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 Tc 2 is not lower than 35°C, and a difference between the crystallization temperature Tc 1 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 (T 2 - T 1 ) between the temperature T 2 at 3%-weight loss on heating of the polyglycolic acid composition and the temperature T 1 at 3%-weight loss on heating of the crystalline polyglycolic acid is not lower than 5°C.