Optimization of SEBS Loading and Comprehensive Properties of PP / SEBS / CB Semiconductive Shielding Composites

ABSTRACT To address the lag in formulating semiconductive shielding materials for thermoplastic polypropylene (PP) insulated cables, styrene‐ethylene‐butylene‐styrene block copolymer (SEBS) serves as the toughening modifier. PP/SEBS/carbon black (CB) semiconductive shielding samples with SEBS contents of 20phr, 30phr, 40phr, and 50phr are fabricated. The effects of SEBS content on the material's microstructure, electrical conductivity, tensile properties, thermal properties, and aging durability are systematically investigated. A comprehensive multi‐performance evaluation system screens the optimal formulation, which is applied to the cabling trial of 110 kV PP insulated cables to verify engineering feasibility. The sample with 30 parts SEBS shows the best performance: CB aggregate size ≤ 0.3 μm, PP relative crystallinity 21.1%, volume resistivities 24.14 Ω·cm (25°C) and 15.61 Ω·cm (90°C), tensile strength 24.05 MPa, elongation at break 628.36%. The optimal formulation meets all standard requirements in cabling trials. This study clarifies SEBS's optimization mechanism and provides experimental basis for PP‐based semiconductive shielding materials.