YU Wenlong, HAO Fayi, MA Shuang
The work aims to systematically summarize the research progress, modification strategies, processing bottlenecks, and industrialization prospects of polyhydroxyalkanoates (PHA) in packaging, to provide theoretical and practical guidance for their large-scale application, technological innovation, and related research, so as to alleviate plastic pollution, promote the green transformation of the packaging industry, and address the non-biodegradability of single-use plastics. Relevant domestic and international research was systematically reviewed, with a focus on five key aspects: molecular structure classification of PHA, industrial microbial synthesis pathways, forming and processing technologies, multidimensional performance regulation strategies, and end-of-life (EOL) treatment approaches through a stepwise synthesis and analysis. Centered on modification methods including blending, filling, multilayer composites, and surface coating, their effects on mechanical, barrier, optical, and antibacterial properties were compared. Additionally, four disposal routes, including biodegradation, composting, recycling, and landfilling were compared in terms of their differences and applicable scenarios. PHA achieves conditional biodegradability under specific environmental conditions and is suitable for food-contact applications upon compliance with relevant regulations, making it a highly promising alternative to single-use plastics. PHA, after blending, nano-filler incorporation, and multi-layer structural modification, exhibits significantly enhanced mechanical strength and gas barrier properties, and has now achieved small-scale commercial adoption in fresh-food flexible packaging. However, PHA still faces challenges including poor thermal stability, relatively high production costs, and insufficient controllability of degradation rates, which limit its large-scale adoption. In the future, through strain optimization, low cost fermentation processes, and upgrading of processing equipment, its overall performance can be further improved and its costs can be further reduced, thereby presenting broad application prospects in ocean-friendly materials, fresh produce preservation packaging, and intelligent antibacterial packaging.
