Abstract: Copolyimides from 1,4-bis(4-aminophenoxy)-2-phenylbenzene and m- or p-phenylene diamine with biphenyl dianhydride exhibit a high Tg and reduced melt viscosity.

Abstract: A polyimide precursor composition solution includes a tetracarboxylic acid component containing not less than 70 mol % of at least one selected from the group consisting of benzenetetracarboxylic acid and its reactive derivatives; a maleimide compound; and a diamine component containing not less than 70 mol % of 2,2'-substituted-4,4'-benzidine represented by the general formula (I) and siloxydiamine amounting to from 1 to 10 mol %. The tetracarboxylic acid component, the maleimide compound and the diamine component are dissolved in a solvent which is consisting essentially of .gamma.-butyrolactone. The amount of the tetracarboxylic acid component is substantially equivalent to that of the diamine component. The amount of the maleimide compound is from 5 to 30 wt % of the total weight of the tetracarboxylic acid and the diamine component.

Abstract: Polyimides comprising recurring units of the following general formula (1) ##STR1## wherein R.sub.1 represents a tetravalent aromatic group. Polyimide copolymers and preparations of the polyimides and the polyimide copolymers are also described.

Abstract: A solvent resistant copolyimide was prepared by reacting 4,4'-oxydiphthalic anhydride with a diaimine blend comprising, based on the total amount of the diamine blend, about 75 to 90 mole percent of 3,4'-oxydianiline and about 10 to 25 mole percent p-phenylene diamine. The solvent resistant copolyimide had a higher glass transition temperature when cured at 350.degree. , 371.degree. and 400.degree. C. than LaRC.TM.-IA. The composite prepared from the copolyimide had similar mechanical properties to LaRC.TM.-IA. Films prepared from the copolyimide were resistant to immediate breakage when exposed to solvents such as dimethylacetamide and chloroform. The adhesive properties of the copolyimide were maintained even after testing at 23.degree., 150.degree., 177.degree. and 204.degree. C.

Abstract: Reactive aminoquinones of formula I or II ##STR1## wherein R is hydrogen, branched, linear or cyclic C.sub.1 -C.sub.6 alkyl, aralkyl, or phenyl which may be substituted by linear, branched or cyclic C.sub.1 -C.sub.4 alkyl, --NO.sub.2, F, OR.sup.2, NR.sup.3.sub.2, wherein R.sup.2 and R.sup.3 are linear, branched or cyclic C.sub.1 -C.sub.6 alkyl, aralkyl or phenyl,R.sup.1 is a linear, branched or cyclic C.sub.2 -C.sub.18 alkylene chain, phenylene, aralkylene, alkarylene, or --(CH.sub.2 CH.sub.2 --O).sub.n --CH.sub.2 --CH.sub.2 --, wherein n is an integer from 1 to 50,X is hydroxy, epoxy, vinyl, vinyloxy, acrylate, methacrylate or acylchloroY is N or CH; andR.sup.4 is linear or branched C.sub.1 -C.sub.6 alkyl which are useful in forming copolymers to prepare corrosion resistant binder compositions for magnetic information storage media, the copolymers formed, the magnetic information storage media and a method for improving corrosion resistance in magnetic particles are provided.

Abstract: The present invention relates to a polyimide based resin composition comprises 1 to 50 parts by weight of polyetherimide for 100 parts by weight a resin composition comprising 50 to 99 parts by weight of polyarylether ketone and 50 to 1 parts by weight of polyimide having specific structural units.The polyimide based resin compositions have excellent fatigue characteristics and creep resistance and are expected widely to apply in field of machine and automobile parts which is required permanence for mechanical strength.

Abstract: The invention is a direct process for preparing semi-crystalline polyimides. This process comprises the steps of: providing a polar aprotic solvent, adding a dianhydride and a diamine to the solvent to form a mixture, stirring the mixture at ambient temperature, and adding glacial acetic acid to the mixture to provide a ratio of polar aprotic solvent to glacial acetic acid which ranges from about 90 to 10 to about 75 to 25 by volume to form a solution. The solution was heated to a range from about 110.degree. C. to about 140.degree. C. to form a polyimide precipitate. The polyimide precipitate was recovered as a semi-crystalline polyimide powder.

