| 摘要 |
A process for separating bifunctional perfluoropolyethers (PFPEs) having two terminations -CH<SUB>2</SUB>OH from their mixtures with monofunctional PFPEs with one termination -CH<SUB>2</SUB>OH, of general formula <?in-line-formulae description="In-line Formulae" end="lead"?>X<SUB>1</SUB>-O-Rf-Y (I) <?in-line-formulae description="In-line Formulae" end="tail"?> wherein Rf is a perfluoropolyoxyalkylene chain having a number average molecular weight of 500-10,000; X<SUB>1 </SUB>and Y are end groups selected from -CFXCH<SUB>2</SUB>OH (wherein X is F or CF<SUB>3</SUB>), -CF<SUB>3</SUB>, -CF<SUB>2</SUB>Cl, -CF<SUB>2</SUB>CF<SUB>2</SUB>Cl, -C<SUB>3</SUB>F<SUB>6</SUB>Cl, -CF<SUB>2</SUB>Br, -CF<SUB>2</SUB>CF<SUB>3</SUB>, wherein at least one of the two end groups is -CFXCH<SUB>2</SUB>OH, said process comprising the steps of: a) addition of the PFPE mixture to an adsorbing solid phase, under stirring; b) filtration of the mixture obtained in a): c) addition to the solid phase filtered in b), of a PFPE mixture having an average functionality higher than that of the PFPE mixture of the liquid filtered in b); c 2 ) filtration of the mixture obtained in c); and subsequent treatment of the solid phase separated in c 2 ) with a polar solvent obtaining a liquid containing the PFPE having high functionality.
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