Abstract: Salts that contain AA-PBZ monomer ions and BB-PBZ monomer ions can be precipitated from an aqueous solution by contacting soluble salts of the monomers in an aqueous solution. The monomer salt can be polymerized by ordinary techniques to form polybenzazole polymers without the need for devolatilization and with very accurate stoichiometric control.

Abstract: A liquid crystal aligning agent containing a polymer selected from the group consisting of a polyamic acid having a steroidal skeleton and an imidized product thereof; and a liquid crystal display device to which the liquid crystal aligning agent is applied.

Abstract: The present invention provides a polyimide having all of small dielectric constant, small thermal expansion coefficient, high heat resistance, high glass transition temperature and high mechanical properties, a precursor of the polyimide, and processes for producing them. A polyimide precursor whose molecular chain comprises repeating units represented by the following general formula (1) and repeating units represented by the following general formula (2): ##STR1## wherein R.sup.1 is at least one kind of tetravalent organic group selected from the group consisting of ##STR2## R.sup.2 is at least one kind of divalent organic group having a linear structure which is selected from the group consisting of ##STR3## m is an integer of 1 to 4, and R.sup.3 is a divalent organic group having a non-linear structure which contains at least two aromatic rings.

Abstract: A process for preparing polyamides having enhanced melt flow properties is described. The process consists of heating a mixture of a high molecular weight poly(amic acid) or polyimide with a low molecular weight amic acid or imide additive in the range of 0.05 to 15% by weight of additive. The polyimide powders so obtained show improved processability, as evidenced by lower melt viscosity by capillary rheometry. Likewise, films prepared from mixtures of polymers with additives show improved processability with earlier onset of stretching by TMA.

Abstract: A fluorine-containing polyimide having a low dielectric constant, low water absorption and excellent heat resistance and moisture resistance and a precursor thereof such as a fluorine-containing polyamide-acid, can be prepared by reacting an acid anhydride with an aromatic diamine having perfluoroalkyl group.

Abstract: A readily melt processable polyimide obtained by reacting diamine represented by the formula: 4,4' ##STR1## wherein n is an integer of 1 or 2, with 3,3'4,4' -diphenylethertetracarboxylic dianhydride and/or 4,4' -(p-phenylenedioxy)diphthalic dianhydride or a mixture of these tetracarboxylic acid dianhydrides and pyromellitic dianhydride in the presence of phthalic anhydride.

Abstract: Polyetherimide oligomers having crosslinking end cap moieties which provide improved solvent-resistance to cured composites are generally represented by the formula: ##STR1## wherein X=--O-- or --S--; ##STR2## n=1 or 2; ##STR3## E=allyl or methallyl; R=a trivalent C.sub.(6-13) aromatic organic radical;R.sub.1 =any of lower alkyl, lower alkoxy, aryl, or substituted aryl;R'=a divalent C.sub.(6-30) aromatic organic radical;j=0, 1, or 2; andG=--CH.sub.2 --, --O--, --S--, or --SO.sub.2 --Blends generally comprise substantially equimolar amounts of the oligomers and a comparable, compatible, noncrosslinking, etherimide polymer of substantially the same backbone. The crosslinkable oligomers are made by reacting substituted phthalic anhydrides with hydroxyaryl amines and suitable crosslinking end cap reactants, or by self-condensation of phthalimide salts followed by capping the polymers.

Abstract: Solutions of polyimide-forming starting materials are provided containing diamines and tetracarboxylic diesters; the tetracarboxylic diesters comprise a mixture of from 0.05 to 0.95 mol % of oxydiphthalic diesters and from 0.05 to 0.95 mol % of benzophenonetetracarboxylic diesters, biphenyltetracarboxylic diesters or mixtures thereof.

Abstract: There are provided fusible, rod-like graft copolymers having repeating units of the formula: ##STR1## wherein a ranges from about 0.75 to 0.97 and b is 1-a; wherein Z is a benzbisoxazole or benzbisthiazole moiety, wherein Ar is a linear phenylene or polyphenylene moiety, wherein Ar' is ##STR2## and wherein Y is a poly(etherketone) or a poly(etheretherketone), wherein the poly(etherketone) has repeating units of the formula ##STR3## wherein Q is a divalent phenylene or substituted phenylene moiety and c is an integer having a value of 1 to 4, and the poly(etheretherketone) has repeating units of the formula ##STR4## wherein Q' is a divalent phenylene or substituted phenylene moiety, d is an integer having a value of 1 to 4 and e is an integer having a value of 2 to 5.Also provided are methods for making these graft copolymers.

