Rheological Behavior of Partially Neutralized Oligomeric Sulfonated Polystyrene Ionomers

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• 作者：Chongwen HuangQuan Chen ; R. A. Weiss
• 刊名：Macromolecules
• 出版年：2017
• 出版时间：January 10, 2017
• 年：2017
• 卷：50
• 期：1
• 页码：424-431
• 全文大小：489K
• ISSN：1520-5835

文摘

The linear viscoelastic (LVE) behavior of partially neutralized oligomeric sulfonated polystyrene (SPS) ionomers with different degrees of sulfonation (p) and degrees of neutralization (x) was investigated. The ionic dissociation time, τ_s, obtained from the reversible gelation model [Chen Macromolecules 2015, 48, 1221−1230] is mainly controlled by the neutralization degree, x, rather than the functional group (i.e., sulfonic acid and metal sulfonate) concentration, p. For a fixed p, increasing x significantly increases τ_s and the zero shear viscosity, η₀, especially near complete neutralization. These results explain the observations reported by Lundberg et al. [ Ions in Polymers; American Chemical Society: 1980; Vol. 187, pp 67−76] that the increase of the viscosity of SPS ionomers with neutralization undergoes a substantial increase between 90% and 100% neutralization of the sulfonic acid groups to metal salts. This rapid increase of τ_s and η₀ is probably related to the decrease of sulfonic acid groups in the ionic aggregates with increasing x.