with Example 12 to provide a copolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning, or drawing. The copolymer obtained is of the following structure: ##STR756##

The procedure of Example 49 was essentially repeated. Instead of using 95 mol% of monomer 1a, 5 mol% of monomer 1b, and 100 mol% of monomer 2a, a mixture of 80 mol% of monomer 1a and 20 mol% of monomer 1l was substantially dehydrochlorinated in a comparable weight percent of PPA with essentially similar P.sub.2 O.sub.5 content. After the addition of a stoichiometric amount of monomer 2a and an appropriate amount of P.sub.2 O.sub.5 (thereby raising the final P.sub.2 O.sub.5 content to substantially above about 82%), the resultant mixture was then heated in essentially the same manner in accordance with Example 12 to provide a copolymerization product. The product so formed was anisotropic-liquid crystalline (exhibited stir-opalescence) and was formed into ordered fibers by simple drawing. The copolymer obtained is believed to be of the following structure: ##STR757##

The procedure of Example 49 is essentially repeated. Instead of using 95 mol% of monomer 1a, 5 mol% of monomer 1b, and 100 mol% of monomer 2a, a mixture of 85 mol% of monomer 1c and 15 mol% of monomer 1l is substantially dehydrochlorinated in a comparable weight percent of PPA with essentially similar P.sub.2 O.sub.5 content. After the addition of a stoichiometric amount of monomer 2a and an appropriate amount of P.sub.2 O.sub.5 (thereby raising the final P.sub.2 O.sub.5 content to substantially above about 82%), the resultant mixture is then heated in essentially the same manner in accordance with Example 12 to provide a copolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning, or drawing. The copolymer obtained is of the following structure: ##STR758##

The procedure of Example 52 is essentially repeated. Instead of using 100 mol% of monomer 1a, 90 mol% of monomer 2a, and 10 mol% of monomer 2aa, 100 mol% of monomer 1b is substantially dehydrochlorinated in a comparable weight percent of PPA with essentially similar P.sub.2 O.sub.5 content. After the addition of 95 mol% of monomer 2a and 5 mol% of monomer 2aa and an appropriate amount of P.sub.2 O.sub.5 (thereby raising the final P.sub.2 O.sub.5 content to substantially above about 82%), the resultant mixture is then heated in essentially the same manner in accordance with Example 12 to provide a copolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning, or drawing. The copolymer obtained is of the following structure: ##STR759##

The procedure of Example 53 is essentially repeated. Instead of using 100 mol% of monomer 1a, 95 mol% of monomer 2a, and 5 mol% of monomer 2gg, 100 mol% of monomer 1b is substantially dehydrochlorinated in a comparable weight percent of PPA with essentially similar P.sub.2 O.sub.5 content. After the addition of 95 mol% of monomer 2a and 5 mol% of monomer 2gg and an appropriate amount of P.sub.2 O.sub.5 (thereby raising the final P.sub.2 O.sub.5 content to substantially above and about 82%), the resultant mixture is then heated in essentially the same manner in accordance with Example 12 to provide a copolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning, or drawing. The copolymer obtained is of the following structure: ##STR760##

The procedure of Example 53 is essentially repeated. Instead of using 100 mol% of monomer 1a, 95 mol% of monomer 2a, and 5 mol% of monomer 2gg, 100 mol% of monomer 1a is substantially dehydrochlorinated in a comparable weight percent of PPA with essentially similar P.sub.2 O.sub.5 content. After the addition of 95 mol% of monomer 2a and 5 mol% of monomer 2ff and an appropriate amount of P.sub.2 O.sub.5 (thereby raising the final P.sub.2 O.sub.5 content to substantially above about 82%), the resultant mixture is then heated in essentially the same manner in accordance with Example 12 to provide a copolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning, or drawing. The copolymer obtained is of the following structure: ##STR761##

Two polymerizations (Step A and Step B) were conducted simultaneously in separate resin kettles and combined at a later stage (Step C) to give a product of a block copolymer believed to have the following structure: ##STR762## where a.sub.1 b.sub.1 is 0.793 and a.sub.1 b.sub.2 is 0.207 and y.sub.11 is greater than about 30.

Step A: Preparation of --AI--.sub.n. A mixture of 92.06 g of 115% PPA and 39.45 g of concentrated orthophosphoric acid (85.7% H.sub.3 PO.sub.4) was stirred at 100.degree. C. for 2 h under reduced pressure. A portion (128.63 g) of the hot PPA (77.3% P.sub.2 O.sub.5) was added under a flow of argon to a resin kettle containing 41.42682 g (0.16896 mol) of 1a. The mixture was stirred at 50.degree. C. under argon flow for 15 h, then under reduced pressure at 60.degree. C. for 23.5 h, 70.degree. C. for 6 h, and 80.degree. C. for 8.5 h to effect dehydrochlorination. Terephthalic acid (2a) (28.0688 g, 0.16895 mol) was then added in four portions. The mixture was cooled to approximately 40.degree. C. and 92.22 g of P.sub.2 O.sub.5 was added. The mixture was stirred at the following temperatures for the specified times under a flow of argon: 100.degree. C. for 42.5 h; 120.degree. C. to 160.degree. C. in increments of 10.degree. C. per 0.5 h; 170.degree. C. for 2.5 h. At this time the mixture became stir-opalescent and a sample of the dope exhibited birefrigence under plane-polarized light. After an additional 3 h at 170.degree. C. the polymer from Step B was added (See Step C). The intrinsic viscosity of Polymer --AI--.sub.n isolated from the reaction mixture immediately before Step C was 2.3 dL/g which corresponds to an n value (average number of recurring units) of 30 and a p value (extent of reaction) of 0.983.

Step B: Preparation of --AG"--.sub.n. A mixture of 30.72 g of 115% PPA and 13.13 g of concentrated orthophosphoric acid (85.7% H.sub.3 PO.sub.4) was stirred at 100.degree. C. for 2 h under reduced pressure. The PPA (41.66 g; 77.3% P.sub.2 O.sub.5) was added without cooling under a flow of argon to a resin kettle containing 13.80877 g (0.05632 mol) of 1a. The mixture was stirred at 50.degree. C. under argon flow for 15 h, then under reduced pressure at 60.degree. C. for 23.5 h, 70.degree. C. for 6 h, and 80.degree. C. for 35.5 h. Isophthalic acid (2ss) (9.3569 g, 0.05632 mol) that had been obtained from Aldrich Chemical Company in 99% purity was twice recrystallized from 90% aqueous ethanol and dried at 110.degree. C. for 24 h and was then added in two portions incorporating the solid after each addition. The mixture was cooled to approximately 40.degree. C. and then 31.59 g of P.sub.2 O.sub.5 was added. The mixture was then heated simultaneously and at the same heating schedule as the solution in Step A.

Step C: Block Copolymerization. After 5.5 h at 170.degree. C., 72 g of the viscous, red, optically isotropic product from Step B was added to the kettle from Step A under an argon atmosphere at the time indicated in Step A. Both kettles were heated under an argon flow as follows: 170.degree. C. for 12.8 h; 190.degree. C. for 2 h; 200.degree. C. for 26 h. The resulting mixture remained stir-opalescent and continued to polymerize as indicated by intrinsic viscosities of samples removed at various times. Upon precipitation in H.sub.2 O, the final sample of the resulting copolymer had an intrinsic viscosity of 17.5 dL/g in MSA at 30.degree. C. The final precipitated sample of the portion of the product from step B that had not been added to the product from Step A (but had been heated according to the same schedule as the mixture) had an intrinsic viscosity of 1.8 dL/g in MSA at 30.degree. C. The weight percent of polymer --AI--.sub.n in the product from Step A was 16.2; the weight percent of polymer --AG"--.sub.n in the product from Step B was 16.3. The weight percent of block copolymer ##STR763## was therefore calculated to be 16.2; the weight percents of the individual --AI--.sub.n and --AG"--.sub.n segments of the block copolymer in the final product were 12.9 and 3.4, respectively, as calculated from the weights of the constituent polymers added and the total weight of the resulting product. The mol percent of mesogenic --AI--.sub.n and flexible --AG"--.sub.n units were 79.3 and 20.7, respectively, as calculated from the weights of the constituent polymers added.

Two polymerizations were conducted simultaneously in separate resin kettles (Steps A and B), and combined at a later stage (Step C) to give a block polymer product believed to have the following structure: ##STR764## where a.sub.1 b.sub.1 is 0.587 and a.sub.1 b.sub.2 is 0.413 and Y.sub.11 is greater than about 40.

