UV-A辐射对外绝缘用液态硅橡胶和高温硫化硅橡胶的影响及其机理  

Influence of UV-A Radiation on Liquid Silicone Rubber and High Temperature Vulcanized Silicone Rubber for Outdoor Insulation and Its Mechanism

作　　者：林荧 刘育豪 武康宁 王黎明 丁立健 LIN Ying;LIU Yuhao;WU Kangning;WANG Liming;DING Lijian(School of Electrical and Automation Engineering,Hefei University of Technology,Hefei 230009,Anhui Province,China;Tsinghua Shenzhen International Graduate School,Tsinghua University,Shenzhen 518055,Guangdong Province,China;State Key Laboratory of Electrical Insulation and Power Equipment(Xi’an Jiaotong University),Xi’an 710049,Shaanxi Province,China)

机构地区：[1]合肥工业大学电气与自动化工程学院,安徽省合肥市230009 [2]清华大学深圳国际研究生院,广东省深圳市518055 [3]电力设备电气绝缘国家重点实验室(西安交通大学),陕西省西安市710049

出　　处：《中国电机工程学报》2021年第5期1575-1587,共13页Proceedings of the CSEE

基　　金：安徽省自然科学基金项目(2008085UD11)。

摘　　要：在强紫外环境下,外绝缘用硅橡胶材料(高温硫化(HTV)硅橡胶和液态硅橡胶(LSR))的老化将会威胁输电线路的安全运行。为研究UV-A紫外辐射对二者的影响,该文对UV-A辐射老化后的HTV硅橡胶和LSR进行X射线光电子能谱(XPS)和傅里叶红外光谱(FTIR)等微观结构,以及耐热特性、机电特性和交联密度等宏观性能的测试。研究发现,1000h UV-A老化后,HTV硅橡胶表面碳元素含量减少13.4%,氧元素含量增加10.0%,甲基含量、热稳定性和力学强度下降。但是,LSR表面碳元素含量增加5.8%,氧元素含量下降7.6%,Si(—O)4结构减少,甲基含量增加65.7%,热稳定性增加。分析结果表明,UV-A老化中二者的差异主要是由交联结构、ATH含量,以及含氢硅油造成。最后,基于提出的LSR在UV-A老化过程中发生的提氢反应,建议通过减少含氢硅油的含量和增加生胶的分子量提高LSR的耐UV-A老化性能。该文可为理解外绝缘用硅橡胶材料的紫外老化特性提供支撑,也可用于指导高海拔地区的外绝缘材料选型。In strong ultraviolet(UV) radiation, silicone rubber materials(high temperature vulcanized(HTV) silicone rubber and liquid silicone rubber(LSR)) for outdoor insulation are deteriorated, threatening the operation safety of transmission lines. To study the influence of UV-A radiation on both silicone rubber materials, the experiments about microstructure(X-ray photoelectron spectroscopy and Fourier transform infrared spectrometer) and operation properties(thermal stability, mechanical and electrical properties and crosslinking density) of LSR and HTV silicone rubber were conducted. It was found that after 1000h UV-A aging time, for HTV silicone rubber, the carbon element decreased about 13.4% while oxygen element increased about 10.0%. And methyl, thermal stability and mechanical strength decreased. In contrast, for LSR, the carbon element increased about 5.8% while oxygen element decreased about 7.6%. Si(—O)4 structure decreased while methyl content increased about 65.7% and thermal stability were improved. It is also found that the difference of UV-A resistance between LSR and HTV silicone rubber is caused by crosslinking structure, ATH content and hydrogen containing silicone oil. Based on proposed hydrogen abstraction reaction during UV-A radiation process, the UV-A resistance of LSR can be enhanced by reducing the amount of hydrogen containing silicone oil and by increasing the molecular weight of raw rubber. This paper can provide support for understanding the UV aging characteristics of silicone rubber materials for outdoor insulation, and guide the selection of outdoor insulation materials in high altitude areas.

关 键 词：UV-A辐射 高温硫化硅橡胶 液态硅橡胶 提氢反应 机电特性 

分 类 号：TM72[电气工程—电力系统及自动化]