NEW POLY(AMIDE-IMIDE)S SYNTHESES .17. PREPARATION AND PROPERTIES OF POLY(AMIDE-IMIDE)S DERIVED FROM N-PHENYL-3,3-BIS[4-(4-AMINOPHENOXY)PHENYL]PHTHALIMIDINE, TRIMELLITIC ANHYDRIDE, AND VARIOUS AROMATIC DIAMINES

A dicarboxylic acid (1) bearing two phthalimide rings was prepared by the condensation of N-phenyl-3,3-bis[4-(4-aminophenoxy)phenyl]phthalimidine and trimellitic anhydride. A new family of poly(amide-imide)s having inherent viscosities of 0.65-1.65 dl/g was prepared by the triphenyl phosphite activated polycondensation of the diimide-diacid 1 with various aromatic diamines in a medium consisting of N-methyl-2-pyrrolidone (NMP), pyridine, and calcium chloride. All the resulting polymers showed an amorphous nature and were readily soluble in polar solvents such as NMP and N,N-dimethylacetamide. The soluble poly(amide-imide)s afforded transparent, flexible, and tough films. The glass transition temperatures of these polymers were in the range 249-340 degrees C and the 10% weight loss temperatures were above 545 degrees C in nitrogen.