Compatibility and interaction between C6F12ON2 gas mixture and sealing rubber materials

Abstract

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 × 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.