Effect of annealing on gas permeability and mechanical properties of polylactic acid/talc composite films

Abstract

In this study, composite films based on polylactic acid and talc were prepared by extrusion film blowing to determine the effect of annealing temperature, annealing time, and talc content on the morphology and gas permeability, as well as thermal and mechanical properties. The results showed that annealing temperature, annealing time, and talc content have a direct effect on polylactic acid crystallinity leading to changes in gas permeability and gas diffusion coefficient, while gas solubility was constant. This effect is related to the talc particles and polylactic acid crystals producing higher tortuosity in the films. Finally, a direct relation between crystallinity level, mechanical properties and gas permeability was observed for all the conditions tested.