Synthesis and characteristics of hyperbranched polymer with phosphonic acid groups for high-temperature fuel cells
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- 作者：Takahito Itoh ; Keita Hirai ; Masashi Tamura ; Takahiro Uno ; Masataka Kubo and Yuichi Aihara
- 关键词：Hyperbranched polymer ; Phosphonic acid group ; Proton conductivity ; Fuel cell
- 刊名：Journal of Solid State Electrochemistry
- 出版年：2010
- 出版时间：December 2010
- 年：2010
- 卷：14
- 期：12
- 页码：2179-2189
- 全文大小：268.6 KB
文摘
Two different molecular weight hyperbranched polymers (HBP(L)-(PA)2 and HBP(H)-(PA)2) with two phosphonic acid groups as a functional group at the periphery and a low molecular weight hyperbranched polymer (HBP(L)-(PA)2-Ac) with both two phosphonic acid groups and an acryloyl group as a cross-linker at the periphery were successfully synthesized as thermally stable proton-conducting electrolytes. A cross-linked electrolyte membrane (CL-HBP(L)-(PA)2) was prepared by thermal polymerization of the HBP(L)-(PA)2-Ac using benzoyl peroxide. Ionic conductivities of the HBP(L)-(PA)2, the HBP(H)-(PA)2, and the CL-HBP(L)-(PA)2 under dry condition and their thermal properties were investigated, and also, the effect of the phosphonic acid group number on them was discussed. Ionic conductivities of the HBP(L)-(PA)2 and the HBP(H)-(PA)2 were found to be 1.5 ¡Á 10−5 S cm−1 at 150 ¡ãC and 3.6 ¡Á 10−6 S cm−1 at 143 ¡ãC, respectively, under dry condition, and showed the Vogel–Tamman–Fulcher type temperature dependence. The hyperbranched polymers and the cross-linked electrolyte membrane were thermally stable up to 300 ¡ãC, and the cross-linked electrolyte membrane (CL-HBP-(PA)2) had suitable thermal stability as an electrolyte membrane for the high-temperature fuel cells under dry condition. Fuel cell measurement using a single membrane electrode assembly cell with the cross-linked membrane was performed.