| 초록 |
Direct methanol fuel cell (DMFC) is promising candidates for portable power sources and transport applications because they don’t require the fuel processing equipment such as reformers or catalytic burners and can be operated at low temperature. The electrolyte of DMFC is a polymeric membrane. Perfluorinated copolymers such as Nafion®, Flemion are the current state-of- the-art proton exchange membranes (PEM). They are highly proton conductive and substantially stable; however high cost, high methanol permeability and limited operation temperature urge the necessity to develop alternative PEM. In this study, to produce a polylmer electrolyte to meet the requirements for fuel cells, we have prepared poly(arylene ether sulfone) containing pendant sulfonic acid group via nucleophilic substitution polycondensation reactions and sulfonation. We have prepared six different membranes according to the ratio of dihydroxy monomers. NMR and FT-IR were used to characterize the structures and the sulfonic acid contents (SC) of the polymers. Membrane films were obtained by casting N-metyl-2-pyrrolidone (NMP) solution of copolymers. Glass-transition temperatures (Tg’s) and decomposition temperatures (Td ’s) of Sulfonated PAESs were determined. Water uptake and swelling ratio values increased with SC. The proton conductivities of membrane films increased with SC and temperature. |
