Experimental Study of Compatibility between the Eco-friendly Insulation Mixed Gas CF₃SO₂F/N₂ and EPDM and CR Materials

As a greenhouse gas with strong global warming potential, the use of SF6 needs to be reduced as much as possible. Researching environmentally friendly insulation (EFI) gases to replace SF6 in power electrical equipment is an effective way to reduce its usage. CF3SO2F/N-2, as a newly proposed EFI gas, has certain potential to replace SF6. Compatibility of CF3SO2F/N-2 gas with rubber sealing materials commonly used in electrical equipment is still unknown. In this article, the compatibility of CF3SO2F/N-2 with the ethylene-propylene-diene monomer (EPDM) and chloroprene rubber (CR) was investigated experimentally. It was found that CF3SO2F/N-2 would slightly decompose under the influence of EPDM and CR rubber under certain conditions. The surface morphology of EPDM changed slightly under the influence of CF3SO2F/N-2, and it was similar to the influence of SF6. While the surface morphology of CR deteriorated significantly with obvious defects. The mechanical properties of EPDM were not significantly affected by CF3SO2F, which is similar to the influence of SF6. But CR was affected greatly by CF3SO2F gas. Permanent deformation compression and surface morphology are two effective indicators for characterizing the compatibility between gas and rubber sealing materials. This research provides a reference for the application of CF3SO2F/N-2 as a new EFI gas in power equipment.