Significantly enhanced DC breakdown strength and high‐temperature resistivity of cross‐linked polyethylene through alloying polystyrene strategy

作者：Muneeb Ahmed, Lisheng Zhong, Jinghui Gao, Fei Li, Nuo Xu, Wenpeng Li, Liang Cao · 发表于：High Voltage · 年份：2024 · DOI：10.1049/hve2.12494 · 被引用次数：8 · 研究领域：High voltage insulation and dielectric phenomena、Semiconductor materials and devices、Electrostatic Discharge in Electronics

Abstract Developing a stable insulation material stands as a crucial challenge for high‐voltage direct current (HVDC) cable insulation. This work proposes an alloying strategy to significantly enhance the breakdown strength and high‐temperature resistivity of cross‐linked polyethylene (XLPE). The strategy involves blending low‐density polyethylene (LDPE) with polystyrene (PS), resulting in a polymeric alloy. Confirmation of PS alloying within XLPE is supported by observed shifts in polyethylene miller indices (110) and (200) planes. The dicumyl peroxide used as a crosslinking agent demonstrates an ideal 1.41% enhancement in LDPE‐PS crosslinking. The integration of aromatic ethers in the cross‐linked network enhances temperature stability. Alloying PS at 220°C in XLPE leads to improved inter‐molecular interactions and increased interfacial area, creating a sea–island morphology that resolves voids and limits defect or crack propagation by forming additional trapping sites. The enhanced breakdown strength and reduced conductivity of XLPE‐PS are attributed to increased deep trapping sites and reduced carrier mobility resulting from alloying. The reduced conductivity at 70°C and 90°C demonstrates stability under electric fields. Remarkable breakdown strength improvements of 27.5% and 23.6% are observed at 30°C and 50°C. The proposed alloying strategy suggests replacing XLPE with advanced XLPE‐PS, offering promising prospects for HVDC insulation.