Compatibility between C3F7CN and Epoxy Resin at High Temperature

Fluorinated nitrile (C
₃
F
₇
CN) is a potential SF
₆
-alternative gas in GIL (Gas-Insulated Transmission Line) due to its low GWP and excellent dielectric strength. To ensure the chemical long-term stability of C
₃
F
₇
CN and good insulation performance of epoxy resin used in GIL, the compatibility between C
₃
F
₇
CN and epoxy resin needs to be investigated. The authors did a number of high temperature thermal aging tests to accelerate the reaction between C
₃
F
₇
CN and epoxy resin. Also, the control groups were set to separate the influence of temperature. The dielectric loss and surface flashover voltage of epoxy resins were tested. The composition of the gas was analyzed by GC-MS, surface morphology and chemical elements of epoxy resins were analyzed by SEM and FTIR. A small amount of C
₃
F
₆
was found C
₃
F
₇
CN after aging and the insulation properties of epoxy resins did not deteriorate.