Comparison of epoxy- and cyclocarbonate-functionalised vinyl ethers in radical copolymerisation with chlorotrifluoroethylene

Abstract

The synthesis of functional fluoropolymers is a challenging and highly sought-after objective. Fluoroolefins are indeed in their vast majority non-functional. Their specific reactivity however, can be turned into an advantage. Alternating copolymerisation of electron-acceptor chlorotrifluoroethylene (CTFE) and electron-donor vinyl ethers (VEs) is indeed efficient to prepare poly(CTFE-alt-VE) fluoropolymers with a very high density of functional groups. This article deals with the synthesis of two original functional vinyl ethers (oxirane and cyclocarbonate), and describes two methods to synthesise ammonium-containing Hofmannn degradation-insensitive fluoro-copolymers, that may display interesting properties as component of solid alkaline fuel cell membranes. Both functional vinyl ethers copolymerised to high yield with CTFE. The oxirane-based monomers led to better defined alternating copolymers compared to the cyclocarbonate-containing vinyl ether. The post-polymerisation functionalisation of the copolymers using amines afforded well-defined ammonium-functionalised fluoro-copolymers.