中文摘要：

为研究附生结晶对低密度聚乙烯（low-density polyethylene,LDPE）中空间电荷注入和输运过程的影响,选用玻璃（glass）、聚四氟乙烯（PTFE）和等规聚丙烯（i PP）这3种典型基底材料,制备了具有不同附生结晶试样,即LDPE-G、LDPE-PTFE和LDPE-i PP,开展了室温下空间电荷和直流击穿特性的研究。结果表明：在-100 MV/m电场强度下3组试样均在阳极附近产生正空间电荷包且向阴极迁移;极化30 min时间内,空间电荷引起试样内部最大畸变电场强度值达到177 MV/m;对于LDPE-G、LDPE-PTFE和LDPE-i PP中的空间电荷,由电极注入的负电荷由少到多,正电荷由多到少;3组试样Weibull击穿电场强度由高到低排列顺序依次为：LDPE-i PP、LDPE-PTFE和LDPE-G。分析认为：不同附生结晶结构通过片晶排列方式来改变LDPE表面相对介电常数,导致电荷注入势垒高度变化,3组材料不同的正空间电荷注入难易程度以及表面片晶的排列方式影响了击穿通道的产生概率。

英文摘要：

In order to study the influences of epitaxial crystallization on the space charge injection and transport process in low-density polyethylene （LDPE）, we adopted glass （G）, polytetrafluoroethylene （PTFE）, and isotactic polypropylene （iPP） as the substrates to prepare LDPE samples, denoted as LDPE-G, LDPE-PTFE, and LDPE-iPP, respectively, for the test of space charge and DC breakdown at room temperature. The results show that positive packet-like space charge injects at anode and moves towards cathode at the field of-100 MV/m. The space charge in samples will result in the distortion of electric field with the maximum value of 177 MV/m during the polarization. As for LDPE-G; LDPE-PTFE and LDPE-iPP, the amount of the negative charge injects from the small to the large, and the positive charge injects from the large to the small. The Weibull breakdown strength will arrange as follows： LDPE-iPP〉LDPE-PTFE〉LDPE-G It is analyzed that the epitaxial crystallization changes the surface relative perrnittivity of LDPE through the different lamella arrangement, affecting the charge injection barrier height of both positive and negative charges. In addition, the injection difficulty of positive space charge and the arrangement of lamella on the LDPE surface alters the probability of breakdown channels.