Synthesis of novel poly(amide-imide)s containing trimellitylimido-DL/L-alanine moieties via direct polycondensation

N-Trimellitylimido-DL and L-alanine (3) were prepared from the reaction of trimellitic anhydride (1) with DL and L-alanine (2) in N,N-dimethyl formamide (DMF) solution at refluxing temperature. The direct polycondensation reaction of the monomers imide-diacid (3) with 4,4'-diaminodiphenylsulfone (4a), 4,4'-diaminodiphenylmethane (4b), 1,4-phenylenediamine (4c), 1,3-phenylenediamine (4d), 2,4-diaminotoluene (4e), and 4,4'-diaminodiphenylether (4f) was carried out in a medium consisting of triphenyl phosphite, N-methyl-2-pyrolidone (NMP), pyridine, and calcium chloride. The resulting poly(amide-imide)s PAIs, with inherent viscosities 0.32-0.66 dL/g, were obtained in high yield. All of the above-mentioned compounds were fully characterized by IR, elemental analyses, and specific rotation. Some structural characterization and physical properties of these new optically active PAIs are reported. (C) 2001 John Wiley & Sons, Inc.