Mesoscale structure-based investigation of polyurea dynamic modulus and shock-wave dissipation
Mesoscale structure-based investigation of polyurea dynamic modulus and shock-wave dissipation
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DOI：
10.1016/j.polymer.2020.122741
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发表时间：
2020-08
期刊：
影响因子：
4.6
通讯作者：
Kaili Yao;Zhanli Liu;Ting Li;Baohua Guo;Z. Zhuang
中科院分区：
文献类型：
--
作者：
Kaili Yao;Zhanli Liu;Ting Li;Baohua Guo;Z. Zhuang
聚脲是一种嵌段共聚物，具有优异的减震性能。它具有独特的相分离结构，但介观结构对动态力学性能的影响却鲜有报道。本文采用粗粒分子动力学方法研究了双相结构对聚脲动态模量和冲击波耗散的影响。剪切松弛模量通过Green-Kubo方法计算。脉冲载荷是通过非平衡态分子动力学施加的。两相结构通过限制链段运动提高了动态模量。冲击波能量通过热耗散、粘性阻滞和塑性耗散而耗散。两相组织必须服从变形协调，这导致更多的应变能和内耗。在碰撞过程中发生氢键解离和结构破坏。此外，模拟结果验证了AFM，X射线衍射，DMA实验。
Polyurea is a block copolymer with excellent shock absorption. It has a unique phase separation structure, yet there are few reports on how the mesoscale structure affects the dynamic mechanical properties. In this paper, the effect of two-phase structure on the dynamic modulus and shock-wave dissipation of polyurea is investigated by coarse-grained molecular dynamics. Shear relaxation modulus is calculated by the Green-Kubo method. Pulse load is applied by non-equilibrium molecular dynamics. The two-phase structure improves the dynamic modulus by restricting the segment movement. Shock-wave energy is dissipated by heat dissipation, viscous retardation, and plastic dissipation. The two-phase structure must obey deformation coordination, which results in more strain energy and internal friction. Hydrogen bond dissociation and structure destruction occur during the impact. Furthermore, the simulations results are verified by AFM, X-ray diffraction, and DMA experiments.