Effect of Maleic Anhydride Grafting Modification on the Dielectric Properties of PP / SEBS Based High Voltage Cable Materials

ABSTRACT Polypropylene (PP) is currently the most promising polymer material used in cable insulation, because of its excellent electrical insulation properties and heat resistance. Now, the dynamic changes in composition and properties of multi‐component composites with PP are being studied. In this paper, maleic anhydride grafted polypropylene (MAH‐g‐PP) is used as a compatibilizer to modify the comprehensive properties of PP/SEBS, particularly the mechanical and electrical properties. The method of mutual verification between experiments and simulations is adopted. The elongation at break of the composites decreases slightly. The low‐frequency permittivity increases gradually, and the high frequency is basically maintained at 2.32. The breakdown strength increases first and then decreases, and the composite with 3.5 wt% MAH‐g‐PP content is the highest, 148.14 kV/mm, an increase of 46.12% compared with PP/SEBS. The MS results show that the E int absolute value of SEBS to MAH‐g‐PP is 6.29 times of SEBS and PP, being −313.08 kcal/mol. In addition, the band gap of MAH‐g‐PP is the narrowest, at 4.06 eV, but there are two distinct localized energy levels, which hindered the transport of charge carriers. This work has significant promoting significance for the application of new environmentally friendly polypropylene cables.