Effect of Grafting Modification on Dielectric Losses in Polypropylene-Based Insulating Materials

In order to develop the next generation of recyclable and environmentally friendly high voltage power cables, more and more attentions have been paid to the modification of polypropylene (PP) materials suitable for cable insulating layer application. In this work, the phenomenon of the reduced dielectric loss in grafting modified polypropylene insulation materials was discovered and analyzed by thermal analysis. The result shown that the interaction between the PP molecular chain and the grafted polystyrene (PS) segment inhibited the motion of the molecular segment below the glass transition temperature (Tg) of PS, which could be the reason for the decrease of the dielectric loss. The findings provide fundamental insights into structure-property relationships and propose a promising strategy for optimizing eco-friendly PP-based thermoplastic insulation in sustainable power cable engineering.