| 초록 |
Poly[(2,2’-(p-phenylene)-5,5’-bibenzimidazole)-co-(2,2’-(phenylsulfonyl-p-phenylene))-5,5’-bibenzimidazole)]s (PhSpPBIs) were obtained by copolymerization of phenylsulfonylterephthalic acid (PSTA) and terephthalic acid with 3,3’-diaminobenzidine in poly(phosphoric acid) at 240 ℃. We varied the feed ratio of PSTA from 0 to 100 mol% to study the effect of phenylsulfonyl side groups on physical and electrochemical properties of the polymers. PhSpPBIs having larger content of phenylsulfonyl side group showed increased solubility behavior and decreased crystallinity, which was confirmed from WAXS studies. In spite of the incorporation of non-proton conductive side groups, all PhSpPBI membranes had high proton conductivities of more than 10-2 S/cm at 180 ℃. PhSpPBI-30 containing 30 mol% of phenylsulfonyl side groups exhibited a proton conductivity of 0.08 S/cm at the doping level of 5.84 mol H3PO4 at 180 ℃. |
