Abstract: Optical devices including a molecularly oriented highly birefringent polymer are disclosed. The devices include molecularly oriented polymers comprising recurring units which exhibit a distribution of high electron density about the long axes of the polymer and the recurring units thereof. Transparent birefringent polymers comprising a plurality of recurring units having a substantially cylindrical distribution of electron density about the long axis of such units and the chain-extended polymers are included in optical devices and articles. The polymers exhibit high birefringence and simulate in a polymer the optical properties of a uniaxial crystal.

Abstract: High molecular weight block copolyamides useful in the production of fibers of high strength and modulus, having the following formula: ##STR1## wherein X is --CH.sub.2 --.sub.m, wherein m is 0 to 12, ##STR2## wherein Z is C(CH.sub.3).sub.2, zero, oxygen or SO.sub.2, are prepared from N,N'-bis(4-aminophenyl) terephthalamide having the formula: ##STR3## which is itself prepared by condensing aniline with dimethyl terephthalate or terephthalic acid, nitrating the product produced thereby and finally hydrogenating the resultant compound.

Abstract: High modulus shaped articles such as fibers and films, composed of a wholly aromatic copolyamide, are provided. The wholly aromatic copolyamide is comprised of recurring units of the formulae:--NH--AR.sub.1 --NH--CO--Ar.sub.2 --CO-- (A)and--NH--Ar.sub.3 --CO-- (B)wherein Ar.sub.1, Ar.sub.2 and Ar.sub.3 independently stand for divalent groups selected from ##STR1## in which X's independently stand for a group selected from halogeno, alkyl, aralkyl, aromatic, alkoxy, acetyl and cyano, n is 1 to 3 and Y is selected from ##STR2## in which R' stands for an 1-5C alkyl group, and the copolymerization ratio expressed by the molar ratio of the total of Ar.sub.1, Ar.sub.2 and Ar.sub.3 fails within the square hatched region in a triangular coordinate of FIG. 1, and said copolyamide has an intrinsic viscosity of at least 1.5.

Abstract: The present invention provides containers having unexpectedly superior gas barrier properties. The containers are formed from specified polyamides which comprise an aliphatic diamine and a diacid component which comprises a dicarboxylic acid containing a hetero atom.

Abstract: Polyamides, prepared from aralkylenediamines, such as 5-phenyl-5-methyl-1,9-nonanediamine and dicarboxylic acids such as adipic or azelaic acid are tough, clear resins useful for molding and fibers.

Abstract: Aromatic-aliphatic diamines of the formula ##STR1## in which Ar is an arylene or substituted arylene are useful in preparing thermally stable, rigid, polyamides, polyureas and polyurethanes having a repeating unit of the formula ##STR2## in which Ar is arylene or substituted arylene, X is --NH-- or --O--, n is 0 or 1, and R is a divalent organic radical. Polymers of this invention can be melt-spun into thermally stable fibers.

Abstract: A method of improving the processability of rigid polymers, particularly of unprocessable rigid polymers, wherein the rigid polymer in melt or solution form is subjected to an apparent shear rate between relatively moving surfaces of at least 100 sec.sup.-1, particularly between 100 and 1000 sec.sup.-1. The method reduces the viscosity of the melt or solution and when the melt or solution is fabricated into shaped articles while the viscosity is so reduced the shaped articles have improved properties, particularly more uniform orientation when compared with products prepared by methods which do not include the pre-shearing step prior to fabrication.

Abstract: Optical devices including a molecularly oriented highly birefringent polymer are disclosed. The devices include molecularly oriented polymers comprising recurring units which exhibit a distribution of high electron density about the long axes of the polymer and the recurring units thereof. Transparent birefringent polymers comprising a plurality of recurring units having a substantially cylindrical distribution of electron density about the long axis of such units and the chain-extended polymers are included in optical devices and articles. The polymers exhibit high birefringence and simulate in a polymer the optical properties of a uniaxial crystal.

Abstract: N-(Substituted phosphinyl) polyamides and a method for their production are disclosed. The N-(substituted phosphinyl) polyamides are characterized by the recurring unit structure represented by the formula ##STR1## wherein A is in part hydrogen and in part a substituted phosphinyl radical. One method of producing the N-(substituted phosphinyl) polyamides is treating N-chlorinated polyamide with substituted phosphinyl compounds. The disclosed N-(substituted phosphinyl) polyamides exhibit excellent thermal stability fire resistance, good processability, high water absorption and permeability. The N-(substituted phosphinyl) polyamides are useful for making flame resistant textile materials.

