Optimizing the balance between stiffness and flexibility by tuning the compatibility of a poly(lactic acid)/ethylene copolymer

Abstract

The brittleness of poly(lacticacid) (PLA) is a major drawback for its wide application. In this study, a super-flexible PLA material was prepared by reactive blending of PLA with poly(ethylene-glycidyl methacrylate) (EGMA), and the weight ratio was fixed at 95 : 5. The investigation showed that the PLA/EGMA blend had limited interfacial compatibility. The strong interfacial interaction and fine dispersion of EGMA particles were obtained by using initiator DCP, which it had been demonstrated could accelerate the reaction efficiency between PLA and EGMA. The elongation at break of the PLA/EGMA/DCP blend was remarkably improved, about 58 folds that of neat PLA. More importantly, its outstanding tensile strength and transparency were definitely maintained as that of neat PLA. Our work provides an effective method to largely improve the flexibility of PLA without sacrificing its stiffness and transparency, which is very important for the wide application of PLA materials.