Abstract: Oligomeric monomers are produced by reaction of a bisphenol compound with ther a dihalobenzophenone or a (2,2)bis(4-halophenyl)hexafluoropropane and any other activated halogen containing aromatic compounds in the presence of a base and an appropriate solvent. The resulting oligomeric product, a dialkaline bisphenate terminated salt, is then reacted with 4-nitrophthalonitrile to form an oligomer-based phthalonitrile. These oligomers, in the presence or absence of an curing agent, may then be heated to form high temperature thermosetting polymers. These polymers can potentially be used as advanced materials for composites, as adhesives, and for microelectronic applications.

Abstract: The present invention provides novel substituted biphenyl pyrazines or pyrazine derivatives ("BPD") which are functional and have useful application as a monomer for a variety of high performance polymers such as polyester, polyarylate, polycarbonate, polyetherketones, epoxides, polyimides, polyamides, and polyamides-imides; and as pigments for coating compositions such as paints. These BPD have the general formula: ##STR1## wherein R.sub.1 -R.sub.8 and n are defined herein.

Abstract: Copolyamic acid is obtained from tetracarboxylic acid dianhydride, diamine and a fluorinated diamine and/or fluorinated tetracarboxylic acid dianhydride; and optionally ester or amine salt derivative thereof to obtain radiation sensitive polymer; and low optical high thermally stable polyimide from curing the above polyamic acid and/or derivative thereof.

Abstract: This invention provides (1) a granular material of a polyimide precursor, which has excellent solubility in solvents and excellent moldability and from which a polyimide molding having excellent mechanical properties can be produced, (2) a mixture of a granular material of a polyimide precursor with a solvent, in which the polyimide precursor shows excellent storage stability and (3) a process for the production of a granular material of a polyimide precursor, in which a solvent can be easily removed. Particularly provided are a polyimide precursor granular material having an intrinsic viscosity of 0.7 or higher and a polyimide precursor mixture which consists of a polyimide precursor granular polyimide having an intrinsic viscosity of 0.7 or higher and a solvent that does not exhibit a strong-mutual interaction with the polyimide precursor, as well as a process for the production of the polyimide precursor granular material.

Abstract: In one aspect, the present invention relates to polyimides having excellent thermal resistance and process for preparing the same comprising carrying out condensation of 4,4'-bis(3-aminophenoxy)biphenyl with pyromellitic dianhydride in the presence of a different diamine compound and optionally with a different tetracarboxylic acid dianhydride.In a second aspect, the present invention relates to a heat resistant resin composition consisting essentially of an aromatic polyetherimide and a defined polyimide.In a third aspect, the present invention relates to a polyimide resin composition comprised on a defined polyimide and a separate high-temperature engineering polymer.In a fourth aspect, the present invention relates to a resin composition comprised of a defined polyimide and an aromatic polyamideimide.

Abstract: A moldable polyimide resin composition which has melt-flowability and excellent processability in addition to essential heat-resistant of polyimide and comprises an aromatic bisimide compound and polyimide resin. A further aspect relates to a carbon fiber reinforced polyimide resin composition which has excellent mechanical strengths and comprises a carbon fiber coated with aromatic bisimide compound on the surface and the polyimide resin. A still further aspect relates to a novel bisimide compound which is very useful as the aromatic bisimide compound in the composition.

Abstract: Two monomers containing meta-biphenylenedioxy moieties were prepared. One monomer, a diamine, is used to prepare polyimide, polyamide, and epoxy polymers. The other monomer, a dianhydride, was used to prepare polyimide polymers. These polymers are used to make films, coatings, and selective membranes.

Abstract: A diamine compound of the general formula ##STR1## wherein the arrows denote isomerism, R.sub.1 is a divalent aromatic group selected from the group consisting of ##STR2## R.sub.2 is a tetravalent aromatic group selected from the group consisting of ##STR3## and R.sub.4 is a monovalent aliphatic group selected from the group consisting of ethyl and isopropyl; and, a process for preparing same.

Abstract: Benzophenone iminodiimides of the formula I ##STR1## which Y denotes hydroxyl or carboxyl, R.sub.1 denotes the optionally substituted radicals alkylene, phenylene or benzylidene, R.sub.2 denotes the radicals OH, substituted or unsubstituted alkyl or NH--CO--NHR.sub.3 and R.sub.3 denotes the radicals H, alkyl, phenyl or benzyl, processes for their preparation and polymers prepared therefrom.

