Molecular dynamics simulation insight into the temperature dependence and healing mechanism of an intrinsic self-healing polyurethane elastomer

被引:42
|
作者
Chen, Xianling [1 ]
Zhu, Jing [2 ]
Luo, Yanlong [1 ,3 ]
Chen, Jun [1 ]
Ma, Xiaofeng [1 ,3 ]
Bukhvalov, Danil [1 ,3 ]
Liu, Haobei [4 ]
Zhang, Meng [5 ]
Luo, Zhenyang [1 ,3 ]
机构
[1] Nanjing Forestry Univ, Coll Sci, Nanjing 210037, Peoples R China
[2] Tsinghua Univ, Dept Elect Engn, State Key Lab Power Sys, Beijing 100084, Peoples R China
[3] Nanjing Forestry Univ, Inst Polymer Mat, Nanjing 210037, Peoples R China
[4] China Bldg Mat Federat, Beijing 100037, Peoples R China
[5] CAF, Inst Chem Ind Forestry Prod, Nanjing 210042, Peoples R China
基金
中国国家自然科学基金;
关键词
HYDROGEN-BOND; COMPOSITES; POLYMERS; KINETICS;
D O I
10.1039/d0cp03013a
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
An intrinsic self-healing polyurethane (PU) elastomer was synthesized in our previous work. In this work, three-dimensional (3D) micro-crack models based on experimental samples were further introduced to investigate their self-healing behavior, mechanism, and temperature dependence by molecular dynamics (MD) simulations. In particular, the number, type, strength, and lifetime of hydrogen bonds as well as the microscopic behavior of molecular diffusion in the self-healing process were investigated. It was found that the self-healing capacity of PU mainly results from intermolecular electrostatic interactions, and the hydrogen bond plays a key role in electrostatic interactions. There is an optimum ratio of soft and hard segments at which the number of hydrogen bonds is appropriate and the self-healing capacity is optimum. Besides, the temperature has an optimal value at which the self-healing rate of PU is the fastest. The exchanges of hydrogen bonds, which endowed PU with self-healing capacity, were further revealed intuitively. We found that the exchanges of hydrogen bonds are reversible and more likely to occur on the urethane groups. This study deepened the understanding of the self-healing character of PU at the molecular level.
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页码:17620 / 17631
页数:12
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