Bio-based epoxy vitrimer: fast self-repair under acid-thermal stimulation
Acylhydrazone bonds can participate in dynamic exchange reactions under acid-stimulated conditions, and disulfide bonds can participate in dynamic exchange reactions under thermally stimulated conditions. It is of great significance to prepare epoxy vitrimer that can rapidly self-repair under acid and thermal stimulation conditions. In this paper, vanillin was used as raw material, and monomer (VAN-AD) containing acylhydrazone bond was synthesized by reaction with adipic dihydrazide. Then, VAN-AD and 4-aminophenyl disulfide (SS) were cured together with glycerol triglycidyl ether to prepare an epoxy vitrimer with acylhydrazone and disulfide dual dynamic covalent bonds. Where VAN-AD provides some of the flexible chain segments and acylhydrazone bonds and SS provides the aromatic phenyl and disulfide bonds. The material was prepared in a simple process and under mild condition, and the properties of the material were optimized by changing the ratio of VAN-AD to SS. The T g of the material was 50 °C when the ratio of SS was the highest, the thermal stability was enhanced with the increase of the ratio of SS, and the maximum tensile strength up to 50.9 MPa, and the material can be completely degraded by DMF with 5% HCl. It is worth noting that the material shows rapid self-healing properties under acid-heat conditions, self-healing rates up to 97.37%, and the tensile strength can reach 26 MPa after repair. The material can be successfully remodeled by hot pressing for 1 h at 140 °C and 10 MPa. Graphical abstract
危险品化学品经营许可证（带存储）