Reprocessing and Recycling of Poly(Lactic Acid): A Review

Nowadays, poly(lactic acid) (PLA) is one of the most used biobased polymers with significant growth in the global market. Even though one of the main characteristics of PLA is its biodegradability, this process can generate environmental impact, soil use, and genotoxicity of residues. Additionally, PLA still has a considerably high cost, limiting its competitiveness with conventional oil-based thermoplastics. In this sense, this review discusses the reprocessing and recycling of PLA as an alternative to direct biodegradation to explore more economically viable end-of-life options (EoL). The PLA recycling methods are described, and mechanical recycling is highlighted due to its low environmental impact and common availability. The use of specific additives and their importance in maintaining acceptable PLA properties after reprocessing cycles are presented. The reprocessing and recycling effects on the molecular structure, rheological properties, and thermo-mechanical properties of PLA are shown and discussed. Weathering and abiotic factors are also included since they influence PLA recycling by generating previous degradation. In addition, the environmental impact of PLA recycling methods is presented and compared to other EoL options based on life cycle assessment (LCA).