The application of polypropylene (PP)/elastomer blend in high voltage direct current (HVDC) cable insulation is up against two major problems, the low thermal conductivity and the degraded insulation properties, which threatens the safe operation of power cable. In this paper, a self-support and pressure reinforced three-dimensional nano boron nitride foam (3D-n-BN) was introduced into PP/propylene-based elastomer (PBE) blend to synergistically improve the thermal conductivity and electrical properties. Microstructures, thermal conductivity, charge transport behaviors and mechanical properties were estimated. It was found that 3D-n-BN micro skeleton structure was formed in PP/PBE blend matrix. The thermal conductivity was improved and more deep traps were introduced with the addition of 3D-n-BN, while the elongation at break (EAB) of PP/PBE/3D-n-BN composite was a little higher than that of PP/PBE blend. It is proposed that the introduction of 3D-n-BN micro skeleton structures can synergistically improve the thermal conductivity and electrical properties of PP/elastomer blend without causing the degradation of mechanical performance.

polypropylene;elastomer;boron nitride;thermal conductivity;trap distribution;mechanical properties