Abstract: New transparent polyamides consisting of recurring structural elements of formula I ##STR1## wherein the carbonyl groups are linked to the benzene ring in 1,3- and/or 1,4-position are described. The novel polyamides are suitable for the manufacture of transparent shaped articles, and are distinguished by good thermoplastic processing characteristics, low water absorption, high stability to hydrolysis and good dimensional stability under the action of moisture.

Abstract: The compounds are of the class of aromatic polyamides useful as matrix resins in the manufacture of composites or laminate fabrication. The process for preparing this thermoplastic-thermoset polyamide system involves incorporating a latent crosslinking moiety along the backbone of the polyamide to improve the temperature range of fabrication thereof wherein the resin softens at a relatively low temperature (.congruent.154.degree. C.) and subsequently "sets-up" or undergoes crosslinking when subjected to higher temperature (.congruent.280.degree. C.).

Abstract: New transparent polyamides consisting of recurring structural elements of formula I or II ##STR1## in which the carbonyl groups are linked to the benzene ring in 1,3- and/or 1,4-position are described. The novel polyamides are suitable for the manufacture of transparent shaped articles, and are distinguished by good thermoplastic processing characteristics, low water absorption, high stability to hydrolysis and good dimensional stability under the action of moisture.

Abstract: Shaped articles composed of polymers formed from residues which are not melt processable characterized in that the shaped article has been formed from a readily processable melt of a copolymer containing said residues together with in-chain temperature labile residues and has been subsequently heated to remove the labile constituents with recombination of the resultant polymeric residues. Preferably the processable melt should be in the form of an anisotropic melt so that the shaped article may be in oriented form prior to removal of the residues. Typically the shaped articles are articles of thin section composed of p-hydroxybenzoic acid residues.

Abstract: A polymer capable of forming an anisotropic melt characterized in that the polymer chain includes residues of cross-linking reactants at a concentration sufficient to give a polymer with a melt viscosity of not greater than 10.sup.7 Nsec/m.sup.2 measured by capillary rheometry at a shear rate of 10.sup.4 N/m.sup.2. The polymers exhibit favorable shear dependent viscosity characteristics in that the viscosity is high under low shear conditions and is low under high shear conditions, as judged by the viscosity characteristics of polymers of the same composition but not containing the residues of cross-linking reactants.

Abstract: A melt-processable aromatic polyester anhydride characterized in that from 5 to 80% of the units linking the reactant residues in the polymer chain have the formula: ##STR1## the remaining linkages between the residues of the reactants being of the formula: ##STR2## optionally together with linkages of the formula: ##STR3## substantially all of said remaining linkages being disposed in coaxial or parallel and oppositely directed manner with respect to the residues to which they are linked, the polyester anhydride having a solubility of less than 5% by weight in dimethyl sulphoxide at room temperature.

Abstract: An aromatic copolyamide comprising recurring units (A) of the formula (I), (B) of the formula (II) and (C) of the formula (III): ##STR1## wherein in (I), (II) and (III), Ar.sub.1 is phenylene, naphthylene or biphenylene radicals, each having two valence bonds oriented meta; Ar.sub.2 is phenylene, naphthylene or biphenylene radicals, each having two valence bonds oriented coaxially or in parallel to each other and radicals of the formula (IV): ##STR2## wherein Y.sub.1 and Y.sub.2 are independently ##STR3## and; X.sub.1, X.sub.2, X.sub.3, X.sub.4, X.sub.5 and X.sub.6 respectively are independently --NH-- and --CO-- radicals, connected to each other to form an amide bond (--NHCO-- or --CHNH--), and the molar proportions of said recurring units (A), (B), and (C) fall within a quadrilateral defined by the co-ordinates P, Q, R and S or on a twice-turned line defined by the co-ordinates Q, R, S and P:P (A 50, B 5, C 45)Q (A 5, B 5, C 90)R (A 5, B 40, C 55) andS (A 50, B 15, C 35)on a triangular composition diagram.

Abstract: Phthalonitrile resins useful as high-temperature coatings and plastics and n high-temperature composites are obtained by heating a diphthalonitrile monomer with a primary amine from a temperature from about the melting point of the monomer to about the decomposition temperature of the resin. The resins can also be prepared by dissolving a diphthalonitrile monomer in a solvent, e.g. acetonitrile, adding a primary amine to form a suspension, heating the suspension to the B-stage, quenching the suspension, removing the solvent, and heating the residue at a temperature from about its melting point to about the decomposition temperature of the resin.

