Abstract: The thermooxidative stability and thermomechanical properties of advanced composites which use high performance resin matrices such as polyimides and high strength carbon fibers may be improved by sizing the carbon fibers with uncapped or capped linear polyamideimides.The uncapped linear polyamideimides useful as carbon fiber sizings generally contain repeating units having the general formula: ##STR1## wherein R.sub.2 =a trivalent organic radical and generally benzenetriyl;R.sub.3 =a divalent organic radical; andn=an integer sufficiently large to provide a strong, tough coating.Useful capped, linear polyamideimide oligomers may be formed by including end caps with an unsaturated functionality (Y) containing a residue selected from the group consisting of: ##STR2## wherein R.sub.1 =lower alkyl, lower alkoxy, aryl, aryloxy, substituted alkyl, substituted aryl, halogen, or mixtures thereof;j=0, 1, or 2;i=1 or 2;G=--CH.sub.2 --, --O--, --S--, --SO.sub.2 --, --SO--, --CO--, --CHR--, or --CR.sub.

Abstract: The new aromatic ether imides corresponding to the following formula ##STR1## may be used for the production of plastics which in turn may be worked up into moulded articles, films, sheet products and filaments. The plastics produced from the new aromatic ether imides are distinguished by their exceptional dimensional stability under heat.

Abstract: Hydroxypolyamides can be obtained in a simple and economical way in a chloride-free manner when(a) aromatic amino hydroxy carboxylic acids or(b) aromatic diaminodihydroxy compounds and aromatic dicarboxylic acids or(c) aromatic diaminodihydroxy compounds, aromatic dicarboxylic acids and aromatic amino hydroxy carboxylic acids are converted in the presence of 1-ethoxycarbonyl-2-ethoxy-1.2-dihydroquinoline, 1.1'-carbonyldioxy-di-1.2.3-benzotriazole or dicyclohexyl carbodiimide/1-hydroxy-1.2.3-benzotriazole.

Abstract: A copolyesterimide composed of bis-trimellitimide units, 2,6-naphthalenedicarboxylic acid units, hydroquinone units and p-hydroxybenzic acid units. This copolyesterimide is melt-processable, and excels in heat resistance and mechanical properties.

Abstract: Polybenzazole polymers are conveniently synthesized in the presence of a reducing agent, such as tin (II) chloride.

Abstract: Premelting of the bis-lactam inhibits crystal formation when reacting certain bis-lactams with certain diamine mixtures.

Abstract: PBZ polymers are synthesized by the reaction of AA- and BB-monomers. The BB-monomer is conveniently synthesized and isolated as a phosphate salt having a uniform number of phosphate ions associated with each BB-monomer ion. Such high purity monophosphate and diphosphate salts can be obtained by precipitating the monomer from an aqueous acid solution by adjusting the pH balance or from a mixture of phosphoric acid and a volatile, polar, saturated organic liquid at a relatively low temperature.

Abstract: Melt-processible aromatic polyamides are obtained by reacting certain N,N'-isophthaloyl bis(lactam) compounds with certain aromatic diamines.

Abstract: Aromatic copolyamides are described, which are soluble in organic amide solvents. The polymers are composed to at least 95 mol % of repeat structural unitsA: --OC--AR--CO--B: --HN--Ar'--NH--C: --HN--Ar"--NH-- ##STR1## in the combinations A+B+C+D, or A+C+D+E and up to 5 mol % of m-bond-containing structural units F and/or G derived from aromatic dicarboxylic acids (F') and/or from aromatic diamines (G'), the sum total of the mole fractions of structural units A+F and the sum total of the mole fractions of the structural units of B+C+D+E+G being essentially the same, --Ar-- and --Ar'-- are divalent aromatic radicals whose C--N valence bonds are in a para-position or in a similar coaxial or parallel position and which may be substituted by one or two inert radicals, such as lower alkykl or halogen, ##STR2## is a trivalent aromatic radical which after removal of the --SO.sub.2 R group has the same meaning as --Ar-- or --Ar'-- or else is the structural unit ##STR3## wehre X is --O--, --NHCO--, --SO.sub.

