Abstract: A novel copolyesteramide made up of monomeric units of formula I to IV in molar proportions of 40-60% of I, 10-20% of II, 1-12% of III and 15-30% of IV are obtained by polymerizing the corresponding monomers in molten or dissolved state, in an inert atmosphere, during a period of time between 2 and 18 hours and a temperature between 220.degree. and 350.degree. C.The product is useful in the preparation of filaments with high tensile strenght and high tensile modulus, as well as for the preparation of products molded by extrusion or injection and also for the preparation of films.

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: The present invention provides novel heat stable polyamide-imide polymers having excellent flow properties which render them more readily processible into fibers, films, sheets and other molded articles. The polymers are prepared by forming the polycondensation product of one or more aromatic diamines and one or more trifunctional acid anhydride monomers, wherein at least one of said diamine monomers is a 12F-Diamine or 12F-Oxydiamine containing at least two CF.sub.3 ##STR1## R groups linking two aromatic moieties, wherein R is CF.sub.3 or phenyl. In addition to improved flow properties, the polyamide-imide polymers of this invention also exhibit improved solubility properties in most organic solvents, improved resistance to attack by chlorinated solvents such as trichloroethylene as compared with polyimides, improved hydrophobic properties as well as excellent thermal properties including resistance to thermooxidative degredation.

Abstract: Storage stable polyimide precursors are prepared from diesters of certain tetracarboxylic acids, including pyromellitic acid and 2,2-bis[4-(3,4-dicarboxyphenoxy)-phenyl]propane, and m-phenylenediamine, p-phenylenediamine, 4-aminophenyl ether or mixtures thereof. These polyimide precursors may be cured to form flexible polyimides useful in composite preparation.

Abstract: Linear polyethersulfones are prepared by ring-opening of a macrocyclic spirobiindane polyethersulfone oligomer composition. The ring-opening reaction is conducted in the presence of a basic reagent such as an alkali metal bisphenol salt, at a temperature in the range of about 300.degree.-400.degree. C.

Abstract: Polyamide resins useful for forming containers having improved resistance to gas permeability comprising the reaction product of(A) a dicarboxylic acid corresponding to the structure ##STR1## wherein X is hydrogen or unsubstituted alkyl containing 1-5 carbons and n is an integer in the range of 4 to 10, and(B) a diamine containing 5 to 16 carbon atoms.

Abstract: This invention relates to a novel polyimide and describes method of its preparation, adhesives of the polyimide and the method for their application.The polyimide has recurring units of the formula ##STR1## (where the positions of two carbonyl radicals in a benzene ring are meta or para, and R is a tetra-valent radical selected from the group consisting of aliphatic radical having not less than two carbons, cyclo-aliphatic radical, monoaromatic radical, condensed polyaromatic radical, and non condensed polyaromatic radical wherein aromatic radicals are mutually connected with a bond or a crosslinking function).The polyimide can be prepared by reacting diamine with tetracarboxylic dianhydride in organic solvents and imidizing resultant polyamic acid.The diamine in use is ether diamine and includes 1,3-bis[4-(3-aminophenoxy)benzoyl]benzene and 1,4-bis[4-(3-aminophenoxy)benzoyl]benzene.

Abstract: An intra-ocular lens comprising a lens part and a fixing part is disclosed, said lens part comprising a colorless transparent polyimide consisting mainly of a repeating unit represented by formula (I): ##STR1## The intra-ocular lens exhibits compatibility with the organism, chemical inactivity, and insusceptibility to modification or deterioration by the organism, has a refractive index of 1.6 or higher, completely absorbs ultraviolet rays while exhibiting substantial transparency to visible rays, and possesses heat resistance enough to withstand autoclaving.

Abstract: A solvent-soluble polyimide obtained from an exo-form dicarboxylic acid anhydride with an aromatic diamine, e.g. 2,2,-bis[4-(4-aminophenoxy)phenyl]propane is improved in film-forming properties and transparency, and particularly suitable for producing an orientation controlling film in a liquid crystal display device.

Abstract: The present invention provides for shaped articles made from novel heat stable polyamide-imide polymers having excellent flow properties which render them more readily processible into fibers, films, sheets and other molded articles. The polymers are prepared by forming the polycondensation product of one or more aromatic diamines, one or more trifunctional acid anhydride monomers, and one or more tetrafunctional aromatic dianhydrides, at least one of said monomers containing the groups ##STR1## linking two aromatic moieties, wherein R is CF.sub.3 or phenyl. In addition to improved flow properties, the polyamide-imide polymers of this invention also exhibit improved solubility properties in most organic solvents, improved resistance to attach by chlorinated solvents such as trichloroethylene as compared with polyimides, improved hydrophobic properties as well as excellent thermal properties including resistance to thermooxidative degradation.

