초록 |
Although hydrocarbon-based proton exchange membranes (PEMs) generally show excellent proton conductivity under fully hydrated condition, their proton conductivities were significantly decreased with dwinding of humidity. Multi-block copolymer systems can have much higher water diffusion coefficients than random copolymers, which is an important factor in maintaining proton conductivity of PEMs under low humidity condition. In this study, sulfonated multi-block copolymers with highly sulfonated poly(arylene sulfone) block were developed. We prepared highly sulfonated hydrophilic oligomers and non-sulfonated hydrophobic oligomers in various molecular weights. Using these oligomers, multi-block copolymers with controlled ion exchange capacities (IECs) were synthesized by condensation reaction. The synthesized polymers were characterized in terms of H-NMR, IEC, proton conductivity, water uptake, and single cell performance. |