Entanglement Kinetics in Polymer Melts Are Chemically Specific,ACS Macro Letters

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Entanglement Kinetics in Polymer Melts Are Chemically Specific
ACS Macro Letters ( IF 5.1 ) Pub Date : 2024-07-03 , DOI: 10.1021/acsmacrolett.4c00092
Benjamin E Dolata _{1,

2} , Marco A Galvani Cunha ₃ , Thomas O'Connor ₄ , Austin Hopkins ₅ , Peter D Olmsted ₁

Affiliation

We investigate the universality of entanglement kinetics in polymer melts. We compare predictions of a recently developed constitutive equation for disentanglement to molecular dynamics simulations of both united-atom polyethylene and Kremer-Grest models for polymers in shear and extensional flow. We confirm that entanglements recover on the retraction time scale, rather than the reptation time scale. We find that the convective constraint release parameter β is independent of molecular weight, but that it increases with the ratio of Kuhn length b_K to packing length p as β ∼ (b_K/p)^α, with an exponent α = 1.9, which may suggest that disentanglement rate correlates with an increase in the tube diameter. These results may help shed light on which polymers are more likely to undergo shear banding.

中文翻译：

聚合物熔体中的缠结动力学具有化学特异性

我们研究了聚合物熔体中缠结动力学的普遍性。我们将最近开发的解缠结本构方程的预测与剪切和拉伸流中聚合物的联合原子聚乙烯和 Kremer-Grest 模型的分子动力学模拟进行了比较。我们确认纠缠在回缩时间尺度上恢复，而不是在爬行时间尺度上恢复。我们发现对流约束释放参数 β 与分子量无关，但它随着库恩长度b _K与堆积长度p的比值 β ∼ ( b _K / p ) ^α的增加而增加，其指数 α = 1.9，其中可能表明解缠结率与管直径的增加相关。这些结果可能有助于揭示哪些聚合物更有可能发生剪切带。

更新日期：2024-07-03

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