Multiscale Interface Design for Toughened Polylactic Acid Green Composites

In response to the significant environmental impact of global plastic waste, high-performance poly(lactic acid) (PLA) with excellent biodegradability and mechanical robustness is being selected as an effective alternative to mitigate the impact of conventional plastics. This work reports a multiscale interface engineering strategy for the development of high-performance PLA biocomposites. The interfacial reaction between PLA and epoxidized soybean oil was manipulated in situ through the use of lignin, resulting in a favorable phase structure and enhanced interfacial adhesion. Effective energy dissipation and stress reduction were achieved through the synergistic effects of the structure and interface design. The resulting biocomposite demonstrated a remarkable 30-fold increase in elongation and a 21-fold increase in toughness while retaining the modulus, 3D printability, and sustainability of PLA. This multiscale interfacial engineering strategy offers a cost-effective method to improve the performance of biobased polymers, providing new insights and solutions to the global challenge of plastic pollution.