Abstract: Processes for producing oriented films of semicrystalline thermoplastic polymers, such as polyimides, and films produced thereby are disclosed. One process includes partial crystallization or imidization, orientation and further crystallization or imidization. Another process includes rendering a film of semicrystalline thermoplastic polymer amorphous, orienting the film and introducing crystallinity.

Abstract: A process for preparing a polyetherimide-polyimide copolymer by (a) reacting a bis (ether anhydride) with a stoichiometric excess of an organic diamine in an inert, non-polar solvent to form an amine-terminated oligomer-solvent mixture; (b) removing unreacted organic diamine from the oligomer-solvent mixture; and (c) reacting the oligomer with an aromatic dianhydride.

Abstract: A curable fluorine-containing polyimide of the formula: ##STR1## wherein R.sup.1 is a group derived from an aromatic tetracarboxylic acid dianhydride by the removal of two acid anhydride groups,R.sup.2 is a group derived from an aromatic diamine by the removal of two amino groups,A.sup.1 is a residue of the formula: ##STR2## (wherein R.sup.2 is the same as defined above, and Z is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms),A.sup.2 is a residue of the formula: ##STR3## (wherein R.sup.1 and Z are the same as defined above), and n is a number of 0 to 90, and at least one of the groups R.sup.1 and R.sup.

Abstract: Polyimide compositions, films, and electronic devices using polyimides, based on 9,9-bis(perfluoroalkyl)xanthene-2,3,6,7-tetracarboxylic dianhydride or 9-aryl-9(perfluoroalkyl)xanthene-2,3,6,7-tetracarboxylic dianhydride and 3,3',4,4'-biphenyl tetracarboxylic dianhydride or 2,2-bis(3,4-carboxyphenyl)hexafluoropropane dianhydride and benzidine derivatives which offer a combination of desirable properties including, low linear coefficient of thermal expansion, low moisture absorption, high glass transition temperature, low dielectric constant, and improved tensile elongation.

Abstract: An aromatic polyimide film coated with a thermally stable, heat-sealable thermoplastic polyimide for use as a wire insulation for superconducting magnets is disclosed. The inclusion of inorganic particles in the film improves compressive strength of the coated polyimide film.

Abstract: Polyetherketoneimides and copolymers thereof having an imide repeat unit of formula ##STR1## wherein Ri is ##STR2## in which A is a direct bond or --O--or another substantially non-electron-withdrawing group, and/or Ra is an at least partly arylene moiety other than m- or P-phonylene.These polymers tend to have improved melt stability and other properties, especially when made from a pre-existing imide monomer, instead of by the known amic acid route which results in uncyclised amic acid residues in the polymer.

Abstract: A polyimide film essentially consisting of polyimide having recurring units of the formula (I): ##STR1## which has a density of 1.335 to 1.390 g/cm.sup.3 at 23.degree. C. and/or a refractive index of 1.605 to 1.680 at 23.degree. C. in the direction of thickness and is transparent; and a preparation process of the polyimide film by extruding the polyimide having recurring units of the above formula (I) through a common melt-extrusion process, casting in a chill-roller to obtain an unstretched film, uniaxially or biaxially stretching the unstretched film to cause molecular orientation, and successively setting the stretched film through heat-treatment.

Abstract: A terminal-modified imide oligomer composition, comprising(A) 100 parts by weight of a terminal-modified imide oligomer obtained by a reaction in a solvent of a biphenyltetracarboxylic acid compound with an aromatic diamine compound and a monoamine compound containing a carbon-carbon triple bond, and having an unsaturated terminal group at the terminal of the oligomer and an imide bond in the oligomer, and having a logarithmic viscosity number at 30.degree. C., as determined at a concentration of 0.5 g/100 ml of N-methyl-2-pyrrolidone as a solvent, of from 0.1 to 1 and;(B) 5 to 180 parts by weight of an unsaturated imide compound obtained by a reaction in a solvent of a substituent-containing nadic anhydride with a monoamine compound having a carbon-carbon triple bond in an equimolar ratio, and having an unsaturated terminal group at the terminal thereof and an imide bond therein.

