1P-401 : Partially fluorinated sulfonated multi-block copolymers with hydrophobic block containing perfluorocyclobutyl moieties for proton exchange membrane fuel cell

Partially fluorinated multi-block copolymers containing perfluorocyclobutyl (PFCB) moieties were developed for proton exchange membrane fuel cells. The PFCB structure with high hydrophobicity was included in hydrophobic blocks, which is expected to be effective in constructing well-developed ion conducting channel. Hydroxyended hydrophobic oligomers containing PFCB were synthesized by chain growth polymerization using 4,4’-bis(trifluorovinyl oxy)diphenyl ether and 4-(trifluorovinyl oxy)methoxybenzene. Halogen-ended hydrophilic oligomers were prepared by nucleophilic substitution using disodium 3,3’-disulfonated-4,4’-difluorodiphenylsulfone and lithium sulfide. The synthesis of multi-block copolymers were proceeded by coupling reactions with these two oligomers. The chemical structure of the copolymers were confirmed by 1H and 19F NMR. The polymer membranes were characterized in terms of ion exchange capacity, molecular weight, dimensional change, and proton conductivity.