Process for preparing polyarylates

摘要

Described herein is a process for preparing crystalline polyarylates which comprises (a) forming a crystalline polyarylate prepolymer having a reduced viscosity of from 0.05 to about 0.4 dl/g by reacting at least one diester derivative of a dihydric phenol with at least one aromatic dicarboxylic acid in the presence of a solvent, at a temperature of from about 250 DEG to about 300 DEG C., and (b) heating the prepolymer so formed below its melting point to form a crystalline polyarylate having a reduced viscosity of from about 0.45 to about 1.2 dl/g.