Mh. Hung et al., A NEW SYNTHETIC APPROACH TO POLYFLUORINATED AND PERFLUORINATED POLYETHERS, Journal of the American Chemical Society, 115(20), 1993, pp. 8954-8959
Linear and cyclic perfluorinated polyethers are prepared by a new rout
e involving polymerization of a trifluorovinyl ether alcohol (CF2=CFOR
fCH2OH (1), R(f) = CF2CF(CF3)OCF2CF2) followed by fluorination of the
intermediate polyfluorinated polyethers. Polymerization occurs by ioni
c addition of OH groups to trifluorovinyl ether groups. In the absence
of solvent, linear polymers with M(n) values up to 29000 are obtained
in excellent yield. In glyme solution, cyclic oligomers are the major
products and a cyclic dimer is obtained in yields as high as 60%. Flu
orinated macrodiols with M(n) values to 5000 are obtained by copolymer
ization of 1 with a fluorinated diol. The intermediate linear and cycl
ic partially fluorinated polyethers have excellent solubility in organ
ic solvents and the cyclics can complex anions through hydrogen bondin
g. Photofluorination of these polyethers with elemental fluorine in pe
rfluorinated solvents proceeds smoothly with little fragmentation to a
fford the corresponding perfluorinated analogues in excellent yield.