中文摘要：

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，减少了参与仪松弛的分子形成的缺陷数量，降低了LDPE内的陷阱密度。

英文摘要：

To investigate the influence of carbon density polyethylene （LDPE）, blending with the black （CB） on space charge of the composites of low conductive carbon black （C -CB） and insulating carbon black （ I - CB） were employed as filler particles, respectively. The microstructure and surface chemical 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 dynamic 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 demonstrated 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 characteristic 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 α relaxation and decreases the density of trans in the LDPF.