Step A: Preparation of --AI--.sub.n. A mixture of 36.73 g of 115% PPA and 24.43 g of concentrated orthophosphoric acid (85.0% H.sub.3 PO.sub.4) was stirred at 100.degree. C. for 4.5 h under reduced pressure. A portion (58.69 g) of the hot PPA (74.9% P.sub.2 O.sub.5) was added under a flow of argon to a resin kettle containing 20.71434 g (0.08448 mol) of 1a. The mixture was stirred under reduced pressure at 50.degree. C. for 1 h, 70.degree. C. for 1.3 h, and 80.degree. C. for 23 h. To dissolve monomer, 6.02 g of P.sub.2 O.sub.5 was added, and the kettle was heated at 80.degree. C. for an additional 26 h. Terephthalic acid (2a) (14.0351 g, 0.08448 mol) was then added in three portions. The acid monomer was incorporated by stirring after each addition. The kettle was cooled to 50.degree. C. and an additional 46.24 g deaerated P.sub.2 O.sub.5 was added. The mixture was stirred under argon flow at the following temperatures for the specified times: 100.degree. C. for 18 h; 150.degree. C. for 2 h; 170.degree. C. for 5 h. (After 1 h at 170.degree. C. the mixture exhibited stir-opalescence). At this time the polymer from Step B was added. (See Step C).

Step B: Preparation of --AN"--.sub.n A mixture of 63.88 g of 115% PPA and 42.51 g of concentrated orthophosphoric acid (85.0% H.sub.3 PO.sub.4) was stirred at 100.degree. C. for 4.5 h under reduced pressure. A portion (104.41 g) of the PPA (74.9% P.sub.2 O.sub.5) was added without cooling under a flow of argon to a resin kettle containing 20.26865 g (0.08266 mol) of 1a. The mixture was stirred under reduced pressure at 50.degree. C. for 0.8 h, 60.degree. C. for 7.5 h, and 80.degree. C. for 9.5 h. Sebacic acid, (monomer 2zz, purified by crystallization of the disodium salt, then repeated recrystallization of the free acid in H.sub.2 O and dried in vacuo at 80.degree. C. for 24 h) (16.7190 g, 0.08266 mol), was then added in three portions to the resin kettle, incorporating after each addition. The mixture was cooled to 50.degree. C. and 70.91 g of P.sub.2 O.sub.5 was added slowly. The polymerization proceeded rapidly, and the gel-like solid was heated without stirring at 100.degree. C. for 16.5 h and at 130.degree. C. for 7.8 h. At this time the polymer was removed in an inert atmosphere, leaving a portion in the kettle which was reassembled and heated according to the same schedule as the block copolymer.

Step C: Block Copolymerization. A portion of the polymer from Step B (153.13 g) was added under an argon atmosphere to the kettle from Step A. The mixture was then stirred under argon flow at 170.degree. C. for 16 h and at 200.degree. C. for 28 h. The mixture remained stir-opalescent and continued to polymerize as shown by an increase in the bulk viscosity. The weight percent of polymer --AI--.sub.n in the product from Step A was 16.1; the weight percent of polymer --AN"--.sub.n in the product from Step B was 12.1. The weight percent of block copolymer was calculated to be 12.1; the weight percents of --AI--.sub.n and --AN"--.sub.n segments of the block copolymer in solution were 6.8 and 5.6 respectively. The mole percent of mesogenic --AI--.sub.n and --AN"--.sub.n units were 58.7 and 41.3 respectively, as calculated from the weights of the constituent polymers added. The resulting polymer isolated was not completely soluble in methanesulfonic acid thus precluding intrinsic viscosity measurements.

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 8 and 13 are diverted into a common agitated reaction vessel in amounts to give a ratio of 3:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR765##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 8 and 13 are diverted into a common agitated reaction vessel in amounts to give a ratio of 1:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR766##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 8 and 13 are diverted into a common agitated reaction vessel in amounts to give a ratio of 1:3. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR767##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 8 and 13 are diverted into a common agitated reaction vessel in amounts to give a ratio of 1:4. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR768##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 8 and 28 are diverted into a common agitated reaction vessel in amounts to give a ratio of 2:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR769##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 13 and 28 are diverted into a common agitated reaction vessel in amounts to give a ratio of 1:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR770##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 8 and 16 are diverted into a common agitated reaction vessel in amounts to give a ratio of 1:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR771##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 8 and 17 are diverted into a common agitated reaction vessel in amounts to give a ratio of 1:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR772##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 8 and 18 are diverted into a common agitated reaction vessel in amounts to give a ratio of 1:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR773##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 13 and 17 are diverted into a common agitated reaction vessel in amounts to give a ratio of 1:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR774##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 8 and 19 are diverted into a common agitated reaction vessel in amounts to give a ratio of 1:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR775##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 8 and 22 are diverted into a common agitated reaction vessel in amounts to give a ratio of 1.5:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR776##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 28 and 22 are diverted into a common agitated reaction vessel in amounts to give a ratio of 1.5:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR777##

The procedure of Example 73 is essentially repeated. Instead of using monomers 1a and 2ss in Step B, equimolar quantities of monomers 1a and 2ff are polymerized at a comparable concentration and to a comparable extent of reaction. The (partially completed) separate polymerization products (i.e., homo-oligomers) from Steps A and b are diverted into a common agitated reaction vessel in amounts to give a ratio of 1.5:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR778##

The procedure of Example 73 is essentially repeated. Instead of using monomers 1a and 2ss in Step B, equimolar quantities of monomers 1a and 2xx are polymerized at a comparable concentration and to a comparable extent of reaction. The (partially completed) separate polymerization products (i.e., homo-oligomers) from Steps A and B are diverted into a common agitated reaction vessel in amounts to give a ratio of 1.5:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR779##

The procedure of Example 73 is essentially repeated. Instead of using monomers 1a and 2ss in Step B, equimolar quantities of monomers 1a and 2uu are polymerized at a comparable concentration and to a comparable extent of reaction. The (partially completed) separate polymerization products (i.e., homo-oligomers) from Steps A and B are diverted into a common agitated reaction vessel in amounts to give a ratio of 1.5:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR780##

The procedure of Example 73 is essentially repeated. Instead of using monomers 1a and 2ss in Step B, equimolar quantities of monomers 1q and 2a are polymerized at a comparable concentration and to a comparable extent of reaction. The (partially completed) separate polymerization products (i.e., homo-oligomers) from Steps A and B are diverted into a common agitated reaction vessel in amounts to give a ratio of 1.5:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR781##

The procedure of Example 73 is essentially repeated. Instead of using monomer 1a in Step A, an equimolar quantity of 1b is used. Instead of using monomers 1a and 2ss in Step B, equimolar quantities of monomers 1b and 2ss are polymerized at a comparable concentration and to a comparable extent of reaction. The (partially completed) separate polymerization products (i.e., homo-oligomers) from Steps A and B are diverted into a common agitated reaction vessel in amounts to give a ratio of 1.5:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR782##

The procedure of Example 73 is essentially repeated. Instead of using monomer 1a in Step A, an equimolar quantity of 1b is used. Instead of using monomers 1a and 2ss in Step B, equimolar quantities of monomers 1b and 2xx are polymerized at a comparable concentration and to a comparable extent of reaction. The (partially completed) separate polymerization products (i.e., homo-oligomers) from Steps A and B are diverted into a common agitated reaction vessel in amounts to give a ratio of 2:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR783##

The procedure of Example 73 is essentially repeated. Instead of using monomer 1a in Step A, an equimolar quantity of 1b is used. Instead of using monomers 1a and 2ss in Step B, equimolar quantities of monomers 1b and 2zz are polymerized at a comparable concentration and to a comparable extent of reaction. The (partially completed) separate polymerization products (i.e., homo-oligomers) from Steps A and B are diverted into a common agitated reaction vessel in amounts to give a ratio of 2:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR784##

The procedure of Example 27 is essentially repeated. Instead of using monomer 3a, a mixture of 80 mol% of monomer 3a and 20 mol% of monomer 3c is substantially dehydrochlorinated in a comparable weight percent of PPA with essentially similar P.sub.2 O.sub.5 content. After the addition of appropriate amount of P.sub.2 O.sub.5 (thereby raising the final P.sub.2 O.sub.5 content to substantially above about 82%), the resultant mixture is then heated in essentially the same manner in accordance with Example 27 to provide a copolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning, or drawing. The copolymer obtained is of the following structure: ##STR785##

