Self-healing and shape-memory epoxy thermosets based on dynamic diselenide bonds

The fabrication and development of excellent thermoset polymers with self-healing and shape memory properties is highly desirable. Herein, a novel high-strength epoxy resin (EP-SeSe) with diselenide bonds was rationally designed for rapid repair materials in building constructions and electrical packaging. The resultant resins exhibit excellent shape memory performance and self-healing performance due to the dynamic diselenide bonds (SeSe), while maintaining a high mechanical strength (tensile strength = 105 MPa and E = 2.0GPa), and exceptional thermal stability. It is especially noteworthy that the diselenide bonds of the bis(4-aminophenyl) diselenide (BAPDSe) allow EP-SeSe to exchange molecular chains in a dynamic manner, facilitating transport of chain segments while the ortho-phenyl groups prevent the side effects of weak bonds on mechanical properties. Furthermore, when the temperature exceeds Tg, EP-SeSe displays fast stress relaxation, self-healing, remodeling, and weldability due to the [2 + 1] radical-mediated mechanism of the diselenide bonds. We envision that this study provides a facile method for constructing robust multifunctional epoxy resins, which have great potential applications for self-healing and shape-memory epoxy resins.