Abstract: The present invention provides novel heat stable polyamide-imide polymers having excellent flow properties which render them more readily processible into fibers, films, sheets and other molded articles. The polymers are prepared by forming the polycondensation product of one or more aromatic diamines and one or more trifunctional acid anhydride monomers, at least one of said diamine monomers containing the group ##STR1## linking two aromatic moieties, wherein R is CF.sub.3 or phenyl. In addition to improved flow properties, the polyamide-imide polymers of this invention also exhibit improved solubility properties in most organic solvents, improved resistance to attack by chlorinated solvents such as trichloroethylene as compared with polyimides, improved hydrophobic properties as well as excellent thermal properties including resistance to thermooxidative degradation.

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: Thermotropic polyester imides having recurrent structural units corresponding to the following formulae: ##STR1##

Abstract: Heat resistant, shapable, hydroxy and/or alkoxy-substituted polyamides derived from at least one diamine selected from unsubstituted and substituted 4,4'-bis[2-(4-amino-3-hydroxyphenyl)hexafluoroisopropyl)]diphenyl ether 4,4'-bis-[2-(3-amino-4-hydroxyphenyl)hexafluoroisopropyl]diphenyl ether and a dicarboxylic acid or a derivative thereof e.g. its acid halo or ester. The polyamides of the invention may be thermally cured to form polybenzoxazoles of higher heat resistance which are stable to hydrolytic, chemical and radiation attack.The polyamides of the invention may be formed into shaped articles by molding, extrusion and solvent casting processes preferably in the presence of a solvent or diluent and then optionally converted into heat resistant, insoluble polybenzoxazoles. These shaped articles are useful in aircraft, electronic and other commercial applications where heat, chemical and radiation resistance are desired in conjunction with good mechanical and electrical properties.

Abstract: A film comprised of at least one monomolecular layer composed essentially of a polyimide having repeating units of the formula: ##STR1## wherein R.sup.1 is a tetravalent organic group and R.sup.2 is a bivalent organic group.

Abstract: Aromatic polyimides of the formula: ##STR1## where --Ar-- is ##STR2## --Ar'-- is ##STR3## --Ar"-- is ##STR4## where --Z, and --Z.sub.1, independently are --Cl, --Br or --I; where --X, --X.sub.1, --X.sub.2 and --X.sub.3 independently are --CH.sub.3 or --C.sub.2 H.sub.5 ; and --Y,--Y.sub.1,--Y.sub.2 and --Y.sub.3 are primary or secondary alkyl groups having 3 to 12 carbon atoms, provided that when m is greater than 0, r is 0 and that when L is greater than 0, r and s are 0, are disclosed. These polyimides are very soluble, even in weak solvents such as toluene.

Abstract: The present invention provides a process for preparing shaped articles and articles prepared by such process based on a polyimide polymer, the polymer prepared by subjecting a mixture of aromatic dianhydride and aromatic diamine monomers, at least one of which contains the group ##STR1## linking two aromatic moieties, wherein R is CF.sub.3 or phenyl, to a low temperature, substantially isothermal solution polymeriazation process wherein the content of the mixed monomers in solvent is maintained within the range of from about 8 to about 12% by weight solids concentration during the polymerization process. The process is conducted for a sufficient length of time and uniformity of temperature, generally below about 35.degree. C., to achieve a weight average polyimide polymer molecular weight within the range of about 80,000 to about 135,000, more preferably of about 90,000 to about 125,000, a polyimide inherent viscosity within the range of from about 0.45 to about 0.

Abstract: This invention relates to a novel polyimide which is high-temperature resistant and capable of being molded in a fused state. This invention also relates to a high-temperature adhesive using the polyimide.The polyimide consists essentially of recurring units of the formula: ##STR1## where R is a tetra-valent radical selected from the group consisting of an aliphatic radical having 2 or more carbon atoms, alicyclic radical, monoaromatic radical, condensed polyaromatic radical, and non-condensed polyaromatic radical wherein aromatic radicals are linked to one another directly or via a bridge member.The polyimide can be prepared by reacting bis[4-(4-aminophenoxy)phenoxy)phenyl] sulfone with a tetracarboxylic dianhydride in an organic solvent and imidizing the resultant polyamic acid.

