Effect of MWCNTs/ZnO inorganic fillers on the electrical, mechanical and thermal properties of SiR-based composites

Rubber insulation materials were widely used in the fields of electrical and electronic engineering, especially, which have excellent nonlinear electrical conductivity and can be employed to homogenize the electric field distribution of cable accessories. To enable the rubber materials, such as silicon rubber (SiR), to possess excellent nonlinear electrical conductivity has been a hot issue. In this paper, MWCNTs/ZnO inorganic fillers were prepared by mixing a small amount of multi-wall carbon nanotubes (MWCNTs) with zinc oxide (ZnO) nanosheets, and MWCNTs/ZnO/SiR composites were prepared. The macroscopical properties results show that the nonlinear electrical conductivity characteristics can be induced by filling appropriate content of MWCNTs/ZnO fillers, and the threshold field strength corresponding to the nonlinear conductivity gradually decreases with the increase of MWCNTs filling content, which further decreases with the increase of measured temperature. The COMSOL simulation results also verify that MWCNTs/ZnO/SiR composite with nonlinear conductivity can effectively reduce the electric field strength at the stress cone of cable accessories. In addition, the thermal conductivity and tensile strength for MWCNTs/ZnO/SiR composite are also improved comparing to pristine SiR. This work demonstrates MWCNTs/ZnO/SiR composites possess outstanding overall properties and have good potential to be used in the cable accessory.