Effect of triallyl isocyanurate-assisted grafting maleic anhydride poly(lactic acid) as a compatibilizer for poly(lactic acid)/talc composites

Abstract

Poly(lactic acid) (PLA), a biodegradable aliphatic polyester derived from renewable resources, is widely used as a substitute for conventional petrochemical polymers in various fields such as packaging, building, and automobiles. In particular, PLA/talc composites have garnered significant interest because they can address the drawbacks associated with PLA, such as their poor thermal/mechanical properties and high cost. Nevertheless, due to low compatibility between PLA and talc, coupling agents or compatibilizers capable of increasing the adhesion between the two materials are required. Herein, triallyl isocyanurate (TAIC)-assisted maleic anhydride (MAH)-grafted PLA (i.e., PLA-g-(MAH/TAIC)) copolymers are developed as compatibilizers for achieving PLA/talc composites with significantly enhanced mechanical properties. The TAIC used as the co-monomer increases the MAH activity and inhibits the degradation of the PLA, thus effectively increasing the MAH grafting degree by 45 % compared to that obtained with only MAH (without TAIC). The PLA-g-(MAH/TAIC) copolymers improve the interfacial properties between the PLA matrix and talc filler, thus leading to a significant improvement in the mechanical properties (25 and 12 % increases in the elongation at break and Izod impact strength, respectively) compared to those of the PLA/talc composite with PLA-g-MAH. In addition, as the degree of grafting of MAH increases, the interfacial adhesion between PLA and talc is enhanced, resulting in reduced water absorption and biodegradability.