Preparation and Study on Gas Barrier Properties of PLLA/PVA‑g‑PDLA Blends

This study aims to enhance the oxygen barrier property of poly(lactic acid) (PLA) by utilizing the excellent gas barrier performance of poly(vinyl alcohol) (PVA). To mitigate the adverse effects arising from the poor compatibility between PVA and PLA, poly(d-lactic acid) (PDLA) is grafted on PVA, forming a PVA-g-PDLA copolymer, to improve the interaction of the copolymer with the poly(l-lactic acid) (PLLA) matrix. The effects of the content and grafting degree of PVA-g-PDLA on the compatibility, mechanical properties, and oxygen/water vapor barrier performance of PLLA blend films are systematically investigated. The results indicate that this strategy significantly enhances the oxygen barrier performance of PLA under dry conditions and maintains favorable mechanical properties, thereby providing an effective approach to high-performance biodegradable packaging materials.