Abstract: A polyimide optical material, composed of a perfluorinated polyimide having a perfluorinated repeating unit represented by general formula (1) ##STR1## wherein R.sub.1 is a tetravalent perfluorinated organic group; and R.sub.2 is a divalent perfluorinated organic group.

Abstract: Polyimide optical waveguide structures comprising a core within a cladding wherein at least one of the core and the cladding is a polyimide containing 6FDA, BTDA, an aromatic diamine having bulky methyl groups ortho to the amine, and a co-diamine wherein the polyimides have the properties of low optical loss, low optical absorbance, controllable refractive index, and high thermal stability, and wherein the polyimides are photosensitive and solvent resistant.

Abstract: New photosensitive polyamic acid precursors are disclosed which have the formula: ##STR1## where Z is a tetravalent organic radical which contains at least one aromatic ring, Z' is a divalent organic radical which contains at least one aromatic ring, and R* is a photosensitive group. Particularly preferred compounds include BPDA-PDA and BPDA-ODA polyamic acid precursors. The precursor compositions within the practice of this invention are i-line, g-line, and i-/g-line active and show good photoresolution. The films formed exhibit excellent self-adhesion and adhesion to glass ceramic and silicon wafer substrates have low internal stress, a very low degree of solvent swelling, high thermal stability, and excellent mechanical properties such as high modulus/tensile strength and high elongation at break.

Abstract: Soluble polyimides are formed from oxydiphthalic anhydride and 2,4-diaminotoluene. Optionally, up to 30 mole % of an alternate diamine and up to 50 mole % of an alternate dianhydride can be used with the oxydiphthalic anhydride and 2,4-diaminotoluene.

Abstract: Polyimides are made from the novel diamines 1,2-bis(3-aminophenyl)perfluorocyclobutane, 1,2-bis(3- or 4-aminophenyl)perfluorocyclobutene, -cyclopentene and -cyclohexene, by reaction with aromatic carboxylic anhydrides. The polyimides are useful for coatings and films.

Abstract: In order to produce a polymer electrolyte membrane from sulfonated, aromatic polyether ketone, an aromatic polyether ketone of the formula (I) ##STR1## in which Ar is a phenylene ring having p- and/or m-bonds,Ar' is a phenylene, naphthylene, biphenylene, anthrylene or another divalent aromatic unit,X, N and M, independently of one another are 0 or 1,Y is 0, 1, 2 or 3,P is 1, 2, 3 or 4,is sulfonated and the sulfonic acid is isolated. At least 5% of the sulfonic groups in the sulfonic acid are converted into sulfonyl chloride groups, and these are reacted with an amine containing at least one crosslinkable substituent or a further functional group, and unreacted sulfonyl chloride groups are subsequently hydrolyzed. The resultant aromatic sulfonamide is isolated and dissolved in an organic solvent, the solution is converted into a film, and the crosslinkable substituents in the film are then crosslinked.In specific cases, the crosslinkable substituents can be omitted.

Abstract: Novel aromatic poly(ether ketones) having imide, amide, ester, azo, quinoxaline, benzimidazole, benzoxazole, or benzothiazole groups, comprising, for example, a repeat unit ##STR1## are prepared by Friedel Crafts polymerization.

Abstract: Disclosed herein are novel poly(imide-ethers) containing ortho substitution in the main chain of the polymer. These polymers are made from novel aromatic bis-carboxylic anhydrides which contain two ether groups attached to an aromatic ring in ortho positions to each other. The polymers are particularly useful for films, fibers and encapsulation, as well as thermoplastics.

Abstract: The present invention provides a liquid crystal aligning film having a reduced after image and a good liquid crystal aligning property caused by a rubbing treatment of a thin film consisting of organics, and its liquid crystal display device.

Abstract: A series of polyimides based on the dianhydride of 1,4-bis(3,4-dicarboxyphenoxy)benzene (HQDEA) or on 2,2-bis[4(3-aminophenoxy)phenyl]hexafluoropropane (3-BDAF) are evolved from high molecular weight polyamic acid solutions yielding flexible free-standing films and coatings in the fully imidized form which have a dielectric constant in the range of 2.5 to 3.1 at 10 GHz.

