DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Molecular Dynamics Investigation of the Relaxation Mechanism of Entangled Polymers after a Large Step Deformation

Abstract

The chain retraction hypothesis of the tube model for nonlinear polymer rheology has been challenged by the recent small-angle neutron scattering (SANS) experiment. In this study, we further examine the microscopic relaxation mechanism of entangled polymer melts after a large step uniaxial extension by using large-scale molecular dynamics simulation. We show that the unique structural features associated with the chain retraction mechanism of the tube model are absent in our simulations, in agreement with the previous experimental results. In contrast to SANS experiments, molecular dynamics simulations allow us to accurately and unambiguously determine the evolution of the radius of gyration tensor of a long polymer chain after a large step deformation. Contrary to the prediction of the tube model, our simulations reveal that the radius of gyration in the perpendicular direction to stretching increases monotonically toward its equilibrium value throughout the stress relaxation. These results provide a critical step in improving our understanding of nonlinear rheology of entangled polymers.

Authors:
ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
Research Org.:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1479793
Grant/Contract Number:  
AC05-00OR22725
Resource Type:
Accepted Manuscript
Journal Name:
ACS Macro Letters
Additional Journal Information:
Journal Volume: 7; Journal Issue: 2; Journal ID: ISSN 2161-1653
Publisher:
American Chemical Society (ACS)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE

Citation Formats

Xu, Wen -Sheng, Carrillo, Jan-Michael Y., Lam, Christopher N., Sumpter, Bobby G., and Wang, Yangyang. Molecular Dynamics Investigation of the Relaxation Mechanism of Entangled Polymers after a Large Step Deformation. United States: N. p., 2018. Web. doi:10.1021/acsmacrolett.7b00900.
Xu, Wen -Sheng, Carrillo, Jan-Michael Y., Lam, Christopher N., Sumpter, Bobby G., & Wang, Yangyang. Molecular Dynamics Investigation of the Relaxation Mechanism of Entangled Polymers after a Large Step Deformation. United States. https://doi.org/10.1021/acsmacrolett.7b00900
Xu, Wen -Sheng, Carrillo, Jan-Michael Y., Lam, Christopher N., Sumpter, Bobby G., and Wang, Yangyang. Thu . "Molecular Dynamics Investigation of the Relaxation Mechanism of Entangled Polymers after a Large Step Deformation". United States. https://doi.org/10.1021/acsmacrolett.7b00900. https://www.osti.gov/servlets/purl/1479793.
@article{osti_1479793,
title = {Molecular Dynamics Investigation of the Relaxation Mechanism of Entangled Polymers after a Large Step Deformation},
author = {Xu, Wen -Sheng and Carrillo, Jan-Michael Y. and Lam, Christopher N. and Sumpter, Bobby G. and Wang, Yangyang},
abstractNote = {The chain retraction hypothesis of the tube model for nonlinear polymer rheology has been challenged by the recent small-angle neutron scattering (SANS) experiment. In this study, we further examine the microscopic relaxation mechanism of entangled polymer melts after a large step uniaxial extension by using large-scale molecular dynamics simulation. We show that the unique structural features associated with the chain retraction mechanism of the tube model are absent in our simulations, in agreement with the previous experimental results. In contrast to SANS experiments, molecular dynamics simulations allow us to accurately and unambiguously determine the evolution of the radius of gyration tensor of a long polymer chain after a large step deformation. Contrary to the prediction of the tube model, our simulations reveal that the radius of gyration in the perpendicular direction to stretching increases monotonically toward its equilibrium value throughout the stress relaxation. These results provide a critical step in improving our understanding of nonlinear rheology of entangled polymers.},
doi = {10.1021/acsmacrolett.7b00900},
journal = {ACS Macro Letters},
number = 2,
volume = 7,
place = {United States},
year = {Thu Jan 25 00:00:00 EST 2018},
month = {Thu Jan 25 00:00:00 EST 2018}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 35 works
Citation information provided by
Web of Science

Figures / Tables:

Figure 1 Figure 1: Mean-square internal distance 〈R2(𝑠)〉 divided by the chemical distance 𝑠 for various chain lengths. s = |𝑖 ― 𝑗| is the difference in indices of two beads 𝑖 and 𝑗 within a chain. The results for 𝑁 = 40, 120, and 500 are included here as references. Errormore » bars represent the standard deviations over ten independent simulations. The gray solid line is the benchmark function in the literature.41« less

