POS2-0593
Deformation Behavior of Vitrimers under Strain and Temperatures
Topic
S2. High-End Characterization/Polymer Physics/Properties
When and Where
Sep 29, 2026
08:30 - 09:30
Room 301 (Grand Ballroom)
Session Chairs
Hae Jung SON
Boseok KANG
Presenter(s)
Ji Eun Hyun (Seoul National University)
Co-Author(s)
Abstract
In response to climate change, demand for polymer recycling has increased significantly. Vitrimers have attracted considerable attention as promising alternatives to conventional thermoset polymers, which are hard to recycle, because their dynamic covalent bonds enable reprocessing and reuse similar to that of thermoplastic polymers. Mechanical recycling of vitrimer involves severe deformation under stress at high temperature; however, the processing guidelines considering such complex conditions remain undeveloped.
In this work, tensile deformation behavior was investigated under various temperatures and strain rates. The deformation behavior is governed by the competition between the applied deformation rate and stress relaxation rate, which depends on temperature and the exchange reaction rate of dynamic bonds.
We used an epoxy-based vitrimer model system, which has a transesterification reaction and controlled exchange reaction rate by catalyst content. Relaxation dynamics were characterized by frequency sweep measurement at different temperatures. At high temperatures, the loss modulus increased, indicating enhanced energy dissipation through network rearrangement and resulting in faster stress relaxation.
A small-angle X-ray scattering (SAXS) experiment was used to investigate the microstructure of the network in the undeformed state. Based on these results, in-situ tensile-SAXS experiments were performed to correlate microstructural evolution with macroscopic deformation behavior during stretching. At low temperatures, both vitrimer and non-vitrimer showed similar behavior to that of a permanent network. In contrast, at high temperatures, vitrimer exhibited plastic deformation when the applied strain rate was lower than the relaxation rate due to network rearrangement. During this structural rearrangement, SAXS profiles showed peak broadening, indicating a decrease in structural regularity. Through this study, it is expected to provide a clue for determining the optimal processing condition.
In this work, tensile deformation behavior was investigated under various temperatures and strain rates. The deformation behavior is governed by the competition between the applied deformation rate and stress relaxation rate, which depends on temperature and the exchange reaction rate of dynamic bonds.
We used an epoxy-based vitrimer model system, which has a transesterification reaction and controlled exchange reaction rate by catalyst content. Relaxation dynamics were characterized by frequency sweep measurement at different temperatures. At high temperatures, the loss modulus increased, indicating enhanced energy dissipation through network rearrangement and resulting in faster stress relaxation.
A small-angle X-ray scattering (SAXS) experiment was used to investigate the microstructure of the network in the undeformed state. Based on these results, in-situ tensile-SAXS experiments were performed to correlate microstructural evolution with macroscopic deformation behavior during stretching. At low temperatures, both vitrimer and non-vitrimer showed similar behavior to that of a permanent network. In contrast, at high temperatures, vitrimer exhibited plastic deformation when the applied strain rate was lower than the relaxation rate due to network rearrangement. During this structural rearrangement, SAXS profiles showed peak broadening, indicating a decrease in structural regularity. Through this study, it is expected to provide a clue for determining the optimal processing condition.
