Effect of TiO2 nanoparticles on the electrical aging life of PP cable insulation materials

Polypropylene (PP) as an environmentally friendly cable insulation material has become an emerging research topic in recent years. To improve the long-term operational stability of PP cables, this study aims to enhance the electrical aging life of PP by incorporating TiO 2 nanoparticles through melt blending, both before and after surface treatment. The dispersion behavior of TiO 2 in the PP matrix, the associated functional groups, and the crystallization characteristics of PP were characterized. In addition, polarization depolarization current (PDC) measurements were used to examine the effects of TiO 2 on trap depth and density in the polymer. Accelerated electrical aging tests based on the inverse power law were conducted to predict the aging lifespan of TiO 2 /PP composites and to investigate how the surface treatment of TiO 2 influences insulation performance through its effects on particle dispersion and trap distribution. The results indicate that the incorporation of nano-TiO 2 effectively enhances the electrical aging lifespan of PP. However, high concentrations of untreated TiO 2 lead to particle agglomeration, which reduces performance. Surface modification improves the dispersion of TiO 2 in the PP matrix. Notably, adding 0.5wt% surface-treated TiO 2 to PP results in the greatest improvement in electrical aging lifespan, as evidenced by a 17.02% increase in the electrical aging lifetime index compared to pure PP and a 14.32% increase compared to TiO 2 /PP composites containing the same concentration of untreated TiO 2 . • A high-performance eco-friendly cable insulation material was developed by melt blending TiO 2 and PP insulation material. • Accelerated electrical aging tests were conducted to predict the aging lifespan of TiO 2 /PP composites. • The effects of TiO 2 on the electrical aging life of PP insulation materials were analyzed. • TiO 2 surface-treated with trimethoxy (2-methylpropyl) silane introduces oxygen vacancies, acting as deep traps to enhance the electrical aging life of PP. • Hydrophobic surface-treated TiO 2 improves nanoparticle dispersion, significantly enhancing the electrical aging life of PP insulation materials.