Rapid synthesis of optically active poly(amide-imide)s by direct polycondensation of aromatic dicarboxylic acid with aromatic diamines

4,4'-(Hexafluoroisopropylidene)-N,N'-bis(phthaloyl-L-leucine-p-amidobenzoic acid) (2) was prepared from the reaction of 4,4'-(hexafluoroisopropylidene)-N,N'-bis(phthaloyl-L-leucine) diacid chloride with p-aminobenzoic acid. The direct polycondensation reaction of monomer (2) with p-phenylenediamine (2a), 4,4'-diaminodiphenylsulfone (2b), 2,4-diaminotoluene (2c), 2,6-diaminopyridine (2d), m-phenylene diamine (2e), benzidine (2f), 4,4'-diaminodiphenylether (2g) and 4,4'-diaminodiphenyl methane (2h) was carried out in a medium consisting of triphenyl phosphite, N-methyl-2-pyrolidone, pyridine, and calcium chloride. The homogeneous mixture was heated at 220 degreesC for I min under nitrogen. The resulting poly(amide-imide)s (PAIs) having inherent viscosities 0.27-0.78 dl/g were obtained in high yield and are optically active and thermally stable. All of the above polymers were fully characterized by IR spectroscopy, elemental analyses and specific rotation. Some structural characterization and physical properties of this new optically active PAIs are reported. (C) 2002 Published by Elsevier Science Ltd.