Fast step-growth polymerization of 5-(3-acetoxynaphthoylamino)isophthalic acid with different diisocyanates under microwave irradiation

The direct polycondensation reactions of diacid, 5-(3-acetoxynaphthoylamino)isophthalic acid with variousaromatic and aliphatic diisocyanates such as 4,4'-methylene bis(4-phenylisocyanate), toluylene-2,4-diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate were carried out under microwaveirradiation conditions. in order to compare this method with classical heating, the polymerization reactionswere also performed under solution polycondensation conditions. the polymerization reactions occurredrapidly under microwave conditions and produced a series of polyamides containing pendentacetoxynaphthalamide group, with good yields and moderate inherent viscosities of 0.26-0.45 dl/g. thecomparable yields and higher inherent viscosities were obtained by microwave irradiation versus thermalheating with substantial reduction in reaction time.