Abstract: A heat-resistant and thermoplastic polyimide which has low dielectric characteristics and recurring structural units of the following formula ##STR1## wherein R is a tetravalent radical having from 2 to 27 carbon atoms and selected from the group consisting of an aliphatic radical, alicyclic radical, monoaromatic radical, condensed polyaromatic radical and noncondensed aromatic radical connected each other with a direct bond or a bridge member; aromatic diamines which are useful for the raw material monomers of the polyimide and have following formulas: ##STR2## and ##STR3## and a process for preparing the polyimide of the above formula by reacting these aromatic diamines with a tetracarboxylic dianhydride in the presence of an aromatic dicarboxylic anhydride or aromatic monoamine, and successively thermally or chemically imidizing the resultant polyamic acid.

Abstract: The heat resistant adhesive of the invention comprises polyamic acid and/or polyimide which are prepared by using 1,3-bis(3-aminophenoxy)benzene as an aromatic diamine component and 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride and/or 3,3',4,4'-diphenylethertetracarboxylic dianhydride as tetracarboxylic acid dianhydrides, and further by blocking the polymer chain end with dicarboxylic anhydride or a monoamine compound; or comprises a polyimide solution containing the polyimide in a good solvent.The adhesive of the invention is a heat-resistant adhesive capable of adhering under mild temperature/mild pressure conditions. The adhesive of polyimide solution can provide desired adhesion by simple procedures such as applying to the adherend and heating under pressure and exhibits excellent adhesive strength.

Abstract: The invention is concerned with novel water-dispersible copolymers which contain at least one UVA light-absorbing monomer, one UVB light-absorbing monomer, one hydrophilic monomer, and optionally one hydrophobic monomer component. The UVA light-absorbing monomer absorbs at .lambda.max ultraviolet light in the 320-400 nm range. The UVB light-absorbing monomer absorbs at max ultraviolet light in the 290-320 nm range. Because of the R.sub.3 group used in the invention, the copolymers of the invention permit higher loading of UV monomers than previously obtainable.

Abstract: The invention comprises curing polyamic acid solutions into polyimide solutions by adding a hydrophilic reagent to a polyamic acid solution. The hydrophilic reagent is selected to have little or no reactivity with amines or carboxylic acids, and is of the type that will react with water to form by-products that shift the equilibrium between polyamic acid as a reactant and polyimide and water as products toward the production of polyimide.

Abstract: A new class of polymers is provided as well as the monomers used for their preparation. The polymers provided in accordance with practice of the present invention include repeating units comprising one or more quinoline groups, wherein at least a portion of the repeating units includes a hexafluoroisopropylidene (6F) group or a 1-aryl-2,2,2-trifluoroethylidene (3F) group, or both.The hexafluoroisopropylidene group is referred to herein as a "6F" group and has the following structure: ##STR1## The "6F" group includes a tetravalent carbon atom bound to two trifluoromethyl moieties with its other two bonds forming linkages in the polymer chain.the 1-aryl-2,2,2-trifluoroethylidene group is referred to herein as "3F" group and has the following structure: ##STR2## wherein Ar' is an aryl group. The "3F" group comprises a tetravalent carbon atom bound to one trifluoromethyl moiety and one aryl group with its other two bonds forming linkages in the polymer chain.

Abstract: Improved imide-containing copolymers comprising, in the aromatic diamine component, p-phenylene diamine and at least one additional aromatic diamine have increased rigidity and useful processability. The copolymers of this invention also may exhibit improved resistance to the detrimental effects of humid environments and retain mechanical properties at elevated temperatures after exposure to humid environments.

Abstract: A thermotropic copolyesteramide, with a nematic structure of the liquid crystalline phase within a desired temperature range of the mesophase, contains metered amounts of units derived from: (a) a saturated aliphatic -dicarboxylic acid; (b) 4,4'-dihydroxydiphenyl; (c) 4-hydroxybenzoic acid and (d) 4-aminobenzoic acid or (d') 4-aminophenol.This thermotropic copolyesteramide, produced by the copolymerization of monomers in the molten state, is a material with self-reinforcing characteristics capable of yielding, by normal injection or extrusion processes, remarkable molecular orientations which impart a high rigidity to the manufactured products.The copolyesteramide may be used as a reinforcement material for traditional thermoplastic polymers, by usual techniques.

