The Compatibility of C6F12O/CO2 gas mixture with sealing rubber materials and the effect of O2

C6F12O (1,1,1,2,2,4,5,5,5-Nonafluoro-4-(trifluoromethyl)-3-pentanone) has excellent insulation and environ-mental performance, which can be used as an insulating medium in medium and low voltage electrical equip-ment after mixing with buffer gas. Additionally, considering that C6F12O may react with sealing materials in the equipment, its compatibility with rubber materials remains to be studied. In this study, the compatibility of Ethylene-Propylene-Diene Monomer Rubber (EPDM), Nitrile Butadiene Rubber (NBR), Fluororubber (FKM) and Silicone rubber (VMQ) with C6F12O gas mixture is investigated, as well as the influence of adding O2, and analysis of the changes in rubber surface morphology, element, mechanical properties and gas composition before and after the thermal aging experiments. Furthermore, the interaction between C6F12O gas mixtures and rubber materials is calculated based on molecular dynamics (MD). The results indicate that varying degrees of degradation exhibit on the surfaces of the rubbers, which deepen with the increase of temperature and the introduction of O2. The C-F bonds, organic fluorides, and metal fluorides are presented on the surfaces of EPDM, NBR, and VMQ, which are relatively low in the original samples. Raising the temperature and introducing O2 accelerate the diffusion of C6F12O gas mixture in rubbers. Combined with experimental and theoretical calcu-lation results, the compatibility between C6F12O gas mixtures and EPDM is the excellent.