Compatibility and Interaction Between C6F12O N2 Gas Mixture and Sealing Rubber Materials

The C6F12O gas mixture has good insulating properties and can replace the strong greenhouse gas sulfur hexafluoride (SF6) in power equipment. To ensure the safe operation of the equipment, the compatibility between the C6F12O/N2 gas mixture and commonly sealing rubber materials Ethylene-Propylene-Diene Monomer (EPDM), Nitrile Butadiene Rubber (NBR), and Fluororubber (FKM)) is an important factor. In this paper, the compatibility between the C6F12O/N2 gas mixture and rubber materials at different temperatures is studied. Moreover, the free volume fraction, diffusion coefficient, and radial distribution function are calculated. It is found that there exists a chemical reaction between the C6F12O/N2 gas mixture and rubbers, which leads to the appearance of folds or crystalline particles and the accumulation of a large number of F elements on the surface of NBR and EPDM. The simulation results show that the diffusion of the C6F12O/N2 gas mixture in the rubber is enhanced with the increase of temperature, and the diffusion coefficient of C6F12O in NBR is the largest, reaching 33.439 x 10-11m2/s. The experimental and theoretical results show that compatibility between the C6F12O/N2 gas mixture and FKM is better. FKM will have a better application prospect in C6F12O/N2-containing power equipment.