Preparation of poly(lactic acid) grafted glycidyl neodecanoate by solid phase grafting and its compatibilization for poly(lactic acid)/poly(butylene adipate‐co‐terephthalate) composite

Abstract

AbstractPoly(lactic acid) (PLA) grafted glycidyl neodecanoate (GND) with a single epoxy group (PLA‐GND) is prepared in this paper by solid phase grafting, and the effects of different reaction conditions on the grafting percentage of PLA‐GND are investigated. Furthermore, PLA‐GND is used as a nonreactive compatibilizer to prepare PLA‐GND/PLA/poly(butylene adipate‐co‐terephthalate) (PBAT) composite by melt blending. The results show that PLA‐GND has the highest grafting percentage of 2.15% when the feed weight ratio of GND to PLA is 0.2, the feed weight ratio of triphenylphosphine to PLA is 0.02, the additive amount of xylene is 1 mL, the reaction temperature is 120°C, and the reaction time is 115 min. The GND segments of PLA‐GND and PBAT segments could form a physical entanglement microdomain because of the similar aliphatic chain of GND and PBAT, which would improve the compatibility of PLA and PBAT. PLA‐GND/PLA/PBAT composite has the highest tensile strength, elongation at break, impact strength, crystallinity, heat deformation temperature, and melt flow rate at a PLA‐GND content of 5%, which are 38.54 MPa, 118.65%, 15.83 kJ/m2, 5.71%, 65.3°C, and 36.3 g/10 min, 14.53%, 390.90%, 68.94%, 224.43%, 16.19%, and 224.40% higher than those of PLA/PBAT composite, respectively.Highlights PLA grafted GND with a single epoxy group is prepared by solid phase grafting. PLA‐GND as a non‐reactive compatibilizer compatibilizes PLA/PBAT composite. The similar chain of GND and PBAT is helpful to form the physical entanglement. The physical entanglement is essential to improve compatibility of PLA and PBAT. PLA/PBAT composite has excellent overall performance at a PLA‐GND content of 5 wt%.