Preparation and Properties of 110 kV Polypropylene-Based Semiconductive Shielding Materials

Two types of low-temperature resistant semiconductive shielding materials withstanding –25 ℃ and –40 ℃ were prepared to develop polypropylene-based semiconductive shielding materials suitable for thermoplastic 110 kV polypropylene insulated cables. After the samples were prepared by internal mixing and sheet pressing processes, dispersion of conductive carbon black in shielding materials, surface smoothness, low-temperature resistance, mechanical properties and volume resistivity before and after aging, rheological properties, thermal stability, and peelability were investigated. Results showed that excellent compatibility, rheological properties, matching properties, and carbon black dispersion were demonstrated by both semiconductive shielding materials. Besides, electrical-mechanical-thermal properties of both materials were found to meet technical requirements, which could be used as 110 kV polypropylene-based semiconductive shielding materials. As a result, an important theoretical basis could be provided for subsequent application of polypropylene-based semiconductive shielding materials.