Recent Advances in Polyvinyl Alcohol–Based Biodegradable Packaging: Preparation, Modification, and Applications in Food Packaging

With the rapid expansion of the food industry, the extensive use of nondegradable plastic packaging has caused severe environmental pollution and widespread microplastic contamination, posing critical challenges to sustainable development and public health. Consequently, the development of biodegradable food-packaging materials has become a central focus of current research. Polyvinyl alcohol (PVA) is a water-soluble polymer exhibiting conditional biodegradability and excellent biocompatibility. Its outstanding film-forming properties, mechanical toughness, thermal stability, and optical transparency have garnered significant attention, positioning it as a promising alternative to conventional plastics. However, systematic research integrating fundamental preparation strategies with functionalization modification methods remains scarce, particularly in comprehensive investigations addressing PVA's inherent hydrophilicity and its impact on high-humidity food systems. This review fills that gap by systematically examining the preparation methods, physicochemical properties, and applications of PVA-based films. It uniquely integrates recent advances in hydrophobic modification, gas-barrier enhancement, and functional additives into a unified framework that links molecular design to practical food-packaging performance. Furthermore, the prospects and challenges of PVA-based packaging are critically discussed. By articulating these insights, this review provides a novel, application-driven perspective that guides targeted modifications and advanced processing technologies to unlock the full potential of PVA for sustainable food packaging.