Résumé
The radical copolymerisation of electron-acceptor chlorotrifluoroethylene (CTFE) with electron-donorvinyl ethers (VEs) produced poly(CTFE-alt-VE) alternating fluorinated copolymers with a high content offunctional groups. This article describes methods to synthesise poly(CTFE-alt-VE) copolymers that bearammonium-groups insensitive to Hofmann degradation. Direct preparation and post-polymerisationfunctionalisation methods are presented. First, the radical copolymerisation of CTFE with a tertiaryamine-carrying vinyl ether led to low molecular weight-copolymers with an imperfect structure. Thatcopolymerisation and the quaternisation of the amino groups using methyl iodide were howeveraccompanied by side reactions, including transfer reactions and significant loss of functionality. Incontrast, the second strategy dealt with the post functionalisation of an alternated poly(CTFE-alt-2-chloroethyl vinyl ether) copolymer. Halogen exchange of poly(CTFE-alt-CEVE) copolymers was carriedout using the efficient Finkelstein reaction. Then, the nucleophilic substitution of the iodine atoms on theobtained poly(CTFE-alt-IEVE) copolymer led to a poor yield of functionalisation and was accompaniedby a substantial amount of side reactions. Then, the iodine atoms in poly(CTFE-alt-IEVE) copolymerswere chemically changed quantitatively into azides (especially from microwave activation) and theresulting azido-containing copolymer was reacted with 1-dimethylamino-2-propyne. An optimisation ofthis Huisgen's or thermal cycloaddition showed that (i) a copper catalyst led to cross-linked copolymers,(ii) whereas in the absence of the copper catalyst, the cycloaddition was slow and only converted ca.60% of the azides; (iii) then, microwave activation led to high yield in a few minutes. Dimethylaminogroups were inserted onto the copolymeric backbone and subsequently quaternised using iodomethaneefficiently. Such copolymers, potentially resistant to alkaline media and able to promote hydroxide anionconduction, may exhibit interesting properties as a component of solid alkaline fuel cell membranes.