Abstract: Aralkylenediamines such as 5-phenyl-5-methyl-1,9-nonanediamine, or cycloalkylalkylenediamines such as 5-cyclohexyl-5-methyl-1,9-nonanediamine, are polymerized with dicarboxylic acids such as adipic or azelaic acid, optionally with a tricarboxylic acid such as benzene tricarboxylic acid, to produce tough clear colorless polyamide resins useful for molding and fibers.

Abstract: Fibrides of synthetic heterochain polymers are produced by a non-equilibrium polycondensation of an aqueous alkaline solution of bifunctional compounds supplied into the reaction zone as a continuous stream oriented in the horizontal plane of the reaction zone to be acylated with diacylchlorides of dicarboxylic acids in the state of a superheated vapor with a carrier supplied into the reaction zone in the vertical plane, the contacting of the reagents being effected in a cross-current stream under shear stress conditions.

Abstract: A class of polyamides comprising recurring units having substituted-quaterphenylene radicals is disclosed. The polymers comprise recurring units of the formula ##STR1## wherein each of A and B is a divalent radical, except that B can represent a single bond; R and R.sup.1 are each hydrogen, alkyl, aryl, alkaryl or aralkyl; and c is zero or one; and wherein, when c is one, at least one of A and B is a substituted-quaterphenylene radical having the formula ##STR2## where each U is a substituent other than hydrogen, each W is hydrogen or a substituent other than hydrogen, each p is an integer from 1 to 3, each X is hydrogen or a substituent other than hydrogen and each r is an integer from 1 to 4, the U, W.sub.p and X.sub.r substitution being sufficient to provide the radical with a non-coplanar molecular configuration; and wherein, when c is zero, A is a substituted-quaterphenylene radical as aforedescribed.

Abstract: A class of polyamides comprising recurring units having certain substituted-biphenylene or substituted-stilbene radicals is disclosed. The substituted radicals include substituents so as to confer a non-coplanar molecular configuration and a substantially cylindrical distribution of electron density about the long axis of the recurring units and the chain-extended polymers including such radicals.Molecularly oriented polymers of the invention exhibit optically uniaxial properties. The highly birefringent polymers are suited to application in optical filter and other devices where a refractive and birefringent material is desired.

Abstract: Novel polyamides and copolyamides prepared from 2,2'4,4'6,6'-hexamethyl 3,3'-diaminobiphenyl (3,3'-M.sub.2 DAM) and aliphatic or aromatic diacids. 3,3'-M.sub.2 DAM and a mixture of other aliphatic or aromatic diamines may also be suitably used to react with the diacids. These novel polyamides and copolyamides are useful in preparing molded articles, fibers, films, laminates and coatings.

Abstract: Novel copolyamides and polyamides and molding compositions are prepared from 4,4'-diamino-2,2', 6,6'-tetramethylbiphenyl and aliphatic or aromatic diacids, dianhydride and mixtures of diamines. The polyamides and copolyamides are useful as engineering plastics.

Abstract: A high Young's modulus poly-p-phenylene-terephthalamide fiber having a unique fine-structure and excellent properties, including excellent resistance to lateral stress and to friction. The fiber is made by extruding an anisotropic dope in a non-coagulating layer, passing the extrudate through a coagulating layer, washing and drying the resulting coagulated fibers in the absence of substantial tension, and heating the fibers under tension.

Abstract: A poly-p-phenylene-terephthalamide fiber with excellent fatigue resistance resulting from a unique combination of properties. The fibers are prepared by extruding an anisotropic polymer dope in a non-coagulating layer, passing the extrudate through a coagulating layer, depositing the resulting coagulated fibers on a net conveyor, and in the absence of substantial tension sequentially washing the fibers, holding the fibers in saturated steam, and drying the fibers under specified conditions.

Abstract: New processable polyaromatic amides were prepared from the acid chloride of bis-m-carboxyphenyl acetylene and several aromatic diamines. The polyamides containing the acetylene units were cured by Diels-Alder cycloaddition reaction with 1,4-diphenyl-1,3-butadiene. Cured polyamides showed increase in Tg. thermal and heat stabilities. The polyamides can be cast into films and give good glass fiber laminates.

