Synthesis and Properties of New Aromatic Polyamides and Polyimides based on 1,4-Bis[N-(4-aminobenzoyl)-N-phenyl]phenylenediamine

Abstract

A new N-phenylated amide (N-phenylamide) unit-containing aromatic diamine, 1,4-bis[N-(4-aminobenzoyl)-N-phenyl]phenylenediamine, was prepared by the condensation of NŃ-diphenyl-1,4-phenylenediamine with 4-nitrobenzoyl chloride, followed by catalytic reduction. Two series of aromatic poly(N-phenylamide-imide)s and poly(N-phenylamide-amide)s with inherent viscosities of 0.25-0.42 and 0.25-0.54 dL g-1 were prepared by a conventional two-stage method and the direct phosphorylation polycondensation, respectively, from the diamine with various aromatic dianhydrides and aromatic dicarboxylic acids. Some polymers based on rigid dianhydrides and diacids were semi-crystalline and insoluble in organic solvents. The other polymers were amorphous and organosoluble and could afford freestanding or tough films via solution casting. These polyimides and polyamides had glass transition temperatures in the range of 248-267 and 177-198°C, respectively. Decomposition temperatures of the polyimides for 10% weight loss all occurred above 470°C in both nitrogen and air atmospheres.