Preparation and self-healing properties of epoxy vitrimer materials based on imine bonds

Vitrimer materials have machinability and stability because of their shape remodeling and self-healing properties at high temperatures. This article reports the synthesis of epoxy resin using vanillin, p-aminophenol, and epichlorohydrin as raw materials, and polyetheramine-400 as a curing agent. To study the effect of free amine on the mechanical and self-healing properties, two materials with epoxy and amine stoichiometric ratios of 1:1 and 1:1.2 were studied, respectively. The experimental results show that when the molar ratio of epoxy to amine stoichiometric is 1:1.2 (V 1:1.2 ), the tensile strength of vitrimer materials can reach 5.4 MPa and the self-healing efficiency can reach 99.5% after 6 h of healing at 120°C. When the molar ratio is 1:1 (V 1:1 ), the obtained epoxy material has a higher tensile strength of 9.5 MPa. After 24 h of healing at 120°C, the self-healing efficiency can reach 83.4%. In addition, epoxy vitrimer materials can be remodeled at 120°C, and the self-healing and mechanical properties are not influenced after remodeling. This work proposes a novel preparation method for epoxy vitrimer materials, which is beneficial to the development of high-strength remodelable self-healing materials.