Coarse-grained molecular-level analysis of polyurea properties and shock-mitigation potential

M. Grujicic, J. S. Snipes, S. Ramaswami, R. Yavari, James Patrick Runt, J. Tarter, Gregory P. Dillon

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

Several experimental investigations reported in the open literature clearly established that polyurea (PU), an elastic copolymer, has an unusually high ability to attenuate and disperse shock waves. This behavior of PU is normally attributed to its unique nanometer-scale two-phase microstructure consisting of (high glass-transition temperature, T g) hydrogen-bonded discrete, hard domains dispersed within a (low T g) contiguous soft matrix. However, details regarding the mechanism(s) responsible for the superior shock-wave mitigation capacity of PU are still elusive. In the present study, molecular-level computational methods and tools are used to help us identify and characterize these mechanism(s). Because the shock-wave front structure and propagation involve coordinated motion of a large number of atoms and nano-second to micro-second characteristic times, these phenomena cannot be readily analyzed using all-atom molecular-level modeling and simulation techniques. To overcome this problem, all-atom PU microstructure is coarse-grained by introducing larger particles (beads), which account for the collective degrees of freedom of the constituent atoms, the associated force-field functions determined and parameterized using all-atom computational results, and the resulting coarse-grained model analyzed using conventional molecular-level computational methods and tools. The results thus obtained revealed that a combination of different deformation mechanisms (primarily shock-induced ordering and crystallization of hard domains and coordinated shuffle-like lateral motion of the soft-matrix segments) is most likely responsible for the superior ability of PU to attenuate/disperse shock waves.

Original languageEnglish (US)
Pages (from-to)1964-1981
Number of pages18
JournalJournal of Materials Engineering and Performance
Volume22
Issue number7
DOIs
StatePublished - Jul 1 2013

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Shock waves
Atoms
Computational methods
Microstructure
Crystallization
Hydrogen
Copolymers
polyurea

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

Cite this

Grujicic, M., Snipes, J. S., Ramaswami, S., Yavari, R., Runt, J. P., Tarter, J., & Dillon, G. P. (2013). Coarse-grained molecular-level analysis of polyurea properties and shock-mitigation potential. Journal of Materials Engineering and Performance, 22(7), 1964-1981. https://doi.org/10.1007/s11665-013-0485-3
Grujicic, M. ; Snipes, J. S. ; Ramaswami, S. ; Yavari, R. ; Runt, James Patrick ; Tarter, J. ; Dillon, Gregory P. / Coarse-grained molecular-level analysis of polyurea properties and shock-mitigation potential. In: Journal of Materials Engineering and Performance. 2013 ; Vol. 22, No. 7. pp. 1964-1981.
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Grujicic, M, Snipes, JS, Ramaswami, S, Yavari, R, Runt, JP, Tarter, J & Dillon, GP 2013, 'Coarse-grained molecular-level analysis of polyurea properties and shock-mitigation potential', Journal of Materials Engineering and Performance, vol. 22, no. 7, pp. 1964-1981. https://doi.org/10.1007/s11665-013-0485-3

Coarse-grained molecular-level analysis of polyurea properties and shock-mitigation potential. / Grujicic, M.; Snipes, J. S.; Ramaswami, S.; Yavari, R.; Runt, James Patrick; Tarter, J.; Dillon, Gregory P.

In: Journal of Materials Engineering and Performance, Vol. 22, No. 7, 01.07.2013, p. 1964-1981.

Research output: Contribution to journalArticle

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