Abstract: A high strength fibrid-floc sheet is made of a floc which can be carbon, aramid or glass. The fibrids are made from the following units: ##STR1## where n is 4 or 5; X is from 0.03 to 0.30 and Ar is a radical selected from 3,4'-oxydiphenylene, 4,4'-oxydiphenylene, 4,4'-sulfonyldiphenylene, 1,3-phenylene, 1-methyl-2,4-phenylene, and mixtures of such radicals with each other or mixtures of such radicals with up to 50 mol percent of 1,4-phenylene radicals based on the mixtures of radicals.

Abstract: Disclosed herein is a process for producing an azo group-containing polymer comprising polycondensing a compound having an azo group in the main molecular chain and an alcoholic hydroxyl group, phenolic hydroxyl group, imino group or amino group at both ends thereof with a dicarboxylic acid chloride or a carbonate precursor except the polycondensation of a compound having an azo group in the main molecular chain and an alcoholic hydroxyl group at both ends thereof with a carbonate precursor.

Abstract: Aromatic copolyamides, preparation thereof and structures formed therefromThere are described aromatic copolyamides which are soluble in organic solvents for polyamides and which comprise at least 95 mol % of recurring structural units of formulae ##STR1## and up to 5 mol % of meta-bonded structural units E and/or F derived from aromatic dicarboxylic acids (E') and/or from aromatic diamines (F'), the sum total of the mole fractions of structural units A+E and the sum total of the mole fractions of structural units B+C+D+F being essentially of equal magnitude.The copolyamides of the present invention can be processed into fibers having high strengths and high breaking extensions.

Abstract: A preferred class of polyimide oligomers include (1) linear, difunctional crosslinking oligomers prepared by condensing an imidophenylamine end cap with a lower alkylene diamine or a polyaryldiamine such as 3,3'-phenoxyphenylsulfone diamine and with a dianhydride, particularly 4,4'-phenoxyphenylsulfone dianhydride; and (2) multidimensional, crosslinking, polyimide oligomers having an aromatic hub and at least two radiating arms connected to the hub, each arm including a crosslinking imidophenylamine end cap at its distal end and at least two imide linkages.Blends, prepregs, and composites can be prepared from the oligomers.

Abstract: Disclosed herein are processes for the preparation of polyimide-isoindroquinazolinediones and precursor thereof. These polymers are useful as heat-resistant electric insulation materials, surface coating films for electronic instrument parts and especially suitable for manufacturing a photoresist. The above precursor is produced by reacting a an alkylenebistrimellitate dianhydride, a diaminoamide compound and the other amine. The precursor is readily dehydrated and ring-closed to produce polyimide-isoindroquinazolinedione, which is often conveniently conducted by producing a varnish of the precursor, applying it onto adequate substrates such as silicon wafers, glass plates, metal plates, etc. and then subjecting the coated film to dehydration. The resulting films have excellent physical properties such as good adherence, high tensile strength, low elasticity, etc.

Abstract: A thermoplastic, liquid-crystalline, wholly aromatic polyimide ester comprising(a) at least one structural unit derived from an aromatic dicarboxylic acid,(b) at least one structural unit derived from a substituted hydroquinone having an aralykyl substituent group in its benzene nucleus, and at least one structural unit selected from (c) structural units derived from carboxy-N-(carboxyphenyl)phthalimides and (d) structural units derived from carboxy-N-(hydroxyphenyl)phthalimidesis able to be molded by injection molding, has excellent dimensional stability and dimensional accuracy in both flow direction and a direction making a right angle with the flow direction, and is also excels in strength, elastic modulus, and heat resistance.

