Recent Advances in Barrier Property Enhancement of Biodegradable Polymer Films: Strategies and Challenges.

Over the past decades, biodegradable polymer films have gained significant attention owing to their environmental friendliness and abundant raw material availability. However, the barrier properties of biodegradable polymers as packaging materials remain inferior to those of traditional petroleum-based plastic films, limiting their suitability for applications sensitive to oxygen or moisture such as food preservation, pharmaceutical packaging, and electronic device protection. In this paper, we summarize effective strategies to enhance the barrier properties of biodegradable polymer packaging films, such as surface coating, polymer blending, multilayer compounding, copolymerization and modification, nanocomposite technology, and filler reinforcement. Subsequently, we discuss the application of these strategies to biodegradable polymers, including both natural and synthetic varieties. A central focus is elucidating the relationship between the modification approaches, molecular structure, and oxygen/water barrier properties in high-barrier biodegradable polymer materials, aiming to provide valuable guidance for the development of advanced biodegradable polymer packaging materials. Finally, we present the existing challenges and future prospects for the development of high-barrier biodegradable polymer packaging materials.