Abstract: A process for synthesizing novel polyaromatic amides containing 1,3-butadiene groups along the polymer chain by effecting a reaction between the acid chloride of 1,4-bis-p-carboxyphenyl-1,3-butadiene and an aromatic diamine. These polyamides have been found to be especially useful as laminating resins for a variety of laminating applications.

Abstract: Injection moldable copolymers are prepared from fully or partially acylated aromatic diamines and aromatic tricarboxylic anhydride compounds, aromatic dicarboxylic acids or mixtures of aromatic tricarboxylic acid anhydrides and aromatic dicarboxylic acids. These copolymers are useful for the preparation of injection molded articles and fibers.

Abstract: An aromatic copolyamide comprising recurring units (A) of the formula (I), (B) of the formula (II) and (C) of the formula (III): ##STR1## wherein in (I), (II) and (III) Ar.sub.1 is phenylene, naphthylene or biphenylene radicals, each having two valence bonds oriented meta; Ar.sub.2 is phenylene, naphthylene or biphenylene radicals, each having two valence bonds oriented coaxially or in parallel to each other and radicals of the formula (IV): ##STR2## wherein Y.sub.1 and Y.sub.2 are independently; ##STR3## and; X.sub.1, X.sub.2, X.sub.3, X.sub.4, X.sub.5 and X.sub.6 respectively are independently --NH-- and --CO-- radicals, connected to each other to form an amide bond (--NHCO-- or --CHNH--), and the molar proportions of said recurring units (A), (B) and (C) fall within a quadrilateral defined by the co-ordinates P, Q, R and S or on a twice-turned line defined by the co-ordinates Q,R,S, and P:P (A 50, B 5, C 45)Q (A 5, B 5, C 90)R (A 5, B 40, C 55) andS (A 50, B 15, C 35)on a triangular composition diagram.

Abstract: A method of improving the processability of rigid polymers, particularly of unprocessable rigid polymers, wherein the rigid polymer in melt or solution form is subjected to an apparent shear rate between relatively moving surfaces of at least 100 sec.sup.-1, particularly between 100 and 1000 sec.sup.-1. The method reduces the viscosity of the melt or solution and when the melt or solution is fabricated into shaped articles while the viscosity is so reduced the shaped articles have improved properties, particularly more uniform orientation when compared with products prepared by methods which do not include the pre-shearing step prior to fabrication.

Abstract: Novel copolymers and terpolymers of the amide-imide type are prepared from tricarboxylic acid anhydride compounds, N,N'-diacylated diamines, N-acylated diamines, and primary diamines. These copolymers and terpolymers are useful for preparing injection molded articles of superior properties. A novel process for the manufacture of amide-imide copolymers and terpolymers is disclosed wherein the imide, imide-imide, amide, and amide-amide moieties incorporated into the polymer backbone can be controlled by acylating the amine functionality which is to form the amide and amide-amide moieties while reacting directly those diamines with a tricarboxylic anhydride compound which are intended to form the imide and imide-imide moieties.

Abstract: Film of a wholly aromatic polyamide, at least 85% of the repeating units of which are meta-phenylene isophthalamide units, which is undrawn and noncrystalline and which has improved impact strength. Such film is made by heat-treating film of the polyamide which is undrawn and noncrystalline at 400.degree. to 300.degree. C. for from 2 seconds to 2 minutes while maintaining the film at constant length and width or while permitting it to shrink by at most 20% in each of the length and width.

Abstract: Injection moldable copolymers are prepared from fully or partially acylated aromatic diamines and aromatic tricarboxylic anhydride compounds or mixtures of tricarboxylic anhydrides and dicarboxylic acids. These copolymers are useful for the preparation of injection molded articles and fibers.

Abstract: A process for making poly-p-phenyleneterephthalamide having an inherent viscosity of at least 2.5 comprises reacting p-phenylene diamine with terephthaloyl chloride in a solvent which contains N-methyl pyrrolidone and at least 5% by weight of calcium chloride based on the weight of N-methyl pyrrolidone.

Abstract: A continuous process is disclosed for the production of poly-(para-phenylene terephthalamide) and its copolymers, having an inherent viscosity of at least 3. Molten terephthaloyl chloride, and optionally adipoyl chloride, are reacted in stoichiometric amounts with a solution of para-phenylenediamine and/or of 4,4'-diaminoadipanilide, and optionally of a prepolymer formed from at least one chloride and at least one diamine from amongst those mentioned above, in a mixture of N-methylpyrrolidone-2 and calcium chloride which is homogeneous and substantially anhydrous, with a molar ratio of CaCl.sub.2 /unit: ##STR1## of at least 1, and preferably at least 1.15, and under conditions such that the final composition contains at least 5% by weight of polymer, relative to the N-methylpyrrolidone-2, where R represents p-phenylene or p-phenylene and up to 50% of n-butylene of the total polymer units.

