摘要
为研究纳米颗粒接枝密度对交联聚乙烯(XLPE)纳米复合介质空间电荷特性的影响,分别将未接枝和经不同含量硅烷偶联剂(MDOS)接枝的胶体SiO2纳米颗粒通过熔融共混法添加到XLPE中。扫描电镜观测表明未接枝组别出现数微米尺寸的严重团聚,接枝后纳米颗粒分散性改善;红外光谱分析表明接枝后的纳米颗粒出现MDOS吸收峰,随接枝密度增大而增强;由热重分析结果计算得到了纳米颗粒的接枝密度;差示量热扫描测试结果表明随接枝密度的提高,纳米复合XLPE的熔点略呈上升趋势。-50 kV/mm电场下,XLPE和MDOS/XLPE试样均出现正极性空间电荷包现象,说明仅仅添加MDOS并无捕获或抑制空间电荷的效果。纳米复合后空间电荷受到抑制,随接枝密度的提高抑制效果更加明显。分析认为,MDOS接枝SiO2纳米颗粒,减小SiO2纳米颗粒与基体的表面能之差,促进纳米颗粒的分散,增大了纳米颗粒-聚合物的界面面积,产生的更多陷阱所捕获的电荷进一步降低电极-电介质界面附近的局部电场,但也减小了去极化过程残余电荷的消散速度。
In order to study the influence of graft density of nanoparticles （NPs） on the space charge properties of XLPE nanocomposites （NCs）, we added colloidal SiO2 NPs, both unmodified and modified with different contents of silane- coupling agent （MDOS）, separately into XLPE matrix using the melt blending method. FESEM shows that severe agglomerate of several micrometers appeared in the unmodified group, but nanoparticle dispersion was improved in the MDOS modified group. FTIR spectra indicates the functional groups of MDOS on the surface of SiO2 NPs, and the cor- responding absorption peak rises with the graft density of SiO2 NPs, which was calculated according to TGA results. DSC results show that the melting points of XLPE NCs increases lightly with the graft density. Positive packet-like space charge phenomenon were observed both in XLPE and MDOS/XLPE groups under -50 kV/mm, thus it seems that just adding MDOS has no effect on trapping or suppressing space charge. However, space charge was significantly suppressed in XLPE NCs and the suppression effect strengthened with the graft density. According to our analysis, grafting MDOS agent on the surface of SiO2 NPs helps to decrease the difference of surface energy between SiO2 NPs and the matrix, promotes the dispersion of SiO2 NPs, and enlarges the nanoparticle-polymer interface. It also produces more traps that capture more space charge and consequently decrease the local electric field in the vicinity of electrodes, but slow down the dissipation of residue charge during the depolarization in XLPE NCs
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2014年第9期2653-2660,共8页
High Voltage Engineering
基金
国家重点基础研究发展计划(973计划)(2014CB239501)
国家自然科学基金(51377089)
国家电网公司科技项目(EPRIGYJSKF[2013]2441)~~