Abstract: Azole rings, such as oxazole and thiazole rings, can activate an aromatic ring bonded to a leaving group such as a halogen atom so that the aromatic ring will undergo aromatic nucleophilic substitution. The reaction is useful for making ethers, thioethers and amines containing azole rings. In particular, monomers having azole rings, activated aromatic rings with leaving groups and nucleophilic moieties can react under conditions of aromatic nucleophilic displacement to form non-rigid rod PBZ polymers. The non-rigid rod PBZ polymers can be used to form molecular composites with rigid rod PBZ polymers which molecular composites are not substantially phase separated.

Abstract: A conjugated system-containing organic high molecular compound is described, which contains a recurring unit represented by the following structural formula (I) and has a number-average molecular weight of 1,000 or more: ##STR1## wherein m represents an integer of from 2 to 10; n represents an integer of from 1 to 23; B and B' respectively represent --NHCO-- and --CONH--, --CONH-- and --NHCO--, ##STR2## --A-- is selected from the group consisting of ##STR3## wherein R.sup.1-4 and R.sup.5-8 each independently is selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an amino group, an alkylamino group having 1 to 5 carbon atoms, a hydroxyl group, an alkoxyl group having 1 to 5 carbon atoms, a cyano group, a nitro group, and groups of the following formulae (a), (b), and (c), provided that the groups of --A-- may be the same or different: ##STR4## wherein R.sup.9-12, R.sup.13-16, and R.sup.

Abstract: Flame-resistant thermoplastic branched polycarbonates of high molecular weight are prepared from:(1) a carbonate precursor;(2) at least one dihydroxyaromatic compound of formula: ##STR1## where: R is a single bond, or a substituted or non-substituted linear or branched C.sub.1 -C.sub.5 alkylene radical, or a group chosen from O, S, SO.sub.2 and CO;X and Y, which may be the same or different, are H or CH.sub.3 ;m and n, which may be the same or different, are whole numbers from 1 to 4;(3) at last one halogenated pyrimidine compound of formula: ##STR2## where: R.sub.2, R.sub.3, R.sub.4, which may be the same or different, are chlorine or bromine or hydrogen, on condition that at least one is chlorine or bromine;R.sub.1 is chlorine or bromine, or a radical of formula: ##STR3## where Z is NH or S or O; (4) at least one polyfunctional organic compound as branching agent, characterized by possessing at least three equal or different groups chosen from the groups OH, COOH, COCl and SO.sub.2 Cl.

Abstract: The present invention relates to a paper releasing guide-claw for a copying machine and a method for producing the same including molding a material containing from about 50-90% by weight of a polyimide consisting essentially of recurring units of the formula: ##STR1## from about 5 to about 40% by weight of a fibrous reinforcing material, and from about 5 to about 30% by weight of a solid lubricant, wherein the sum of the content of the fibrous reinforcing material and the solid lubricant is from about 10 to about 50% by weight, heat treating the molded guide-claw at a temperature of from about 250.degree. C. to about 340.degree. C. for a time sufficient to increase the density of the polyimide component by 1.5%.

Abstract: A transparent polyester-ester amide having a permanently antistatic property is obtained by copolymerizing (a) an aminocarboxylic acid, a lactam, or a salt derived from a diamine and a dicarboxylic acid; (b) a diol of the formula: ##STR1## wherein R.sup.1 and R.sup.2 are an ethylene oxide or propylene oxide group, Y is covalent bond, alkylene, alkylidene, cycloalkylidene, arylalkylidene, O, SO, SO.sub.2, CO, S, CF.sub.2, C(CF.sub.3).sub.2 or NH, X is H, alkyl, halogen, sulfonic acid or salt thereof, l is 0 or an integer of 1-4, and m and n an integer of 1-15; (c) a poly(alkylene oxide)glycol or a diol of the formula:HO--R.sup.3 --OH (IV)wherein R.sup.3 is alkylene, alkylidene, cycloalkylidene or arylalkylidene; and (d) a dicarboxylic acid; wherein the content of the polyether-ester units is 10 to 90 wt. %.

