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

Poly(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 degrees 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 degrees 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%. Schematic diagram of compatibilization effect of non-reactive compatibilizer PLA-GND on PLA/PBAT composite. image