Free-Radical Copolymerization of Perfluorinated Vinyl Ether, Post-Modification by “SuFEx” Click Reaction and Properties

Six kinds of perfluorinated vinyl ether-based copolymers were synthesized by thermal radical polymerization under normal atmospheric pressure and in nonfluorinated solvents. The “SuFEx” click reaction was used to conjugate with amine-terminated small molecules or polyethylene glycol（PEG） to form the graft copolymer or the polymer brush, and the related polymeric nanoparticles with high fluorine content were fabricated by aqueous self-assembly. The structure, molecular weight and glass transition temperature of the fluorinated copolymers were tested by nuclear magnetic resonance spectroscopy (¹H-NMR, ¹⁹F-NMR), Fourier-transform infrared spectroscopy (FT-IR), gel permeation chromatography (GPC) and differential scanning calorimetry (DSC). The results confirm the structures of those copolymers, and the copolymerization of perfluorinated vinyl ether with their nonfluorinated counterparts produce alternative copolymers compared to random copolymers from that copolymerization with vinyl acetate. Those copolymers containing sulfonyl fluoride group (―SO₂F) can be further grafted with amine-containing molecules with high efficiency by “SuFEx” reaction, and the micellar nanoparticles with high fluorine content, low critical aggregation concentration, and uniform size can be self-assembled in aqueous solution. Results of ultraviolet-visible spectroscopy(UV-Vis), dynamic light scattering (DLS) , transmission electron microscopy (TEM) indicate that fluorinated copolymers can self-assemble to form micelle like nanoparticles with a hydrodynamic diameter of about 120 nm as well as has low critical aggregation concentration. This work provides a simple method to synthesize fluorinated copolymers with high fluorine content that can be effectively modified by the “SuFEx” click reaction.