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

Six kinds of perfluorinated vinyl ether-based copolymers have been synthesized by thermal radical polymerization under normal atmospheric pressure and in non-fluorine 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 non-fluorinated 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. The critical aggregation concentration, size and morphology of self-assembled nanoparticles were tested by ultraviolet-visible spectroscopy (UV-Vis), dynamic light scattering (DLS) and transmission electron microscopy (TEM). This work provides a simple method to synthesize fluorinated copolymers with high fluorine content that can be effectively modified by the “SuFEx” click reaction.