Polysulfone ionomers functionalized with benzoyl(difluoromethylenephosphonic acid) side chains for proton‐conducting fuel‐cell membranes
Polysulfone ionomers functionalized with benzoyl(difluoromethylenephosphonic acid) side chains for proton‐conducting fuel‐cell membranes
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DOI：
10.1002/pola.21755
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发表时间：
2007-01
期刊：
影响因子：
--
通讯作者：
B. Lafitte;P. Jannasch
中科院分区：
文献类型：
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作者：
B. Lafitte;P. Jannasch
制备了含苯甲酰基（二氟亚甲基膦酸）侧链的聚砜，并研究了其作为质子传导燃料电池膜的性能。在第一步中，聚砜被锂化并与碘苯甲酸甲酯反应以制备对-和邻-碘苯甲酰基聚砜。接下来，通过CuBr介导的碘化聚合物和[（二乙氧基氧膦基）二氟甲基]溴化锌之间的交叉偶联反应制备膦酸化聚砜。最后，用溴三甲基硅烷脱烷基化得到高酸性的-CF 2-PO 3 H 2衍生物。在邻碘苯甲酰基聚砜的情况下，碘原子被-CF2-PO 3Et 2单元的置换几乎是定量的。基于具有0.90 mmol膦酸单元/g干聚合物的离聚物的膜在室温下浸渍时吸收6重量%的水，并且记录了在100 °C下高达5 mS cm-1的电导率。该电导率水平与基于具有0.86mmol磺酸/g干聚合物的磺化聚砜的膜所达到的电导率水平相当。热重分析显示，芳基-CF2-PO 3 H2排列通过C-P键的断裂在约230 °C下分解。（减）
Polysulfones carrying benzoyl(difluoromethylenephosphonic acid) side chains were prepared and investigated for use as proton-conducting fuel-cell membranes. In the first step, polysulfones were lithiated and reacted with methyl iodobenzoates to prepare p- and o-iodobenzoyl polysulfones. Next, the phosphonated polysulfones were prepared via CuBr-mediated cross-coupling reactions between the iodinated polymer and [(diethoxyphosphinyl)difluoromethyl]zinc bromide. Finally, dealkylation with bromotrimethylsilane afforded highly acidic -CF2-PO3H2 derivatives. The replacement of the iodine atoms by -CF2-PO3Et2 units was almost quantitative in the case of o-iodobenzoyl polysulfone. Membranes based on ionomers having 0.90 mmol of phosphonic acid units/g of dry polymer took up 6 wt % water when immersed at room temperature, and conductivities up to 5 mS cm-1 at 100 °C were recorded. This level of conductivity was comparable to that reached by a membrane based on a sulfonated polysulfone having 0.86 mmol of sulfonic acid/g of dry polymer. Thermogravimetry revealed that the aryl-CF2-PO3H2 arrangement decomposed at approximately 230 °C via cleavage of the C-P bond. (Less)