Reactive graphene as highly efficient compatibilizer for cocontinuous poly(lactic acid)/poly(ε-caprolactone) blends toward robust biodegradable nanocomposites

Polymer blend nanocomposites with cocontinuous morphology are popular options for realizing various functions, whereas their miscibility and mechanical properties are usually marginalized. Herein, mechanically strong biodegradable nanocomposites were achieved by exploiting the vinyl functionalized graphene (VGN) as a highly efficient compatibilizer for cocontinuous poly (lactic acid)/poly (ε-caprolactone) (PLA/PCL) blends. After being reactively compatibilized using 0.5, 1.0, and 2.0 wt% of VGN, the phase size of cocontinuous PLA/PCL blend was remarkably decreased, and the tensile strength was increased by 200%, 280%, and 253%, respectively. Moreover, the reactively compatibilized PLA/PCL/VGN blend nanocomposites were more ductile than the PLA/PCL blend. Efficient compatibilization and strong interfacial interactions were responsible for the enhanced mechanical properties. The strong interfacial interactions in reactively compatibilized PLA/PCL/VGN blend nanocomposites were evidenced by the linear rheological and atomic force microscopical modulus measuring results. This work provides a facile strategy for compatibilizing and reinforcing biodegradable polymer blend nanocomposites using reactive graphene, which can be potentially used as highly efficient compatibilizers for immiscible biopolymer blends.