Experimental study of chemo-mechanical response of amorphous poly(lactic acid) films exposed to UV irradiation
Résumé
In this work, the impact of ultra-violet (UV) irradiation on the mechanical behaviour of amorphous biodegradable poly(lactic acid) (PLA) films is analysed. PLA films were submitted to UV irradiation for increasing exposure time. Two kinds of experiments were conducted, chemical and mechanical. The chemical degradation was measured by gel permeation chromatography technique. The PLA films were mechanically investigated by stretching experiments before and after UV exposure. Their mechanical properties were obtained by a video-controlled system. Our purpose is to establish the relationship between macroscopic mechanical response and molecular parameters such as the molecular weight, and external solicitations such as temperature, strain rate and UV irradiation. The interactions between photodegradation and changes in polymer properties are discussed.