Abstract: A process is disclosed for the discontinuous production of a polyamide having the generic formula: ##STR1## and an inherent viscosity of at least 3, wherein 50 to 100% of the radicals R are p-phenylene radicals and 0 to 50% are n-butylene radicals. Terephthaloyl chloride, and optionally adipoyl chloride, are reacted in stoichiometric amounts with a solution of paraphenylenediamine and/or of 4,4'-diaminoadipanilide in a mixture of N-methylpyrrolidone-2 and calcium chloride which is homogeneous and substantially anhydrous, with a molar ratio of CaCl.sub.2 / unit: ##STR2## of at least 0.7, and under conditions such that the final composition contains 5 to 16% by weight of polymer, relative to the N-methylpyrrolidone-2. The polymer obtained can be converted into films, fibers and high-performance yarns for reinforcing composite materials or articles made of rubber.

Abstract: Novel tailor made copolymers and terpolymers of the amide-imide type are prepared from tricarboxylic acid anhydride compounds, N,N'-diacylated diamines, N-acylated diamines, and primary diamines. These copolymers and terpolymers are useful for preparing injection molded articles of superior properties. A novel process for the manufacture of amide-imide copolymers and terpolymers is disclosed wherein the imide, imide-imide, amide, and amide-imide moieties incorporated into the polymer backbone are controlled by acylating the amine functionality which is to form the amide and amide-amide moieties while reacting directly those diamines with a tricarboxylic anhydride compound which are intended to form the imide and imide-imide moieties.

Abstract: Aromatic polyamide film, having an excellent thermal resistance and a high dielectric breakdown strength, which comprises an aromatic polyamide containing repeating units of the formula----NH--Ar.sub.1 --CO----or----NH--Ar.sub.1 --NHCO--Ar.sub.2 --CO----and cross-linked with a cross-linking compound having at least one radical selected fromR.sup.1 --C(R.sup.2).dbd.C--CH.sub.2 (R.sup.3)--,R.sup.1 --C(R.sup.2).dbd.CR .sup.3 --,R.sup.1 --C(R.sup.2).dbd.C(R.sup.3)--COO--andR.sup.1 --C(R.sup.2).dbd.C(R.sup.3)--CONH--,or another cross-linking cyanuric or isocyanuric acid compound, by means of heat, ultraviolet rays or electron beam.

Abstract: Methyl-substituted polyphenylacyl compounds are prepared by selective oxidation of oligomers of mesitylene. These methyl-substituted polyphenylacyl compounds are useful as intermediates for polyamides and polyesters. The esters are useful as plasticizers for polyvinylchloride.

Abstract: Process for the preparation of shaped articles of poly(metaphenylene isophthalamide) by simultaneously heating poly(metaphenylene isophthalamide) and applying moderately elevated pressures.

Abstract: High molecular weight processible polymers derived from 2,6- and 2,7-diacids, diols and diamines of 9,10-dihydro-9,10-ethanoanthracenes and various complementary comonomers are prepared. These are converted into rigid, thermally-stable anthraceno polyesters and polyamides by thermal removal of the 9,10-ethano bridge.

Abstract: The invention relates to membranes which consist of aromatic polyamides containing disulphimide groups and have relative viscosities .eta..sub.rel of .gtoreq.1.4 as measured on a 0.5% N-methylpyrrolidone solution at 20.degree. C., and which may be used for ultrafiltration and inverse osmosis. The membranes of these polyamides according to the invention have a high permeability to water, for example, a throughflow of 1000-5000 1/m.sup.2 d under a pressure of 20 bars, and a high retention capacity for dissolved substances.

Abstract: A wholly aromatic polyamide composition which is suitable for producing filaments or fibers having not only an excellent heat-resisting property but also, a superior dyeing property, which comprises:(A) 50 to 95% by weight of poly-m-phenylene isophthalamide, and;(B) 5 to 50% by weight of at least one other aromatic polyamide comprising:(1) an amine moiety consisting of essentially of (a) 35 to 100 molar % of at least one phenylene diamine in which the phenylene group has 1 to 4 substituents respectively selected, independently from each other, from the group consisting of halogen atoms and alkyl radicals having 1 to 4 carbon atoms, and (b) 0 to 65 molar % of at least one other aromatic diamine, and;(2) an acid moiety consisting essentially of at least one aromatic dicarboxylic acid.

