热重分析法研究硅橡胶复合绝缘子热解动力学  

Study of Pyrolysis Kinetics of Silicone Rubber Composite Insulators by Thermogravimetric Analysis

作　　者：李子由 雷鸣东 李强 干强 赵银山 陈健哲 LI Zi-you;LEI Ming-dong;LI Qiang;GAN Qiang;ZHAO Yin-shan;CHEN Jian-zhe(Dali Bureau of Southern Power Grid Ultra High Voltage Transmission Company,Dali 671014,China)

机构地区：[1]南方电网超高压输电公司大理局,云南大理671014

出　　处：《塑料科技》2024年第11期30-36,共7页Plastics Science and Technology

基　　金：中国南方电网重点科技资助项目(110002022030301SJ0001)。

摘　　要：通过热重分析(TGA)研究硅橡胶绝缘子(SiR)在氮气(N_(2))和空气环境中的热解动力学。将3种不同的等转化模型Flynn-Wall-Ozawa(FWO)、Kissinger-Akahira-Sunose(KAS)和Friedman(FR)方法应用于TGA结果分析,以计算活化能和指数前因子。在N_(2)气氛下采用FWO、KAS和FR方法计算的平均活化能分别为421.46、431.60、433.98 kJ/mol,指数前因子范围为109~1016,热解与表面积无关。在空气气氛下采用FWO、KAS和FR方法计算的平均活化能分别为127.21、120.93、123.38 kJ/mol,指前因子范围为108~109,热解受表面积控制。在N_(2)气氛下,反应的热力学性质,如焓变(ΔH)、吉布斯自由能(ΔG)和熵变(ΔS)远高于空气气氛,证实了N_(2)气氛下反应的复杂性。研究结果有助于加深对SiR燃烧机理的理解,并为其作为一种更有效的耐高温材料的可行性研究提供参考。The pyrolysis kinetics of silicone rubber insulators(SiR)in nitrogen(N_(2))and air environments were studied by thermogravimetric analysis(TGA).Three transformation models,Flynn-Wall-Ozawa(FWO),Kissinger-Akahira-Sunose(KAS),and Friedman(FR)methods,were applied to calculate activation energy and pre-exponential factors.The average activation energies of FWO,KAS,and FR methods under N_(2) atmosphereare were 421.46,431.60,433.98 kJ/mol,respectively.The pre-exponential factor ranged from 109 to 1016,which illustrated that the pyrolysis was independent of surface area.Under the air atmosphere,the average activation energies of FWO,KAS,and FR methods were 127.21,120.93,123.38 kJ/mol,respectively.The value of pre-exponential factor ranged from 108to 109,and pyrolysis was controlled by surface area.The thermodynamic properties of the reaction under N_(2) atmosphere,such as enthalpy changes(ΔH),Gibbs free energy(ΔG)and entropy change(ΔS)were much higher than that under air atmosphere,confirming the complexity of the reaction in N_(2).The results of the study contribute to a deeper understanding of the combustion mechanism of SiR and provide a reference for its feasibility as a more effective high-temperature resistant material.

关 键 词：硅橡胶绝缘子 热重分析 热解动力学 活化能 

分 类 号：TQ33[化学工程—橡胶工业] TM216[一般工业技术—材料科学与工程]