Nitroxide-Mediated Alternating Copolymerization of Vinyl Acetate with tert-Butyl-2-trifluoromethacrylate Using a SG1-Based Alkoxyamine
Résumé
Unique alternating copolymers based on vinyl
acetate (VAc) and tert-butyl-2-trifluoromethacrylate (MAFTBE,
a nonhomopolymerizable monomer under radical
conditions) have been synthesized by nitroxide-mediated
polymerization (NMP) using a SG1-based BlocBuilder
alkoxyamine (MAMA-SG1) at moderate temperature (at 40
°C) in dimethyl sulfoxide. First-order kinetics and linear
evolutions of the molecular weight (up to 17100 g mol−1),
maintaining low dispersity values (Đ ≤ 1.33), confirmed the
controlled nature of the copolymerization. Interestingly, none
of the starting monomers could undergo homopolymerization
under the NMP condition initiated by MAMA-SG1. The
resulting alternating copolymers were characterized by 1H, 13C, 19F, and 31P NMR spectroscopies and size exclusion
chromatography (SEC). The poly(VAc-alt-MAF-TBE) copolymer is amorphous and exhibited a single glass transition
temperature of 59 °C. This is the first report of nitroxide-mediated (co)polymerization of VAc leading to well-defined
copolymers with satisfactory yields. The results presented in this study established a new route via NMP toward the synthesis of
strictly 1:1 alternating fluorocopolymers that can display diverse functionalities.