CRYSTALLINE POLYGLYCOLIC ACID, POLYGLYCOLIC ACID COMPOSITIONAND PROCESSES FOR PRODUCTION OF BOTH

摘要

A crystalline polyglycolic acid which has a difference between melting temperature (Tm) and crystallization temperature (Tc2) of 35 ~C or above and a difference between crystallization temperature (Tc1) and glass transition temperature (Tg) of 40 ~C or above; a process for production of polyglycolic acid modified in crystal properties which comprises subjecting crystalline polyglycolic acid to heat history at Tm plus 38 ~C or above; and a polyglycolic acid composition comprising a crystalline polyglycolic acid and a heat stabilizer wherein there is a difference (T2 -T1) of 5 ~C or above between the temperature (T2) of the composition for 3% weight loss on heatin g and the temperature (T1) of the crystalline polyglycolic acid for 3 % weight loss on heating.