Expanding the scope of cobalt-mediated radical polymerization towards the synthesis of novel poly(vinyl acetate-alt-tert-butyl-2-trifluoromethacrylate) alternating fluorocopolymers

Cobalt mediated radical polymerization (CMRP) is a nice technique to control the radical polymerization of vinyl acetate, VAc, but has never been reported on fluoromonomers. This presentation aims at showing recent works on the use of CRMP to prepare well-defined unprecedented 1:1 alternating fluorocopolymers with narrow dispersity (≤1.3) comprised of a polar monomer (VAc) and a non-homopolymerizable fluoromonomer (tert-butyl-2-trifluoromethacrylate, MAF-TBE), under mild conditions.[1] The resulting poly(VAc-alt-MAF-TBE) copolymers have a precise 1:1 alternating structure over a wide range of the comonomer feed compositions in CMRP conditions as well as under free radical polymerization conditions,[2] as confirmed by NMR spectroscopies. Kinetics of radical copolymerization led to their reactivity ratios: rVAc = 0.014; rMAF-TBE = 0 at 40 °C). Simple adjustments of the monomer feed ratio and of the polymerization time, allow the synthesis of well-defined alternating copolymer or of novel poly(VAc- alt- MAF-TBE)-b-PVAc block copolymer composed of an alternating block and of a PVAc block. The block copolymer exhibited two glass transition temperatures (Tg) at 43 and 67 °C, which correspond to those of PVAc segment and poly(VAc-alt-MAF-TBE) alternating sequences, respectively. In contrast, the poly(VAc-alt-MAF-TBE) alternating copolymer displayed only one Tg at 40 °C. For the first time, CMRP of fluorinated monomer was achieved and this fluorine-containing alternating monomer system provides access to a wide range of new polymer materials, under progress.