Jump to main content
Jump to site search
PLANNED MAINTENANCE Close the message box

Scheduled maintenance work on Wednesday 27th March 2019 from 11:00 AM to 1:00 PM (GMT).

During this time our website performance may be temporarily affected. We apologise for any inconvenience this might cause and thank you for your patience.

Issue 14, 2016
Previous Article Next Article

Finite cohesion due to chain entanglement in polymer melts

Author affiliations


Three different types of experiments, quiescent stress relaxation, delayed rate-switching during stress relaxation, and elastic recovery after step strain, are carried out in this work to elucidate the existence of a finite cohesion barrier against free chain retraction in entangled polymers. Our experiments show that there is little hastened stress relaxation from step-wise shear up to γ = 0.7 and step-wise extension up to the stretching ratio λ = 1.5 at any time before or after the Rouse time. In contrast, a noticeable stress drop stemming from the built-in barrier-free chain retraction is predicted using the GLaMM model. In other words, the experiment reveals a threshold magnitude of step-wise deformation below which the stress relaxation follows identical dynamics whereas the GLaMM or Doi–Edwards model indicates a monotonic acceleration of the stress relaxation dynamics as a function of the magnitude of the step-wise deformation. Furthermore, a sudden application of startup extension during different stages of stress relaxation after a step-wise extension, i.e. the delayed rate-switching experiment, shows that the geometric condensation of entanglement strands in the cross-sectional area survives beyond the reptation time τd that is over 100 times the Rouse time τR. Our results point to the existence of a cohesion barrier that can prevent free chain retraction upon moderate deformation in well-entangled polymer melts.

Graphical abstract: Finite cohesion due to chain entanglement in polymer melts

  • This article is part of the themed collection: Polymers
Back to tab navigation

Publication details

The article was received on 19 Jan 2016, accepted on 19 Feb 2016 and first published on 22 Feb 2016

Article type: Paper
DOI: 10.1039/C6SM00142D
Author version
Download author version (PDF)
Citation: Soft Matter, 2016,12, 3340-3351

  •   Request permissions

    Finite cohesion due to chain entanglement in polymer melts

    S. Cheng, Y. Lu, G. Liu and S. Wang, Soft Matter, 2016, 12, 3340
    DOI: 10.1039/C6SM00142D

Search articles by author