Save / Share:

Works referenced in this record:

Reptation of a Polymer Chain in the Presence of Fixed Obstacles
journal, July 1971

  • de Gennes, P. G.
  • The Journal of Chemical Physics, Vol. 55, Issue 2
  • DOI: 10.1063/1.1675789

Dynamics of concentrated polymer systems. Part 1.—Brownian motion in the equilibrium state
journal, January 1978

  • Doi, Masao; Edwards, S. F.
  • J. Chem. Soc., Faraday Trans. 2, Vol. 74, Issue 0
  • DOI: 10.1039/F29787401789

Dynamics of concentrated polymer systems. Part 2.—Molecular motion under flow
journal, January 1978

  • Doi, Masao; Edwards, S. F.
  • J. Chem. Soc., Faraday Trans. 2, Vol. 74, Issue 0
  • DOI: 10.1039/F29787401802

Dynamics of concentrated polymer systems. Part 3.—The constitutive equation
journal, January 1978

  • Doi, Masao; Edwards, S. F.
  • J. Chem. Soc., Faraday Trans. 2, Vol. 74, Issue 0
  • DOI: 10.1039/F29787401818

Dynamics of concentrated polymer systems. Part 4.—Rheological properties
journal, January 1979

  • Doi, Masao; Edwards, S. F.
  • J. Chem. Soc., Faraday Trans. 2, Vol. 75, Issue 0
  • DOI: 10.1039/F29797500038

Microscopic theory of linear, entangled polymer chains under rapid deformation including chain stretch and convective constraint release
journal, September 2003

  • Graham, Richard S.; Likhtman, Alexei E.; McLeish, Tom C. B.
  • Journal of Rheology, Vol. 47, Issue 5
  • DOI: 10.1122/1.1595099

Dynamics of entangled linear, branched, and cyclic polymers
journal, January 1986


Dynamics of entanglements: A nonlinear model consistent with the Cox-Merz rule
journal, February 1996


Microscopic theory of convective constraint release
journal, March 2001

  • Milner, S. T.; McLeish, T. C. B.; Likhtman, A. E.
  • Journal of Rheology, Vol. 45, Issue 2
  • DOI: 10.1122/1.1349122

Transient behavior of entangled polymers at high shear rates
journal, December 1991

  • Pearson, D.; Herbolzheimer, E.; Grizzuti, N.
  • Journal of Polymer Science Part B: Polymer Physics, Vol. 29, Issue 13
  • DOI: 10.1002/polb.1991.090291304

Small-angle neutron scattering from a polymer coil undergoing stress relaxation
journal, September 1981


Polymer coil relaxation in uniaxially strained polystyrene observed by small angle neutron scattering
journal, January 1982


Molten Polymers in Strong Flows: A Nonclassical Proposal
journal, January 1991


Small Angle Neutron Scattering Observation of Chain Retraction after a Large Step Deformation
journal, October 2005


Fingerprinting Molecular Relaxation in Deformed Polymers
journal, July 2017


Tube Model Under Tension
journal, July 2017


Dynamics of entangled linear polymer melts:  A molecular‐dynamics simulation
journal, April 1990

  • Kremer, Kurt; Grest, Gary S.
  • The Journal of Chemical Physics, Vol. 92, Issue 8
  • DOI: 10.1063/1.458541

Entangled Polymer Dynamics in Equilibrium and Flow Modeled Through Slip Links
journal, June 2014


Simulating the Flow of Entangled Polymers
journal, June 2014


Molecular modelling of entanglement
journal, February 2003

  • Doi, Masao; Takimoto, Jun-ichi
  • Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences, Vol. 361, Issue 1805
  • DOI: 10.1098/rsta.2002.1168

Deviations from Dynamic Dilution in the Terminal Relaxation of Star Polymers
journal, October 2001


Segment connectivity, chain-length breathing, segmental stretch, and constraint release in reptation models. I. Theory and single-step strain predictions
journal, December 1998

  • Hua, Chi C.; Schieber, Jay D.
  • The Journal of Chemical Physics, Vol. 109, Issue 22
  • DOI: 10.1063/1.477670

Simulating Startup Shear of Entangled Polymer Melts
journal, November 2015


Simple models for complex nonequilibrium fluids
journal, February 2004


Effect of Chain Orientation and Stretch on the Stress Overshoot of Entangled Polymeric Materials under Start-Up Shear
journal, April 2017


