Dynamically vulcanized poly (lactic acid)/polyurethane/MXene nanocomposites with balanced stiffness and toughness

When brittle poly (lactic acid) (PLA) toughened by elastomers, loss of strength and modulus are inevitable, how to avoid the strength and modulus loss for elastomer toughened PLA is an urgent problem to be solved. In this study, a one-step dynamic vulcanization strategy was reported to prepare PLA/polyurethane (PU)/MXene nanocomposites with balanced stiffness and toughness based on the reaction between polyethylene glycol (PEG) and isophorone diisocyanate trimer (IPDIT). The effect of MXene content on the morphology, mechanical properties, thermal transitions and rheological behavior were investigated in detail. The results show that the PU generated during the dynamic vulcanization process and PLA have very good compatibility, and MXene nanosheets can be well dispersed in PLA/PU polymer matrix after pre-intercalation with PEG molecular chains. This study provides a promising strategy for manufacturing high performance PLA with balanced stiffness and toughness at industrial level.