Catalyst-Free,Self-Healing,and Recyclable Tung Oil-Based Epoxy Vitrimers with Dynamic Ester Bonds

Low toughness and nonrecyclability severely limit the applications of traditional thermosets and are not in line with the concept of sustainable development. To solve these problems, water is used as the solvent, and a tung oil-based tetrafunctional carboxylic acid (TFA) curing agent is obtained through a “one-pot” method based on previous works. This green synthesis method is suitable for synthesizing tung oil-based polycarboxylic acid curing agents from various olefin-containing polyacids. At the same time, the vitrimers (DGEBA-TFA) are prepared with diglycidyl ether of bisphenol (DGEBA) as the skeleton, and applied to carbon fiber reinforced composites (CFRCs). The tensile strength, tensile modulus and elongation at break of DGEBA-TFA are 64.62 MPa, 2.55 GPa, and 4.31%, respectively, which are comparable to previous works. Hence, the performance of the vitrimers is not reduced while simplifying the experimental steps. Meanwhile, DGEBA-TFA exhibits excellent self-healing, shape memory, and recycling abilities. The vitrimers can be reprocessed without additional catalysts, and the recovery rate remained at 91.3% in the third cycle. DGEBA-TFA-CFs exhibite excellent tensile strength. This work solves the problems in previous works and makes TFA more likely to be applied into practical industrial production.