Preparation of polylactic acid ternary blend film with improved compatibility for promising application in food packaging

Polylactic acid (PLA), a favored bioplastic, is often limited in the packaging industry due to its inherent hardness and brittleness. To achieve a flexible PLA composite film through the extrusion-blowing method, we introduced a glycidyl methacrylate-grafted polyolefin elastomer (gPOE) and a reactive compatibilizer, ethylene methyl acrylate-glycidyl methacrylate random terpolymer (AX8900), into PLA to fabricate ternary blend films. In this film, both the gPOE and AX8900 offered multiple reactive sites to interact with the COOH and OH groups of PLA, thus leading to a stronger interfacial adhesion. The SEM micrographs also revealed its rough fracture surface with rich fibers, indicating its excellent compatibility performance. Compared to the neat PLA film and the binary blend films, those were PLA blended with picked single elastomers, the ternary blend films exhibited significantly enhanced elongation at break and demonstrates exceptional performance in terms of barrier properties and opacity. This work presents a facile approach for the fabrication of flexible PLA films, which holds great potential for application in the food packaging.