COPOLYMERIZATION OF DICARBOXYLIC ACIDS AND DIALKYL ESTERS OF DICARBOXYLIC ACIDS TO FORM POLYESTERS

摘要

The present invention relates to a process for copolymerizing a dicarboxylic acid, a dialkyl ester, and a diol in the presence of a transesterification catalyst. The process involves heating a mixture containing carboxylic acids and esters in excess diol at elevated temperatures in the presence of a transesterification catalyst and returning any vaporized diol to the reaction vessel until the theoretical amount of alcohol and/or water have been involved. The alcohol and/or water of reaction is not allowed to return to the vessel. When the theoretical weight of alcohol and/or water is collected, the excess diol is removed and the polymerization is allowed to proceed.