Preparation of aromatic copolyesters via in situ esterification with isopropenyl esters of an alkyl acid

Abstract

Provided is a method for preparing aromatic copolyesters involving in situ esterification with an isopropenyl ester of an alkyl acid, e.g., isopropenyl acetate. The process comprises reacting the aromatic hydroxy monomers with an isopropenyl ester of an alkyl acid such as isopropenyl acetate in a polymerization vessel in order to esterify the hydroxy moieties, and then polymerizing the esterified hydroxy monomers with aromatic carboxylic acid monomers in the resultant esterification reaction medium to form the aromatic copolyester. Both the esterification and polymerization reactions can be effectively conducted in the same vessel without having to separate out and/or transfer the esterification products from a separate vessel as the polyester polymerization is conducted in the esterification reaction mixture. The esterification is generally carried out in the presence of an acid esterification catalyst, which is preferably neutralized upon completion of the esterification reaction with a suitable basic neutralizing agent, e.g., barium hydroxide.

Dependencies are inferred from the claim text.