Study on electrical, thermal, mechanical and corrosion resistance properties of conductive silicone rubber for polymer-based metal composite grounding electrodes

The power grounding grid is a critical apparatus for ensuring the safe operation of electrical networks. However, the long-term burial of grounding grids underground makes them susceptible to soil corrosion, undermining their grounding effectiveness and posing threats to personnel and equipment safety. This paper developed silicone rubber with excellent mechanical properties, outstanding corrosion resistance, and high electrical conductivity to mitigate the corrosion rate of grounding electrodes and extend the lifespan of grounding grids. The effects of graphite and carbon nanotubes mixed conductive fillers on silicone rubber’s electrical, thermal, mechanical, and corrosion resistance were investigated. The results show that when the addition amount of carbon nanotubes and graphite mixed conductive filler is less than 4%, the content of conductive filler increases with the increase of the content of conductive filler. The electrical conductivity, tensile strength, thermal conductivity, and thermal stability of conductive silicone rubber gradually increase, and its corrosion resistance and adhesion are unaffected. With a filler loading of only 4 wt%, the silicone rubber achieves an electrical conductivity of 0.41 s/cm, a tensile strength of 4.08 MPa, and a fracture elongation of 113%. These results confirm that the corrosion resistance, heat resistance, and adhesion meet the requirements of grounding electrodes. The outcomes of this research provide robust support for the advancement of green electrical equipment.