The procedure of Example 27 is essentially repeated. Instead of using monomer 3a, a mixture of 80 mol% of monomer 3a and 20 mol% of monomer 3d is substantially dehydrochlorinated in a comparable weight percent of PPA with essentially similar P.sub.2 O.sub.5 content. After the addition of appropriate amount of P.sub.2 O.sub.5 (thereby raising the final P.sub.2 O.sub.5 content to substantially above about 82%), the resultant mixture is then heated in essentially the same manner in accordance with Example 27 to provide a copolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning, or drawing. The copolymer obtained is of the following structure: ##STR786##

The procedure of Example 27 was essentially repeated. Instead of using monomer 3a, a mixture of 80 mol% of monomer 3a and 20 mol% of monomer 3e was substantially dehydrochlorinated in a comparable weight percent of PPA with essentially similar P.sub.2 O.sub.5 content. After the addition of appropriate amount of P.sub.2 O.sub.5 (thereby raising the final P.sub.2 O.sub.5 content to substantially above about 82%), the resultant mixture was then heated in essentially the same manner in accordance with Example 27 to provide a copolymerization product. The product so formed was anisotropic-liquid crystalline (exhibits stir-opalescence), highly drawable, and could be directly utilized for forming into articles by spinning, or drawing. The copolymer obtained is believed to be of the following structure: ##STR787##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 27 and 29 are diverted into a common agitated reaction vessel in amounts to give a ratio of 2:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR788##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 27 and 30 are diverted into a common agitated reaction vessel in amounts to give a ratio of 2:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR789##

3,4-diaminobenzoic acid (3e) (Aldrich, 97%) was recrystallized from hot warer with 3-4 g of carbon black and 0.5 g of sodium dithionite added for every 30 g of 3e. The recovered light orange crystals were dried at room temperature under reduced pressure for 24 h. An acid mixture prepared from 183.4 g of 115% PPA and 78.6 g of 85.7% H.sub.3 PO.sub.4 (J. T. Baker Analyzed Reagent) was deaerated by heating in a 3-necked flask at 100.degree. C. for 2 h under reduced pressure and then at 50.degree. C. under reduced pressure for 17 h. To a 500 mL resin kettle was added 20.24 g of 3e. The kettle was then deaerated by applying reduced pressure and then filling with nitrogen three times. 51.11 g of the above-mentioned PPA was added to the kettle and the contents stirred until well mixed. 38.77 g of P.sub.2 O.sub.5 (J. T. Baker Analyzed Reagent, 99.1%) was added. The temperature of the kettle was raised to 100.degree. C. and the P.sub.2 O.sub.5 incorporated into the mixture. The following heating schedule was used with color changes as noted: 100.degree. C. for 20 min; 110.degree. C. for 20 min; 120.degree. C. for 20 min; 130.degree. C. for 20 min; color changed from tan to green; 140.degree. C. for 20 min; the green color became darker. Reduced pressure was briefly applied which caused considerable foaming; 105.degree. C. for 20 min; 160.degree. C. for 20 min. A sample was removed and precipitated in water to give a red polymeric substance with an intrinsic viscosity in MSA at 30.0.degree. C. of 4.25 dL/g. Heating at 160.degree. C. was continued for another 30 h. The intrinsic viscosity in MSA at 30.degree. C. of polymer component of a sample removed at this time was measured to be 4.5 dL/g. The reaction was heated at 175.degree. C. an additional 35 h. The resultant red-brown polymeric material isolated from this solution had an intrinsic viscosity of 4.5 dL/g in methanesulfonic acid at 30.0.degree. C. Final reaction product contained 16.8% of polymer --W--.sub.n in PPA. Initial P.sub.2 O.sub.5 content was 77.3%, final P.sub.2 O.sub.5 content was 82.2%.

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 27 and 100 are diverted into a common agitated reaction vessel in amounts to give a ratio of 2.5:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR790##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Example 8 and 27 are diverted into a common agitated reaction vessel in amounts to give a ratio of 1:3. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR791##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 8 and 26 are diverted into a common agitated reaction vessel in amounts to give a ratio of 2:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR792##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 13 and 27 are diverted into a common agitated reaction vessel in amounts to give a ratio of 1:4. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR793##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 13 and 26 are diverted into a common agitated reaction vessel in amounts to give a ratio of 2:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpoymer obtained is of the following structure: ##STR794##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 8 and 30 are diverted into a common agitated reaction vessel in amounts to give a ratio of 1:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR795##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 8 and 30 are diverted into a common agitated reaction vessel in amounts to give a ratio of 3:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR796##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 13 and 30 are diverted into a common agitated reaction vessel in amounts to give a ratio of 1:3. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR797##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 13 and 30 are diverted into a common agitated reaction vessel in amounts to give a ratio of 1.5:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR798##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 8 and 100 are diverted into a common agitated reaction vessel in amounts to give a ratio of 1.5:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR799##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 13 and 100 are diverted into a common agitated reaction vessel in amounts to give a ratio of 1.5:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR800##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 28 and 100 are diverted into a common agitated reaction vessel in amounts to give a ratio of 2:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR801##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 19 and 27 are diverted into a common agitated reaction vessel in amounts to give a ratio of 1:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR802##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetermined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 23 and 27 are diverted into a common agitated reaction vessel in amounts to give a ratio of 1:1. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR803##

The procedure of Example 73 is essentially repeated. Subsequent to the start of polymerization and at a preselected range of intrinsic viscosities or after a predetemined selected temperature and rate of reaction, the (partially completed) separate polymerization products (i.e., homo-oligomers) of Examples 22 and 27 are diverted into a common agitated reaction vessel in amounts to give a ratio of 1:2. The polymerization of the resultant mixture is allowed to continue to form a substantially polymerized blockpolymerization product. The product so formed is anisotropic-liquid crystalline (exhibits stir-opalescence) and can be directly utilized for forming into articles by spinning or drawing and the like. The blockpolymer obtained is of the following structure: ##STR804##

A mixture of 42.13 g of PPA (83.8% P.sub.2 O.sub.5) and 18.06 g of H.sub.3 PO.sub.4 (85.9%) was stirred and heated to 100.degree. C. in a 100 ml 3-necked flask. The flask was placed under reduced presure overnight. 21.34 g of 3,4-diaminobenzoic acid.2HCl was added to a 100 ml resin kettle. The resin kettle was deaerated and flushed with Ar and 42.81 g of the above prepared PPA solvent with a P.sub.2 O.sub.5 content of 77.32% was then added to the kettle. The flask was heated with an oil bath at 55.degree. C. with slow stirring under a water aspirator (reduced pressure) for 0.33 hours. The flask was then placed under vacuum for an additional 45.87 hours. During the initial 5 hours of dehydrochlorination, the temperature was increased from 55.degree. C. to 70.degree. C. Near the end of the dehydrochlorination, the mixture changed from a very pale pink to a blue-green color that was almost transparent. 26.56 g of deaerated P.sub.2 O.sub.5 was added as a powder under Ar flow. The P.sub.2 O.sub.5 was incorporated using a combination of stirring and vacuum at about 70.degree. C. The mixture was allowed to equilibrate at 100.degree. C. with stirring under Ar flow for 17.33 hours. The amount of P.sub.2 O.sub.5 added was calculated to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 86% prior to the beginning of polymerization and an effective P.sub.2 O.sub.5 content of approximately 81.97% subsequent to substantial complete polymerization. The mixture was heated to a final temperature of 200.degree. C. following the heating schedule outlined below.

The reaction product obtained is optically isotropic characterized as having a polymer concentration of 13.14% and an intrinsic viscosity of 6.57 dL/g in MSA at 30.degree. C. The polymer obtained is of the following structure:

The reaction product of Example 13 was placed in a constant displacement spinning apparatus and extruded at about 3.4 MPa (500 psi) through a 0.381 mm (0.015 in.) diameter orifice and passed through a 20.96 cm (8.25 in.) air gap at a selected take up rate to give a spin draw ratio of about 6.12:1. The extrusion temperature was about 63.degree. C. The coagulation medium was water. The average tensile properties of seven single filaments (ASTM D 3379, 2.54 cm (1.0 in.) gage length) were 2.96 GPa (4.3.times.10.sup.5 psi) tensile strength, 89.6 GPa (13.times.10.sup.6 psi) modulus, and elongation at break range from 4.2-6%. The fiber diameters ranged from 33-37 micrometer (0.00129 to 0.00146 inches). Heat treated filaments (conditioned under tension at 500.degree. C. for 60 seconds in a nitrogen atmosphere) gave average values of tensile strength 3.45 GPa (5.0.times.10.sup.5 psi), modulus 317 GPa (46.times.10.sup.6 psi), and elongation at break 1.8-2.4%. The heat treated fiber diameters ranged from 29.7-33.3 micrometer (0.00117 to 0.00133 inches).

