纳米TiO_(2)表面精准修饰对硅橡胶直流绝缘性能的影响  

Influence of Precise Modification of Nano-TiO 2 Surface on DC Insulation Properties of Silicone Rubber

作　　者：周远翔 高德[1] 朱小倩 张灵 黄欣[2] ZHOU Yuanxiang;GAO De;ZHU Xiaoqian;ZHANG Ling;HUANG Xin(The Wind Solar Storage Division of State Key Laboratory of Control and Simulation of Power System and Generation Equipment,School of Electrical Engineering,Xinjiang University,Urumqi 830047,China;State Key Laboratory of Control and Simulation of Power System and Generation Equipment,Department of Electrical Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]新疆大学电气工程学院电力系统及发电设备控制和仿真国家重点实验室风光储分室,乌鲁木齐830047 [2]清华大学电机工程与应用电子技术系电力系统及发电设备控制和仿真国家重点实验室,北京100084

出　　处：《高电压技术》2023年第12期4879-4889,共11页High Voltage Engineering

基　　金：国家自然科学基金(51977186,52037009)。

摘　　要：为研究纳米TiO_(2)颗粒表面精准修饰对硅橡胶直流电气性能的影响,分别在纳米TiO_(2)表面单峰和不同密度双峰接枝长链与短链聚二甲基硅氧烷(polydimethylsiloxane,PDMS)。将具有不同接枝类型的纳米TiO_(2)以相同质量分数(1%)添加到硅橡胶(silicone rubber,SIR)中,制作得到纳米TiO_(2)/SIR复合薄膜样品。热失重分析试验结果证明长链与短链PDMS成功接枝到纳米TiO_(2)表面;Zeta电位试验结果表明,长链与短链PDMS双峰接枝增强了相邻TiO_(2)颗粒之间的静电排斥力;TEM观测结果表明,经过双峰接枝长短链PDMS,纳米TiO_(2)颗粒在SIR中的分散性大幅改善。空间电荷、直流击穿和直流电导试验结果表明,双峰接枝长短链PDMS的组别抑制注入同极性空间电荷效果更佳、直流击穿场强更高、体积电导率更低。这是由于随着纳米TiO_(2)表面长短链PDMS双峰有效接枝密度的提高,使得界面区域分子链排列更加质密,自由体积减少;同时,纳米TiO_(2)与SIR基体之间的表面能差降低,促进了SIR基体中纳米TiO_(2)颗粒的分散,增强了SIR与纳米Ti O_(2)颗粒间的界面作用,从而提高了纳米TiO_(2)/SIR复合材料的直流绝缘性能。To investigate the influence of precise surface modification of nano TiO_(2) on the DC electrical properties of silicone rubber(SIR),long and short chain polydimethylsiloxane(PDMS)were grafted onto the surface of nano TiO_(2) with monomodal and bimodal different densities,respectively.Nano TiO_(2) with different grafting types were added to SIR at the same mass fraction(1%)to produce nano TiO_(2)/SIR composite film samples.The results of thermogravimetric analysis confirmed that long and short chain PDMS were successfully grafted onto the surface of nano TiO_(2).The Zeta potential test results indicated that bimodal grafting of long and short chain PDMS enhanced the electrostatic repulsion between adjacent TiO_(2) particles.TEM observations showed that the dispersibility of nano TiO_(2) in SIR was greatly improved by bimodal grafting of long and short chain PDMS.The results of space charge,DC breakdown,and DC conductivity tests indicated that the group with bimodal grafting of long and short chain PDMS exhibited better suppression of injected space charge effects,higher DC breakdown field strength,and lower volume conductivity.The reason is that the increase in the effective grafting density of long and short-chain PDMS on the surface of nano-TiO_(2) particles will result in a denser mesh structure in the interfacial region and reduce the free volume.Additionally,the difference in surface energy between nano TiO_(2) and SIR is reduced,which can promote the dispersion of nano TiO_(2) particles in the silicone rubber matrix,en-hance the interfacial interaction between silicone rubber and nano TiO_(2),and thus improve the direct current insulation performance of the nano TiO_(2)/SIR composite material.

关 键 词：硅橡胶 双峰接枝 纳米TiO_(2) 界面 空间电荷 

分 类 号：TM855[电气工程—高电压与绝缘技术] TM21[一般工业技术—材料科学与工程]