Polypropylene nanocomposites containing carbon nanofillers for MV and HV power cables

Abstract

Cross-linked polyethylene (XLPE) is widely used as an insulation material in power cables. With recent advancements in medium and high-voltage power transmission and distribution, there is a growing need for new insulation materials that offer high performance, recyclability, and high operating temperatures as alternatives to traditional XLPE insulation. Polypropylene (PP) has shown excellent properties, making it an attractive candidate for medium and high-voltage direct current insulation and screening (Figure 1) [1,2]. It belongs to the group of polyolefins which can be obtained through the process of polymerization of propylene monomers. PP can be found in three stereo-specific configurations based on the attachment of methyl group ( CH3) on the polymer backbone (syndiotactic, isotactic, and atactic) [1]. The intrinsic high melting temperature of PP allows it to carry high voltages and withstand higher working temperature thus avoiding the use of crosslinking agents. Moreover, PP does not have impurities problems like XPLE and this favours the dielectric properties of PP [1]. Therefore, with respect to XLPE, PP shows the advantages of enhancing thermal and electrical properties, no by-product formation, no degassing treatment requirement, and is recyclable [1]. Thus, developing PP-based MV and HV power cable insulation and screens with enhanced electrical, thermal, and mechanical properties is crucial for finding a recyclable insulation material. The advancements in nanodielectrics suggest that nanotechnology could significantly improve the overall dielectric properties of PP-based materials. This work explores the key aspects of PP-based nanocomposites for MV and HV power cables, with a focus on how different nanofiller parameters affect the dielectric, and mechanical properties, as well as the water treeing effect. Based on the collected information, future directions for enhancing the properties of PP-based nanocomposites for MV and HV power cables will be discussed.