The procedure of Example 13 was essentially repeated using 21.0018 g (0.09857 mol) of 1b and 16.3768 g (0.09858 mol) of 2a. The P.sub.2 O.sub.5 content during dehydrochlorination was 75.16% for 8 hours and was increased to 81.37% by the addition of deaerated P.sub.2 O.sub.5 for an additional 24 hours. The concentration of monomer 1b during dehydrochlorination was initially 21.94%. After the addition of 2a, P.sub.2 O.sub.5 was added so as to raise the P.sub.2 O.sub.5 content to 87.5% before polymerization and to give a P.sub.2 O.sub.5 content after substantial polymerization of 83.17%. The mixture was then heated at 185.degree. C. for 28 hours. The concentration of polymer --BI--.sub.n was 13.8 weight percent. The isolated polymer --BI--.sub.n had an intrinsic viscosity of 24.4 dL/g.

The reaction product from Example 118 was dry-jet-wet spun as in Example 117 except that the extrusion temperature was 70.degree. C., the jet diameter was 0.254 mm (0.010 in.), the air gap was 20.3 cm (8 in.) and the required extrusion pressure was 1.17 MPa (170 psi). The average tensile strength of nine single filaments was 3.12 GPa (453,000 psi) which ranged from about 2.82 to about 3.35 GPa (410,000 to 486,000 psi). The average tensile modulus was 303 GPa (43.9.times.10.sup.6 psi). After treating this fiber at 450.degree. C. in air for 30 seconds with a 2% stretch the strength was unchanged and the modulus had increased to an average of 410 GPa (59.5.times.10.sup.6 psi). Repeating these conditions with a 2.8% stretch gave identical strength and a modulus of 394 GPa (57.09.times.10.sup.6 psi). After treating the as spun fiber at 500.degree. C. in air for 30 seconds with a 2.5% stretch the tensile strength increased to an average of 3.58 GPa (519,000 psi) and the modulus increased to 467 GPa (67.8.times.10.sup.6 psi).

A mixture of 13.35 g of 115% PPA and 8.89 g of 85.9% H.sub.3 PO.sub.4 was stirred under reduced pressure for 3.3 h at 100.degree. C. To a 100-mL resin kettle was added 17.76096 g (0.09368 mol) of 3-amino-4-hydroxybenzoic acid hydrochloric (3d). The kettle was flushed with argon, and 20.45 g of the above PPA (P.sub.2 O.sub.5 content=75.2%) was added. This mixture was stirred under reduced pressure; however, the mixture solidified overnight. 115% PPA (8.20 g, P.sub.2 O.sub.5 content=83.8%) was added to obtain a stirrable mixture with a P.sub.2 O.sub.5 content of 77.6%. After 8 h, 10.17 g of P.sub.2 O.sub.5 was added as a powder, giving a P.sub.2 O.sub.5 content of 83.49%. Dehydrochlorination was substantially complete after stirring for an additional 15 h at 80.degree. C. Additional P.sub.2 O.sub. 5 (12.65 g) was then added at 100.degree. C. in accordance with equation b.sup.* to give an f of 82.2% and an intermediate P.sub.2 O.sub.5 content of 87.55%. The kettle was placed under reduced pressure before incorporating the P.sub.2 O.sub.5 by stirring. The mixture was then stirred for 2.4 h at 100.degree. C., and the temperature was then increased to 140.degree. C. After 1 h at this temperature, a clear amber solution was obtained. The temperature was raised to 150.degree. C. for 1 h and then raised to 185.degree. C. After 1 h at 185.degree. C., the reaction mixture showed a tan pearlescence when stirred and was birefringent when viewed at rest under crossed polars. The reaction mixture was then heated at 185.degree. C. for an additional 40 h. Nearly colorless, high strength fibers were readily formed by drawing the reaction product. The concentration of polymer --V--.sub.n in the product was calculated to be 16.67%. The intrinsic viscosity of polymer --V--.sub.n isolated from the product was measured to be 13.84 dL/g in MSA at 30.degree. C. The dried polymer had a TGA break in air at 10.degree. C./min of 640.degree. C. Anal. Calcd. for C.sub.7 H.sub.3 NO: C, 71.80; H, 2.58; N, 11.96. Found: C, 71.09; H, 2.64; N, 11.67; Residue, 0.8.

The reaction mixture of Example 120 was placed in a constant displacement spinning apparatus and extruded at about 3.4 MPa (500 psi) through a 0.381 mm (0.015 in.) diameter orifice into a 31.75 cm (12.5 in.) air gap with a take-up rate to supply a spin draw ratio of 6.6:1. The temperature of the spinning dope was 65.degree. C. The as spun fiber was of poor quality and very non-uniform. The as-spun properties were (340.times.10.sup.3 psi) tensile strength, 41.3-96.5 GPa (6-14.times.10.sup.6 psi) modulus, with no elongation to break determined. After heat treatment under tension at 500.degree. C. for 60 seconds in nitrogen, the strength was essentially unchanged and the modulus had increased to an average value of 136 GPa (19.7.times.10.sup.6 psi).

The procedure of Example 120 was essentially repeated using 80.95 g (0.4269 mol) of monomer 3d, 34.37 g of 85.9% H.sub.3 PO.sub.4, 80.13 g of 115% PPA and 118.06 g of P.sub.2 O.sub.5. These amounts gave a m.sub.o of 77.32%, an intermediate P.sub.2 O.sub.5 content of 88.83%, and (because of the loss of 1.54 g of water during polycondensation) a P.sub.f of 83.8%. The P.sub.2 O.sub.5 content profile for this example is graphically presented by the step-wise curve of FIG. 13. The concentration of polymer --V--.sub.n in the reaction product was calculated to be 16.87 weight %. The total reaction time above 100.degree. C. was 43.5 hours. The stir-opalescent reaction product was birefringent at rest and gave colorless fibers after drawing and precipitating in water. The intrinsic viscosity of isolated polymer --V--.sub.n was 12.0 dL/g.

The reaction product of Example 122 was placed in a constant displacement spinning apparatus and extruded at about 3.4 MPa (500 psi) through a 0.25 mm (0.010 in.) diameter orifice into a 20.3 cm (8 in.) air gap with a take up rate to supply a spin draw ratio of 145:1. The temperature of the spinning dope was 90.degree. C. The tensile strength of fibers (average of nine breaks) spun from said dope was 3.57 GPa (518,000 psi). One of the fibers tested gave a break value of 5.01 GPa (727,000 psi). The average tensile modulus was 133 GPa (19.3.times.10.sup.6 psi). This value does not take into account the machine compliance. The average strain at break was 3.3%. The fiber diameter was 16 micrometer (0.63.times.10.sup.-3 in.).

The reaction product of Example 122 was placed in a constant displacement spinning apparatus and extruded at about 3.4 MPa (500 psi) through a 0.250 mm (0.010 in.) diameter orifice into a 20.3 cm (8.0 in.) air gap with a take up rate to supply a spin draw ratio of 125:1. The temperature of the spinning dope was 90.degree. C. The tensile strength of fibers (average of ten breaks) spun from said dope was 2.57 GPa (373,000 psi). One of the fibers tested gave a break value of 3.38 GPa (491,000 psi). The average tensile modulus was 79 GPa (11.5.times.10.sup.6 psi). This value does not take into account the machine compliance. The average strain at break was 4.6%. The fiber diameter was 19 micrometer (0.748.times.10.sup.-3 in.).

The reaction product of Example 122 was placed in a constant displacement spinning apparatus and extruded at about 3.4 MPa (500 psi) through a 0.25 mm (0.010 in.) diameter orifice into a 20.3 cm (8.0 in.) air gap with a take up rate to supply a spin draw ratio of 100:1. The temperature of the spinning dope was 90.degree. C. The tensile strength of fibers (average of seven breaks) spun from said dope was 2.83 GPa (410,000 psi). One of the fibers tested gave a break value of 3.29 GPa (491,000 psi). The average tensile modulus was 61 GPa (8.8.times.10.sup.6 psi). This value does not take into account the machine compliance. The average strain at break was 4.8%. The fiber diameter was 21 micrometer (0.827.times.10.sup.-3 in.).

