Synthesis and characterization of novel poly(amide imide)s based on bis( p ‐amidobenzoic acid)‐ n ‐trimellitylimido‐ L ‐leucine

N ‐Trimellitylimido‐ L ‐leucine was reacted with thionyl chloride, and N ‐trimellitylimido‐ L ‐leucine diacid chloride was obtained in a quantitative yield. The reaction of this diacid chloride with p ‐aminobenzoic acid was performed in dry tetrahydrofuran, and bis( p ‐amidobenzoic acid)‐ N ‐trimellitylimido‐ L ‐leucine (5) was obtained as a novel optically active aromatic imide–amide diacid monomer in a high yield. The direct polycondensation reaction of the monomer imide–amide diacid 5 with 4,4′‐diaminodiphenylsulfone, 4,4′‐diaminodiphenylether, 1,4‐phenylenediamine, 1,3‐phenylenediamine, 2,4‐diaminotoluene, and benzidine (4,4′‐diaminobiphenyl) was carried out in a medium consisting of triphenyl phosphite, N ‐methyl‐2‐pyrolidone, pyridine, and calcium chloride. The resulting novel poly(amide imide)s (PAIs), with inherent viscosities of 0.22–0.52 dL g −1 , were obtained in high yields, were optically active, and had moderate thermal stability. All of the compounds were fully characterized with IR spectroscopy, elemental analyses, and specific rotation. Some structural characterization and physical properties of these new optically active PAIs are reported. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 35–43, 2002; DOI 10.1002/app.10181