SOLUTION POLYMERIZED HALOGENATED POLYESTERS

摘要

A process for preparing certain halogenated aromatic polyesters having a predetermined molecular weight is provided. Such polyesters are prepared by solution polymerization of an appropriate bisphenol and diacid halide wherein the diacid halide is added to a solution containing the bisphenol until the viscosity of the resulting polymer containing solution reaches a predetermined solution viscosity limit at which time the further addition of diacid halide is terminated. The solution limit is indicative of the attainment of said predetermined molecular weight. The identification of said solution viscosity limit is achieved by a feedback mechanism wherein the viscosity of the polymer containing solution is monitored or sensed during or after the addition of the diacid halide to the bisphenol containing solution.