Gas-phase fluorination of perfluoropolyether functional groups

We have carried out gas-phase fluorination of perfluoropolyether (PFE) functional groups by CoF3 and by elemental fluorine on a NiF2/carrier catalyst. CF3O(C3F6O)nCF2CFOCF3O(C3F6O)nCF3+CF2O Gas-phase fluorination of PFE No. Catalyst Temperature Conversion PFE losses (°C) of PFE (%) (%) 1 CoF3 300 78.3 16.3 2 same 350 87.8 18.7 3 same 400 95.2 20.8 4 NiF2/carrier 300 91.3 7.1 5 same 350 99.3 8.5 6 same 400 99.9 10.6 Catalyst charges: CoF3-250 g, NiF2/carrier-50 g; feed rates: PFE-50 g/h, fluorine-4 g/h Direct fluorine treatment of PFE with NiF2/carrier catalyst is carried out selectively and is characterized by a higher conversion rate of acyl fluorides. Their residual content is a factor of 102 lower than the residual content by the CoF3 process.