| 摘要 |
<p>A process for separating bifunctional perfluoropolyethers (PFPEs) having two terminations -CH 2 OH from their mixtures with monofunctional PFPEs with one termination -CH 2 OH, of general formula
€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ X 1 -O-Rf-Y€ƒ€ƒ€ƒ€ƒ€ƒ(I)
wherein Rf is a perfluoropolyoxyalkylene chain having a number average molecular weight of 500-10,000; X 1 and Y are end groups selected from -CFXCH 2 OH (wherein X is F or CF 3 ), -CF 3 , -CF 2 Cl, -CF 2 CF 2 Cl, -C 3 F 6 Cl, -CF 2 Br, -CF 2 CF 3 , wherein at least one of the two end groups is -CFXCH 2 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);
c2) filtration of the mixture obtained in c); and
subsequent treatment of the solid phase separated in c2) with a polar solvent obtaining a liquid containing the PFPE having high functionality.</p> |