The reaction product of Example 122 was placed in a constant displacement spinning apparatus and extruded at about 3.4 MPa (500 psi) through a 0.025 mm (0.010 in.) diameter orifice into a 20.3 cm (8.0 in.) air gap with a take up rate to supply a spin draw ratio of 17.2:1. The temperature of the spinning dope was 80.degree. C. The tensile strength of fibers (average of seven breaks) spun from said dope was 2.76 GPa (400,000 psi). The average tensile modulus was 41 GPa (6.0.times.10.sup.6 psi). This value does not take into account the machine compliance. The fiber diameter was 45 micrometer (1.76.times.10.sup.-3 in.).

A mixture of 13.25 g of concentrated orthophosphoric acid (85.9% H.sub.3 PO.sub.4) and 29.75 g of 115% PPA was stirred under reduced pressure at 100.degree. C. for 2.5 hours. The resulting solution was then poured under a stream of argon at 20.degree. C. into a 100 ml resin kettle containing 10.8621 g (0.050980 mol) of 4,6-diamino-1,3-benzenediol dihydrochloride (1b) that was prepared according to the method of Wolfe, et al., Macromolecules, Vol. 14, 909 (1981), recrystallized from aqueous hydrochloric acid containing 3 wt% stannous chloride, and dried for 72 hours at 20.degree. C. under reduced pressure immediately before use. The mixture was stirred at 55.degree. C. for 18 hours, at 76.degree. C. for 24 hours under reduced pressure. 2,5-pyridinedicarboxylic acid (2i) (8.5720 g, 0.050984 mol) was then added under argon flow. Additional P.sub.2 O.sub.5 (31.18 g) was then added. The solution was stirred, and heated as follows: 100.degree. C. for 1 hour; 120.degree. C. for 3 hours; 130.degree. C. for 0.5 hours; 140.degree. C. for 0.5 hours; 150.degree. C. for 0.5 hours; 185.degree. C. for 48 hours (the dark red solution became stir-opalescent during the first hour of this last period). The resulting product was deep red with metallic luster, exhibited stir-opalescence, and is further characterized as having a final effective P.sub.2 O.sub.5 content of 84% with the --BK--.sub.n polymer concentration being 13.4% by weight. The intrinsic viscosity of the polymer --BK--.sub.n isolated from the reaction product was 4.96 dL/g in MSA at 30.degree. C., which corresponds to an average number of recurring units, n, of approximately 50.

The reaction products from Examples 27 and 120 were precipitated in water and the polymers obtained (polymers --T--.sub.n and --V--.sub.n, respectively) were chopped in a Waring Blender and dried. The reaction product from Example 12 was dry-jet wet spun into fiber (polymer --AI--.sub.n) and dried. All of the precipitated polymers and spun fiber of Examples 12, 27, and 120 including as spun fiber (polymer --BI--.sub.n) produced in Example 117 were tested as follows: the precipitated polymers and spun fibers were placed in four of the ten positions in an isothermal aging apparatus developed by SRL Laboratories of Dayton, Ohio and heated at 371.degree. C. in circulating air for 200 hours. The apparatus has ten positions and the weight remaining in each of the positions is recorded at 20 minute intervals. Each of the polymer samples lost approximately 14% of their original weight initially indicating the presence of residual volatile species (e.g. water). The weight losses due to isothermal aging of the individual polymers (after the initial weight loss) were as follows:

The results are shown graphically in FIGS. 1 and 2.

The samples described in Example 128 were analyzed in a Du Pont 990 Thermogravimetric Analyzer at a heating rate of 5.degree. C./min. The weight retention in He and air atmospheres (flow rate=60 ml/min) as a function of temperature is shown for the four polymers in FIGS. 3, 4 (in He) and 5, 6 (in air). The isothermal aging (see FIGS. 1 and 2) of all four polymers of Example 128 show a marked improvement especially for polymers --V--.sub.n, and --BI--.sub.n. Polymer --BI--.sub.n can be compared directly with Wolfe and Loo U.S. Pat. No. 4,225,700. The improvement is presumed to be caused by the increase in molecular weight and/or the more highly ordered morphology of the resulting polymers/fibers formed from compositions of the invention. Thermogravimetric analysis in air (at a heating rate of 10.degree. C./min) was also performed on two block polymers of the instant invention; these block polymers were isolated and dried from the reaction products of Example 73 and 74. The results of the TGA are shown in FIG. 2A.

A mixture of 173.59 g of concentrated orthophosphoric acid (85.5% H.sub.3 PO.sub.4) and 414.71 g of 115% PPA was stirred under reduced pressure for 2 hours. The resulting solution was then poured at approximately 30.degree. C. under an argon stream into a 2 L resin kettle containing 118.70422 g (0.557127 mol) of 4,6-diamino-1,3-benzenediol dihydrochloride (1b) that was prepared according to the method of Wolfe and Arnold, Macromolecules, vol. 14, 909 (1981), recrystallized from aqueous hydrochloric acid containing 3 wt % stannous chloride, and dried for 3.5 days at 20.degree. C. under reduced pressure immediately before use. The mixture was stirred at 60.degree. C. for 48 hours and 80.degree. C. for 6 hours under reduced pressure. Monomer 2a (92.55800 g, 0.55713 mol) was then added under argon flow. Deaerated P.sub.2 O.sub.5 (404.45 g) was added. The mixture was then heated at 100.degree. C. for 18 hours, and 185.degree. C. for 29 hours. The dark blue-black solution became stir-opalescent after 1.5 hours at 185.degree. C. The reaction product was deep purple with a golden metallic luster, exhibited stir-opalescence, and was further characterized as having a final effective P.sub.2 O.sub.5 content of 83.2%, with the --BI--.sub.n polymer concentration being 11.3% by weight. The intrinsic viscosity of the polymer --BI--.sub.n isolated from the reaction product was 20.4 dL/g in MSA at 30.degree. C., which corresponds to an average number of recurring units, n, of approximately 100.

The reactor used for the preparation of polymer --AI--.sub.n of this Example was constructed with all wetted parts made of Hastelloy C-276. The working volume was 115 L (30 gal). Mixing was provided by four vertical, stationary baffles attached to the reactor lid and a rotating assembly with four vertical members. The rotating assembly was driven by a 5 hp-2.5 hp two-speed motor and had a bearing and seal at top and bottom. The reactor was charged with 13.4888 kg (55.0129 mol) of monomer 1a and then with 49.1 kg of a PPA prepared from 19.64 kg of 85.8% H.sub.3 PO.sub.4 and 29.46 kg of 115% PPA. The reactor was then heated to 60.degree. C. within 1 hour and placed under reduced pressure for 20 hours. The P.sub.2 O.sub.5 content was then raised to 78.5% by the addition of 7.751 kg of P.sub.2 O.sub.5 over a 2 -hour period, which caused the temperature to rise spontaneously to 92.degree. C. After cooling to 68.degree. C., an additional 5.647 kg of P.sub.2 O.sub.5 was added in 30 minutes, causing the temperature to rise to 84.degree. C. The mixture was stirred at 80.degree. C. under reduced pressure for an additional 17 hours, at which time all the HCl appeared to have been evolved. Monomer 2a (9.1396 kg, 55.015 mol) was then added in four portions. Each portion was added under reduced pressure by first adding the monomer to a 12 L addition bulb, placing both the reactor and bulb under reduced pressure, and then opening a ball valve between the two chambers. Additional P.sub.2 O.sub.5 (26.296 kg) was then added in two portions according to equation b* to give an intermediate P.sub.2 O.sub.5 content of 86.26% and a final P.sub.2 O.sub.5 content of 82.57%. The reaction mixture was then stirred at slow speed overnight at 100.degree.-112.degree. C. under an argon atmosphere. Using the faster stirring speed, the mixture was then heated, and samples were removed for intrinsic viscosity determinations according to the following schedule:

The reaction mixture was then cooled to 110.degree. C. over a period of four hours, at which time the intrinsic viscosity was 24.6 dL/g. The green, opalescent product was then reheated to 130.degree. C. and removed from the reactor for spinning. A sample taken at the end of the removal was measured to have an intrinsic viscosity of 27.26 dL/g. A small sample was heated at 185.degree. C. for an additional 24 hours, and the intrinsic viscosity rose to 34.11 dL/g.