Abstract: Aromatic copolyamides are described which are soluble in organic polyamide solvents and contain at least 95 mol % of repeating structural units of the formulae ##STR1## and up to 5 mol % of structural units E and/or F containing m-bonds and being derived from aromatic dicarboxylic acids (E') and/or aromatic diamines (F'), the sums of the molar proportions of structural units A+E and the molar proportions of structural units B+C+D+F being essentially the same. In these formulae, --Ar-- is a divalent aromatic radical whose valence bonds are in the para or comparable coaxial or parallel position, --R is hydrogen, lower alkyl radicals, lower alkoxy radicals or halogen, and R' is a direct bond, a polymethylene chain of 2 to 6 carbon atoms, --O--, --S--, --CO-- or --SO.sub.2 --, or a group of the formula --O--Ar'--O--, in which Ar' has the same meanings as Ar.

Abstract: A reactive oligoimide, which may serve as an adhesive for bonding at least one layer or film to another layer, preferably a flexible metallic layer to a flexible layer of a polyimide, in order to form a flexible multilayer metal-clad laminate.

Abstract: Hydroxypolyamides can be obtained in a simple and economical way in a chloride-free manner when(a) aromatic amino hydroxy carboxylic acids or(b) aromatic diaminodihydroxy compounds and aromatic dicarboxylic acids or(c) aromatic diaminodihydroxy compounds, aromatic dicarboxylic acids and aromatic amino hydroxy carboxylic acids are converted in the presence of 1-ethoxycarbonyl-2-ethoxy-1.2-dihydroquinoline, 1-1'-carbonyldioxy-di-1.2.3-benzotriazole or dicyclohexyl carbodiimide/1-hydroxy-1.2.3-benzotriazole.

Abstract: A polypeptide thin film obtained by polymerizing a monomolecular film comprising a monomer mixture of(a) an amphiphilic compound having a hydrophobic moiety and a hydrophilic moiety having an amino acid ester structure per molecule, the conjugated acid of the elimination group of the ester having a pKa of not higher than 14, and(b) an amphiphilic compound having two amino groups per molecule or an amphiphilic compound having two ester structures per molecule, the conjugated acid of the elimination group of the ester having a pKa of not higher than 16,or a built-up film of the monomolecular film; and a process for preparing a material carrying the polypeptide thin film.

Abstract: Polybenzazole polymers can be advanced rapidly to high molecular weight at relatively high temperatures and high shear in a dehydrating solvent acid.

Abstract: The present invention relates to aromatic compounds corresponding to formula (I) ##STR1## to their production and to their use as modifiers for thermoplastic aromatic polycarbonates and/or thermoplastic aromatic polyester carbonates and/or thermoplastic aromatic polyesters.

Abstract: The present invention relates to aromatic compounds corresponding to formula (I) ##STR1## to their production and to their use as modifiers for thermoplastic aromatic polycarbonates and/or thermoplastic aromatic polyester carbonates and/or thermoplastic aromatic polyesters.

Abstract: Thermoprocessible aramid matrix polymer based composites have high flex and short beam shear strengths and low moisture uptake.

Abstract: The present invention provides polyamide-polyimide and polybenzoxazole-polyimide polymers derived therefrom with improved processing and film characteristics having incorporated into the polymeric backbone the polymeric condensation residuum of novel aromatic diamino compounds having the formula: ##STR1## wherein A is selected from the group consisting of SO.sub.2, O, S, CO, C.sub.1 to C.sub.6 alkyl, perfluoroalkyl or perfluoroarylalkyl having from 1 to 10 carbon atoms and a carbon-carbon double bond directly linking the two aromatic groups, and R is hydrogen.The polyamide-polyimide polymers of this invention are prepared by reacting compounds of the above formula, alone or admixed with other aromatic diamines, with one or more aromatic tetracarboxylic acids or anhydrides thereof. Polybenzoxazole-polyimide derivatives of such polyamide-polyimide.

