Synthesis of new poly(amide-imide)s derived from trimellitylimido-L-phenylalanine

N-Trimellitylimido-L-phenylalanine was prepared from the reaction of 1,2,4-benzene-tricarboxylic anhydride with L-phenylalanine in N,N-dimethylformamide solution at refluxing temperature. The direct polycondensation reaction of the monomer imide-diacid with 4,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylmethane, 1,4-phenylenediamine, 1,3-phenylenediamine, 2,4-diaminotoluene, 4,4'-diaminodiphenylether and benzidine was carried out in a medium consisting of triphenyl phosphite, N-methyl-2-pyrrolidone, pyridine and calcium chloride. The resulting poly(amide-imide)s, PAIs, having inherent viscosities of 0.21-0.45 dlg(-1) were obtained in high yield. All of the above compounds were fully characterized by IR spectroscopy and elemental analyses. The optical rotation of all PAIs has also been measured. Some structural characterization and physical properties of these new optically active PAIs are reported. (C) 2001 Society of Chemical Industry.