Crystalline polyglycolic acid, polyglycolic acid composition and production process thereof

摘要

Crystalline polyglycolic acid wherein a difference between the melting point Tm and the crystallization temperature Tc2 is not lower than 35° C., and a difference between the crystallization temperature Tc1 and the glass transition temperature Tg is not lower than 40° C. A production process of polyglycolic acid modified in crystallinity, comprising applying heat history to crystalline polyglycolic acid at a temperature of not lower than (the melting point Tm of the crystalline polyglycolic acid+38° C.). A polyglycolic acid composition comprising crystalline polyglycolic acid and a heat stabilizer, wherein a difference (T2-T1) between the temperature T2 at 3%-weight loss on heating of the polyglycolic acid composition and the temperature T1 at 3%-weight loss on heating of the crystalline polyglycolic acid is not lower than 5° C.