Huanyu Lei, Shengli Qi, Dezhen Wu
Sep 28, 2019
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Influential Citations
36
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Journal
Polymer
Abstract
Abstract The molecular dynamics simulations are adopted to investigate the thermo-mechanical properties of pyromellitic dianhydride(PMDA)/2-(4-aminophenyl)-1H-benzimidazole-5-amine(BIA), PMDA/p-phenylene diamine(PDA), PMDA/4,4′-oxidianiline(ODA), 3,3′,4,4′-biphenyldianhydride(BPDA)/BIA, BPDA/PDA, and BPDA/ODA polyimide films in hierarchical multiscale level. The results indicate that the properties follow the order of BIA > PDA > ODA. At a small scale, the hydrogen bonding in the BPDA/BIA polyimide strengthens the chain interactions and results in a coiling-shaped chain conformation, endowing the polyimide with superior properties. But the ODA increases the helical-shaped segments conformation, therefore possessing large elongation under small tension. At the scale of the entire polymeric chain, the chain mobility was discussed by the ratio of to and MSD. And higher chain mobility corresponds to lower tensile modulus. At a large scale, the torsion angle distribution changes apparently before and after stretching, which increases the d-spacing and elongates the entire molecular chain simultaneously, serving as the main cause of polyimide tensile deformation.