Recoverably and destructively deformed domain structures in elongation process of thermoplastic elastomer analyzed by graph theory. (3rd February 2020)

• Record Type: Journal Article
• Authors: Morita, Hiroshi; Miyamoto, Ayano; Kotani, Motoko
• Is Part Of: Polymer. Volume 188(2020)
• Publication Date: 2020-02-03
• Subjects: Thermoplastic elastomer -- Coarse-grained molecular dynamics simulation -- Triblock copolymer; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2019.122098
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: 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. Graphical abstract: Image 1038925 Highlights: Graph theory is applied to analyze the bridge chain network and domain structures. Graph described the coalescence and breaking of domains in the elongation process. The recoverably and destructively deformed structures are distinguished by graph.