基于α松弛分析CB/LDPE纳米复合介质空间电荷特性

摘要

To investigate the influence of carbon black ( CB ) on space charge of the composites of low density polyethylene (LDPE),blending with the conductive carbon black (C-CB) and insulating car-bon black ( I-CB) were employed as filler particles,respectively.The microstructure and surface chemi-cal property of the two kinds of CB particles were characterized.The space charge distribution of LDPE and the CB/LDPE nanocomposites were obtained by the pulsed electro-acoustic ( PEA) method.The dy-namic mechanical analysis ( DMA) and thermally stimulated current( TSC) methods were also introduced to explore the mechanism for improving space charge performance of LDPE.Experimental results demon-strated that the C-CB particle has longer branched structures and less surface groups compared with I-CB particle,which can be more effective interacted with LDPE.Both of the C-CB/LDPE and I-CB/LDPE nanocomposites can effectively suppress the space charge accumulation,and the former′s ability of suppressing space charge accumulation is stronger.It could be concluded that the space charge character-istic improvement of CB/LDPE nanocomposites is attributed to the interaction between CB particles and LDPE,which reduces the number of defects formed from molecules participating in αrelaxation and de-creases the density of traps in the LDPE.%分别以导电炭黑(C-CB)和绝缘炭黑(I-CB)作为纳米填充相,研究不同性能炭黑(CB)对低密度聚乙烯(LDPE)空间电荷特性的影响.采用多种测试方法对CB微观形貌和表面化学特性进行表征.利用电声脉冲(PEA)法测量LDPE及其纳米复合介质的空间电荷分布,并结合动态机械分析法(DMA)和热刺激电流法(TSC)探索CB改善LDPE空间电荷特性的作用机理.结果表明:C-CB比I-CB具有更长的链状结构和较少的表面基团,可与LDPE产生更强的相互作用;C-CB/LDPE和I-CB/LDPE纳米复合介质均能够有效地抑制空间电荷积聚,其中前者的空间电荷抑制能力更强.分析认为复合介质空间电荷性能改善是由于CB与LDPE相互作用,减少了参与α松弛的分子形成的缺陷数量,降低了LDPE内的陷阱密度.