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Updated: Sep 21, 2025
06:55
Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level
Published on: September 26, 2016
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Threading-Unthreading Transition of Linear-Ring Polymer Blends in Extensional Flow
Anine Borger1, Wendi Wang2, Thomas C O'Connor3
1Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark.
ACS Macro Letters
|June 2, 2022
Summary
Adding ring polymers to linear polymers increases viscosity and causes a stress overshoot. This phenomenon is due to a transient threading-unthreading transition of rings within the polymer network, uniquely altering chain elongation mechanisms.
Area of Science:
- Polymer physics
- Rheology
- Materials science
Background:
- Ring polymers mixed with linear polymers increase viscosity due to threading.
- Pure linear and ring polymers do not exhibit stress overshoot in rheology.
Purpose of the Study:
- Investigate the cause of stress overshoot in linear-ring polymer blends.
- Understand the role of ring polymers in altering transient polymer elongation.
Main Methods:
- Uniaxial extensional rheology measurements
- Ex-situ small-angle neutron scattering
- Nonequilibrium molecular dynamics simulations
Main Results:
- Linear-ring blends show a stress overshoot in extensional rheology.
- This overshoot is driven by a transient threading-unthreading of rings.
- Rings deform affinely and enhance linear chain elongation before unthreading.
Conclusions:
- Ring polymers uniquely modify the transient elongation mechanisms of linear polymers.
- The threading-unthreading transition is key to the observed rheological behavior.
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