Synthesis and characterization of controlled molecular weight disulfonated poly(arylene ether sulfone) copolymers and their applications to proton exchange membranes

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• 作者：Yanxiang Li ; Feng Wang ; Juan Yang ; Dan Liu ; Abhishek Roy ; Scott Case ; Jack Lesko and James E. McGrath
• 关键词：Disulfonated poly(arylene ether sulfone) copolymer ; Controlled molecular weight ; Proton exchange membrane fuel cells
• 刊名：Polymer
• 出版年：2006
• 出版时间：17 May 2006
• 年：2006
• 卷：47
• 期：11
• 页码：4210-4217
• 全文大小：250 K

文摘

tert-Butylphenyl terminated disulfonated poly(arylene ether sulfone) copolymers with controlled molecular weights (M_n), 20–50 kg mol⁻¹, were successfully prepared by direct copolymerization of the two activated halides, biphenol and the endcapper, 4-tert-butylphenol. The high molecular weight copolymer (molecular weight over 80 kg mol⁻¹) was also synthesized with 1:1 stoichiometry without an endcapping reagent. The chemical compositions and the molecular weights of the endcapped copolymers were characterized by their ¹H NMR spectra utilizing the 18 unique protons at the chain ends. Modified intrinsic viscosity measurements in 0.05 M LiBr/NMP solution further correlated well with NMR results. Combining the endcapping chemistry with proton NMR end group analysis and intrinsic viscosity measurements, one can demonstrate a powerful tool for characterizing molecular weight of sulfonated poly(arylene ether sulfone) random copolymers. This enables one to further investigate the influence of molecular weight on several critical parameters important for proton exchange membranes, including water uptake, in-plane protonic conductivity and selected mechanical properties. These are briefly discussed herein and will be more fully described in subsequent publications.