Re-evaluating bioplastic blend wastes through mechanical recycling and chemical modification

The escalating environmental challenges posed by conventional plastics have amplified the importance of biodegradable polymers as sustainable alternatives. However, addressing their recyclability and reprocessing is critical to enhancing their environmental and economic viability. This review delves into the multiple reprocessing of biodegradable polymer blends, focusing on mechanical recycling's effects on their structure, properties, and performance. Unlike single polymers, blends offer tailored properties by combining the strengths of individual components, making them more suitable for diverse applications. However, their complex morphologies and phase interactions demand unique strategies for effective recycling. Key findings highlight that polymer blends, such as PLA/PHB and PLA/PBAT, exhibit greater resilience to repeated processing compared to their pure counterparts, owing to enhanced intermolecular interactions and progressive crystallinity. Compatibilizers, including chain extenders like Joncryl®, play a pivotal role in mitigating degradation by improving phase adhesion and maintaining mechanical and thermal properties. Rheological analyses reveal the critical interplay between phase morphology and processing conditions, emphasizing the importance of tailoring blend compositions and additives for optimal recyclability. This review sets itself apart by providing the first comprehensive examination of the effects of multiple mechanical reprocessing cycles specifically on biodegradable polymer blends, filling a significant gap in the literature. By addressing current challenges, it offers a roadmap for advancing biodegradable materials toward a circular economy.