Abstract: Filaments, fibers and films from aromatic copolyamides (polyaramids) of the dicarboxylic acid/diamine type of at least four aromatic monomeric compounds of A', B', C' and D' which each contain a group of the following formulae:A: --CO--Ar--CO--B: --NH--Ar.sup.1 --NH--C: --NH--Ar.sup.2 --NH--D: --NH--Ar.sup.3 --Z--Ar.sup.3 --NH--and processes for their preparation and possible applications. Filaments, fibers and films having a high elongation at break and a high initial modulus are obtained using easily accessible monomers and polyaramids synthesized therefrom which are highly soluble in organic solvents.

Abstract: There is provided an aromatic benzoxazole polymer having repeating units of the formula ##STR1## wherein Ar is ##STR2## wherein R is an alkyl group having 8 to 12 carbon atoms. The polymers of this invention are prepared by the polycondensation of 4,4'-hexafluoroisopropylidene bis(2-aminophenol) with a dicarboxylic acid selected from the group consisting of isophthalic acid, terephthalic acid, 2,5-pyridine dicarboxylic acid, 2,6-pyridine dicarboxylic acid and a 2,5-bis(alkoxy) terephthalic acid of the formula ##STR3## wherein R is an alkyl group having 8 to 12 carbon atoms, in a suitable reaction medium containing a suitable dehydrating agent.

Abstract: The present invention provides novel heat stable polyamide-imide polymers having excellent flow properties which render them more readily processible into fibers, films, sheets and other molded articles. The polymers are prepared by forming the polycondensation product of one of more aromatic diamines, one or more trifunctional acid anhydride monomers, and one or more tetrafunctional aromatic dianhydrides, at least one of said monomers containing the groups ##STR1## linking two aromatic moieties, wherein R is CF.sub.3 or phenyl. In addition to improved flow properties, the polyamide-imide polymers of this invention also exhibit improved solubility properties in most organic solvents, improved resistance to attack by chlorinated solvents such as trichloroethylene as compared with polyimides, improved hydrophobic properties as well as excellent thermal properties including resistance to thermooxidative degradation.

Abstract: Polyimides which essentially consist of 0.1 to 100 mol % of at least one structural element of the formula I ##STR1## and 99.9 to 0 mol % of at least one structural element of the formula II and/or III ##STR2## in which Z and Z' are a tetravalent aromatic radical, Q' is a trivalent aromatic radical, X and X' are a divalent radical of an organic amine, are autophotocrosslinkable. They are suitable for the production of protective films and photographic relief images.

Abstract: Polyimides which essentially consist of 0.1 to 100 mol % of at least one structural element of the formula I ##STR1## and 99.9 to 0 mol % of at least one structural element of the formula II and/or III ##STR2## in which Z and Z' are a tetravalent aromatic radical, Q' is a trivalent aromatic radical, X and X' are a divalent radical of an organic amine, are autophotocrosslinkable. They are suitable for the production of protective films and photographic relief images.

Abstract: Described herein are novel crystalline polyarylnitrile polymers which have excellent mechanical and thermal properties. Also, described is a process for producing such polyarylnitrile polymers.

Abstract: Highly soluble, optically transparent to clear aromatic polyimides in the visible range are disclosed. The dianhydrides from which the polyimides are prepared are 4,4'-[2,2,2-trifluoro-1-(trifluoromethyl) ethylidene] bis(1,2-benzenedicarboxylic anhydride) which can be partially replaced with either pyromellitic dianhydride or 3,3',4,4'-benzophenone tetracarboxylic dianhydride. The diamines from which the polyimides are prepared are m- or p- phenylene diamines which are substituted ortho to the amino groups with primary or secondary alkyl groups having 1 to 6 carbon atoms preferably methyl or ethyl.

Abstract: An improved solution polymerization process for the preparation of polyetherimides comprises prereacting an aromatic bis(ether anhydride) with an aromatic diamine, followed by the addition of phthalic anhydride end capping agent and further reaction to form an end capped prepolymer. The prepolymer is converted to polyetherimide. The improved process advantageously greatly reduces the formation of PAMI, an undesired byproduct.

