Darabi Ehsan, Itskov Mikhail
Department of Continuum Mechanics, RWTH Aachen University, Eilfschornsteinstr. 18, 52062 Aachen, Germany.
Soft Matter. 2021 Feb 19;17(6):1675-1684. doi: 10.1039/d0sm02055a.
In the present paper, a new type of micro-mechanically motivated chain network model for rubber-like materials is proposed. The model captures topological constraints of polymer network chains, in particular, entanglements. The model demonstrates how the local molecular packing constraints modify under deformation and shows the impact of these changes on the macroscopic elasticity of the material. To this end, we combine concepts of a confining tube and a slip-link (reptation) model. In these models, entanglements of polymer chains play an important role. The nature of entanglements is discussed, and relationships governing entanglements are formulated in terms of molecular physics. In the context of nonlinear elasticity, we apply a non-affine concept which captures the liquid-like behavior of polymer networks at smaller scales in a more realistic way. Model predictions show good agreement with experimental results from uniaxial and biaxial tension tests.
在本文中，提出了一种新型的用于类橡胶材料的微机械驱动链网络模型。该模型捕捉了聚合物网络链的拓扑约束，特别是缠结。该模型展示了局部分子堆积约束在变形过程中是如何改变的，并显示了这些变化对材料宏观弹性的影响。为此，我们结合了约束管和滑移链（reptation）模型的概念。在这些模型中，聚合物链的缠结起着重要作用。讨论了缠结的本质，并根据分子物理学阐述了控制缠结的关系。在非线性弹性的背景下，我们应用了一种非仿射概念，该概念以更现实的方式捕捉了聚合物网络在较小尺度下的类液体行为。模型预测与单轴和双轴拉伸试验的实验结果显示出良好的一致性。