Abstract: Mixtures of salts of organic carboxylic acids and organic compounds of non-salt character, dissolved in a C.sub.1 -C.sub.4 alkanol, can be concentrated or separated with a semipermeable membrane made from a copolyamide or copolyimide-amide which contains (a) a first aromatic diamine radical and (b) a second aromatic diamine radical which carries --SO.sub.3 M groups, where M is H.sup..sym., a monovalent to polyvalent metal cation or an ammonium cation. Provided the first diamine radical contains C.sub.1 -C.sub.4 alkyl groups in the o-positions to the amino groups, the copolymers are radiation-sensitive and can be used for producing protective layers or relief images, development being carded out in an aqueous alkaline medium.

Abstract: Novel difucntionalized cyclobutabenzene monomers of the general formula: ##STR1## wherein Z can be hydrogens or a cyclobutane ring; and X and Y are carboxyl, amino, alcohol, isocyanate, acid halide, or bis-acyl fluoride groups. In a particularly preferred embodiment, the cyclobutabenzene derivative is 1,2-dihydrocyclobutabenzene-3,6-carboxylic acid. The difunctionalized cyclobutabenzene monomer can form part of a polymer backbone chain, but has an additional functionality, the butane ring, which can be easily opened to produce strong, covalent bond crosslinking between polymer chains. The crosslinking can be induced simply by heating the polymer to a temperature in excess of 300.degree. C.

Abstract: An electroluminescent polymer comprises a main chain and a plurality of side chains, each of the side chains comprising an electroluminescent group and a flexible spacer connecting the electroluminescent group to the main chain, the spacers and the main chain being such that the electroluminescent groups are not conjugated with one another. The nature of the main chain and the spacer groups can be varied to enhance solubility, film-forming ability and other characteristics of the polymer, without significantly changing the electroluminescent properties of the polymer.

Abstract: Novel molecular weight controlled and endcapped polybenzimidazoles (PBI) are prepared by the aromatic nucleophilic displacement reaction of di(hydroxyphenylbenzimidazole) monomers with activated aromatic dihalides or activated aromatic dinitro compounds. The PBI are endcapped with mono(hydroxyphenyl)benzimidazoles. The polymerizations are carried out in polar aprotic solvents such as N-methyl-2-pyrrolidinone or N,N-dimethylacetamide using alkali metal bases such as potassium carbonate at elevated temperatures under nitrogen. Mono(hydroxyphenyl)benzimidazoles are synthesized by reacting phenyl-4-hydroxybenzoate with aromatic (o-diamine)s in diphenylsulfone. Molecular weight controlled and endcapped PBI of new chemical structures are prepared that exhibit a favorable combination of physical and mechanical properties.

Abstract: Polyimide oligomers are described which comprise the intercondensation product of a monomer mixture comprising (A) at least one aromatic bis(ether anhydride), (B) at least one phenylindane diamine, and (C) at least one end-cap monomer selected from the group consisting of monoanhydrides, acyl halides and amines, wherein each end-cap monomer (C) contains at least one crosslinkable group in the molecule and wherein the phenylindane diamine component (B) is present in the mixture in a stoichiometric excess. The monomers react in a suitable solvent under an inert atmosphere to form polyimide oligomers having a number average molecular weight of from about 1,000 to about 15,000. The polyimide oligomers of the present invention are readily processed to form polyimide matrix resins with high temperature and oxidative stability.

Abstract: Four phenylethynyl amine compounds--3 and 4-aminophenoxy-4'-phenylethynylbenzophenone, and 3 and 4-amino-4'-phenylethynylbenzophenone--were readily prepared and were used to endcap imide oligomers. Phenylethynyl-terminated amide acid oligomers and phenylethynyl-terminated imide oligomers with various molecular weights and compositions were prepared and characterized. These oligomers were cured at 300.degree. C. to 400.degree. C. to provide crosslinked polyimides with excellent solvent resistance, high strength and modulus and good high temperature properties. Adhesive panels, composites, films and moldings from these phenylethynyl terminated imide oligomers gave excellent mechanical performance.

