Synergistic dual effect dynamic network regulation of self-healing silicone rubber composites for outdoor insulation

Abstract

Silicone rubber (SR) is an important insulating material in electrical and electronic equipment and self-healing SR can heal electrical/mechanical damage to enhance the service life of the material. However, commercial silicone rubbers contain high content inorganic fillers and irreversible permanent cross-linked networks, creating a great challenge for the research of their self-healing ability. Herein, a novel PDMS-based silicone rubber containing disulfide and hydrogen bonds (PSH) is designed by introducing dynamic reversible hydrogen to construct a synergistic dynamic cross-linked network. The interactions and reversible cleavage-recombination between dynamic hydrogen and disulfide bonds endow the PSH elastomers with excellent mechanical and self-healing ability. Therefore, the tensile strength of the optimal PSH8 elastomer reaches 1.82 MPa, which exceeds that of the original SR. Meanwhile, the mechanical and electrical damage self-healing efficacy of PSH8 elastomer can achieve 91 % and 67 %, respectively. It provides a feasible approach for the commercialization of self-healing SR, which is beneficial for the application in advanced electrical equipment.