Carbon nanotubes and hexagonal boron nitride nanosheets co‐filled ethylene propylene diene monomer composites: Improved electrical property for cable accessory applications

Abstract

Abstract Rubber‐based composites based on ethylene propylene diene monomer (EPDM) with excellent non‐linear electrical conductivity are preferred to serve as reinforced insulation in cable accessories, which can self‐adaptively regulate electric field distribution and avoid electric field concentration due to the non‐linear conductivity. The conductive carbon nanotubes (CNT) are filled into EPDM to improve the non‐linear conductivity, while the insulating hexagonal boron nitride nanosheets (h‐BN) are used to reconcile the electric breakdown strength. The results show that with the increase of CNT loading content, the non‐linear conductivity of CNT/h‐BN/EPDM composites becomes more prominent, accompanying the decrease of threshold field strength and increase of non‐linear coefficient. However, the electric breakdown strength of CNT/h‐BN/EPDM composites seriously deteriorates due to the increase of CNT content and temperature. By incorporating 10 wt.% h‐BN into the composites, the reduction percentage of breakdown strength can be significantly lowered, which is 19.95% of neat EPDM and 13.74% of CNT/h‐BN/EPDM composites at 70°C, respectively. The COMSOL Multiphysics simulation results demonstrate that using the CNT/h‐BN/EPDM composite as the reinforced insulation can eliminate the electric field concentration of the cable accessory as well as enable the cable accessory with good lightning shock resistance.