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Entangled linear polymers in fast shear and extensional flows: evaluating the performance of the Rolie-Poly model
Rheologica Acta ( IF 2.3 ) Pub Date : 2021-08-02 , DOI: 10.1007/s00397-021-01295-z
Hamid Taghipour 1 , Laurence G. D. Hawke 1
Affiliation  

This work evaluates the performance of the Rolie-Poly (RP) model in uniaxial elongation and shear. Predictions of four RP versions are compared against literature data for monodisperse, entangled polystyrene (PS) chains. The examined RP versions differ in two respects, namely, the method by which they implement reptation and finite extensibility (FENE). In some cases, the reptation term leads to unrealistic strain hardening at transient shear. In contrast, predictions at relaxation after shear and uniaxial elongation are practically unaffected by variations in the reptation term. For all examined flows, the FENE treatment has a considerable influence on the model outcomes. Comparison of RP predictions and data reveals successes as well as limitations of the model. For example, some systematic disagreements are evident when the Rouse Weissenberg (\({Wi}_{R}\)) number exceeds ten. Possible improvement of the model by incorporation of overlooked mechanisms like entanglement loss and chain tumbling is discussed.



中文翻译:

快速剪切和拉伸流动中的缠结线性聚合物:评估 Rolie-Poly 模型的性能

这项工作评估了 Rolie-Poly (RP) 模型在单轴拉伸和剪切方面的性能。将四种 RP 版本的预测与单分散、缠结聚苯乙烯 (PS) 链的文献数据进行比较。检查的 RP 版本在两个方面有所不同,即它们实现爬虫和有限可扩展性 (FENE) 的方法。在某些情况下,蠕动项会导致瞬态剪切下不切实际的应变硬化。相比之下,剪切和单轴伸长后松弛的预测实际上不受蠕动项变化的影响。对于所有检查的流,FENE 处理对模型结果有相当大的影响。RP 预测和数据的比较揭示了模型的成功和局限性。例如,当 Rouse Weissenberg (\({Wi}_{R}\) ) 数超过十。讨论了通过结合被忽视的机制(如纠缠损失和链翻滚)来改进模型的可能。

更新日期:2021-08-02
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