A mixture of 34.97 g of PPA (83.8%) and 15.00 g of H.sub.3 PO.sub.4 was stirred and heated to 100.degree. C. in a 100-ml 3-necked flask. The flask was placed under reduced pressure for 2.0 hours. To a 100-ml resin kettle was added 21.32 g of 3,4-diaminobenzoic acid.2 HCl. The flask was deaerated and flushed with argon. 33.84 g of the above prepared PPA solvent (having a P.sub.2 O.sub.5 content of 77.32%) was added to the kettle. The kettle was heated with an oil bath at 50.degree. C. with moderate stirring under water-aspirator reduced pressure for 1.0 hour. The flask was then placed under vacuum-pump reduced pressure for an additional 46.83 hours. The temperature remained at 50.degree. C. for 18.0 hours, at 60.degree. C. for 1.77 hours, at 70.degree. C. for 23.81 hours, and at 80.degree. C. for 4.25 hours. At the time the vacuum was removed, the mixture was riding on the stir blades. Near the end of dehydrochlorination, the mixture was still opaque and the color was mint green. The P.sub.2 O.sub.5 was added as a powder in two additions. The first addition of P.sub.2 O.sub.5 was in the amount of 6.93 g. The P.sub.2 O.sub.5 was added under argon at 80.degree. C. with stirring. The P.sub.2 O.sub.5 was incorporated under reduced pressure. Reduced pressure was maintained for 18.57 hours. The remaining 14.00 g of P.sub.2 O.sub.5 were added and incorporated under reduced pressure with stirring at 80.degree. C. (Total P.sub.2 O.sub.5 =20.93 g.) The amount of P.sub.2 O.sub.5 added was calculated to provide the reaction mixture with an effective P.sub.2 O.sub.5 content of approximately 85.99% prior to the beginning of polymerization and an effective P.sub.2 O.sub.5 content of approximately 80.94% subsequent to substantially complete polymerization. The mixture was heated to a final temperature of 200.degree. C. following the heating schedule outlined below.

A sample of the reaction product was stretchable, fibrous, and turned white as it was drawn. The fiber was precipitated in water. The fiber and a nonprecipitated sample were birefringent at rest at room temperature under crossed polars. The clear green dope appeared hazy as it was cooled. The intrinsic viscosity of the reaction product was 6.58 dL/g in MSA at 30.degree. C. and the polymer concentration was 15.90%. The polymer obtained is of the following structure:

A mixture of 14.71 g of concentrated orthophosphoric acid (85.9% H.sub.3 PO.sub.4) and 22.64 g of 115% PPA was stirred under reduced pressure at 100.degree. C. for 2.5 hours. The resulting solution was then poured at approximately 25.degree. C. under a stream of Argon into a 100 ml resin kettle containing 11.04664 g (0.045053 mol) of 2,5-diamino-1,4-benzenedithiol dihydrochloride (1a). The mixture was stirred under reduced pressure at 50.degree. C. for 2 hours; 60.degree. C. for 16 hours, and 80.degree. C. for 12.5 hours to complete the dehydrochlorination. Monomer 2a (7.4863 g, 0.045001 mol) was then added under an Ar flow. P.sub.2 O.sub.5 (48.29 g) was then added. The mixture was heated at 100.degree. C. for 3 hours and at 185.degree. C. for 33 hours. The resulting reaction product was light green with an iridescent luster, exhibited stir-opalescence, and was further characterized as having a final effective P.sub.2 O.sub.5 content of 83.6% with the --AI--.sub.n polymer concentration being 11.6 wt %. The intrinsic viscosity of the polymer --AI--.sub.n isolated from the reaction product was 47.8 dL/g in MSA at 30.degree. C., which corresponds to an average number of recurring units, n, of approximately 140. The physical properties of as spun and heat treated fibers formed from compositions of Examples 117, 119, 121, 123, 124, 125, and 126 above are shown in Tables 29 and 30 below.

40.6 g of a PPA solution with an effective P.sub.2 O.sub.5 content of 77.1% (prepared by mixing 39 wt% of H.sub.3 PO.sub.4 and 61 wt% of 115% PPA) was added to a 100 mL resin kettle containing 11.0444 g 0.045043 mol) of 1a. (Monomer 1a of large crystal size was prepared with a final recrystallization according to the method of Wolfe, Loo, and Arnold, Macromolecules, 14, 915 (1981) using the final isolation procedure involving a transfer of the dipotassium salt of monomer 1a as solution into 6N hydrochloric acid.) After stirring to incorporate the solid monomer into the PPA, the mixture was substantially dehydrochlorinated by heating the mixture at 55.degree.-70.degree. C. under reduced pressure for approximately 22 h. Monomer 2a (7.4851 g, 0.045054 mol) was added to the resin kettle and incorporated as described in Example 7. Powdered P.sub.2 O.sub.5 (37.09 g) was then added to increase the effective P.sub.2 O.sub.5 content to approximately 88.4% and resulting mixture was stirred at 100.degree. C. for 16 h under an argon flow. The polymerization mixture was then heated with stirring as follows: 100.degree.-185.degree. C. in 1 h, and 185.degree. C. for 75 h. (a total of 0.34 g of water was lost during dehydrochlorination and polymerization). The green reaction product exhibits stir-opalescence and is characterized as having a final effective P.sub.2 O.sub.5 content of 84.8% with --AI--.sub.n polymer concentration being approximately 12.9 wt%. The intrinsic viscosity of the polymer --AI--.sub.n isolated from the reaction product was 30.0 dL/g in MSA at 30.degree. C. which corresponds to an average number of recurring units, n, of approximately 115.

39.42 g of a PPA solution with an effective P.sub.2 O.sub.5 content of 75.9% (prepared by mixing 39 wt% of H.sub.3 PO.sub.4 and 61 wt% of 115% PPA) was added to a 100 mL resin kettle containing 11.0143 g (0.044921 mol) of 1a. (Monomer 1a was taken from the same batch as the 1a used in Example 134). After stirring to incorporate the solid monomer into the PPA, the mixture was substantially dehydrochlorinated by heating the mixture at 55.degree.-70.degree. C. under reduced pressure for approximately 17 h. Monomer 2a (7.2769 g, 0.043801 mol) was added to the resin kettle and incorporated as described in Example 7. Benzoic acid (Matheson primary standard 0.2734 g, 0.002239 mol) was then added under a stream of argon and incorporated under reduced pressure. Powdered P.sub.2 O.sub.5 (36.02 g) was then added to increase the effective P.sub.2 O.sub.5 content to approximately 88.6% and the resulting mixture was stirred at 100.degree. C. for 18 h under an argon flow. The polymerization mixture was then heated with stirring at 100.degree.-185.degree. C. for 0.3 h, then at 185.degree. C. for 5.8 h. A total of 1.24 g of water was lost during dehydrochlorination and polymerization. The green reaction product exhibits stir-opalescence and is characterized as having a final effective P.sub.2 O.sub.5 content of 84.9% with --AI--.sub.n polymer concentration being approximately 13.3 wt%. The intrinsic viscosity of the end-capped polymer --AI--.sub.n isolated from the reaction product was 7.5 dL/g in MSA at 30.degree. C. which corresponds to an average number of recurring units, n, of approximately 50.

60.7 kg of a PPA solution with an effective P.sub.2 O.sub.5 content of 75.5% (prepared by mixing 37 wt% of H.sub.3 PO.sub.4 and 63 wt% of 115% PPA) was added to a 30 gal Hastalloy reactor containing 18.75 kg (76.47 mol) of 1a. (Monomer 1a was then taken from the same batch as the 1a used in Example 134). After stirring to incorporate the solid monomer into the PPA, the mixture was substantially dehydrochlorinated by heating the mixture at 55.degree.-70.degree. C. under reduced pressure for approximately 84h. Monomer 2a (12.61 kg, 75.94 mol) was added to the resin kettle and incorporated. Benzoic acid (Matheson primary standard, 130.74 g, 1.0706 mol) was also added and incorporated. Powdered P.sub.2 O.sub.5 (49.86 kg) was then added to increase the effective P.sub.2 O.sub.5 content to approximately 86.6% and resulting mixture was stirred at 100.degree. C. for 24 h under an argon flow. The polymerization mixture was then heated with stirring as follows: 100.degree.-185.degree. C. in 2 h, and 185.degree. C. for 42 h. The intrinsic viscosities (in dL/g) were determined for the end-capped polymer --AI--.sub.n from samples withdrawn at the indicated times: 1.6 (1.8 h), 11.16 (2.2 h), 14.05 (2.4 h), 17.17 (2.8 h), 18.51 (3.5 h), and 18.66 (42 h) (as shown in FIG. 15). A total of 7.0 g of water was lost during dehydrochlorination and polymerization. The green reaction product exhibits stir-opalescence and is characterized as having a final effective P.sub.2 O.sub.5 content of 82.5% with --AI--.sub.n polymer concentration being approximately 14.9 wt%.