Static and dynamic properties of large polymer melts in equilibrium
journal, April 2016

  • Hsu, Hsiao-Ping; Kremer, Kurt
  • The Journal of Chemical Physics, Vol. 144, Issue 15
  • DOI: 10.1063/1.4946033

Communication: Polymer entanglement dynamics: Role of attractive interactions
journal, October 2016

  • Grest, Gary S.
  • The Journal of Chemical Physics, Vol. 145, Issue 14
  • DOI: 10.1063/1.4964617

Fast Parallel Algorithms for Short-Range Molecular Dynamics
journal, March 1995


Implementing molecular dynamics on hybrid high performance computers – short range forces
journal, April 2011

  • Brown, W. Michael; Wang, Peng; Plimpton, Steven J.
  • Computer Physics Communications, Vol. 182, Issue 4
  • DOI: 10.1016/j.cpc.2010.12.021

Equilibration of long chain polymer melts in computer simulations
journal, December 2003

  • Auhl, Rolf; Everaers, Ralf; Grest, Gary S.
  • The Journal of Chemical Physics, Vol. 119, Issue 24
  • DOI: 10.1063/1.1628670

Spatial distribution of entanglements in thin free-standing films
journal, July 2016


Molecular dynamics simulations of deformation mechanisms of amorphous polyethylene
journal, November 2010


Plastic Deformation Mechanisms of Semicrystalline and Amorphous Polymers
journal, January 2015

  • Jabbari-Farouji, Sara; Rottler, Joerg; Lame, Olivier
  • ACS Macro Letters, Vol. 4, Issue 2
  • DOI: 10.1021/mz500754b

Molecular Mechanisms of Plastic Deformation in Sphere-Forming Thermoplastic Elastomers
journal, October 2015


Rheological Evidence for a Dynamical Crossover in Polymer Melts via Nonequilibrium Molecular Dynamics
journal, July 2000


Bond Orientation Decay and Stress Relaxation in a Model Polymer Melt
journal, January 1996

  • Gao, Jianping; Weiner, Jerome H.
  • Macromolecules, Vol. 29, Issue 18
  • DOI: 10.1021/ma9602177

Reconstruction of three-dimensional anisotropic structure from small-angle scattering experiments
journal, August 2017


Works referencing / citing this record:

Nonlinear shear of entangled polymers from nonequilibrium molecular dynamics
journal, November 2019

  • Anwar, Muhammad; Graham, Richard S.
  • Journal of Polymer Science Part B: Polymer Physics, Vol. 57, Issue 24
  • DOI: 10.1002/polb.24904

Entangled chain polymer liquids under continuous shear deformation: consequences of a microscopically anharmonic confining tube
journal, January 2018

  • Xie, Shi-Jie; Schweizer, Kenneth S.
  • Soft Matter, Vol. 14, Issue 34
  • DOI: 10.1039/c8sm01182f

Dynamical structure of entangled polymers simulated under shear flow
journal, August 2018

  • Korolkovas, Airidas; Gutfreund, Philipp; Wolff, Max
  • The Journal of Chemical Physics, Vol. 149, Issue 7
  • DOI: 10.1063/1.5035170

Recovery rheology via rheo‐SANS: Application to step strains under out‐of‐equilibrium conditions
journal, October 2019

  • Lee, Johnny C. ‐W.; Porcar, Lionel; Rogers, Simon A.
  • AIChE Journal, Vol. 65, Issue 12
  • DOI: 10.1002/aic.16797

Slip-Spring and Kink Dynamics Models for Fast Extensional Flow of Entangled Polymeric Fluids
journal, March 2019

  • Moghadam, Soroush; Saha Dalal, Indranil; Larson, Ronald
  • Polymers, Vol. 11, Issue 3
  • DOI: 10.3390/polym11030465

Simulation of semidilute polymer solutions in planar extensional flow via conformationally averaged Brownian noise
journal, September 2019

  • Young, Charles D.; Sing, Charles E.
  • The Journal of Chemical Physics, Vol. 151, Issue 12
  • DOI: 10.1063/1.5122811

Dynamical structure of entangled polymers simulated under shear flow
text, January 2017


Contraction of Entangled Polymers After Large Step Shear Deformations in Slip-Link Simulations
journal, February 2019


Clustering of entanglement points in highly strained polymer melts
text, January 2019


Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.