Influence of Supercritical Carbon Dioxide Treatment on Structure of Poly (L-Lactide)

摘要

Supercritical carbon dioxide (scCO_2) treatment was used to improve the brittleness of poly(L-lactide)(PLLA). Amorphous PLLA was treated by scCO_2 at a temperature ranging from 40 deg C to 100 deg C, and it was revealed that crystallization took place even at a temperature below the glass transition temperature(T_g) under scCO_2. The scCO_2 treatment at 40 deg C increased the strain at break together with the increase in the tensile strength and Young's modulus. The crystallite size of PLLA treated by scCO_2 at 40 deg C was smaller than that of cold-crystallized PLLA. We found that the strain at break increased as the decrease of crystallite size.