Copolymerization of fluorinated monomers with nonfluorinated monomers. Reactivity and mechanisms

The copolymerization of two monomers usually leads to random copolymers except when one of both bears an electron‐acceptor group and the other one has an electron‐donor group. Many copolymers are commercially available, mainly in the series of hydrogenated monomers (S.M.A., GANTREZ, MALIALIM resins). The field of fluorinated copolymers is very interesting because of the strong electron‐acceptor behaviour of the fluorine atoms and more generally of halogenated atoms. Thus, after HALAR (CTFEa)‐ethylene), TEFZEL (TFE‐ethylene) and AFLAS (TFEb)‐propylene) resins, a new series of resins have been produced (copolymers of CTFE and vinyl ethers commercialized by ASAHI Corp.). So it can be considered that ACCEPTOR‐DONOR copolymerization with fluorinated monomers is one of the most important applications of that kind of research. After reminding the main mechanisms of that reaction (homopolymerization of charge transfer complex and copolymerization of free monomers), it will be discussed about the mechanism in some examples (CTFE‐vinyl ethers and other pairs of monomers). Then it will be explained how cotelomerization has provided new data to prefer a copolymerization mechanism by free monomers.