Abstract: There is provided an aromatic polyamide having repeating units of the formula: ##STR1## wherein X is -O-, -S-, -CO- or -SO.sub.2 - and y has a value of 1 or 2. Also provided is an aromatic polyamide having repeating units of the formula: ##STR2## and a new composition of matter 3-[4-(3-aminophenoxy benzoyl)phenoxy] benzoic acid.

Abstract: Polyphenylquinoxalines are prepared by the nucleophilic displacement reaction of di(hydroxyphenyl)quinoxaline monomers with activated aromatic dihalides or dinitro compounds. The reactions are carried out in polar aprotic solvents using alkali metal bases at elevated temperatures under nitrogen. The di(hydroxyphenyl)quinoxaline monomers are prepared either by reacting stoichiometric quantities of aromatic bis(o-diamines) with a hydroxybenzil or by reacting o-phenylenediamine with a dihydroxybenzil or bis(hydroxyphenylglyoxylyl)benzene.

Abstract: A method is provided for enhancing the crystallization rate of certain polyetherimide to provide an improved molding mehod for making solvent resistant shaped thermoplastics. Polyetherimide blends containing crystallization rate enhancing agents such as bisimides or imide oligomers also are provided.

Abstract: A polyamideimide having an inherent viscosity of above 0.48 which comprises a unit of the following formula (II) ##STR1## and a unit of the following formula (IV) ##STR2## as main units forming the molecular chains of the polyamideimide, and an intimate mixture of the polyamideimide and a plasticizing material for the polyamideimide.

Abstract: Linear aromatic polyimides with low dielectric constants are produced by adding a diamic acid additive to the polyamic acid resin formed by the condensation of an aromatic dianhydride with an aromatic diamine. The resulting modified polyimide is a better electrical insulator than state-of-the-art commercially available polyimides.

Abstract: An aromatic hetero ring-containing polyimide comprising substantially equal equivalent amount of (1) structural units of Group 1 and (2) structural units of Group 2, wherein the structural units of Group 1 comprise (i) from 30 to 100 mol % of a unit of the formula: ##STR1## wherein X is S, O or NH, and (ii) from 0 to 70 mol % of a unit of the formula: ##STR2## wherein Ar.sub.1 is ##STR3## wherein each of y, y.sub.1, and y.sub.2 and y.sub.3 is a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom, and each of Z, Z.sub.1 and Z.sub.2 is a single bond, --O--, --CH.sub.2 --, ##STR4## --C--, --SO.sub.2 --, --C(CH.sub.3).sub.2 -- or --C(CF.sub.3).sub.2, and the structural units of Group 2 comprise (i) from 70 to 100 mol % of a unit of the formula: ##STR5## and (ii) from 0 to 30 mol % of a unit of the formula: ##STR6## wherein Ar.sub.2 is ##STR7## wherein Z, y and y.sub.

Abstract: A polyimide copolymer having a repeating unit of formula (I): ##STR1## wherein each of R.sub.1 and R.sub.2 is independently ##STR2## and R.sub.1 and R.sub.2 are different from each other, R.sub.0 is an aromatic group having a valency of 4, and m is a positive integer. The polyimide copolymer is excellent in heat resistance, mechanical properties (e.g., tensile elongation) and thermal dimensional stability.

Abstract: This invention relates to flexible copper-clad circuit substrates where copper foil is directly and firmly jointed with a polyimide film.Polyimide used is obtained conventionally by reacting diamine components including 3,3'-diaminobenzophenone, 1,3-bis(3-aminophenoxy)-bezene, 4,4'-bis(3-aminophenoxy)biphenyl, 2,2-bis[4-(3-aminophenoxy)-phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, bis[4(3-aminophenoxy)phenyl] sulfide, bis[4-(3-aminophenoxy)phenyl] ketone and bis[4-(3-aminophenoxy)phenyl] sulfone, with tetracarboxylic acid dianhydride including pyromellitic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-biphenyl tetracarboxylic dianhydride and bis(3,4-dicarboxyphenyl) ether dianhydride, in organic solvent, and by thermally or chemically imidizing resultant polyamic acid.Polyimide thus obtained has relatively lower melt viscosity and is flowable at high temperatures.

Abstract: Described is a way of sealing a carbon body such as monolithic graphite tooling so that it retains its vacuum integrity through numerous thermal cycles typical of thermoplastic processing. This is accomplished by (a) applying to the body surface a coating formulation composed of a carbon-filled solution of a polyamic acid formed by reaction between pyromellitic acid dianhydride and 2,2-bis[4-(aminophenoxy)phenyl]hexafluoropropane, and (b) heat curing the coated body to cause the polyamic acid to imidize into a thermally cured polyimide.

