Synthesis and Characterization of Fully Biobased Epoxy Elastomers Prepared from Different Plant Oils

A simple and facile method to prepare fully biobased epoxy elastomers with a high toughness is still a big challenge. In this study, a series of fully biobased epoxy elastomers were prepared by curing different epoxidized plant oils with a biobased diamine Priamine 1074. The curing behavior and catalytic process of these biobased epoxy elastomers was systematically studied. The effects of the different numbers of epoxy groups of these epoxidized plant oils and the equivalent ratios of amine and epoxy groups on the performance (thermal stability, mechanical properties, etc.) of the epoxy elastomers were studied and discussed. Furthermore, the potential of these epoxy elastomers as wearable flexible sensors was explored. It is found that ring opening polymerization and ester aminolysis reaction between amine groups of diamines and ester groups of epoxidized plant oils simultaneously occurred during the curing process. The properties, (thermal stability, thermophysical and mechanical properties, etc.) of these epoxidized plant oils could be tailored by selecting epoxidized plant oils with different numbers of epoxy groups and controlling equivalent ratios of amine and epoxy groups. The maximum elongation at break of the epoxy elastomers could reach up to 338.58%. After spray coating with Ag nanowires, these epoxy resins demonstrated excellent detection of motion signals at various joints and other regions of the body. Combining with the results of not being cytotoxic to Caco-2 cells, the epoxy elastomers reported in this study are expected to be applied in the field of wearable flexible sensors.