Abstract: Nadimide-terminated polyarylate prepolymers having the formula (I) ##STR1## wherein n is an integer not less than 1, and cured polyarylate resins produced by thermal curing the prepolymers, and processes for producing them are disclosed.The cured polyarylate resins according to the present invention have excellent chemical resistance and high-temperature resistance as well as good mechanical properties and processability.

Abstract: Disclosed is a polyimide ammonium salt comprising the reaction product of an ethylenically unsaturated amine with an aromatic polyimide having pendant carboxylic acid groups, said polyimide comprising the reaction product of diamine and aromatic dianhydride, where the diamine comprises an aromatic carboxylic acid diamine having at least one carboxylic acid. A substrate can be coated with the polyimide ammonium salt by forming a composition of a crosslinking agent and a solution of the polyimide salt in an organic solvent, spreading the composition on the substrate, evaporating the solvent to form a coating, exposing at least some of the coating to actinic radiation to crosslink and insolubilize the exposed portions of the coating, and washing the unexposed portions away by dissolving them in an organic solvent.

Abstract: This invention is that of high temperature polyamides containing the hexafluoroisopropylidene group. The high temperature polyamides of the invention and photo or radiation sensitizers provide improved high temperature positive resists which can be developed in aqueous alkaline developer and thermally anneal to form heat resistant, polyoxazole relief structures suitable for use in microelectronic and printing applications. The positive photoresists of the invention have improved solubility in coating solvents and improved photospeed. The polyamides of the invention can be prepared by conventional condensation reactions; e.g. the condensation of a diamine and diacid chloride. In addition the polyamides of this invention provide high temperature protective coatings with superior adhesion properties in applications other than the photoresist area.

Abstract: Poly(dianhydride) compounds having formulae (I) and (II): ##STR1## where m is 0 to 50. ##STR2## wherein n is 0 to 20 and X is bond junction, oxygen atom, sulfur atom, SO.sub.2, C(CF.sub.3), CO, C(CH.sub.3).sub.2, CF.sub.2 --O--CF.sub.2, CH.sub.2, and CHOH.

Abstract: Polyimide sheets having excellent thermal resistance and good surface appearance of the resultant sheets are obtained by a melt-extrusion process from a specific polyimide in the temperature range of 300.degree. C. to 450.degree. C. and a moisture content of 200 ppm or less.

Abstract: The invention is a condensation polymerization reaction in which functionally terminated polybenzazole ligomers are reacted in a solvent acid at a temperature of at least 150.degree. C. and a shear of at least about 10 sec..sup.-1 under conditions so that the desired molecular weight is reached in no more than about 4 hours. The oligomers may be, for example, derived from the reaction of 4,6-diaminoresorcinol bis(hydrochloride) and terephthalic acid. The concentration of oligomers is high enough so that the reaction mixture contains liquid crystalline domains.

Abstract: A perfluorinated polyimide comprising a repeating unit represented by general formula (1): ##STR1## and a perfluorinated poly(amic acid) comprising a repeating unit represented by general formula (6): ##STR2## wherein R.sub.1 is a tetravalent organic group; and R.sub.2 is a divalent organic group, provided that chemical bonds between carbon atoms and monovalent elements contained in R.sub.1 and R.sub.2 are exclusively carbon-to-fluorine bonds; methods for preparing them; and optical material including the perfluorinated polyimide. 1,4-Bis(3,4-dicarboxytrifluorophenoxy)tetrafluorobenzene dianhydride, 1,4-difluoropyromellitic anhydride, 1,4-bis(3,4-dicarboxytrifluorophenoxy)tetrafluorobenzene, 1,4-difluoropyromellitic acid, and 1,4-bis(3,4-dicyanotrifluorophenoxy)tetrafluorobenzene as well as methods preparing them. The perfluorinated polyimide has a thermal stability and has a low optical loss in an optical communication wavelength region (0.8 to 1.7 .mu.m).

Abstract: A novel aromatic diamine; a polyimide comprising 1,3-bis(3-aminobenzoyl)benzene or 4,4'-bis(3-aminobenzoyl)biphenyl as a diamine component and having recurring structural units represented by the formula (III): ##STR1## wherein R is a tetravalent radical selected from the group consisting of an aliphatic radical having from 2 to 27 carbon atoms, alicyclic radical, monoaromatic radical, condensed polyaromatic radical, and noncondensed aromatic radical connected each other with a direct bond or a bridge member, and X is a divalent radical of ##STR2## and a polyimide having a terminal aromatic group which is essentially unsubstituted or substituted with a radical having no reactivity with amines or dicarboxylic acid anhydrides or a composition comprising said polyimide.

