Effect of Fumed Silica Content on the Microstructure and Hydrophobicity Recovery of Silicon Rubber
Wang Kang1, 2, Wang Jianguo1, Zheng Feng3, Fang Pengfei3, Peng Xiangyang4, Xu Zhihai4
1. School of Electrical Engineering Wuhan University Wuhan 430072 China; 2. State Grid Jibei Electric Power Company Limited Electric Power Research Institute Beijing 100045 China; 3. Department of Physics & Hubei Nuclear-Solid Physics Key Laboratory Wuhan University Wuhan 430072 China; 4. Guangdong Power Grid Company Electric Power Research Institute Guangzhou 510080 China
Abstract:Hydrophobicity recovery is an important characteristic of silicon rubber. Silica as reinforcing filler is the basic material of silicon rubber composite insulators. In order to study the microstructure and hydrophobicity recovery of silicon rubber with different contents of silica, the silicon rubber samples with different quality contents were refined. The results of the positron lifetime spectra showed fumed silica interacted with rubber chains. Since fumed silica could be served as physical cross-link junction, when the content of fumed silica increased, the cross-link degree of whole system also increased. On the other hand, more fumed silica resulted in bigger size agglomeration. Thus more positrons annihilated in fumed silica, and suppressed the production of Ps. So τ3 increased while I3 and I4 both decreased. Otherwise, after 5 min Ar plasma treatment, the results of the hydrophobicity recovery showed that increasing fumed silica would decrease hydrophobic recovery speed. But too much fumed silica will affect the hydrophobicity recovery of silicone rubber and shorten the lifetime.
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