Study on the Reaction Mechanism of Ethylene Propylene Diene Monomer Sealing Material and CFO-CO Gas Mixture.

The eco-friendly insulating medium CFO gas has attracted the attention of many researchers due to its superior environmental protection and insulation properties. However, there are few studies on the compatibility of CFO gas with sealing materials for the gas-insulated equipment (GIE), which will bury hidden dangers for its engineering application. In this study, the compatibility of CFO gas with an ethylene propylene diene monomer (EPDM) sealing material which is most used in equipment was tested, and its reaction mechanism was simulated. The study found that the O element on the carbonyl group of CFO gas has high chemical reactivity and will interact with EPDM rubber. During the interaction process, EPDM rubber will also react with the CF gas generated by the decomposition of CFO gas, and at the same time, it will also decompose CFO gas to produce more CFO and CHF. The surface of EPDM rubber will produce oily substances and a large number of crystal particles, which will cause its mechanical properties to deteriorate and shorten its service life. Therefore, it is necessary to carry out anti-corrosion treatment on the surface of EPDM rubber or replace the sealing material with better compatibility when designing and manufacturing GIE.