SYNTHESIS OF PERFLUORINATED ETHERS BY AN IMPROVED SOLUTION PHASE DIRECT FLUORINATION PROCESS

We have developed schemes to make perfluorinated ethers that cover a wide range of molecular weights and boiling points. We describe a relationship that can be used to predict the boiling points of perfluoro polyethers; this is used to assist in the combination of reagents for synthesizing a target having particular physical properties such as boiling point, etc. Our first scheme is to build molecular weight by condensing polyols with fluoro-olefins such as TFE and HFP. These intermediates are then fluorinated by a simple solution phase, batch, photo-assisted direct fluorination to give high yields of isomerically pure perfluorinated ethers. In a second scheme we use ethylene oxide to fine-tune the molecular weight of the polyol, and the weight of these can be extended by reaction with an appropriate fluoro-olefin. These intermediates can be fluorinated using our batch fluorinator to make new perfluorinated ethers of a specific molecular weight and boiling point.