Gas-phase fluorination of perfluoropolyether functional groups

Abstract We have carried out gas-phase fluorination of perfluoropolyether (PFE) functional groups by CoF 3 and by elemental fluorine on a NiF 2 /carrier catalyst. CF 3 O(C 3 F 6 O) n CF 2 CFO CF 3 O(C 3 F 6 O) n CF 3 +CF 2 O Gas-phase fluorination of PFE No. Catalyst Temperature Conversion PFE losses (°C) of PFE (%) (%) 1 CoF 3 300 78.3 16.3 2 same 350 87.8 18.7 3 same 400 95.2 20.8 4 NiF 2 /carrier 300 91.3 7.1 5 same 350 99.3 8.5 6 same 400 99.9 10.6 Catalyst charges: CoF 3 -250 g, NiF 2 /carrier-50 g; feed rates: PFE-50 g/h, fluorine-4 g/h Direct fluorine treatment of PFE with NiF 2 /carrier catalyst is carried out selectively and is characterized by a higher conversion rate of acyl fluorides. Their residual content is a factor of 10 2 lower than the residual content by the CoF 3 process.