Abstract: Aromatic polycondensates are prepared in a continuous process froma) aromatic hydroxy-, thio- and/or amino-carboxylic acids,b) aromatic dihydroxy-, dithio-, diamino- and/or hydroxy-amino compounds,c) urea as an optional component andd) a molar amount equivalent to the sum of components b) and c) of aromatic dicarboxylic acids,by1. reacting components a), b), d) and optionally c) with lower fatty acid anhydrides in excess at from 140.degree. to 280.degree. C. with distillative removal of fatty acids and fatty acid anhydrides,2. passing the oligomer mixture downward through a perpendicular precondensation zone to form a two-phase mixture of prepolymers and vaporous fatty acids,3. separating the prepolymers from the vaporous fatty acids and4. condensing the prepolymer in a condensation zone to give a granulable polycondensate.

Abstract: A positively photosensitive polyimide composition is disclosed, which composition comprises polyimide having repeating unit represented by formula (I): ##STR1## wherein Ar.sup.1 represents a tetravalent aromatic hydrocarbon group; Ar.sup.2 represents a divalent aromatic hydrocarbon group having an acyloxy group at the ortho-position and/or the meta-position of the aromatic ring; Ar.sup.3 represents a divalent aromatic hydrocarbon group; and the subunit having an amount ratio of m in the repeating unit is present in an amount of at least 20% by weight based on the polyimide. The composition exhibits high photosensitivity in reproduction of a fine pattern and excellent dimensional stability.

Abstract: High molecular weight aromatic polyamides with pendant carboxyl groups.

Abstract: The liquid crystal polycondensates according to the invention based on aromatic hydroxycarboxylic acids, if appropriate aromatic aminocarboxylic acids, diphenols, if appropriate aminophenols, aromatic dicarboxylic acids and if appropriate carbonic acid which are obtainable by polycondensation of the difunctional monomers mentioned in the melt in the presence of aromatic esters with a defined sequence of the structural units of the formula ##STR1## of oligomers with random distribution of the structural units of the formula ##STR2## have a good heat stability and exhibit a stable viscosity under the processing conditions. The liquid crystal polycondensates can be used for the production of shaped articles, films, fibers and filaments.

Abstract: The reactivity of aromatic copolyamide fiber and film is enhanced by incorporation of small amounts of 4,4'-diaminodiphenic acid units in the polymer chain.

Abstract: The aromatic polyester and aromatic polyester-amide of the present invention have an excellent heat resistance (soldering resistance) and are excellent in fluidity, and therefore, excellent in moldability, because they show liquid crystallinity in a molten state. In view of mechanical characteristics, the aromatic polyester and aromatic polyester-amide of the present invention have a high modulus of elasticity and are excellent in mechanical strength. In addition, the aromatic polyester and aromatic polyester-amide of the present invention have an advantage that they can be molded at a temperature of 350.degree. C. or below, especially, 320.degree. C. or below.The aromatic polyester and aromatic polyester-amide of the present invention have utility in injection molded articles, films, fibers, etc., due to the above properties thereof.In addition, the aromatic polyester and aromatic polyester-amide of the present invention become molten state at a temperature of 320.degree. C.

Abstract: Copolyamides are described comprising: (1) 0.22-0.28 mole fraction units derived from terephthalic acid; (2) 0.2-0.28 mole fraction units derived from paraphenylene diamine; (3) 0.22-0.28 mole fraction units derived from isophthalic acid; and (4) 0.22-0.28 mole fraction units derived from a 3,3'- or 4,4'-diamine of diphenyl methane, diphenylpropane-2,2, diphenyl cyclohexane-1,1, diphenyl ether, diphenyl sulfide, diphenyl sulphone, or benzophenone.

Abstract: A polyimide having a repeating unit of the formula (I), (II), or (III): ##STR1## where LG is a linking group and W is an oligomeric chain selected from the group consisting of polyether, a polythioether, a polyetherthioether, polycarbonyl, or polysulfonyl, or a copolymer thereof.

