Effect of strain history on stress and permanent set in cross-linking networks: A molecular dynamics study
Effect of strain history on stress and permanent set in cross-linking networks: A molecular dynamics study
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DOI：
10.1021/ma049723j
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发表时间：
2004-07-13
期刊：
影响因子：
5.5
通讯作者：
Thompson, AP
中科院分区：
文献类型：
--
作者：
Rottach, DR;Curro, JG;Thompson, AP
利用分子动力学模拟研究了聚合物网络的交联反应，探讨了交联和变形之间的耦合对应力的影响。对于在未变形状态下交联的网络，模量随交联密度线性增加，如橡胶弹性理论所预期的。当交联被添加到单轴变形的网络中时，根据Tobolsky的独立网络假设，应力保持恒定。当变形的网络随后被释放时，观察到永久变形。使用独立的网络假设，连同仿射理论的橡胶弹性，本构模型的开发，占交联密度和应变历史的网络之间的耦合的效果。从仿射模型的永久集的预测是高于发现从MD模拟。
Polymer networks undergoing cross-linking reactions are studied using molecular dynamics simulations to investigate how the stress is influenced by the coupling between cross-linking and deformation. For networks cross-linked in the undeformed state, the modulus increases linearly with the cross-link density as expected from rubber elasticity theory. When cross-links are added to a network that was uniaxially deformed, the stress remains constant in accordance with the independent network hypothesis of Tobolsky. When the deformed network is subsequently released, permanent set is observed. Using the independent network hypothesis, together with the affine theory of rubber elasticity, a constitutive model is developed that accounts for the effect of the coupling between the cross-link density and strain histories of the network. The permanent set predictions from the affine model are higher than found from MD simulations.