Effects of Conductive Carbon Black Type and Content on the Performance of Polypropylene Cable Shielding Materials

ABSTRACT Semiconductive shielding materials are essential for homogenizing electric fields and ensuring reliability in high‐voltage cables. This study systematically investigates the influence of conductive carbon black (CB) type (C1, C2, C3, C4) and content (5–30 wt.%) on the performance of polypropylene (PP)‐based shielding composites. Through comprehensive characterization of dispersion uniformity, thermal stability (TGA/DSC), mechanical properties, and volume resistivity (10 2 –10 5 Ω cm), we demonstrate that CB with moderate specific surface area (55–59 m 2 /g) achieves optimal balance. C4 (1408 m 2 /g) exhibits severe aggregation due to excessive surface activity, leading to processing brittleness and disqualifying it as a filler. At 22.5 wt.% loading, C3 achieves the lowest volume resistivity (18.22 Ω cm) alongside superior tensile strength (28.01 MPa) and thermal stability ( T max = 483°C). In contrast, C2 requires 27.5 wt.% to attain comparable conductivity (34.49 Ω cm) but shows better processability. This work establishes a framework for tailoring PP shielding materials, highlighting C3's potential in industrial applications requiring high conductivity and mechanical robustness.