Abstract: The application discloses compositions which can be shaped to form yarns, fibers, films, membranes and fibrids. They contain a particular statistical or ordered copolyamide, with an inherent viscosity of at least 1, or units containing radicals of which at least 5% are flexible radicals and the others are rigid radicals. These compositions make it possible to produce yarns, fibers, films, membranes and fibrids possessing superior mechanical properties, which find applications in the textile field, as reinforcements in composite materials in the rubber industry and coated fabrics.

Abstract: Aromatic polyamide foams having a density of 0.025 to 0.7 g./cm..sup.3 are prepared by heating N-alkyl aromatic polyamides having at least one .beta. hydrogen atom on the alkyl groups, a plasticizer and an aromatic sulfonic acid catalyst at 250.degree. to 340.degree. C. for a length of time sufficient to remove substantially all of the N-alkyl groups.

Abstract: A method for preparing heterochain polymers, viz. polyamides or polyarylates which comprises an interphase polycondensation of diamines or bisphenols with dihaloanhydrides of dicarboxylic acids; said interphase polycondensation is performed by atomization of dihaloanhydrides of dicarboxylic acids in the form of an aerosol by means of a compressed gas into an aqueous solution of said diamines or bisphenols; concentration of said dihaloanhydrides of dicarboxylic acids in the aerosol is maintained within the range of from 0.4.times.10.sup.-4 to 2.times.10.sup.

Abstract: The invention relates to semipermeable membranes with a water absorption capacity of from 4.5 to 11% by weight, preferably from 4.5 to 8% by weight, as measured on approximately 40.mu. thick symmetrical films at room temperature and at 65% relative air humidity, a throughflow of 130 to 200 l/m.sup.2 d for a desalination level of 94.6 to 99.5% and consisting of an aromatic heterocycle-containing copolyamide with a relative viscosity of .gtoreq.1.4, as measured on a 0.5% N-methyl pyrrolidone solution at a temperature of 20.degree. C.

Abstract: Terephthalic acid and either 5-methyl-1,9-nonanediamine or an isomeric mixture of 5-methyl-1,9-nonanediamine with 2,4-dimethyl-1,8-octanediamine and/or 2,4,6-trimethyl-1,7-heptanediamine are admixed in a methanol/water medium, wherein the volume ratio of methanol to water is in the range of about 99:1 to about 80:20, and the weight ratio of terephthalic acid and diamine to the methanol/water medium is in the range of about 1:1 to about 1:3. The resulting slurry can be cooled to promote precipitation of the salt. The precipitated salt can be recovered by filtration and employed for the production of a polyamide.

Abstract: An aromatic polyamide having a high degree of polymerization is produced by polymerizing(A) a mixture of an aromatic diamine of the formula (1):H.sub.2 N--Ar.sub.1 --NH.sub.2 (1)and an aromatic dicarboxylic acid dihalide of the formula (2):XOC--Ar.sub.2 --COX (2)(b) a mixture of the aromatic diamine of the formula (1), the aromatic dicarboxylic acid dihalide of the formula (2) and a hydrogen halide salt of an aromatic amino carboxylic acid halide of the formula (3):XH.multidot.H.sub.2 N--Ar.sub.3 --COX (3)or(C) the hydrogen halide salt of the aromatic amino carboxylic acid halide of the formula (3) alone,Wherein Ar.sub.1, Ar.sub.2 and Ar.sub.

Abstract: A method of producing poly-p-phenyleneterephthalamide or its copolymers residing in that p-phenylenediamine or p-phenylenediamine and an aromatic diamine of the diphenyl series is/are disclosed in amide-salt solvents consisting of linear or cyclic N-alkyl-substituted amides of acids and of salts of alkaline or alkaline-earth metals soluble in said amides in amounts of 1-3 moles per mole of diamines; terephthalic acid dichloride or a mixture of terephthalic acid dichloride and aromatic acid dichloride of the diphenyl series are introduced into the solutions obtained at 0.degree.-20.degree. C. in amounts equimolar to those of the diamines, a reaction mixture being thus formed; tertiary amines are introduced into said reaction mixture in amounts 2-6 moles per mole of the initial diamines; the reaction mixture is stirred for 3-70 minutes and the end product is separated from the mass obtained.