초록 |
Copolymers of tetrafluoroethylene and perfluorovinyl ether with sulfuric acid groups have been used as proton exchange membranes for fuel cell applications. The copolymers can be prepared using an emulsion polymerization method because of the poor solubility of the monomers in most conventional solvents. In particular, the mini-emulsion polymerization technique is applied to minimize the effect of large differences in reactivity and diffusion in the polymerization medium. The mini-emulsion polymerization method has been widely used in the manufacture of commercial products, but detailed information on the polymerization system has not been reported. In this study, we report the correlation between polymerization conditions and the structure of the resulting copolymers. Various characterization methods such as DLS, FT-IR, and solid state 19F NMR are used to identify the effect of the polymerization conditions. |