Abstract: The use of certain catalysts provide for an improved process for the preparation of soluble polyimides, polyamides, and polyamideimides. The catalysts are compounds of formula ##STR1## WHEREIN M represents an alkali metal, and n is an integer from 2 to 5 inclusive. The improved process comprises reacting organic diisocyanates with polycarboxylic compounds consisting of tetracarboxylic acids or the intramolecular dianhydrides thereof, tricarboxylic acids or the monoanhydrides thereof, dicarboxylic acids, and mixtures thereof, in the presence of said catalysts. The polymers are obtained in solution at low reaction temperatures and short reaction times thereby avoiding side-reactions which otherwise would be detrimental to polymer molecular weight and ultimate polymer properties.

Abstract: The use of certain catalysts provide for an improved process for the preparation of soluble polyimides, polyamides, and polyamideimides. The catalysts are compounds of formula ##STR1## wherein M represents an alkali metal, and n is an integer from 2 to 5 inclusive. The improved process comprises reacting organic diisocyanates with polycarboxylic compounds consisting of tetracarboxylic acids or the intramolecular dianhydrides thereof, tricarboxylic acids or the monoanhydrides thereof, dicarboxylic acids, and mixtures thereof, in the presence of said catalysts. The polymers are obtained in solution at low reaction temperatures and short reaction times thereby avoiding side-reactions which otherwise would be detrimental to polymer molecular weight and ultimate polymer properties.

Abstract: Novel copolyamides having the recurring unit ##STR1## are disclosed wherein R, in 60 percent to 85 percent of the recurring units, is --CH.sub.2 --.sub.x wherein x is an integer from 7 to 12 inclusive, and, in 15 percent to 40 percent of the recurring units, R is m-phenylene; and Ar is an arylene radical. The copolyamides are characterized by ease of melt processing such as in molding, extruding, and injection molding, while at the same time possessing good high temperature stability, and being further characterized by unexpectedly high impact and flexural strengths.

Abstract: Novel copolyamides having the recurring unit ##STR1## are disclosed wherein x, in 50 percent to 85 percent of the recurring units, is an integer from 6 to 10 inclusive, and, in 15 percent to 50 percent of the recurring units is 4, and Ar is an arylene radical. The copolyamides are characterized by ease of melt processing such as in molding, extruding, and injection molding, while at the same time possessing good physical properties, and being further characterized by their ease of conversion from the amorphous to the crystalline state which, in turn, gives rise to a high degree of versatility in their fabrication.

Abstract: The use of certain catalysts provide for an improved process for the preparation of soluble polyimides, polyamides, and polyamideimides. The catalysts are alkali metal salts of formula MOR, wherein R represents alkyl or aryl and M represents an alkali metal. The improved process comprises reacting organic diisocyanates with polycarboxylic compounds consisting of tetracarboxylic acids or the intramolecular dianhydrides thereof, tricarboxylic acids or the monoanhydrides thereof, dicarboxylic acids, and mixtures thereof, in the presence of said catalysts. The polymers are obtained in solution at low reaction temperatures and short reaction times thereby avoiding side-reactions which otherwise would be detrimental to polymer molecular weight and ultimate polymer properties.

Abstract: The use of certain catalysts provide for an improved process for the preparation of soluble polyimides, polyamides, and polyamideimides. The catalysts are alkali metal salts of formula MOR, wherein R represents alkyl or aryl and M represents an akali metal. The improved process comprises reacting organic diisocyanates with polycarboxylic compounds consisting of tetracarboxylic acids or the intramolecular dianhydrides thereof, tricarboxylic acids or the monoanhydrides thereof, dicarboxylic acids, and mixtures thereof, in the presence of said catalysts. The polymers are obtained in solution at low reaction temperatures and short reaction times thereby avoiding side-reactions which otherwise would be detrimental to polymer molecular weight and ultimate polymer properties.

Abstract: The use of certain catalysts provide for an improved process for the preparation of soluble polyimides, polyamides, and polyamideimides. The catalysts are compounds of formula ##STR1## wherein M represents an alkali metal, and n is an integer from 2 to 5 inclusive. The improved process comprises reacting organic diisocyanates with polycarboxylic compounds consisting of tetracarboxylic acids or the intramolecular dianhydrides thereof, tricarboxylic acids or the monoanhydrides thereof, dicarboxylic acids, and mixtures thereof, in the presence of said catalysts. The polymers are obtained in solution at low reaction temperatures and short reaction times thereby avoiding side-reactions which otherwise would be detrimental to polymer molecular weight and ultimate polymer properties.

Abstract: Polyamide-imides are described which are derived by conventional procedures from 2,2-bis[4-(p-aminophenoxy)-phenyl]propane (or the corresponding diisocyanate) and trimellitic acid (preferably through the anhydride acid chloride). Copolyamide-imides derived from trimellitic acid, the above diamine (or diisocyanate) and certain other aromatic diamines or diisocyanates (4,4'-diaminodiphenyl ether, m-phenylene diamine and corresponding diisocyanates are preferred) are also described. The above polyamide-imides are engineering thermoplastics which, unlike closely related polyamides and polyimides, can be extruded and injection molded to form parts having good mechanical properties.

Abstract: The use of certain catalysts provide for an improved process for the preparation of soluble polyimides, polyamides, and polyamideimides. The catalysts are alkali metal salts of formula MOR, wherein R represents alkyl or aryl and M represents an alkali metal. The improved process comprises reacting organic diisocyanates with polycarboxylic compounds consisting of tetracarboxylic acids or the intramolecular dianhydrides thereof, tricarboxylic acids or the monoanhydrides thereof, dicarboxylic acids, and mixtures thereof, in the presence of said catalysts. The polymers are obtained in solution at low reaction temperatures and short reaction times thereby avoiding side-reactions which otherwise would be detrimental to polymer molecular weight and ultimate polymer properties.

Abstract: High temperature resistant aromatic copolyimide fibers are disclosed together with processes for their preparation by wet and dry spinning techniques from solvent soluble copolyimides. The latter are prepared from benzophenone-3,3',4,4'-tetracarboxylic acid dianhydride and a mixture of 4,4'-methylenebis(phenyl isocyanate) and toluene diisocyanate (2,4-, or 2,6-isomer, or mixtures thereof). The wet spinning process can be stopped at any one of the stages taught, to yield useful fibers. The choice of coagulant fluid in the spin bath controls the fiber cross-section which in turn controls certain fiber characteristics. When glycerine or a low molecular weight aliphatic glycol is employed as coagulant fluid, the high temperature fiber obtained has advantageous properties which are otherwise difficult or impossible to obtain.