Optimization and Mechanism Study on Electrothermal Performance of Polypropylene/Antioxidant Composite Systems Based on Molecular Dynamics

Polypropylene (PP) emerges as a promising power cable insulation material, with its electrothermal performance fundamentally determining application potential and operational durability. Meanwhile, antioxidants, renowned for their ability to enhancing thermal stability and insulating performance of polyolefins, offer a viable strategy for optimizing PP. Thus, this study establishes molecular dynamics models for PP/antioxidant systems with antioxidant type as a variable, to investigate the microstructural evolution and electrothermal properties of antioxidant-modified PP across different temperatures. The simulation results indicate that compared to PP neat system, PP/AO736 system shows a 26K increase in glass transition temperature, a 13.88% reduction in relative dielectric constant, and a 37.6% enhancement in breakdown strength at 400 K. Besides, PP/HP system demonstrates advantages in regulating heat transfer, with a 33.1% improvement in thermal conductivity at 300 K. These findings provide methodological guidance for improving the electrical and thermal properties of PP.