AROMATIC POLYESTERS VIA TRANSESTERIFICATION OF DIMETHYLTEREPHTHALATE ISOPHTHALATE WITH BISPHENOL-A/

As a part of our work in the area of transesterification chemistry, we have studied the transesterification of dimethyl terephthalate/isopht halate with bisphenol-A for the synthesis of aromatic polyester. The p rocess comprises two steps. The first step comprises preparation of ar omatic polyester prepolymer by reacting the dimethyl esters of terepht halic/isophthalic acids and bisphenol-A in the melt phase via catalyze d interchange reaction. The second step involves the postpolycondensat ion of aromatic polyester prepolymer under reduced pressure, eliminati ng the by-product and driving the equilibrium of the reversible reacti on to the formation of a high molecular weight aromatic polyester. In both steps, methanol is eliminated as a by-product. The method explore d is the simplest one, permits the use of commercial materials as the feed stock, and leads to a low boiling by-product that can be recycled . (C) 1996 John Wiley & Sons, Inc.