Preparation and properties of poly(etber ketone)s derived from 2,6-naphthalenedicarboxylic acid chloride

Poly(ether ketone)s derived from diphenyl ether and mixed diacid chlorides containing 2,6-naphthalenedicarboxyliUc acid chloride (NDC) with terephthaloyl chloride (TPC) or isophthaloyl chloride (IPC) were prepared by Friedel-Crafts acylation in 1,2-dichloroethane with aluminium trichloride as a catalyst. Their thermal properties were widely controlled by changing the composition of diacid chlorides; the glass transision temperature was in the range of 156-203 °C and the melting temperature was 235-390 °C. The order of the structural effect of acid chlorides in increasing the glass transition temperature was NDC > TPC> IPC, and that in decreasing the gas permeability was IPC — NDC > TPC.