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 .