Method for improving elastic modulus of biodegradable resin composition

摘要

A method for improving elastic modulus of a biodegradable resin composition in a simple and rapid manner was disclosed. According to such method, a molded product made of poly-lactic acid is subjected to an aging at a temperature higher by 15° C. or more than the glass transition point of such poly-lactic acid and under a humidified atmosphere with a relative humidity (RH) of 60% or above. This successfully raises the elastic modulus from 107 Pa to 109 Pa within a short time. Such improvement in the elastic modulus allows production of a molded product not causative of deformation in an aging test typically conducted at 80° C. and 80% RH for 100 hours.