Differential Scanning Calorimetry study of plasticized poly(lactic acid) films during aging

Abstract

The aim of the present work is the evaluation of the aging behaviour of plasticized poly(lactic acid) (PLA) films depending on their plasticizer concentration. The main effect of plasticizer addition was a decrease on the glass transition temperature and an increase in PLA chains mobility which induced crystallization during heating. Standard storage conditions for food packaging materials were simulated and the influence of aging in plasticized PLA films was studied by Differential Scanning Calorimetry (DSC). Good compatibility was observed between the polyadipate used as plasticizer and the matrix. Aging time strongly affected the thermal behaviour of plasticized PLA during heating in DSC experiments, but the samples remained amorphous at ambient temperature after 240 days of storage.