RAPID SYNTHESIS OF NOVEL OPTICALLY ACTIVE POLY（AMIDE-IMIDE）S DERIVED FROM N,N′-（PYROMELLITOYL）-BIS-L-ALANINE DIACID CHLORIDE AND HYDANTOIN DERIVATIVES UNDER MICROWAVE IRRADIATION

Eight novel poly(amide-imide)s were synthesized under microwave irradiation by using a domestic microwave oven from the polycondensation reactions of N,N'-(pyromellitoyl)-bis-L-alanine diacid chloride (1) with eight different derivatives of hydantoin compounds (2a-h) in the presence of a small amount of a polar organic medium such as o-cresol.The polycondensation proceeded rapidly, compared with the conventional solution polycondensation and was completed within 8-10 min, producing a series of new poly(amide-imide)s (3a-h) with inherent viscosities about 0.35-0.68 dL/g in high yields. The obtained PAIs (3a-h) were fully characterized by means of FT-IR spectroscopy, elemental analyses, inherent viscosity (ηinh), solubility and specific rotation measurements. All of the resulting polymers show optical rotation and are optically active. Thermal properties of the poly(amide-imide)s were investigated by using thermal gravimetric analysis(TGA).