Aromatic polyamides derived from unsymmetrical diamines containing the phthalazinone moiety

Two unsymmetrical and kink non-coplanar heterocyclic diamines, 1,2-dihydro-2-(4-aminophenyl)-4-[4-(4-aminophenoxy)phenyl](2H)phthalazin-l-one and 1,2-dihydro-2-(4-aminophenyl)-4-[4-(4-aminol)henoxy)-3,5-dimethylphenyl](2H) phthalazin-1-one, were successfully synthesized by readily available heterocyclic bisphenol-like monomers through two steps in high yields. A series of novel poly(arylene ether amides)s containing the phthalazinone moiety with inherent viscosities of 1.16-1.67 dL/g were prepared by the direct polymerization of novel diamines and aromatic dicarboxylic acids using triphenyl phosphite and pyridine as condensing agents. The polymers were readily soluble in a variety of solvents such as N,N-dimethylformamide, N,N-dimethylacctamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, and even in pyridine, chloroform and m-cresol. The glass-transition temperatures were in the range of 291-329 degreesC, and the temperatures for 5% weight loss in nitrogen were above 490 degreesC. (C) 2002 Wiley Periodicals, Inc.