Thermal and electrical decomposition products of C5F10O and their compatibility with Cu (1 1 1) and Al (1 1 1) surfaces.

• C 5 F 10 O starts to decompose at 500 ℃ and CO 2 , C 3 F 6 , and C 4 F 10 are dominant by-products. • A unique by-products C 2 F 6 O 3 is produced under partial discharge in C 5 F 10 O-air mixture. • Decomposition products CF 4 , C 3 F 6 , CF 2 O, CHF 3 , and C 3 HF 7 have good compatibility with Al (1 1 1) and Cu (1 1 1) surfaces. • The O atoms in C 2 F 6 O 3 show strong reaction activity with Al (1 1 1) and Cu (1 1 1) surfaces. Perfluoroketone C 5 F 10 O has drawn much attention in recent years as a promising environmental-friendly gas to substitute SF 6 in power equipment. In this paper, the decomposition characteristics of C 5 F 10 O and C 5 F 10 O/air mixture under pyrolysis and partial discharge conditions were explored by experiments using a gas chromatography/mass spectrometer. Besides, the compatibility of decomposition products with the copper and aluminum was evaluated based on the density functional theory calculation. We found that C 5 F 10 O has good thermal stability at 300 ℃. At 500 ℃, C 5 F 10 O starts to decompose and it produces CO, CO 2 , C 2 F 6 , C 2 F 4 , C 3 F 8 , C 3 F 6 , C 4 F 10 , C 4 F 8 and CHF 3 , among which CO 2 , C 3 F 6 , and C 4 F 10 are dominant. For C 5 F 10 O/air mixtures, the pyrolysis products are mainly saturated fluorocarbons and more CO 2 is produced. Partial discharges in C 5 F 10 O/air mixture mainly produce CO 2 , saturated fluorocarbons and a unique compound C 3 F 6 O 3. It is found that CF 4 , C 3 F 6 , CF 2 O, CHF 3 , and C 3 HF 7 have good compatibility with Al (1 1 1) and Cu (1 1 1) surfaces, while the interactions between C 2 F 6 O 3 and Al (1 1 1), Cu (1 1 1) surfaces are relatively strong, which are chemisorption. The identified by-products of C 5 F 10 O and C 5 F 10 O/air mixture under different conditions as well as their compatibility with metal materials is essential for online fault-diagnostic and long-term maintenance in engineering applications. [ABSTRACT FROM AUTHOR]