Abstract: In humid atmospheres (e.g., 40% relative humidity or above) solutions of 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride/2,2-bis[4-(aminophenoxy)phenyl]hexafluoropropane polyimides tend to be unstable in the sense that during spin coating operations undesirable precipitate formation occurs on the rotating surface of the wafer. The result is the formation of unacceptable coatings due to their irregularity and lack of uniformity. Described are solutions of these polyimide polymers in a solvent containing one or more liquid aromatic hydrocarbons having a boiling point of at least about 110.degree. C. and one or more dipolar aprotic solvents having a boiling point of at least about 150.degree. C., such that the solution (a) contains on a weight basis from about 5% to about 50% of the polyimide, and (b) does not undergo precipitate formation during spin coating in an atmosphere of at least up to about 55% relative humidity.

Abstract: Aromatic copolyamides, soluble in organic polyamide solvents, comprise at least 95 mol % of the recurrent structural units of the formulae ##STR1## and up to 5 mol % of structural units containing m-bonds. Here, --Ar--and --Ar'-- are divalent, unsubstituted or substituted aromatic radicals, the valency bonds of which are in the para-position or in a comparable coaxial or parallel position, and --R is a lower alkyl radical.

Abstract: Aromatic copolyamides, soluble in organic polyamide solvents, comprise at least 95 mol % of the recurrent structural units of the formulae ##STR1## and up to 5 mol % of structural units containing m-bonds. Here --Ar--is a divalent, unsubstituted or substituted aromatic radical, the valency bonds of which are in the para-position or in a comparable coaxial or parallel position, and --R--and --R' are different from one another and are lower alkyl radicals or lower alkoxy radicals.

Abstract: Aromatic copolyamides, soluble in organic polyamide solvents, comprise at least 95 mol % of the recurrent structural units of the formulae ##STR1## and up to 5 mol % of structural units containing m-bonds. --Ar-- and --Ar'-- are here divalent, unsubstituted or substituted aromatic radicals, the valency bonds of which are in the para-position or in a comparable coaxial or parallel position, and --R and --R' are different from one another and are lower alkyl radicals or lower alkoxy radicals.

Abstract: Polymer compositions comprising poly(benzhydrolimide) chains ending with ethylenic unsaturated groups complying with the general formula: ##STR1## wherein Ar is a divalent aromatic radical and R a hydrogen atom or a monovalent hydrocarbon radical. They can be prepared by reacting, under imidation condition, at least one primary diamine with at least one benzydrol 3,3', 4,4'-tetracarboxylic acid, a bis (ortho-acid-ester) or a tetraester of such acid and with an anhydride, an acid-ester or a diester of dicarboxylic cycloaliphatic acid with ethylenic unsaturation. These compositions may be converted to cross-linked polymides by thermal polyemrization. They can be used in particular for manufacturing composite materials, adhesives, molded articles and protective coatings withstanding high temperatures.

Abstract: The present invention provides polyamide-polyimide and polybenzoxazole-polyimide polymers derived therefrom with improved processing and film characteristics having incorporated into the polymeric backbone the polymeric condensation residuum of novel aromatic diamino compounds having the formula: ##STR1## wherein A is selected from the group consisting of SO.sub.2, O, S, CO, C.sub.1 to C.sub.6 alkyl, perfluoroalkyl or perfluoroarylalkyl having from 1 to 10 carbon atoms and a carbon-carbon double bond directly linking the two aromatic groups, and R is selected from the group consisting of hydrogen, hydroxy and C.sub.1 to C.sub.4 alkoxy.The polyamide-polyimide polymers of this invention are prepared by reacting compounds of the above formula, alone or admixed with other aromatic diamines, with one or more aromatic tetarcarboxylic acids or anhydrides thereof. Polybenzoxazole-polyimide derivatives of such polyamide-polyimide polymers are prepared utilizing compounds of the above formula wherein R is hydroxy or C.

