Influence of Temperature on Thermal and Electrical Conductivities for PP/Elastomer/BN Nanocomposite

The use of polypropylene (PP)/elastomer blend in HVDC cable insulation is widespread due to its eco-friendliness. However, the low thermal conductivity of this material limits its application due to the temperature gradient caused by Joule heat from the current in the cable conductor. To address this issue, boron nitride (BN) nanosheets with high thermal conductivity and excellent insulation performance were added to the PP/propylene-based elastomer (PBE) blend. Threedimensional (3D) thermal conductive pathways were created by a self-support and pressure-reinforced method. Thermal and electrical conductivities were measured at 30, 60, and 90°C. The results showed that the addition of BN improved the thermal conductivity and reduced the electrical conductivity of the PP/PBE blend. As the temperature increased, the thermal conductivity of the PP/PBE/BN nanocomposite sample decreased. However, samples with the 3D structure exhibited better thermal conductivity performance at high temperatures. The electrical conductivity increased with the temperature, and the electrical conductivity dependence on temperature was reduced by the introduction of BN. It is suggested that the technique of incorporating the 3D thermal conduction pathways established by thermal conductive nanoparticles into the PP/elastomer blend is advantageous in enhancing its thermal conductivity and insulation performance.