Synthesis of novel optically active poly(esterimide)s with benzophenone linkages by microwave-assisted polycondensation

A new simple and rapid polycondensation reaction of 4,4'-carbonyl-bis(phtha loyl-L-alanine) diacid chloride [N,N'-(4,4'-carbonyldiphthaloyl)]bisalanine diacid chloride with several diphenols, such as bisphenol-A, phenolphthale in, 1,8-dihydroxyanthraquinone, 4,4'-dihydroxybiphenyl, 1,5-dihydroxynaphth alene and hydroquinone, in the presence of a small amount of a polar organi c medium such as o-cresol was performed using a domestic microwave oven. Th e polycondensation reaction proceeded rapidly and was almost complete withi n 12 min to give a series of poly(ester-imide)s with inherent viscosities o f about 0.35-0.58 dl g(-1). The resulting poly(ester-imide)s were obtained in high yield and are optically active and thermally stable. All the above compounds have been fully characterized by IR spectroscopy, elemental analy sis, inherent viscosity (eta (inh)), solubility test and specific rotation. Thermal properties of the poly(ester-imide)s have been investigated using thermal gravimetric analysis (TGA). (C) 2000 Society of Chemical Industry.