Process for the preparation of high molecular weight polyesters

Abstract

A process for producing high molecular weight polyester is provided which allows the production of small quantities of very high molecular weight polyester in a commercially convenient manner, comprising: polycondensing an aromatic dicarboxylic acid with a mixture of an alkanediol and an alkenediol in the presence of a catalyst and in the substatial absence of oxygen, up to a viscosity number in the range from 50 to 140 cm.sup.3 /g to obtain a polyester, contacting said polyester with 0.001 to 8% by weight of an agent which forms free radicals and dissociates with a half-life of 5 seconds to 120 minutes at temperatures in the range from 130.degree. to 350.degree. C., and reacting said polyester and said agent which forms free radicals to provide the high molecular weight polyester.

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