Comprehensive Performance Regulation and Characterization of Polypropylene/Elastomer Composite Insulation Materials

Polypropylene (PP) represents an important development direction for recyclable cable insulation materials. This paper investigates the synergistic improvement mechanism of the mechanical and electrical properties of PP. The effect of elastomers on the aggregation structure and carrier migration of the samples was investigated by analyzing the microstructure, crystallization, and mechanical and electrical properties of PP/elastomer composites. The results show that elastomers can reduce the tensile modulus of PP, while improving the tensile strength and elongation at break, thereby enhancing the mechanical properties of PP. The elastomer and the PP matrix have better compatibility and introduce amorphous regions, generating a large number of crystalline-amorphous interfaces, which introduce deep traps and reduce the mobility of carriers. Meanwhile, with an increase in elastomer content, the breakdown strength and volume resistivity both increase and then decrease. Among the samples tested, PP/PBE-2 has the best electrical properties and is the insulation material with the best mechanical and electrical properties. This study provides an important reference for the comprehensive performance regulation of PP insulation materials for high-voltage cables.