The synthesis of fluoroether-fluorosilicone hybrid polymers

The replacement of the fluorocarbon segment in the general class of hybrid fluorocarbon-fluorosilicones by fluoroether units was investigated in order to improve low temperature properties without sacrificing high temperature performance. The effects of the co-reactant halogens (bromine and iodine) and metallic fluorides (potassium fluoride and cesium fluoride) on the product yields in the syntheses of the requisite α,ω-dihalo-F-ether intermediates [1] from the corresponding acyl or diacyl fluorides were studied. While a better yield was obtained with bromine than with iodine, the iodoperfluoroethers produced superior yields in the subsequent ethylene addition reactions, as expected. Potassium fluoride was preferable to cesium fluoride in the synthesis of the iodo-F-ethers, since cesium fluoride effects decomposition of the ethers.