| Summary: | 碩士 === 國立中山大學 === 光電工程學系研究所 === 101 === Proton exchange membrane fuel cell(PEMFCs) are considered to be a promising technology in the twenty-first century, the researchers have focused on reaching the proton exchange membrane with high proton conductivity, good chemical/thermal stability, good mechanical properties and low cost. In this paper, we adopt the structure of multi-benzene ring poly aromatic ether which have been studies for time in our laboratory, is not only cheap than the commercial material Nafion, but owns more higher proton conductivity at low relative humidity and high temperature as we expected. It is synthesized from the bisphenol monomers with the bisfluoro monomers via nucleophilic polycondensation reation for obtaining three polymers with different numbers of substitutent of benzene ring(A7、A8、A9). The molecular weight of the polymer is 5.6×104~2.9×105g/mol by GPC measurement.
The degradation temperature of three polymers are over than 550℃, they are belonged to the materials of high thermal stability. All high degree of sulfonation, the degradation temperature are decreased and the IEC of membranes is on 1~2.6meq./g. Three polymer membranes showed much tougher(Young’s modulus 0.25GPa~1.46GPa) than the Nafion 117 membranes(Young’s modulus 0.1GPa).The membranes demonstrated good oxidative stability with little weights loss at high temperature. The dimensional swelling of high sulfonated SA8 membrane is similar to that of Nafion(45%). Proton conductivity of SA7-3、SA8-3.5、SA9-2.5 membranes(9.03×10-2、2.17×10-1、7.14×10-2) at 80℃ and 95%RH was higher than that of Nafion 117(3.2×10-2), therefore, we can promise the aromatic poly(arylene ether)s to be good represent in applications as proton exchange membranes.
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