A NEW SYNTHETIC APPROACH TO POLYFLUORINATED AND PERFLUORINATED POLYETHERS

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.