Modeling non-Gaussian extensibility effects in elongation of nearly monodisperse polystyrene melts
Modeling non-Gaussian extensibility effects in elongation of nearly monodisperse polystyrene melts
复制标题
模拟近单分散聚苯乙烯熔体伸长率的非高斯伸长率效应
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
T. Schweizer
中科院分区：
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作者：
V. H. Rolón;M. Wagner;C. Luap;T. Schweizer
Luap 等人同时测量了摩尔质量 MW 分别为 206000gmol−1 (PS206k) 和 465000gmol−1 (PS465k) 的两种近单分散聚苯乙烯熔体的拉伸粘度和双折射率。 [瑞奥尔.学报。 45, 83–91 (2005)]。样品不遵循应力光学规则 (SOR)。伸长粘度数据可以通过 Wagner 等人的分子应力函数 (MSF) 模型进行定量建模。 [J。流变。 49, 1317–1327 (2005)]，它基于 Marrucci 和 Ianniruberto [Macromolecules 37, 3934–3942 (2004)] 的应变相关管直径和链间压力项的假设，并在此进行修改，以使用反 Langevin 函数的 Pade 近似来解释非高斯链延伸。管直径弛豫时间与 MW2 成比例。虽然瞬态伸长粘度对有限延伸性的依赖性很小，但预测的稳态伸长粘度不受非高斯效应的影响。幂律指数...
Elongational viscosity and birefringence of two nearly monodisperse polystyrene melts with molar mass MW of 206000gmol−1 (PS206k) and 465000gmol−1 (PS465k), respectively, were measured simultaneously by Luap et al. [Rheol. Acta. 45, 83–91 (2005)]. The samples did not follow the stress optical rule (SOR). Elongational viscosity data can be modeled quantitatively by the molecular stress function (MSF) model of Wagner et al. [J. Rheol. 49, 1317–1327 (2005)], which is based on the assumption of a strain-dependent tube diameter and the interchain pressure term of Marrucci and Ianniruberto [Macromolecules 37, 3934–3942 (2004)], and which is modified here to account for non-Gaussian chain extension using the Pade approximation of the inverse Langevin function. The tube diameter relaxation time scales with MW2. While the transient elongational viscosity shows a small dependence on finite extensibility, the predicted steady-state elongational viscosity is not affected by non-Gaussian effects. The power-law exponen...