The sulfonated aromatic polymers are competitive proton conducting materials for proton exchange membrane fuel cells because of their relatively low costs and adequate performances compared with the perfluorinated sulfonic acid ionomers. These polymeric materials can be economically synthesized by the sulfonation of existing aromatic polymers; however, the inadequate sulfonation degree has prevented the further optimization of their overall performances. In order to improve the overall performances of sulfonated aromatic polymeric proton conducting materials, the sulfonation mechanisms of typical aromatic polymers, including bisphenol A type polysulfone (BPA-PSF), 4,4’-biphenol type polysulfone (44BP-PSF), poly(ether ether ketone) (PEEK), and poly(ether sulfone) (PES), are studied in terms of transition states and activation energies using density functional theory calculations with satisfactory results. It is concluded that the sulfonations are favored at the ortho-position of direct arylene-arylene linkage and ether bond linkage, but retarded by the bulky sulfonyl linkage, dimethyl methylene linkage, and carbonyl linkage. It is also concluded that the solvation effect from polar solvent reduces the activation barrier more efficiently than that from nonpolar solvent.

中文翻译：

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用于 PEMFC 应用的芳族聚合物的磺化机理

与全氟化磺酸离聚物相比，磺化芳族聚合物具有相对较低的成本和足够的性能，因此是用于质子交换膜燃料电池的有竞争力的质子传导材料。这些聚合物材料可以通过现有芳香族聚合物的磺化来经济地合成；然而，磺化度不足阻碍了其整体性能的进一步优化。为了提高磺化芳香族高分子质子传导材料的综合性能，对典型芳香族聚合物的磺化机理进行了研究，包括双酚A型聚砜（BPA-PSF）、4,4-双酚型聚砜（44BP-PSF）、聚（醚醚酮）（PEEK）和聚（醚砜）（PES），使用密度泛函理论计算在过渡态和活化能方面进行了研究，结果令人满意。得出的结论是，在直接亚芳基-亚芳基键和醚键键的邻位有利于磺化，但受庞大的磺酰基键、二甲基亚甲基键和羰基键的阻碍。还得出结论，极性溶剂的溶剂化作用比非极性溶剂的溶剂化作用更有效地降低了活化势垒。