On-Demand Recycling of Polylactic Acid–Based Blends into Upgraded Materials with Customizable Compositions

On-demand chemical recycling of hybrid plastics based on sustainable and renewable polymers like poly(lactic acid) (PLA) into upgraded materials is highly desired but still challenging. Herein, we report a solvent-free, one-pot, two-step strategy to on-demand recycle PLA and poly(butylene adipate-co-terephthalate) (PLA/PBAT) immiscible blends into upgraded polymers (UPs) materials with customizable compositions and enhanced performance, through switching the ascendancy of alcoholysis and transesterification controlled by catalysts. By employing ppm-level catalysts with different catalytic activities, UPs featuring either a blended composition (Sn-UPs) or a copolymeric structure (Ti-UPs) were obtained severally, with a better compatibility between PLA and PBAT phases, leading to the superior performance. Specifically, the tensile toughness of Sn-UPs with an elongation at break of 820.9% and the impact toughness of Ti-UPs with an impact strength of 69.33 kJ/m2 are much better than that of pristine PLA/PBAT blends. Besides, the films of Sn-UPs and Ti-UPs not only demonstrate the potential application for fruit fresh-keeping, being comparable to polyethylene film, but also is completely visually invisible in the natural soil environment after 50 days. This on-demand recycling approach offers exciting opportunities for upgrading the waste hybrid plastics to create the high-performance new materials.