Viscoelastic Behavior of Lightly Sulfonated Polystyrene Ionomers
Viscoelastic Behavior of Lightly Sulfonated Polystyrene Ionomers
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DOI：
10.1021/ma00005a015
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发表时间：
1991-09
期刊：
影响因子：
5.5
通讯作者：
R. Weiss;J. Fitzgerald;D. Kim
中科院分区：
文献类型：
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作者：
R. Weiss;J. Fitzgerald;D. Kim
通过动态力学分析研究了每 1000 个苯乙烯重复单元仅含 1 个磺酸基团的磺化聚苯乙烯离聚物的线性粘弹性行为。磺酸基团的相互作用将末端流动区域移至较低频率，并产生未改性聚苯乙烯中不存在的新的低频弛豫。在非常低的磺化水平下对低频弛豫的观察表明，即使对于 0.11 mol% 的磺化，也会形成离子簇，但对于具有如此低磺化水平的离聚物，没有解析出 SAXS 峰。对于固定的磺化水平，离子基团对粘弹性的影响可以通过减弱离子对的离子偶极强度而改变。这可以通过用铵 (NH4+) 阳离子替代金属阳离子（例如 Na+）来实现。
The linear viscoelastic behavior of sulfonated polystyrene ionomers with as few as one sulfonate group per 1000 styrene repeat units was studied by dynamic mechanical analysis. Interactions of the sulfonate groups shifted the terminal flow region to lower frequency and produced a new low-frequency relaxation that was not present in the unmodified polystyrene. The observation of the low-frequency relaxation at very low sulfonation levels suggests that even for 0.11 mol % sulfonation, ionic clusters formeven though, no SAXS peak has been resolved for ionomers with that low a sulfonation level. The effect of the ionic groups on the viscoelastic properties can be varied for a fixed sulfonation level by weakening the ion-dipole strength of the ion pair. This can be achieved by substituting ammonium (NH4+) cations for metal cations such as Na+.