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-dimethylformami de solution at refluxing temperature. The direct polycondensation reaction of the monomer imide-diacid with 4,4'-diaminodiphenylsulfone, 4,4'-diaminod iphenylmethane, 1,4-phenylenediamine, 1,3-phenylenediamine, 2,4-diaminotolu ene, 4,4'-diaminodiphenylether and benzidine was carried out in a medium co nsisting of triphenyl phosphite, N-methyl-2-pyrrolidone, pyridine and calci um chloride. The resulting poly(amide-imide)s, PAIs, having inherent viscos ities of 0.21-0.45 dlg(-1) were obtained in high yield. All of the above co mpounds were fully characterized by IR spectroscopy and elemental analyses. The optical rotation of all PAIs has also been measured. Some structural c haracterization and physical properties of these new optically active PAIs are reported. (C) 2001 Society of Chemical Industry.