Molecular Insight into the Toughness of Polyureas: A Hybrid All-Atom/Coarse-Grained Molecular Dynamics Study
Molecular Insight into the Toughness of Polyureas: A Hybrid All-Atom/Coarse-Grained Molecular Dynamics Study
复制标题
对聚脲韧性的分子洞察：混合全原子/粗粒分子动力学研究
DOI：
10.1021/acs.macromol.1c02453
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发表时间：
2022-04
期刊：
影响因子：
--
通讯作者：
Baohua Guo
中科院分区：
文献类型：
--
作者：
Tianze Zheng;Jun Xu;Baohua Guo
聚氨酯以其卓越的韧性而闻名，这源于纳米级的分离形态和尿素基团之间的氢键。然而，微观结构如何导致宏观韧性的潜在分子机制尚不完全清楚。本文采用基于全原子/粗粒混合模型的非平衡分子动力学模拟，研究了聚脲模型在单轴变形下的力学响应和微观结构演变。仿真得到的应力应变曲线捕捉到了聚氨酯非线性力学响应的关键特征。显微应变和应力以及硬畴结构和节段构象的统计特征表征了结构演变。确定了两种不同的分子机制：定向硬段的自我强化和软段的应力适应性释放。通过这些机制，微观结构的演变与聚氨酯的宏观增韧有关，为开发更好的材料提供了启示。
Polyureas are known for their remarkable toughness, which originates from the nanoscale segregated morphology and hydrogen bonding between urea groups. However, the underlying molecular mechanism of how the microscopic structure results in the macroscopic toughness is not fully understood. In this work, the mechanical response and microstructural evolution of a model polyurea under uniaxial deformation were investigated via nonequilibrium molecular dynamics simulations based on a hybrid all-atom/coarse-grained model. The stress–strain curve obtained from the simulation captured the key features of the nonlinear mechanical response of polyureas. The structural evolution was characterized by the microscopic strain and stress as well as statistics of the hard-domain structure and segment conformations. Two distinct molecular mechanisms were identified: self-reinforcement by oriented hard segments and stress-adaptive release of soft segments. Through these mechanisms, the evolution of microscopic structure was related to the macroscopic toughening of polyureas, shedding light on the development of better materials.
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影响因子：
4.6
作者：
Kaili Yao;Zhanli Liu;Ting Li;Baohua Guo;Z. Zhuang
通讯作者：
Kaili Yao;Zhanli Liu;Ting Li;Baohua Guo;Z. Zhuang
影响因子：
4.6
作者：
Minghao Liu;J. Oswald
通讯作者：
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影响因子：
4.6
作者：
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通讯作者：
Kroon, Martin
DOI：
10.1002/pol.20210060
发表时间：
2021-04
期刊：
--
影响因子：
--
作者：
G. Scetta;Jianzhu Ju;N. Selles;P. Heuillet;M. Ciccotti;C. Creton
通讯作者：
G. Scetta;Jianzhu Ju;N. Selles;P. Heuillet;M. Ciccotti;C. Creton
影响因子：
4.6
作者：
Sami, Selim;Yildirim, Erol;Wilkes, Garth L.
通讯作者：
Wilkes, Garth L.