Synthesis of highly branched perfluoroethers by direct fluorination, promising new materials based on the hexafluoroacetone–ethylene copolymer

Direct fluorination of the hexafluoroacetone‐ethylene copolymer, [CH2CH2OC(CF3)2]n, under conditions designed to promote fragmentation of the polymer chain has led to the synthesis of a number of structurally unusual branched perfluoropolyethers [CF2CF2O‐C(CF3)2]n. These new perfluoropolyethers have been characterized by 19F‐NMR, and their physical properties are reported. Direct fluorination under milder conditions yields a high‐molecular‐weight perfluoropolyether.