Cooperative Optimization Strategy for the Electrical and Mechanical Properties of Silicone Rubber Composites During Aging

ABSTRACT Silicone rubber (SR) composite materials used for high‐voltage cable intermediate connections exhibit significant performance degradation during aging. To enhance the operational stability of SR composite materials, this paper proposes an “electromechanical” synergistic control approach, combining experimental and simulation methods to systematically investigate the effects of nano‐SiO 2 doping on SR aging behavior and electric field distribution. Experimental results show that after accelerated aging, samples doped with 10 wt% SiO 2 exhibit tensile strength and elongation at break that are twice those of pure SR, and the breakdown field strength reaches 22.6 kV/mm, significantly outperforming undoped SR. Mechanistic analysis revealed that an appropriate amount of SiO 2 can form a dense three‐dimensional cross‐linked network, suppressing chain segment slippage and charge injection; however, excessive doping leads to defects due to agglomeration, thereby weakening performance. The nonlinear conductivity model demonstrated that SiO 2 /SR composite materials can homogenize the local electric field at cable jointing points. This study provides new strategies for the lifespan assessment of SR composite insulation and electric field regulation in cable accessories.