A Self-Healable High Glass Transition Temperature Bioepoxy Material Based on Vitrimer Chemistry

The design of high glass transition temperature (T-g) thermoset materials with considerable reparability is a challenge. In this study, a novel biobased triepoxy (TEP) is synthesized and cured with an anhydride monomer in the presence of zinc catalyst. The cured TEP exhibits a high T-g (187 degrees C) and comparable strength and modulus to the cured bisphenol A epoxy. By adopting the vitrimer chemistry, the cross-linked polymer materials are imparted significant stress relaxation and reparability via dynamic transesterification. It is noted that the reparability is closely related to the repairing temperature, external force, catalyst content, and the magnitude of rubbery modulus of the sample. The width of the crack from the cured TEP can be efficiently repaired within 10 min. This work introduces the first high-T-g biobased epoxy material with excellent reparability and provides a valuable method for the design of high-T-g self-healing materials suitable for high service temperature.