Tailoring interfacial adhesion and mechanical performance of biocomposites based on poly(lactic acid)/rice straw by using maleic anhydride through reactive extrusion process

In this study, all-green biocomposites based on poly(lactic acid) (PLA)/rice straw (RS) as an agricultural waste were prepared, and the physical, structural, and mechanical properties of these biocomposites were enhanced by alkali-pulping of RS and chemical grafting of PLA onto the lignocellulosic fiber. The reactive compatibilizers of maleic anhydride grafted PLA (PLA-g-MA) were obtained through a reactive extrusion process at different processing conditions. The probable chemical reactions between the functional groups of PLA-g-MA with hydroxyl groups of RS pulp as well as the end groups of PLA chains can effectively improve the interfacial adhesion between the filler and matrix. However, the findings confirm the great importance of PLA-g-MA chemical structure in controlling the biocomposite performance. By choosing proper processing conditions for preparing PLA-g-MA and incorporating this compatibilizer into the PLA/treated RS biocomposite, Young modulus, tensile strength, impact strength, and tensile toughness of the PLA/RS biocomposite increased by 101%, 156%, 96%, and 327%, respectively.