Abstract: A polyamic acid having a three-dimensional network molecular structure produced by a gel forming ring-opening polyaddition reaction in an organic solvent of the reaction components comprising:(A) an acid component consisting of at least one tetracarboxylic acid dianhydride selected from the group consisting of a tetracarboxy benzene dianhydride, a tetracarboxy dianhydride of a compound having 2 to 5 condensed benzene rings, and compounds represented by formula (III), and substituted compounds thereof: ##STR1## wherein R.sub.1 represents --O--, --CO--, --SO.sub.2 --, --SO--, an alkylene group, an alkylene bicarbonyloxy group, an alkylene bioxycarbonyl group, a phenylene group, a phenylene alkylene group, or a phenylene dialkylene group, n.sub.4 is 0 or 1, n.sub.5 is 0 or 1; and n.sub.6 is 1 or 2, provided that the sum of n.sub.5 and n.sub.

Abstract: The invention relates to soluble homo- or copolyimides of formula I ##STR1## wherein Y is hydrogen or the substituents Y, together with the linking N atom, are a divalent radical of of formulae IIa to IIc ##STR2## and X is the radical of of an aromatic amine after removal of the amino end groups, and n is an integer from 5 to 150.The compounds of the invention are readily soluble in organic solvents and are suitable tougheners for epoxy, bismaleimide and triazine resin systems.

Abstract: Aromatic polyether polymers, illustrated by polyethersulfones, polyetherketones and polyetherimides, are prepared by a phase transfer catalyzed reaction between a salt of a dihydroxyaromatic compound and a substituted aromatic compound such as bis(4-hydroxyphenyl) sulfone, bis(4-hydroxyphenyl) ketone or 1,3-bis[N-(4-chlorophthalimido)]benzene or the corresponding derivative of toluene or diphenyl ether, or the analagous fluoro-, bromo- or nitro-substituted compounds. The phase transfer catalysts employed are those which are stable at temperatures in the range of about 125.degree.-250.degree. C. Particularly preferred phase transfer catalysts are the hexaalkylguanidinium and .alpha.,.omega.-bis(pentaalkylguanidinium)alkane salts and the corresponding heterocyclic salts.

Abstract: Polyimides having high glass transition temperature prepared from 2,2-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride and 1,5-, 1,6-, 2,6- or 2,7-bis(4-aminophenoxy)napthalene.

Abstract: The invention provides a polymer comprising a chain of detectable units joined together by linker arms.The detectable units may be, for example, antigenic or form part of a fluorescent or chemiluminescent or chromogenic or enzyme signal system.The polymer may find an application in the assay of an analyte which is a member of a specific binding pair.The invention also provides a labelled reagent in which the reagent is a member of a specific binding pair and the label is a polymer in accordance with the invention. The invention further provides an assay involving the use of a labelled reagent in accordance with the invention. Also the invention provides a kit for performing an assay, which kit includes a supply of a labelled reagent in accordance with the invention.

Abstract: Polybenzazole polymers can be synthesized rapidly in large quantities at high molecular weight and high concentration by a two-step process of forming oligomers in a batch reactor and advancing the molecular weight of the polymer in an extruder.

Abstract: A high-temperature stable, highly optically transparent-to-colorless, low dielectric linear aromatic polyimide is prepared by reacting an aromatic diamine with 3,3'bis(3,4-dicarboxyphenoxy)diphenylmethane dianhydride in an amide solvent to form a linear aromatic polyamic acid. This polyamic acid is then cyclized to form the corresponding polyimide, which has the following general structural formula: ##STR1## wherein Ar is any aromatic or substituted aromatic group, and n is 10-100.