Abstract: Novel poly(N-arylenebenzimidazole)s (PNABIs) are prepared by the aromatic nucleophilic displacement reaction of novel di(hydroxyphenyl-N-arylene benzimidazole) monomers with activated aromatic dihalides or activated aromatic dinitro compounds. The polymerizations are carried out in polar aprotic solvents such as N-methyl-2-pyrrolidinone or N,N-dimethylacetamide using alkali metal bases such as potassium carbonate at elevated temperatures under nitrogen. The di(hydroxyphenyl-N-arylenebenzimidazole) monomers are synthesized by reacting phenyl-4-hydroxybenzoate with bis(2-aminoanilino)arylenes in diphenylsulfone. Moderate molecular weight PNABIs of new chemical structures were prepared that exhibit a favorable combination of physical and mechanical properties. The use of the novel di(hydroxyphenyl-N-arylenebenzimidazole)s permits a more economical and easier way to prepare PNABIs than previous routes.

Abstract: Poly(arylene ether) sulfones that contain thiophene rings within the aromatic polymer backbone are disclosed, along with fibers, films, and other articles of manufacture formed therefrom.

Abstract: This invention concerns positive-working photodefinable polyimide precursors which make use of chemical amplification based on photoacid catalyzed cleavage of acid labile-poly(amic acetal esters).

Abstract: The invention relates generally to polymers exhibiting second order nonlinear optical properties, and characterized by high thermal stability. Disclosed are polymers prepared by a polycondensation reaction between an aromatic dianhydride and a compound selected from the group consisting of a di(alkylamino)amine and an aromatic diamine. Most preferred are polymers that are the products of a polycondensation reaction between 1,2,4,5-benzenetetracarboxylic dianhydride and nitro(N,N-diethylamino)stilbene, wherein the polymer is imidized by further heat treatment.

Abstract: Thermoplastic poly(imide-esters) and poly(imide-amides) with repeat units derived from the title amino acid. In the polymer the amino group becomes part of an imide group and the carboxyl group becomes part of an ester or amide group. The polymers have a good balance of properties, making them useful for melt forming shaped articles, films and fibers.

Abstract: The invention describes new biphenyl dianhydrides, and new polyimides and copolyimides made from the dianhydrides. The synthesized polyimides exhibit significantly enhanced solubility when the biphenyl dianhydrides are substituted, particularly at the 2 and 2' positions on the phenyl rings.

Abstract: Polyarylene ethers that contain xanthone units and have a very high heat resistance can be prepared from inexpensive, readily accessible monomers by polycondensation in a basic medium under essentially anhydrous conditions in the presence or absence of an aromatic solvent at temperatures of from 150.degree. to 400.degree. C. Xanthone monomers and also hydroxyhalogen-substituted benzophenone compounds may be used as starting materials.

Abstract: A random polyimide copolymer, based on a rigid dianhydride, a rigid diamine and an additional diamine and/or dianhydride containing one or more flexibilizing linkages. Soft-baked coatings of the poly(amic acid) precursor are readily processed using conventional aqueous base developers, such as tetramethylammonium hydroxide. The polyimide and soft-baked coatings are useful as a dielectric layer In multichip module applications or as a stress buffer coating.

Abstract: Polyetherimides, polyesterimides, poly(ester etherimides) and poly(carbonate imides) which are thermoplastic, polymeric materials contain divalent bisimides of formula ##STR1## wherein R is independently in each occurrence hydrogen, alkyl of from 1 to 20 carbons, aryl or aralkyl of from 1 to 20 carbons, halogen or NO.sub.2. Novel monomeric bisimides corresponding to the above formula are also disclosed.

Abstract: There are disclosed flame-retardant, high temperature resistant polyimide fibers of the general formula ##STR1## wherein n is an integer larger than 1, A is a tetravalent aromatic group and R is at least one divalent aromatic group. These polyimide fibers have been heat-treated in the unstretched state and have a maximum shrinkage of 14% when heated to a temperature of 400.degree. C. These polyimide fibers are produced by initially spinning crude fibers from a solution of the appropriate polyimide in an aprotic organic solvent, preferably according to the dry-spinning method, which solution optionally contains additives. The crude fibers obtained are washed with water to remove the solvent. The washed crude fibers are dried to a moisture content of less than 5% by mass, are subjected to a heat treatment at a temperature of between 315.degree. C and 450.degree. C, are cooled and, if desired, are crimped and cut to staple fibers.

