PROCESS FOR THE PRODUCTION OF CYCLIC ESTERS FROM HYDROXY ACIDS AND DERIVATIVES THEREFROM

摘要

Disclosed is a method for producing cyclic esters by the conversion of hydro xy carboxylic acids and their derivatives to their respective cyclic esters. Such cyclic esters, including lactide or glycolide, are particularly useful for producing polymers which can be used to make biodegradable materials, such as biodegradable packaging material. Various methods of cyclic ester production are disclosed, including liquid phase and vapor phase reactions. Also disclosed are various methods for recovering cyclic esters from products-containing streams.