Résumé
Fluorinated polymers are niche macromolecules that play an integral role in modern life[1].Bulk iodine transfer copolymerizations (ITcoPs) of styrene (ST) with either α-fluoromethylstyrene (FMST) or α-trifluoromethylstyrene (TFMST) in the presence of a 1-iodoperfluorohexane as the chain transfer agent (CTA) are presented [2]. The controlled character of these copolymerizations was studied both by supplying a linear evolution of the experimental molar masses (Mns) versus the monomer conversion and evaluating the chain extension ability of the formed copolymers. The amounts of dead chains in all copolymers were lower than 5 %. Bulkier CF3 group induced a slightly lower reactivity of TFMST comonomer since in the first step, the experimental Mns of the copolymers containing TFMST reached 43,000 g.mol-1 while those based on FMST displayed 65,000 g.mol-1. In the second step, the produced diblock copolymers had Mns twice higher than those of the starting copolymers, still containing iodine end-group, as evidenced by a further azidation. Scheme 1. Radical copolymerization of styrene with fluorinated α-methylstyrene in the presence of 1- iodoperfluorohexane initiated by AIBN at 70 °C.References [1]. F. Boschet and B. Ameduri, Chem. Rev., 2014, 114, 927-980.[2]. J. Walkoviak, A. Szwajca F. Boschet, V. Gouverneur, et al., Macromolecules, 2014, 47, 8634–8644