纳米SiO_(2)/硅橡胶复合材料热裂解进程的分子模拟  

Molecular Simulation of Thermal Cracking Process of Nano-SiO_(2)/Silicone Rubber Composites

作　　者：刘兴杰 沈瑶 贾方瑞 梁英 赵涛[3] LIU Xingjie;SHEN Yao;JIA Fangrui;LIANG Ying;ZHAO Tao(School of Electronic and Electrical Engineering,Ningxia University,Yinchuan 750021,China;Xuji Group Comprehensive Energy Service Branch,Xuchang 461000,China;School of Electrical and Electronic,North China Electric Power University,Baoding 071003,China)

机构地区：[1]宁夏大学电子与电气工程学院,银川750021 [2]许继集团综合能源服务分公司,许昌461000 [3]华北电力大学电气与电子工程学院,保定071003

出　　处：《高电压技术》2024年第12期5397-5405,共9页High Voltage Engineering

基　　金：国家自然科学基金(12062023);自治区重点研发计划社发领域项目(2021BEG03029)。

摘　　要：复合绝缘子硅橡胶在长期运行中受到热、电等复杂因素作用下逐渐老化裂解,严重时会造成绝缘击穿失效。为探究高温下纳米SiO_(2)对硅橡胶复合材料的热裂解过程的影响,运用分子模拟软件构建纳米SiO_(2)/硅橡胶复合模型,通过反应动力学方法模拟纳米SiO_(2)/硅橡胶复合材料的高温裂解过程。研究发现:纳米SiO_(2)/MVQ复合体系与MVQ的高温裂解情况、产物相似,均在高温下发生分子链断裂,产生链状硅氧烷,并伴随着大量的小分子物质;纳米SiO_(2)对MVQ的高温裂解过程起到抑制作用,且随着温度的升高,抑制作用逐渐减弱;CH_(4)、C_(2)H_(2)和H_(2)是纳米SiO_(2)/MVQ体系在高温下裂解的主要小分子产物,且H_(2)的数量远远大于其余产物数量,纳米SiO_(2)/MVQ复合绝缘材料的击穿失效可能与H_(2)存在密切联系;纳米SiO_(2)/MVQ复合体系的产物生成速率、数量以及裂解片段与MVQ相比都更少,其热裂解后的小分子含量和类型有望作为评估复合绝缘子硅橡胶热老化程度的参考标准。Silicone rubber of composite insulator is gradually aging and cracking under the action of complex factors such as heat and electricity in long-term operation,which will cause insulation breakdown failure in serious cases.In order to explore the influence of nano-SiO_(2) on the thermal cracking process of silicone rubber composites at high temperatures,a nano-SiO_(2)/silicone rubber composite model was constructed by molecular simulation software,and the thermal cracking process of nano-SiO_(2)/silicone rubber composites was simulated by a reaction kinetics method.The research reveals that nano-SiO_(2)/MVQ composite system has a similar characteristic of MVQ in high temperature cracking and products,and molecular chains break at high temperatures,resulting in chain siloxane,accompanied by numerous molecular substances;nano-SiO_(2) can inhibit the pyrolysis process of MVQ,and the inhibition gradually weakens with the increase in tempera-ture.CH_(4),C_(2)H_(2) and H_(2) are the main small molecular products of nano-SiO_(2)/MVQ system pyrolysis at high temperatures,and the amount of H_(2) is far greater than that of other products.The breakdown failure of nano-SiO_(2)/MVQ composite in-sulation materials may be closely related to H_(2).However,compared with MVQ,the nano-SiO_(2)/MVQ composite system has few products formation rate,quantity and cracking fragments,and the content and type of small molecules after ther-mal cracking are expected to be used as a reference standard for evaluating the thermal aging degree of composite insulator silicone rubber.

关 键 词：硅橡胶 反应动力学 高温裂解 老化 击穿 

分 类 号：TM216[一般工业技术—材料科学与工程]