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

• Glycidyl vinyl ether (GcEV) copolymerises with chlorotrifluoroethylene in a near perfect alternating fashion.
• The copolymerisation of the cyclocarbonate derivative of GcEV (CCEV) with CTFE leads to defects to alternation.
• The ring-opening of the cyclocarbonate moieties of poly(CTFE-alt-CCEV) with primary amines proceeds with good yields.
• Alternating copolymers such as poly(CTFE-alt-CCEV) are very versatile to prepare multifunctional fluorinated copolymers.

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.

Synthesising functional fluoropolymers is challenging due to the lack of readily available functional fluoroolefins. This article demonstrates that alternating copolymerisation of electron-acceptor chlorotrifluoroethylene (CTFE) and electron-donor vinyl ethers (VEs) is a very efficient method to prepare highly functional poly(CTFE-alt-VE) fluoropolymers.Figure optionsDownload as PowerPoint slide