Abstract: In one aspect, the present invention relates to polyimides having excellent thermal resistance and process for preparing the same comprising carrying out condensation of 4,4'-bis(3-aminophenoxy)biphenyl with pyromellitic dianhydride in the presence of a different diamine compound and optionally with a different tetracarboxylic acid dianhydride.In a second aspect, the present invention relates to a heat resistant resin composition consisting essentially of an aromatic polyetherimide and a defined polyimide.In a third aspect, the present invention relates to a polyimide resin composition comprised on a defined polyimide and a separate high-temperature engineering polymer.In a fourth aspect, the present invention relates to a resin composition comprised of a defined polyimide and an aromatic polyamideimide.

Abstract: Polyimide filaments and polyimide films having great strength, high elastic modulus and high crystallinity and comprising a novel polyimide which can be melt-processed without impairing high crystallinity and which essentially consists of recurring structural units represented by the formula (I): ##STR1## more than 85 mol % the polyimide consists of recurring structural units of the formula (II): ##STR2## and from 0.5 to 15 mol % of the polyimide consists of recurring structural units represented by the formula (III), the formula (II) exclusive, the formula (IV) and/or the formula (V).

Abstract: Polyether ketones and polyether sulfones based on phenylindane and the use thereof for optical systemsPolymeric ethers containing phenylindane units, of the formula ##STR1## in which X=CO or SO.sub.2,Y=a divalent heteroarylene radical or an arylene radical or a divalent group of two aryl radicals which are bonded to one another via a bridge,R.sup.1 =CH.sub.3 ; R.sup.2 =R.sup.3 =H, orR.sup.2 =CH.sub.3 ; R.sup.1 =R.sup.3 =(C.sub.1 to C.sub.16)-alkyl or aryl, orR.sup.1 =CH.sub.3 ; R.sub.3 =H; R.sup.2 =(C.sub.1 to C.sub.16)-alkyl or aryl,are transparent and are suitable for optical systems.

Abstract: Amorphous polyimide powder which has recurring structural units of the formula (I): ##STR1## as a fundamental skeleton, is blocked at the polymer chain end with dicarboxylic anhydride represented by the formula (II) ##STR2## wherein Z is a divalent radical having from 6 to 27 carbon atoms and selected from the group consisting of a monoaromatic radical, condensed polyaromatic radical and noncondensed aromatic radical connected to each other with a direct bond or a bridge member, and essentially has no reactive radical at the polymer chain end, preparation process of the amorphous polyimide powder, heat-resistant adhesive comprising the polyimide, and bonding method using the adhesive.

Abstract: The synthesis of a nonlinear chromophoric co-monomer 3,5-diamino-4'-nitrodiphenylamine and use as a reactive component in combination with a bismaleimide monomer in a NLO-active polyimide matrix is disclosed. After concurrent corona or contact poling and thermal polymerization, thin films of these chromophoric polyimides exhibit high second harmonic generation efficiencies and high DSC-determined glass transition temperatures. These poled polyimides also exhibit excellent SHG temporal stability, retaining 85-90% of the initial second harmonic efficiency after more than one month in air at 85.degree. C.

Abstract: Macrocyclic polyetherimide oligomer compositions are prepared by a displacement reaction at a temperature in the range of about 200.degree.-225.degree. C. between at least one fluorinated aromatic phthalimide and at least one phenolic trialkylsilyl ether compound. Preferably, a bis-fluoroimide and a bis-trialkylsilyl ether of a dihydroxyaromatic compound such as resorcinol are employed. The reaction is conducted by maintaining reagents A and B in high dilution in a dipolar aprotic organic liquid such as N-methylpyrrolidone, and in the presence of a catalytic amount of at least one substantially soluble fluoride. Preferably, a mixture of reagents A and B is added to solvent containing the catalyst.

Abstract: A diamine compound of the general formula ##STR1## wherein the arrows denote isomerism, R.sub.1 is a divalent aromatic group selected from the group consisting of ##STR2## R.sub.2 is a tetravalent aromatic group selected from the group consisting of ##STR3## and R.sub.4 is a monovalent aliphatic group selected from the group consisting of ethyl and isopropyl; and, a process for preparing same.

Abstract: Sizing for 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 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.2 --;T=methallyl or allyl;Me=methyl; andR=hydrogen, lower alkyl, or phenyl.Prepregs and composites having carbon fibers sized with such polyamideimides are also described.