PROCESS FOR PREPARING GLYCOLIDE

摘要

The method for preparing glycolide comprises (a) esterifying distilled glycolic acid containing 3.0 wt.% or less of water by polycondensation reaction to obtain polyhydroxy acetic ester; (b) thermolysis of the polymer to obtain crude glycolide; and (c) cooling and stirring it for recrystallization of glycolide. The start temp. of the recrystallization is 80-70 deg.C, and the terminal temp. is 45-15 deg.C. Pref. Mn of the polyhydroxy acetic ester is 10,000-30,000; and Mw is 40,000-100,000.