38.66 g of a PPA solution with an effective P.sub.2 O.sub.5 content of 75.3% (prepared by mixing 40 wt% of H.sub.3 PO.sub.4 and 60 wt% of 115% PPA) was added to a 100 mL resin kettle containing 11.0493 g (0.045063 mol) of 1a. (Monomer 1a was then taken from the same batch as the 1a used in Example 134). After stirring to incorporate the solid monomer into the PPA, the mixture was substantially dehydrochlorinated by heating the mixture at 55.degree.-70.degree. C. under reduced pressure for approximately 31 h. Monomer 2a (7.4543 g, 0.044869 mol) was added to the resin kettle and incorporated. Powdered P.sub.2 O.sub.5 (36.73 g) was then added to increase the effective P.sub.2 O.sub.5 content to approximately 86.4% and the resulting mixture was stirred at 100.degree. C. for 2.5 h under an argon flow. The polymerization mixture was then heated with stirring 100.degree.-185.degree. C. in 0.3 h, then was quickly cooled to 100.degree. C. Benzoic acid (Matheson primary standard 0.0478 g, 0.000391 mol) was then added and incorporated under reduced pressure. The mixture was stirred under an argon atmosphere at 100.degree. C. for 15.3 h, then was heated to 185.degree. C. over 0.3 h, and at 185.degree. C. for 74 h. A total of 0.5 g of water was lost. The reaction product exhibits stir-opalescence and is characterized as having a final effective P.sub.2 O.sub.5 content of 84.1% with --AI--.sub.n polymer concentration being approximately 13.3 wt%. The intrinsic viscosity of the end-capped polymer --AI--.sub.n isolated from the reaction product was 24.2 dL/g in MSA at 30.degree. C. which corresponds to an average number of recurring units, n, of approximately 90.

The procedure of Example 13 is essentially repeated with the following modifications. Instead of the molar amounts of 2a given in Example 13, 8.7066 g, 0.05241 mols of 2a was added. Benzoic acid (Matheson primary standard, 0.3959 g, 0.003242 mol) was then added under a stream of argon and incorporated under reduced pressure.

The resulting reaction product is characterized as having a final effective P.sub.2 O.sub.5 content of 82% with the --BI--.sub.n polymer concentration being 13.3% by weight. The intrinsic viscosity of the end-capped polymer --BI--.sub.n isolated from the reaction product is 6 dL/g in MSA at 30.degree. C., which corresponds to an average number of recurring units, n, of approximately 50.

The procedure of Example 13 is essentially repeated with the following modifications. Instead of the molar amounts of 2a given in Example 13, 8.8412 g, 0.05322 mol of 2a was added. Benzoic acid (Matheson primary standard, 0.1979 g, 0.001621 mol) was then added under a stream of argon and incorporated under reduced pressure.

The resulting reaction product is characterized as having a final effective P.sub.2 O.sub.5 content of 82% with the --BI--.sub.n polymer concentration being 13.3% by weight. The intrinsic viscosity of the end-capped polymer --BI--.sub.n isolated from the reaction product is 15 dL/g in MSA at 30.degree. C., which corresponds to an average number of recurring units, n, of approximately 85.

The procedure of Example 13 is essentially repeated with the following modifications. Instead of the molar amounts of 2a given in Example 13, 8.9534 g, 0.05389 mols of 2a was added. Benzoic acid (Matheson primary standard, 0.0330 g, 0.2701 mmol) was then added under a stream of argon and incorporated under reduced pressure.

The resulting reaction product is characterized as having a final effective P.sub.2 O.sub.5 content of 82% with the --BI--.sub.n polymer concentration being 13.3% by weight. The intrinsic viscosity of the end-capped polymer --BI--.sub.n isolated from the reaction product is 20 dL/g in MSA at 30.degree. C., which corresponds to an average number of recurring units, n, of approximately 100.

The procedure of Example 27 is essentially repeated with the following modification. After dehydrochlorination is substantially complete and the P.sub.2 O.sub.5 is added, benzoic acid (Matheson primary standard, 1.6365 g, 0.01340 mol) is added under a stream of argon and incorporated under reduced pressure. The intrinsic viscosity of end-capped polymer --T--.sub.n isolated from the reaction product is 5.2 dL/g. The reaction product thus obtained is 20.3% by weight of polymer --T--.sub.n in PPA with a final P.sub.2 O.sub.5 content of 82.4%.

The procedure of Example 27 is essentially repeated with the following modifications. After dehydrochlorination is substantially complete and the P.sub.2 O.sub.5 is added, benzoic acid (Matheson primary standard, 0.8181 g, 6.699 mmol) is added under a stream of argon and incorporated under reduced pressure. The intrinsic viscosity of polymer --T--.sub.n isolated from the reaction product is 10.2 dL/g. The reaction product thus obtained is 20.3% by weight of end-capped polymer --T--.sub.n in PPA with a final P.sub.2 O.sub.5 content of 82.4%.

The procedure of Example 27 is essentially repeated with the following modifications. After dehydrochlorination is substantially complete and the P.sub.2 O.sub.5 is added, benzoic acid (Matheson primary standard, 0.1364 g, 1.117 mmol) is added under a stream of argon and incorporated under reduced pressure. The intrinsic viscosity of polymer --T--.sub.n isolated from the reaction product is 16.4 dL/g. The reaction product thus obtained is 20.3% by weight of end-capped polymer --T--.sub.n in PPA with a final P.sub.2 O.sub.5 content of 82.4%.

The procedure of Example 30 is essentially repeated with the following modifications. After dehydrochlorination is substantially complete and the P.sub.2 O.sub.5 is added, benzoic acid (Matheson primary standard, 3.1285 g, 25.62 mmol) is added under a stream of argon and incorporated under reduced pressure. The intrinsic viscosity of polymer --V--.sub.n isolated from the reaction product is 4.0 dL/g. The reaction product thus obtained is 18% by weight of end-capped polymer --V--.sub.n in PPA with a final P.sub.2 O.sub.5 content of 82.2%.

The procedure of Example 30 is essentially repeated with the following modifications. After dehydrochlorination is substantially complete and the P.sub.2 O.sub.5 is added, benzoic acid (Matheson primary standard, 1.5642 g, 12.81 mmol) is added under a stream of argon and incorporated under reduced pressure. The intrinsic viscosity of polymer --V--.sub.n isolated from the reaction product is 9.6 dL/g. The reaction product thus obtained is 20.3% by weight of end-capped polymer --V--.sub.n in PPA with a final P.sub.2 O.sub.5 content of 82.2%.

The procedure of Example 30 is essentially repeated with the following modifications. After dehydrochlorination is substantially complete and the P.sub.2 O.sub.5 is added, benzoic acid (Matheson primary standard, 0.2607 g, 2.135 mmol) is added under a stream of argon and incorporated under reduced pressure. The intrinsic viscosity of polymer --V--.sub.n isolated from the reaction product is 14.2 dL/g. The reaction product thus obtained is 20.3% by weight of end-capped polymer --V--.sub.n in PPA with a final P.sub.2 O.sub.5 content of 82.2%.

The procedure of Example 135 is essentially repeated except that 0.08092 g, 1.348 mmol of glacial acetic acid is added instead of benzoic acid. The reaction product exhibits stir-opalescence and is characterized as having a final effective P.sub.2 O.sub.5 content of 84.9% with end-capped --AI--.sub.n polymer concentration being approximately 13.3 wt%. The intrinsic viscosity of the end-capped polymer isolated from the reaction product is 8 dL/g in MSA at 30.degree. C.

The procedure of Example 138 is essentially repeated except that 0.09734 g, 1.621 mmol of glacial acetic acid is added instead of benzoic acid. The reaction product exhibits stir-opalescence and is characterized as having a final effective P.sub.2 O.sub.5 content of 82% with end-capped --BI--.sub.n polymer concentration being approximately 13.3 wt%. The intrinsic viscosity of the end-capped polymer isolated from the reaction product is 15 dL/g in MSA at 30.degree. C.

The procedure of Example 142 is essentially repeated except that 0.4023 g, 6.699 mmol of glacial acetic acid is added instead of benzoic acid. The reaction product exhibits stir-opalescence and is characterized as having a final effective P.sub.2 O.sub.5 content of 82.4% with end-capped --T--.sub.n polymer concentration being approximately 20.3 wt%. The intrinsic viscosity of the end-capped polymer isolated from the reaction product is 11 dL/g in MSA at 30.degree. C.