Abstract: Disclosed herein are a thermoplastic wholly aromatic polyimide ester consisting essentially of structural units represented by the general formulas I, II, III, and IV: ##STR1## wherein X and Y are either --O-- or --CO-- and may be either identical with or different from each other, n is an integrer of 0 or 1, X group and imide group and imide group in unit II are present at para or meta position to each other, two carbonyl gorups in unit IV are present at para or meta position to each other, and each end of units I, II, III, and IV is bonded to another end trough ester bond, and wherein the polyimide ester has a melt viscosity of 1.0 to 1.0.times.10.sup.5 Pa.multidot.s measured at a shear stress of 0.025 MPa and a temperature of 300.degree. to 400.degree. C.; and a process for producing the thermoplastic wholly aromatic polyimide ester.

Abstract: Described are polyamic acids, at least 50 mole-% of which are comprised of recurrent units corresponding to the general formula I: ##STR1## wherein, R.sup.1 is a mono-, di-, tri- or tetranuclear aromatic group andX is O, S, CO, SO.sub.2 or CR.sup.2 R.sup.3, each one ofR.sup.2 and R.sup.3 being H or CH.sub.3.A polyamic acid of the present invention, in the form of a solution, is applied to a substrate, for example, a semiconductor device, to form a protective layer thereon, and is converted into polyimide by heating. As against comparable compounds known in the art, the polyamic acids of the present invention are distinguished by a lower inherent viscosity at an unchanged molecular weight and, consequently, by an improved processability at an equally good thermal stability.

Abstract: A molding material comprising an imide group-containing aromatic polyamide, obtained by polycondensation of(A) an aromatic diamine of the general formulaH.sub.2 N--Ar--O--Ar'--X--Ar'--O--Ar--NH.sub.2wherein Ar and Ar' are m- or p-phenylene groups and X is --SO.sub.2 -- or --CO--, with at least one aromatic dicarboxylic acid B) selected from the group consisting of(B1) a mixture comprising 40 to 100 mole % of an acid of the structure ##STR1## and 60 to 0 mole % of an acid of the structure ##STR2## in which n is 0-4 and R is selected from the group consisting of (a) an alkyl group having 1-6 carbon atoms,(b) an unsubstituted phenyl or an alkyl- or aryl substituted phenyl group,(c) an alkoxy group having 1-6 atoms,(d) a phenoxy group, in which the phenyl ring is unsubstituted or is alkyl- or aryl substituted, and(e) a halogen,(B2) an acid of the structure ##STR3## and (B3) a dicarboxylic acid of the formulaHO.sub.2 C--Ar--(A--Ar).sub.p --CO.sub.2 Hwherein Ar is m-phenylene or p-phenylene, A=--O--, --S--, --SO.

Abstract: A molding composition, comprising an aliphatic/aromatic copolyamide polymer having statistically distributed throughout the polymer:(A) from greater than 40 to less than 100 mole % aliphatic monomer units containing amino groups, carboxyl groups or mixtures thereof; and(B) up to 60 mole % of aromatic monomer units containing amino groups, carboxy groups or mixtures thereof, said aromatic monomer units containing at least one member selected from the group consisting of 4,4'-bis(4-aminophenoxy)diphenyl sulfone, 4,4'-bis(3-aminophenoxy)diphenyl sulfone, 4,4'-bis(4-aminophenoxy)benzophenone, and 4,4'-bis(3-aminophenoxy)benzophenone.

Abstract: A biscyclobutarene monomer is prepared comprising two cyclobutarene moieties bridged by a divalent radical having at least one benzoxazole linkage. A reactive biscyclobutarene oligomer is also prepared by reacting a cyclobutarene-carboxylic acid, a diaminodihydroxyarene, and either an aromatic diacid or an aromatic diacid chloride. The monomers and reactive oligomers can be polymerized to form polymers exhibiting outstanding thermooxidative stability at high temperatures for prolonged time periods.

Abstract: A method is provided for making 9,10-dithiaanthracene-2,3,6,7-tetracarboxylic acid dianhydride. Polyimides having improved oxidative stability also are provided which can be made intercondensing organic diamine and the aforementioned dianhydride or a dianhydride mixture.

