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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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Influence of weak reversible cross-linkers on entangled polymer melt dynamics
Mohau J Mateyisi1, Jens-Uwe Sommer1, Kristian K Müller-Nedebock2
1Leibniz Institute of Polymer Research, D-01069 Dresden, Germany.
The Journal of Chemical Physics
|July 2, 2018
Summary
This study models entangled polymer chains with reversible cross-links, revealing a higher elastic modulus and delayed relaxation due to linker evolution. This provides insights into polymer dynamics under specific cross-linking conditions.
Area of Science:
- Polymer Physics
- Materials Science
- Rheology
Background:
- Entangled polymer melts exhibit complex dynamics governed by chain connectivity and topological constraints.
- Reversible cross-links introduce dynamic changes to the polymer network structure.
- Understanding the interplay between entanglements and reversible cross-linking is crucial for predicting material properties.
Purpose of the Study:
- To develop and solve a slip-link model for entangled polymer chains with uniformly tethered reversible cross-links.
- To investigate the influence of reversible cross-linkers on the relaxation modulus and elastic properties of polymer melts.
- To analyze the system's behavior when linker survival time (τs) is between entanglement time (τe) and Rouse time (τR).
Main Methods:
- A slip-link model was formulated to represent the system of entangled chains with reversible cross-links.
- The model was analytically solved to determine the relaxation modulus.
- The behavior of the primitive path's motion under the influence of entanglements and cross-links was analyzed.
Main Results:
- The model predicts a significantly higher first plateau in the elastic modulus compared to non-associating entangled systems.
- A delayed terminal relaxation process was observed, attributed to the evolution of entangled chains influenced by reversible linkers.
- The study focused on the specific regime where τe < τs < τR.
Conclusions:
- Reversible cross-links significantly alter the viscoelastic properties of entangled polymer melts.
- The developed slip-link model successfully captures the effects of entanglements and reversible cross-linking on polymer dynamics.
- The findings offer a molecular-level understanding of how dynamic cross-links influence macroscopic material behavior.
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