| 摘要 |
A process to obtain perfluoropolyethers comprising: a) synthesis of the peroxidic perfluoropolyether by one of the following reactions: a1) TFE photooxidation, in the presence of UV light, at low temperature, in solvents selected between perfluorocarbons and (mono)hydrofluorocarbons, of general formula: CyF(2y+2-x)Hx (II) wherein y is an integer from 2 to 4; x is an integer equal to 0 or 1; in the presence of fluorine diluted with an inert gas; or a2) TFE oxidation using as radical initiator fluorine or hypofluorites of formula RfOF (III) (Rf pefluoroalkyl radical from 1 to 3 carbon atoms), operating from -40° C. to -100° C. at a pressure comprised between 0 and 12 bar, in an inert solvent under the reaction conditions; b) thermal treatment of the product obtained in a) at a temperature from 150° C. to 250° C., optionally in the presence of a regulating agent of the molecular weight selected between fluorine or hypofluorite of formula (III); c) treatment with elemental fluorine of the polymer obtained in step b) at temperatures from 100° C. to 250° C., or by treatment with fluorine in the presence of UV radiations, operating at temperatures from -50° C. to 120° C.
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