Compatibilization of polylactide/poly(butylene adipate-co-terephthalate) blends with epoxidized natural rubber as a reactive compatibilizer

Abstract

In this study, the effectiveness of using epoxidized natural rubber (ENR) to compatibilize blend of polylactide (PLA) with poly(butylene adipate-co-terephthalate) (PBAT) has been examined. Interfacial interaction analysis revealed that ENR had higher affinity with PBAT. To achieve better compatibility, a two-step procedure was developed involving blending PLA with ENR first, followed by blending with PBAT. Graft copolymers consisting of PLA, ENR, and PBAT were formed through melt blending, resulting in improved compatibility of PLA blends with PBAT. As the ENR content increased, the dispersed PBAT phase exhibited a gradual reduction in particle size. After compatibilization, the blends showed significantly improved toughness. Ternary PLA/PBAT/ENR blend containing 2 wt% ENR exhibited a drastic increase in break strain, measuring at 589%. This was approximately 2.7 times greater than the break strain of the binary blend PLA/PBAT (221%). The mechanism for tensile toughening of the PLA/PBAT/ENR ternary blends was interfacial bonding cavitation-initiated matrix plastic deformation. Compatibilization of PLA/PBAT blends with ENR is with great promise as it doesn’t compromise the biobased carbon content and sustainability of the materials.