PLA / PHBV Films with Improved Mechanical and Gas Barrier Properties

Blending poly(lactic acid) (PLA) with a small amount of poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV; 10 wt%) using a custom multilayer co‐extrusion process increases both ductility and gas barrier properties of extruded films compared with neat PLA and classical blending methods. The co‐extrusion process allows multiplication of the number of alternate layers of PLA and PHBV within a film. It was observed that for a critical number of theoretical layers, PHBV layers are broken into lamellas. A well‐developed lamellar morphology, with thin and long lamellas of highly crystalline PHBV in PLA matrix was obtained. A balance between aspect ratio and crystallinity of the lamellas, and their dispersion within the PLA matrix was needed to obtain films with improved permeability and mechanical properties.