TY - JOUR
T1 - Coarse–grained molecular modeling of the microphase structure of polyurea elastomer
AU - Liu, Minghao
AU - Oswald, Jay
N1 - Funding Information:
The authors gratefully acknowledge support from the Office of Naval Research under grant N00014–17–1–2694 . The authors acknowledge Research Computing at Arizona State University for providing HPC resources that have contributed to the research results reported within this paper.
Publisher Copyright:
© 2019
PY - 2019/8/2
Y1 - 2019/8/2
N2 - We present a structure–matching coarse–grained model of polyurea, similar to united atom models, in which hydrogen atoms are implicitly represented. The model was trained using iteration Boltzmann inversion and a new heuristically–determined, distance–dependent scaling function that dramatically reduces the iterations required. With its reduced complexity and accelerated dynamics, the coarse–grained model can simulate microphase separation with hard domain spacing of 5 nm, comparable to x-ray scattering measurements of similar polyurea elastomers. An analysis of the morphology of two model systems shows a large, interconnected hard domain within a multiblock system, compared to an interrupted hard phase composed of separate smaller ribbon–shaped domains in a diblock system. To analyze the topology of soft segment connectivity, we calculated their end–to–end distribution, revealing that soft segments are composed of a large population of bridge–like segments and a smaller population of loop–like segments.
AB - We present a structure–matching coarse–grained model of polyurea, similar to united atom models, in which hydrogen atoms are implicitly represented. The model was trained using iteration Boltzmann inversion and a new heuristically–determined, distance–dependent scaling function that dramatically reduces the iterations required. With its reduced complexity and accelerated dynamics, the coarse–grained model can simulate microphase separation with hard domain spacing of 5 nm, comparable to x-ray scattering measurements of similar polyurea elastomers. An analysis of the morphology of two model systems shows a large, interconnected hard domain within a multiblock system, compared to an interrupted hard phase composed of separate smaller ribbon–shaped domains in a diblock system. To analyze the topology of soft segment connectivity, we calculated their end–to–end distribution, revealing that soft segments are composed of a large population of bridge–like segments and a smaller population of loop–like segments.
KW - Coarse-grained model
KW - Iterative Boltzmann inversion
KW - Microphase separation
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U2 - 10.1016/j.polymer.2019.04.039
DO - 10.1016/j.polymer.2019.04.039
M3 - Article
AN - SCOPUS:85065699953
SN - 0032-3861
VL - 176
SP - 1
EP - 10
JO - Polymer
JF - Polymer
ER -