Molecular design of eco-friendly insulating gases based on structureactivity relationship

Sulfur hexafluoride gas has been widely used for its excellent dielectric strength. However, the GWP of SF₆ is 23,500 times greater than that of CO₂ and listed as one of the greenhouse gases with restricted use. Therefore, the eco-friendly insulating gases has become a hot research topic. Although g³ gas and the perfluorinated ketone (PFK) gases have attracted extensive attention for dielectric use, they have ax number of disadvantages. However, their similar molecular structure and atomic composition, which consists of a fluoropropyl group and an electron-withdrawing group, provide the ideas and reference for searching novel alternative gases. In this study, the fluoroalkyl groups and sulfur fluorine groups are used as the main groups. The electron-withdrawing groups such as fluorine atom, cyano, carbonyl and sulfur-containing groups are introduced as the modification. The hybrid designed alternative gas molecules are obtained by combining the main and modification groups. Then a set of methods predicting the dielectric strength of hybrid gas molecular models are established based on structureactivity relationship. Finally, a series of candidate molecular models with high dielectric strength and low boiling point are accurately screened. It provides new insights in designing and screening the eco-friendly alternative gases to SF₆.