Fabrication and performance of biodegradable poly (lactic acid)/poly (butylene adipate-co-terephthalate) composites by regulating the dispersed rice husk with the silane coupling agent and alkaline.

Mixing poly (lactic acid) (PLA) with another biodegradable resin, poly (butylene adipate-co-terephthalate) (PBAT), is a simple strategy to toughen PLA, but its effectiveness is limited, and stiffness is usually compromised. As a consequence, the simultaneous enhancement of strength and toughness in PLA has become of significant challenge in materials driven by growing demand for green polymers in expanded biodegradable fields. In this study, we design and fabricate a novel PLA composites based on a facile processing route consisting of rice husk modified with the silane coupling agent and alkaline (RHM) as the reinforcing agent, and PBAT grafting glycidyl methacrylate (GMA) as the toughening agent. The results indicated RHM promoted the crystalline behavior of the composites and improved the thermal stability, dimensional stability, melt strength and hydrophilicity. PBAT grafted by GMA greatly increased the compatibility of RHM with PLA, which was confirmed in rheological and DSC tests. The toughness of the composites increased by 199 %-237.6 % while maintaining better stiffness and degradability. This work presents a simple and effective strategy for preparing low-cost, and well-balanced stiff and tough PLA, thereby expanding the application range of PLA.