PROCESS FOR PREPARING POLYARYLATES

摘要

Described herein is a process for preparing a polyarylate having a reduced viscosity of from about 0.5 to greater than 1.0 dl/gm which process comprises the following steps: (a) reacting an acid anhydride derived from an aliphatic monocarboxylic acid containing from 2 to 8 carbon atoms with at least one dihydric phenol to form the corresponding diester; (b) after forming the diester, removing by vacuum distillation the bulk of the residual acid anhydride, then adding acetic acid, then vacuum distilling to bring the anhydride concentration to a level low enough to enable the formation of a polymer having a low color and good thermal stability; and (c) reacting said diester with at least one aromatic dicarboxylic acid at a temperature sufficient to form the polyarylate.