Two Strategies to precisely tune the mechanical properties of plant oil-derived epoxy resins

During recent years, the development of mechanically robust epoxy resins from natural abundant plant oils is gaining more and more attention. Herein, two strategies were developed to precisely tune the microstructure of plant oil-derived epoxy polymers and mechanical properties of their thermosets. In strategy 1, plant oil-derived epoxy polymers (EPs) with varied densities of epoxy groups were prepared and epoxy resins with tunable mechanical properties were obtained. Tensile test revealed that the mechanical strength, Young's modulus, and toughness increased with the increase of epoxy group density. In strategy 2, the mechanical performanceof plant oil-derived epoxy resins were greatly improved by introducing vanillin as rigid segments. Moreover, the mechanical properties of plant oil-based epoxy resins could be precisely tuned via either strategy 1 or strategy 2, and thermosets from soft elastomers to rigid plastics were obtained. Due to the existence of well-defined chemical networks, plant oil-based epoxy resins exhibit excellent thermally induced shape memory properties.