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: The semicrystalline polyimide prepared by reaction of 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA) and 1,3-bis(4-aminophenoxy-4'-benzoyl)benzene (1,3-BABB) is modified so that it can be more readily processed to form adhesive bonds, moldings and composites. The stoichiometric ratio of the two monomers, BTDA and 1,3-BABB is controlled so that the intermediate polyamide acid is of a calculated molecular weight. A polyamide acid with excess anhydride groups is then reacted with the stoichiometrically required amount of monofunctional aromatic or aliphatic amine required for complete endcapping. A polyamide acid with excess amino groups is reacted with the stoichiometrically required amount of monofunctional aromatic anhydride required for complete endcapping. The stoichiometrically offset, endcapped polyimide is processed at lower temperatures and pressures than the unmodified high molecular weight polyimide with the same repeat unit, and exhibits an improved melt stability.

Abstract: Linear aromatic polyimides containing the cyclobutene-3,4-dione moiety were produced by reacting 1,2-bis(4-aminoanilino)cyclobutene-3,4-dione with several aromatic dianhydrides. The resulting polymers exhibited glass transition temperatures greater than 500.degree. C., adhered tenaciously to glass, and became more flexible after heating for 1 hour at 300.degree. C.

Abstract: A hot-melt adhesive comprising a special polyamideimide or polyamide is excellent in heat resistance and adhesive strength and usable for providing substrates for printed circuit boards.

Abstract: In a process for the preparation of polyimide by reacting a diamine compound with tetracarboxylic dianhydride in a phenol based solvent, an improved process for reacting the diamine compound with tetracarboxylic dianhydride in a solution by forming separate solutions of the tetracarboxylic dianhydride and the diamine compound and mixing the solutions and/or by dissolving tetracarboxylic dianhydride in the phenol-based solvent containing an organic base.

Abstract: Phosphazene-containing amines having at least one amine or substituted amine moiety reactive with nitrile groups of the phthalonitrile monomers or oligomeric resins are useful curing agents for phthalonitriles. Typically, the phosphazene-containing amines useful as curing agents in the present invention have the formula: ##STR1## wherein each of X.sub.1-6 is a hydrogen, an unsubstituted amine group, or an amine group substituted with C.sub.1 -C.sub.12 alkyl groups or aromatic groups, at least one of X.sub.1-6 includes an amine group, and each of R'.sub.1-6 is an alkyl, aromatic, or alkyl-substituted aromatic moiety, or a linear polymer of the phosphazene-based amine monomer. The curing agents enhance the speed of cure and also add flame retardancy to the cured polymers.

Abstract: Integrated circuit sockets for use in a burn-in test are disclosed. The IC sockets are produced by injection molding of a specific polyimide having an inherent viscosity of 0.35 to 0.65 dl/g and essentially consisting of recurring units represented by the formula (I): ##STR1## wherein X is a radical selected from the group consisting of a bond, divalent hydrocarbon having from 1 to 10 carbon atoms, etc. and R is a tetravalent radical selected from the group consisting of an aliphatic radical having two or more carbon atoms, cycloaliphatic radical, monoaromatic radical etc.

Abstract: A melt processable poly(ester-amide) which is capable of forming an anisotropic melt phase is provided. A poly(ester-amide) of the present invention may have recurring units of: (a) 4-hydroxybenzoyl moiety, (b) 6-oxy-2-naphthoyl moiety, (c) 4,4'-biphenol moiety, (d) terephthaloyl moiety, and (e) an aromatic moiety capable of forming an amide linkage in the proportions indicated. Preferably, the moiety capable of forming an amide linkage is derived from p-aminophenol, p-phenylenediamine, N-acetyl-p-aminophenol, etc. The resulting poly(ester-amide) is capable of undergoing melt-processing in the temperature range of from about 300.degree. to about 400.degree. C.

Abstract: A tri-component polyimide copolymer and the process of preparing the copolymer are disclosed. A mixed reaction medium or solvent system comprising phenol and at least one compound of resorcinol, 1,6-dimethyl phenol and 4-methoxy phenol is used to produce the copolymer by direct imidization without isolating or purifying the imide oligomer as an intermediate.

Abstract: Rigid-rod aromatic heterocyclic polymers having repeating units of the formula: ##STR1## wherein Ba is a benzobisazole moiety of the formula: ##STR2## wherein X is --O--, --S-- or --NH.

Abstract: Macrocyclic oligomers, including polycarbonates, polyesters, polyamides, polyimides, polyetherketones and polyethersulfones, are conveniently prepared from various spiro(bis)indane compounds, especially the 6,6'-difunctional 3,3',3'-tetramethylspiro(bis)indanes. The macrocyclic oligomers may be conveniently converted to linear polymers.