| 摘要 |
A process to obtain perfluoropolyethers comprising: a) synthesis of peroxidic perfluoropolyethers by one of the following reactions: al) TFE photooxidation, in solvents selected between perfluorocarbons and (mono)hydrofluorocarbons, of general formula: <?in-line-formulae description="In-line Formulae" end="lead"?>C<SUB>y</SUB>F(<SUB>2y+2-X</SUB>)H<SUB>x </SUB> (II)<?in-line-formulae description="In-line Formulae" end="tail"?> wherein y is an integer from 2 to 4; x is an integer equal to 0 or 1; in the present of fluorine diluted with an inert gas; or a2) TFE oxidation using as radical initiator fluorine or hypofluorites of formula <?in-line-formulae description="In-line Formulae" end="lead"?>R<SUB>f</SUB>OF (III)<?in-line-formulae description="In-line Formulae" end="tail"?> (R<SUB>f </SUB>perfluoroalkyl radical from 1 to 3 carbon atoms), operating from -40° C. to -100° C. at a pressure comprised between 0 and 12 bar; b) thermal treatment of the product obtained in a) at a temperature from 1500° C. to 250° C.; 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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