Improved Synthesis of Polyether-Aramid Multi-Block Copolymers by Direct Polycondensation

Polyether-aramid multi-block copolymers having structural regularity were synthesized by a one-pot two-step method of direct polycondensation using triphenyl phosphite and pyridine as condensing agents. Amine-terminated telechelic aramid oligomers were prepared by the reaction of bis(4-aminophenyl) ether and isophthalic acid, and subsequently condensed with a,?-poly(oxyethylene)dicarboxylic acid giving the multi-block copolymers with inherent viscosities of 0.5—0.7 dl g-1. No appreciable differences in thermal and tensile properties were observed between the multi-block copolymers thus prepared and those synthesized by the previously reported two-pot method. In contrast, the properties of these block copolymers differed significantly from those of a randomly coupled block copolymers prepared by the one-step procedure.