Abstract: The present invention provides polyamide-polyamide-polyimide and polybenzoxazole-polyamide-polyimide polymers derived therefrom with improved processing and film characteristics having incorporated into the polymeric backbone the polymeric condensation residuum of novel aromatic diamino compounds having the formula: ##STR1## wherein A is selected from the group consisting of SO.sub.2, O, S, CO, C.sub.1 to C.sub.6 alkylene, perfluoroalkylene or perfluoroarylalkylene having from 1 to 10 carbon atoms and a bond directly linking the two aromatic groups, and R is selected from the group consisting of hydrogen, hydroxy and C.sub.1 to C.sub.4 alkoxy.The PA-PA-PI polymers of this invention are prepared by reacting compounds of the above formula alone or admixed with other aromatic diamines, with carboxyphenyl trimellitimide or the acid halide or ester derivatives thereof, alone or admixed with one or more aromatic diacid chlorides and/or one or more aromatic tetracarboxylic acids or anhydrides thereof.

Abstract: The present invention provides polyamide-polyamide and polybenzoxazole-polyamide polymers derived therefrom with improved processing and film characteristics having incorporated into the polymeric backbone the polymeric condensation residuum of novel aromatic diamino compounds having the formula: ##STR1## wherein A is selected from the group consisting of SO.sub.2, O, S, CO, C.sub.1 to C.sub.6 alkylene, perfluoroalkylene or perfluoroalkylene having from 1 to 10 carbon atoms and a bond directly linking the two aromatic groups and R is selected from the group consisting of hydrogen, hydroxy and C.sub.1 to C.sub.4 alkoxy.The polyamide-polyamide polymers of this invention are prepared by reacting compounds of the above formula, alone or admixed with othr aromatic diamines, with one or more aromatic or aliphatic dicarboxylic acid or amide-forming derivatives thereof.

Abstract: The present invention relates to a wholly aromatic polyetherimide further containing sulfur containing groups in the backbone of the polyetherimide. The polyetherimide is characterized by extremely high glass transition temperatures, high chemical resistance and thermogravimetric stability.

Abstract: There are provided aromatic heterocyclic polymers having repeating units of the formula ##STR1## wherein R.sub.1 is --H or R.sub.2 is ##STR2## R.sub.3 is ##STR3## and R.sub.4 is R.sub.2 or ##STR4## and B is ##STR5## wherein X is --S--, --O--, or --NH--.

Abstract: A polyimide having a repeating unit of the formula (I), (II), or (III): ##STR1## where LG is a linking group and W is an oligomeric chain selected from the group consisting of polyether, a polythioether, a polyetherthioether, polycarbonyl, or polysulfonyl, or a copolymer thereof.

Abstract: Molding compounds comprisign aromatic polyamides which contain from 0.01 to 10 mole % of a low molecular weight carboxylic acid amide display low melt viscosities and an increased resistance to hydrolysis and are thermoplastically processible.

Abstract: Wholly aromatic mesomorphic polyester amide imides which form a liquid-crystalline fiber-forming melt below 320.degree. C. and are composed of(a) from 5 to 35 mole % of repeat units of the formula I and/or II ##STR1## where the Xs is the formulae I and II can be identical or different and each is --O--, --S--, --SO.sub.2 --, --CO--, --CH.sub.2 -- or .dbd.C(CH).sub.3).sub.2 and n is 0 or 1.(b) from 0 to 30 mole % of repeat units of the formulae III and/or IV ##STR2## (c) a molar amount corresponding to the total amount of components a and b of one or more of the repeat units of the formulae V, VI, VII, VIII and IX ##STR3## (d) if desired from 5 to 25 mole % of one or more of the repeat units of the formulae X, XI and XII ##STR4## (e) repeat units of the formula XIII ##STR5## the mole percentages of components (a), (b), (c), (d) and (e) adding up to 100 mole % in each case,the preparation thereof and fibers, films and moldings prepared therefrom.