skip to main content

DOE PAGESDOE PAGES

This content will become publicly available on August 2, 2019

Title: Effect of Chain Length Dispersity on the Mobility of Entangled Polymers

While nearly all theoretical and computational studies of entangled polymer melts have focused on uniform samples, polymer synthesis routes always result in some dispersity, albeit narrow, of distribution of molecular weights ( Ð M = M w / M n ~ 1.02 – 1.04 ). Here, the effects of dispersity on chain mobility are studied for entangled, disperse melts using a coarse-grained model for polyethylene. Polymer melts with chain lengths set to follow a Schulz-Zimm distribution for the same average M w = 36 kg / mol with Ð M = 1.0 to 1.16, were studied for times of 600 – 800 μ s using molecular dynamics simulations. This time frame is longer than the time required to reach the diffusive regime. We find that dispersity in this range does not affect the entanglement time or tube diameter. However, while there is negligible difference in the average mobility of chains for the uniform distribution Ð M = 1.0 and Ð M = 1.02 , the shortest chains move significantly faster than the longest ones offering a constraint release pathway for the melts for larger Ð M.
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [1]
  1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
  2. Naval Research Lab. (NRL), Washington, DC (United States)
  3. Duke Univ., Durham, NC (United States)
  4. Clemson Univ., SC (United States)
Publication Date:
Report Number(s):
SAND-2018-7798J
Journal ID: ISSN 0031-9007; PRLTAO; 665881
Grant/Contract Number:
AC04-94AL85000; NA-0003525
Type:
Accepted Manuscript
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 121; Journal Issue: 5; Journal ID: ISSN 0031-9007
Publisher:
American Physical Society (APS)
Research Org:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE
OSTI Identifier:
1478065
Alternate Identifier(s):
OSTI ID: 1462584

Peters, Brandon L., Salerno, K. Michael, Ge, Ting, Perahia, Dvora, and Grest, Gary S.. Effect of Chain Length Dispersity on the Mobility of Entangled Polymers. United States: N. p., Web. doi:10.1103/PhysRevLett.121.057802.
Peters, Brandon L., Salerno, K. Michael, Ge, Ting, Perahia, Dvora, & Grest, Gary S.. Effect of Chain Length Dispersity on the Mobility of Entangled Polymers. United States. doi:10.1103/PhysRevLett.121.057802.
Peters, Brandon L., Salerno, K. Michael, Ge, Ting, Perahia, Dvora, and Grest, Gary S.. 2018. "Effect of Chain Length Dispersity on the Mobility of Entangled Polymers". United States. doi:10.1103/PhysRevLett.121.057802.
@article{osti_1478065,
title = {Effect of Chain Length Dispersity on the Mobility of Entangled Polymers},
author = {Peters, Brandon L. and Salerno, K. Michael and Ge, Ting and Perahia, Dvora and Grest, Gary S.},
abstractNote = {While nearly all theoretical and computational studies of entangled polymer melts have focused on uniform samples, polymer synthesis routes always result in some dispersity, albeit narrow, of distribution of molecular weights ( ÐM = Mw / Mn ~ 1.02 – 1.04 ). Here, the effects of dispersity on chain mobility are studied for entangled, disperse melts using a coarse-grained model for polyethylene. Polymer melts with chain lengths set to follow a Schulz-Zimm distribution for the same average Mw = 36 kg / mol with ÐM = 1.0 to 1.16, were studied for times of 600 – 800 μ s using molecular dynamics simulations. This time frame is longer than the time required to reach the diffusive regime. We find that dispersity in this range does not affect the entanglement time or tube diameter. However, while there is negligible difference in the average mobility of chains for the uniform distribution ÐM = 1.0 and ÐM = 1.02 , the shortest chains move significantly faster than the longest ones offering a constraint release pathway for the melts for larger ÐM.},
doi = {10.1103/PhysRevLett.121.057802},
journal = {Physical Review Letters},
number = 5,
volume = 121,
place = {United States},
year = {2018},
month = {8}
}