脂环族环氧树脂材料湿热老化特性研究

Study on Damp Heat Aging Characteristics of the Alicyclic Epoxy Resin

为了研究脂环族环氧树脂材料在南方高温高湿环境下的老化特性,文中对脂环族环氧树脂护套材料进行了湿热老化试验,然后在不同的老化时间下取出试验样品,进行拉伸强度及拉断伸长率、体积电阻率、吸水率、介电常数和介质损耗角正切值、扫描电镜、热失重、傅里叶红外光谱等测试分析,并和硅橡胶绝缘子护套材料进行了对比。结果表明:脂环族环氧树脂和硅橡胶材料均受湿热环境的影响,拉伸强度、拉断伸长率和体积电阻率减小,介电常数、介质损耗角正切和饱和吸水率增大,热分解温度基本不发生变化。湿热环境对脂环族环氧树脂材料的拉伸强度影响较大,而对硅橡胶材料的拉断伸长率影响较大;湿热老化使得脂环族环氧树脂材料主要发生酯键水解,而硅橡胶材料的Si-O-Si主链发生了断裂。

For studying the aging characteristics of alicyclic epoxy resin in high temperature and high humid environ⁃ment in the south of China,the humid and hot aging test on the sheath material of the alicyclic epoxy resin is per⁃formed in this paper.Then,the samples are taken out at different aging times and such test analysis as the tensile strength,elongation at break,bulk resistivity,water absorption,dielectric constant,dielectric loss angle tangent val⁃ue,scanning electron microscope,thermal weight loss and the Fourier infrared spectroscopy are performed and com⁃pared with the silicone rubber insulator sheath material.The results show that both alicyclic epoxy resin and silicon rubber material are affected by the humid and hot environment with tensile strength,elongation at break and volume resistivity decreased,dielectric constant,dielectric loss angle tangent and saturated water absorption increased and the thermal decomposition temperature basically unchanged.The influence of humid and hot environment on the ten⁃sile strength of alicyclic epoxy resin is larger and the influence on the elongation at break of the silicone rubber is al⁃so larger.The main ester bond hydrolysis of the alicyclic epoxy resin is caused by the humid and hot aging,while the main chain of Si⁃O⁃Si of silicone rubber is broken.