湿热环境下密封橡胶的老化特性研究  

Study on Aging Characteristics of Sealing Rubber in Damp Heat Environment

作　　者：杜钢 李光茂 周鸿铃 李晓 庞志开 DU Gang;LI Guangmao;ZHUO Hongling;LI Xiao;PANG Zhikai(Guangzhou Power Supply Bureau,Guangdong Power Grid Co.,Ltd.,Guangzhou 510420,China)

机构地区：[1]广东电网有限责任公司广州供电局,广州510420

出　　处：《高压电器》2022年第6期112-120,共9页High Voltage Apparatus

基　　金：中国南方电网有限责任公司科技项目(GZHKJXM20190110)。

摘　　要：电力设备中的密封材料在湿热环境中容易因老化而性能下降,由此导致的密封失效会严重影响电力设备的安全稳定运行。为研究湿热环境下密封材料的老化特性,文中选取油封和气封常用的丁腈橡胶、氟橡胶、三元乙丙橡胶进行湿热老化实验。对老化过程中密封材料的力学性能变化进行测试和分析,并利用傅里叶红外光谱、热分析仪、扫描电镜等工具对未老化和湿热老化后的密封材料进行了分析。通过试验得出结论:丁腈橡胶在湿热老化中出现填料的迁移挥发,氟橡胶、三元乙丙橡胶在湿热环境中则以吸湿增重为主;通过压缩永久变形率的变化,说明了氟橡胶容易受到外界应力的影响而出现较大的永久形变;湿热老化后丁腈橡胶和氟橡胶的拉断伸长率显著下降,而三元乙丙橡胶则体现出稳定的力学性能;三种橡胶在湿热老化中都以水解和交联为主,其中丁腈橡胶化学结构和组分变化受湿热老化影响较大,三元乙丙橡胶的化学结构、微观形貌和组分在湿热老化中最稳定,抗湿热老化性能最好。The performance of the sealing material in the electric equipment is prone to be reduced due to aging in the humid and hot environment,the resulting sealing failure will affect safe and stable operation of electrical equip⁃ment.For studying the aging characteristic of the sealing materials in humid and hot environment,the acrylonitrile⁃butadiene rubber(NBR),fluororubber(FKM)and ethylene⁃propylene⁃diene monomer rubber(EPDM),which are commonly used in oil seal and gas seal,are selected in this paper for humid and hot aging experiment.The changes of mechanical properties of the sealing materials during aging period are tested and analyzed,and the unaged as well as humid and hot aged sealing materials are analyzed by such tools as Fourier transform infrared,thermal analyzer and scanning electron microscope.It is concluded through the test that migration volatilization of the filler of NBR oc⁃curs in the humid and hot aging,while FKM and EPDM will absorb moisture and increase weight in humid and hot en⁃vironment.It is shown by the variation in the permanent deformation of compression that FKM is easy to be affected by external stress and has large permanent deformation;The elongation at break of NBR and FKM after hydrothermal ag⁃ing reduces significantly,while the EPDM shows stable mechanical properties;The three kinds of rubbers are mainly hydrolyzed and crosslinked in humid and hot aging,in which the chemical structure and components change of nitrile rubber are greatly affected by he humid and hot aging.The chemical structure,micro morphology and components of EPDM are most stable in the humid and hot aging and the resistance performance to the humid and hot aging is the best.

关 键 词：密封材料 湿热老化 丁腈橡胶 氟橡胶 三元乙丙橡胶 

分 类 号：TM215.2[一般工业技术—材料科学与工程]