Influence of temperature and humidity on the mechanical properties of Nafion® 117 polymer electrolyte membrane
Influence of temperature and humidity on the mechanical properties of Nafion® 117 polymer electrolyte membrane
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DOI：
10.1002/polb.20367
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发表时间：
2005-04-01
影响因子：
--
通讯作者：
Willert-Porada, M
中科院分区：
文献类型：
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作者：
Bauer, F;Denneler, S;Willert-Porada, M
Nafion（R）117的动态机械性能已经在一个专门设计的湿度电池中平行和垂直于层压方向的平面内测量，这允许在燃料电池相关的温度和湿度条件下测量刚度和机械损失（50-100%相对湿度，30 - 120摄氏度）。在不同的温度-湿度条件下获得的结果进行了比较与干燥的机械行为，以及与液态水饱和的膜。发现了机械性能变化的不同机制，尽管通常水在Nafion（R）中充当增塑剂。在高温下，它通过稳定亲水性簇的网络来使膜变硬。在非常低的湿度水平下的机械强度的中间增加归因于通过在邻位磺酸基团之间形成水合物和氢桥键的强制执行。这种增加对于膜的质子化状态是显着的，并在离子交换后消失。(c)2005 Wiley Periodicals，Inc.
The dynamic mechanical properties of Nafion((R)) 117 have been measured in-plane parallel and perpendicular to the lamination direction in a specially designed humidity cell, which allows measurement of the stiffness and mechanic loss under fuel cell relevant temperature and humidity conditions (50-100% relative humidity, 30120 degrees C). The results obtained at different temperature-humidity conditions are compared with the mechanical behavior of the dry as well as the membrane saturated with liquid water. Different regimes of change in mechanical properties were found, although in general water acts as a plasticizer in Nafion((R)). At elevated temperatures it stiffens the membrane by stabilizing the network of hydrophilic clusters. An intermediate increase of mechanical strength at very low humidity levels is attributed to an enforcement by formation of hydrates and hydrogen bridge bonds between vicinal sulfonic acid groups. This increase is significant for the protonated state of the membrane and disappears after ion exchange. (c) 2005 Wiley Periodicals, Inc.