Complex amphiphilic hyperbranched fluoropolymers by atom transfer radical self-condensing vinyl (Co)polymerization

Amphiphilic hyperbranched fluorohomopolymer (M_n = 9.06 kDa, M_w/M_n = 1.90) and fluorocopolymer (M_n = 17.2 kDa, M_w/M_n = 2.50) with tri(ethylene glycol) units incorporated at the molecular level were synthesized by atom transfer radical self-condensing vinyl homopolymerization of an inimer, 4-[oxy(tri(ethylene glycol))bromoisobutyryl]-2,3,5,6-tetrafluorostyrene, and copolymerization of the inimer with 2,3,4,5,6-pentafluorostyrene (1:3, inimer:monomer), using 2,2′-bipyridine together with CuCl/CuCl₂ as the ligand/catalyst/deactivator system. The structure and composition of the fluoropolymers were characterized by ¹H, ¹³C, and ¹⁹F NMR spectroscopies. As detected by thermogravimetric analyses, the homopolymer and the copolymer had thermal stability up to 175 and 210 °C, respectively. Differential scanning calorimetry revealed a glass transition temperature of -19 °C for the homopolymer and 20 °C for the copolymer. Solubility tests indicated that both polymers were soluble in a broad range of organic solvents, and the presence of tri(ethylene glycol) units resulted in the formation of water-dispersible micelles from each of the polymers.