Zhang Chengcheng, Chang Jianxin, Zhang Hongyu, Li Chunyang, Zhao Hong
Key Laboratory of Engineering Dielectrics and Its Application, Ministry of Education, Harbin University of Science and Technology, Harbin 150080, China.
Polymers (Basel). 2019 Oct 8;11(10):1624. doi: 10.3390/polym11101624.
To suppress space charge accumulation and improve direct current (DC) electrical properties of insulation materials, crosslinked polyethylene modified with 2-(4-benzoyl-3-hydroxyphenoxy) ethyl acrylate (XLPE/BHEA) containing polar functional groups was prepared by melt blending. The gel content, thermal elongation, tensile strength, elongation at break, elasticity modulus, differential scanning calorimetry (DSC) and X-ray photoelectron spectra (XPS) measurement results demonstrated that the BHEA could slightly enhance the crosslinking of polyethylene (PE) and affect the mechanical properties and crystallization of XLPE, and the BHEA molecule was not easy to precipitate from XLPE after the crosslinking process. XLPE modified with 3.0 phr (parts per hundreds by weight) BHEA could effectively suppress space charge accumulation, reduce DC conduction and improve DC breakdown strength of XLPE at a higher temperature. Deeper traps were introduced in XLPE/BHEA composites due to the polar functional groups in BHEA, which could raise the potential charge injection barrier and reduce the charge carrier number and mobility to suppress space charge accumulation and reduce the conduction current density.
为了抑制空间电荷积累并改善绝缘材料的直流（DC）电气性能，通过熔融共混制备了含有极性官能团的2-(4-苯甲酰基-3-羟基苯氧基)丙烯酸乙酯（XLPE/BHEA）改性交联聚乙烯。凝胶含量、热伸长率、拉伸强度、断裂伸长率、弹性模量、差示扫描量热法（DSC）和X射线光电子能谱（XPS）测量结果表明，BHEA可略微增强聚乙烯（PE）的交联，并影响XLPE的力学性能和结晶，且交联过程后BHEA分子不易从XLPE中析出。用3.0 phr（每百份重量份数）BHEA改性的XLPE能有效抑制空间电荷积累，降低直流传导，并在较高温度下提高XLPE的直流击穿强度。由于BHEA中的极性官能团，在XLPE/BHEA复合材料中引入了更深的陷阱，这可以提高潜在的电荷注入势垒，减少载流子数量和迁移率，从而抑制空间电荷积累并降低传导电流密度。
