Crystal structure‐flashoverperformance correlation in polybutylene terephthalate: Insights into the mechanism

A deep understanding of the main factors affecting the insulating properties of polymers is essential for the progress of insulation components in various applications, including electric vehicles, electronic devices, and information technology. In this study, we used polybutylene terephthalate (PBT) samples with varying degrees of crystallinity as a model material to investigate the influence of aggregation structure on its electrical performance. The results revealed that increasing the crystallinity of PBT led to a simultaneous increase in the surface flashover voltage. We identified the amorphous region as the weak link in the aggregation structure of PBT. Compared to the amorphous region, the crystalline region exhibited superior resistance to charged ion bombardment, a higher degree of compactness, higher bulk resistivity, and lower surface resistivity. A comprehensive understanding of the relationship between the aggregation structure and electrical performance of polymers is fundamental for developing practical high‐performance insulation components. This study provides valuable guidance for controlling the electrical performance of polymers with high‐performance insulating properties, and is thus of great significance to the electrical aging field.