Abstract: A photosensitive polyimide precursor composed of the structural units (A) represented by the following general formula (I) and the structural units (B) represented by the following general formula (II), in which the ratio of the molar quantity of the structural units (A) to the sum of the molar quantity of the structural units (A) and that of the structural units (B) is 0.01 or greater, and having a viscosity of 100 cP or above as measured at 25.degree. C. in the state of a 10% by weight solution in N-methylpyrrolidone: ##STR1## wherein R.sub.1 represents a tetravalent aromatic hydrocarbon residue; R.sub.2 represents a divalent aromatic hydrocarbon residue; X, identical or different represents a halogen or an alkyl group; and m represents 0 or an integer from 1 to 4. The photosensitivity of the present photosensitive polyimide precursor is about 20 to 100 times that of conventional products. After heat dehydration cyclization, it shows a heat resistance of 400.degree. C. or above.

Abstract: Polyamide-imide compositions, including amic acid precursors thereto, having in their molecules recurring units based on aromatic tri- and tetracarbonyl moieties joined by a bisphenoxyphenyl structure exhibit a desirable combination of chemical, mechanical and thermal properties and retention of these properties on exposure to elevated temperatures even after saturation with water.

Abstract: The present invention relates to compositions comprising(a) at least one polyimide having an inherent viscosity of at least 0.1 dl/g (measured at 25.degree. C. on a 0.5% by weight solution in N-methylpyrrolidone) and containing at least 50 mol % of structural units of the formula I ##STR1## in which m and p independently of one another are integers from 0 to 4, n is an integer from 0 to 3, R.sup.1 and R.sup.2 independently of one another are C.sub.1 -C.sub.6 -alkyl or C.sub.1 -C.sub.6 -alkoxy and R.sup.3 is a divalent radical of an aromatic diamine which is substituted in at least one ortho-position relative to at least one N atom by alkyl, alkoxy, alkoxyalkyl, cycloalkyl or aralkyl or in which two adjacent C atoms of the aromatic radical are substituted by alkylene, and(b) at least one aromatic polyimide which is soluble in organic solvents and photocrosslinkable and which contains at least 50 mol %, relative to the total quantity of diamine units, of radicals R.sup.

Abstract: Highly soluble, optically transparent aromatic polyimides of the following formula are disclosed: ##STR1## where --X and --X.sub.1 are independently primary or secondary alkyl groups having 1 to 6 carbon atoms,--X is different than --X.sub.1,--Y is independently --H, or --Z,--Z is independently --Cl, --Br or --I,r=0-100% of r+t, ands=100%t=100% -r of r+t are disclosed.

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: There are disclosed a process for producing a polyamide acid having at least one siloxane bond, which comprises carrying out the reaction of:(a) a tetracarboxylic dianhydride having at least one siloxane bond of the formula: ##STR1## wherein R represents a monovalent hydrocarbon group and m is an integer of 1 or more;(b) a diamine; and(c) a diaminoamide compound of the formula (II): ##STR2## wherein Ar represents an aromatic residue, Y represents SO.sub.2 or CO, and one amino group and Y--YNH.sub.

Abstract: Rapid process for the formation of heterocyclic aromatic polymers by contacting one or more appropriate multifunctional aromatic compounds, such as a diaminobenzenediol, a terephthaloyl halide and/or an aminohydroxybenzoic acid, with a sulfonic acid and a dehydrating agent.

Abstract: Polyimide having repeating units of the following formula (I) and its polyamic acid precursor having repeating units of the following formula (II) are disclosed; ##STR1## (where Y is a radial selected from the group consisting of a bond, divalent hydrocarbon having 1 to 10 carbons, hexafluorinated isopropylidene, carbonyl, thio, sulfinyl, sulfonyl and oxide, and R is a tetra-valent radical selected from the group consisting of aliphatic radical having 2 and more carbons, cyclo-aliphatic radical, monoaromatic radical, condensed polyaromatic radical, and noncondensed polyaromatic radical wherein aromatic radicals ae mutually connected with a bond or a crosslinking function).Typical examples of polyimide and polyamic acid include where Y is thio radical and R is ##STR2## Y is a bond and R is III or IV, andy is isopropylidene radical and R is IV.The polymers can be prepared from corresponding diamine and tetracarboxylic acid dianhydride.

Abstract: Polyimides are prepared from acetylene substituted polyimide oligomers via an addition polymerization reaction which involves homopolymerization. These polymers exhibit low void content when cured and possess superior thermal stability characteristics and physical properties such as structural strength. One of their unique properties is their ability to be processed into useful articles at moderate pressures and temperatures.