Vinyl monomers bearing a sulfonyl(trifluoromethane sulfonyl) imide group: synthesis and polymerization using nitroxide-mediated polymerization
A series of water-soluble styrene and propyl (meth)acrylate based monomers bearing a sulfonyl(trifluoromethane sulfonyl) imide (STFSI) group was prepared. These monomers were synthesized in good yield from the corresponding chloride sulfonyl monomer and trifluoromethanesulfonamide. Their chemical structures were further confirmed by HR-MS and NMR spectroscopy. Nitroxide-mediated polymerization of the prepared monomers was then performed in aqueous solution at 100 °C, 90 °C and 75 °C for acrylate, styrene and methacrylate derivatives, respectively. Controlled polymerization was successfully achieved as illustrated by the linearity of ln([M]0/[M]) vs. t2/3, the molar mass increase with conversion and the relatively low dispersity values for the resulting homopolymers. Compared to their neutral analogous polymers, the prepared anionic homopolymers exhibited a higher glass-transition temperature. This phenomenon was attributed to the electrostatic interactions between STFSI side groups along the polymer backbone.