Recoverably and destructively deformed domain structures in elongation process of thermoplastic elastomer analyzed by graph theory
Recoverably and destructively deformed domain structures in elongation process of thermoplastic elastomer analyzed by graph theory
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DOI：
10.1016/j.polymer.2019.122098
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发表时间：
2020-02-03
期刊：
影响因子：
4.6
通讯作者：
Kotani, Motoko
中科院分区：
文献类型：
--
作者：
Morita, Hiroshi;Miyamoto, Ayano;Kotani, Motoko
阿坝三嵌段共聚物热塑性弹性体（TPE）发生了桥环链的微相分离。TPE具有多尺度结构，在介观尺度上既有桥链网络结构，又有微相分离结构。在热塑性弹性体的单轴拉伸过程中，畴发生合并和断裂，在高应变下形成不可逆变形结构。为了理解拉伸过程中的结构变化，我们对TPE的拉伸过程进行了粗粒度分子动力学模拟，并通过图论分析了桥链网络和域结构的变化。每个图结构的描述符都可以理解域结构的变化和桥链的重组。利用图形描述，在拉伸过程中可以发现两种类型的结构：可恢复变形结构和破坏变形结构。该图是最有用的数学描述符之一，以了解在拉伸过程中TPE结构内部的桥链网络的拓扑结构，包括具有微观链构象的结构域的断裂。
Thermoplastic elastomer (TPE) by ABA triblock copolymer chains undergoes microphase separation with bridge and loop chains. TPE has a multi-scale structure containing both bridge chain networks and microphase separated structures in meso scale. In the uniaxial elongation process of TPE, coalescence and breaking of domains occur, and an irreversibly deformed structure forms at high strain. To understand the structural changes in an elongation, we performed coarse-grained molecular dynamics simulations of the elongation process of TPE and analyzed the changes of both the bridge chain network and domain structure by graph theory. Both the changes of the domain structures and recombination of bridge chains can be understood by the descriptors of each graph structure. Using the graph description, two types of structures can be found in the elongation process; recoverably and destructively deformed structures. The graph is one of the most useful mathematical descriptors to understand the topology of bridge chain network inside the structures of TPE in the elongation process, including fracture of domains with a microscopic chain conformation.