The procedure of Example 145 is essentially repeated except that 0.7692 g, 12.81 mmol of glacial acetic acid is added instead of benzoic acid. The reaction product exhibits stir-opalescence and is characterized as having a final effective P.sub.2 O.sub.5 content of 82.2% with end-capped --V--.sub.n polymer concentration being approximately 18 wt%. The intrinsic viscosity of the end-capped polymer isolated from the reaction product is 9 dL/g in MSA at 30.degree. C.

182.7 g of a PPA solution with an effective P.sub.2 O.sub.5 content of 77.2% (prepared by mixing 30 wt% of H.sub.3 PO.sub.4 and 70 wt% of 115% PPA) is added to a 500 mL resin kettle containing 53.1448 g (0.2167 mol) of 1a. After stirring to incorporate the solid monomer into the PPA, the mixture is substantially dehydrochlorinated by heating the mixture at 55.degree.-70.degree. C. under reduced pressure for approximately 31 h. Monomer 2a (35.6522 g, 0.21460 mol) is added to the resin kettle and incorporated. Powdered P.sub.2 O.sub.5 (123.35 g) is then added to increase the effective P.sub.2 O.sub.5 content to approximately 86.4% and the resulting mixture is stirred at 100.degree. C. for 17 h under an argon flow. The polymerization mixture is then heated with stirring as follows: 100.degree.-185.degree. C. in 1 h, then at 185.degree. C. for 20 h. The reaction product exhibits stir-opalescence and is characterized as having a final effective P.sub.2 O.sub.5 content of 82.2% with --AI--.sub.n polymer concentration being approximately 15.1 wt%. The intrinsic viscosity of the polymer --AI--.sub.n isolated from the reaction product is 7 dL/g in MSA at 30.degree. C. which corresponds to an average number of recurring units, n, of approximately 50.

182.7 g of a PPA solution with an effective P.sub.2 O.sub.5 content of 77.2% (prepared by mixing 30 wt% of H.sub.3 PO.sub.4 and 70 wt% of 115% PPA) is added to a 500 mL resin kettle containing 52.7502 g (0.2151 mol) of 1a. After stirring to incorporate the solid monomer into the PPA, the mixture is substantially dehydrochlorinated by heating the mixture at 55.degree.-70.degree. C. under reduced pressure for approximately 31h. Monomer 2a (35.6522 g, 0.21460 mol) is added to the resin kettle and incorporated. Powdered P.sub.2 O.sub.5 (123.35 g) was then added to increase the effective P.sub.2 O.sub.5 content to approximately 86.4% and the resulting mixture was stirred at 100.degree. C. for 17 h under an argon flow. The polymerization mixture was then heated with stirring as follows: 100.degree.-185.degree. C. in 1 h, then 185.degree. C. for 23 h. The green reaction product exhibits stir-opalescence and is characterized as having a final effective P.sub.2 O.sub.5 content of 82.2% with --AI--.sub.n polymer concentration being approximately 15.1 wt%. The intrinsic viscosity of the polymer --AI--.sub.n isolated from the reaction product is 29 dL/g in MSA at 30.degree. C. which corresponds to an average number of recurring units, n, of approximately 115.

A mixture of 17.7 g of concentrated orthophosphoric acid (85.7% H.sub.3 PO.sub.4) and 26.6 g of 115% PPA is stirred under reduced pressure at 100.degree. C. for 2 hours. The resulting solution is then poured at approximately 100.degree. C. under a stream of argon into a 200 mL resin kettle containing 11.6265 g (0.05456 mol) of 4,6-diamino-1,3-benzenediol dihydrochloride (1b). The mixture is stirred at 53.degree. C. for 15 h and 62.degree. C. for 4 h under reduced pressure. Upon heating to 70.degree. C., the monomer precipitated. Addition of 16.6 g of P.sub.2 O.sub.5 resulted in redissolution of the monomer. The solution was then heated at 100.degree. C. for 3 h under reduced pressure to complete the dehydrochlorination. Monomer 2a (8.9761 g, 0.05403 mol) was then added under an argon flow. Additional P.sub.2 O.sub.5 (19.0 g) was then added. The solution was then heated as follows: 100.degree.-185.degree. C. in 1 h, and 185.degree. C. for 20 h. The resulting reaction product was deep purple with a metallic luster, exhibited stir-opalescence, depolarized plane-polarized light as evidenced by strong birefringence when viewed between crossed polars, and is further characterized as having a final effective P.sub.2 O.sub.5 content of 82% with the --BI--.sub.n polymer concentration being 13.3% by weight. The intrinsic viscosity of the polymer --BI--.sub.n isolated from the reaction product was 15 dL/g in MSA at 30.degree. C., which corresponds to an average number of recurring units, n, of approximately 85.

The procedure of Example 51 is essentially repeated. Instead of adding 0.10134 mol of 2a, 16.667 g (0.10033 mol) are added and then 2.475 g (2.027 mmol) of benzoic acid are added and incorporated. After a heating schedule as in Example 51, the resulting end-capped copolymer isolated from the reaction product has an intrinsic viscosity of 17.2 dL/g in MSA at 30.degree. C., which corresponds to an n value of approximately 85.

The procedure of Example 73 is essentially repeated with the following modification. In Step C, at the time of addition of the optically isotropic product from Step B is also added 0.025 mole percent (0.0103 g) of benzoic acid to stabilize the molecular weight of the resulting block polymer at an intrinsic viscosity of 16.5 dL/g in MSA at 30.degree. C.

As illustrated in the Examples above, the compositions of the invention are prepared in batch fashion but continuous procedures may be employed.

Some process and product benefits as a result of better control of certain process parameters such as shear and temperature in a continuous process are: (1) a more homogeneous products of reaction as a result of a much higher order of magnitude of mixing; (2) higher throughputs; (3) and improved economics.

Another advantage of continuous processing is that the resulting reaction products can be blended in essentially all portions with other reaction products of different polymer type and/or reaction products at different stages of reaction.

In a continuous process, the aforementioned dehydrochlorination step of "Stage One" and monomer-P.sub.2 O.sub.5 addition of "Stage Two" are conducted at a temperature not to exceed about 100.degree. C. in a batch reactor preferably of the type described in Example 131. "Stage Three" of the invention can be conducted in a motionless (static) mixer. Such mixers for paste and very viscous materials are described in "Chemical Engineers' Handbook", R. H. Perry et al., McGraw-Hill Kogakusha, LTD., International Student Edition, pp. 19-24, (1973); "Fluid Mixing Technology", by James Y. Oldshue, McGraw-Hill Publishing Company, pp. 431-438, (1983); and Grout et al., U.S. Pat. No. 3,800,985. These publications and patent are incorporated herein by reference. The reaction mixture of "Stage Two" is fed from an outlet of the batch reactor through a constant displacement pump to a static mixer (tubular reactor) preferably of the type described in U.S. Pat. No. 3,800,985 where the first mixing element is heated at a temperature between about 140.degree. C. to about 185.degree. C. The second and subsequent intermediate mixing elements are heated at temperatures between about 165.degree. C. and about 200.degree. C. The last mixing elements are heated at temperatures between about 80.degree. C. and about 200.degree. C. depending on the desired temperature selected for spinning the particular extended chain polymer employed.

In order to avoid interruptions in the continuous process, two or more batch reactors (for conducting "Stage One" and "Stage Two") are connected to the static mixer (tubular reactor) in parallel array fashion so as to feed said tubular reactor in time-wise sequence. Preferably, "Stages One and "Stage Two" can be conducted in an emptied batch reactor without the need for clean-up. The volume requirement of the tubular reactor is a function of the size and number of the batch reactor array, the desired (mixing elements) residence time, and the desired flow rate.

Such a continuous process is especially suitable for the preparation of block copolymers of the present invention. Block copolymers can be made by admixing a second reaction mixture after the first reaction mixture has passed through an intermediate number of mixing elements.

A very important aspect of the continuous process as well as for the batch process which must be emphasized is that "Stage One", "Stage Two", and "Stage Three" of the invention must be conducted within the shaded phosphorus pentoxide content profile area bounded by ABCDEFGHI of FIG. 14. This is unrealized by the art. ##STR805##

While certain features of this invention have been described in detail with respect to various embodiments thereof, it will, of course, be apparent that other modifications can be made within the spirit and scope of this invention, and it is not intended to limit the invention to the exact details shown above except insofar as they are defined in the following claims.