Sustainable poly(lactic acid) transformation: Leveraging agri-food waste-compatibilization strategies nexus for enhanced properties

The paper comprehensively reviews the upcycling and utilization of agri-food loss and wastes (FLWs) in poly(lactic acid) (PLA)-based biocomposites from the perspective of material circularity. The massive volume of unwanted and unvalued FLWs contributed from fruit producers (durian husk, pineapple leaf, orange peel, and apple), post-consumer products (spent coffee ground, sugarcane bagasse, coconut husk, crustacean shells), and agricultural sectors (rick husk, rice straw, wheat straw, and corn stover) is generally discarded and incinerated. Notably, these FLWs can be collected and upcycled into valuable products depending on the final application, endowing them with a meaningful second life. This upcycling approach promotes environment-friendliness and reduces the product's carbon footprint. However, gaps and challenges in creating high-performance biocomposites remain critical to a translatable product. To address that, this review comprehensively discussed the recent progress and strategies to enhance the compatibility of PLA and the various FLW biocomposites, such as improved processability, well-balanced properties, heat resistance, and increased interfacial adhesion. The overall mechanical, thermal, processability, and biodegradability performances are further examined and elaborated. Furthermore, the current and prospective applications, such as packaging, automotive, construction, and 3D printing of FLWs/PLA products, are discussed. Finally, the prospects and opportunities of these FLWs/PLA biocomposites are shared to give a view into the future.