The nature of the gamma dielectric relaxation in diglycidyl ether Bisphenol-A (DGEBA) based epoxies
The nature of the gamma dielectric relaxation in diglycidyl ether Bisphenol-A (DGEBA) based epoxies
A γ relaxation dielectric loss peak has been measured in the temperature range 113–163 K for a series of epoxy resins based on diglycidyl ether bisphenol-A (DGEBA). The network architecture of the examined systems were systematically altered using varied types of functional network modifiers featuring different functional groups. Analysis of the temperature dependence of the loss peak frequency leads to a radically new interpretation of the fundamental processes that are associated with the γ relaxation. The analysis has shown that the relaxation process can best be described in terms of a thermally assisted tunnelling displacement of a proton, termed activated tunnelling. The parameters derived not only fit the experimental data well, but have a clear physical origin that is shown to be consistent with the network topology as expressed through the glass transition temperature. The maximum temperature for which such behavior is observable has been determined and shown to be consistent with the measurements. The approach proposed here provides a new method for understanding γ relaxations in these and similar systems.
Barrier energy, Dielectric relaxation, Epoxy resin, Functional network modifiers, Gamma relaxation, Glass transition, Proton tunnelling, vibration frequency
Saeedi, Istebreq
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Chalashkanov, Nikola
fda0afbb-1ec4-4b32-8c14-996a4c6138e8
Dissado, Leonard
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Vaughan, Alun
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Andritsch, Thomas
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17 May 2022
Saeedi, Istebreq
6df4dfcf-9bb8-4edc-952e-ccc4841f7b54
Chalashkanov, Nikola
fda0afbb-1ec4-4b32-8c14-996a4c6138e8
Dissado, Leonard
afe02cda-0a34-4044-9e53-40bdcea006e9
Vaughan, Alun
6d813b66-17f9-4864-9763-25a6d659d8a3
Andritsch, Thomas
8681e640-e584-424e-a1f1-0d8b713de01c
Saeedi, Istebreq, Chalashkanov, Nikola, Dissado, Leonard, Vaughan, Alun and Andritsch, Thomas
(2022)
The nature of the gamma dielectric relaxation in diglycidyl ether Bisphenol-A (DGEBA) based epoxies.
Polymer, 249, [124861].
(doi:10.1016/j.polymer.2022.124861).
Abstract
A γ relaxation dielectric loss peak has been measured in the temperature range 113–163 K for a series of epoxy resins based on diglycidyl ether bisphenol-A (DGEBA). The network architecture of the examined systems were systematically altered using varied types of functional network modifiers featuring different functional groups. Analysis of the temperature dependence of the loss peak frequency leads to a radically new interpretation of the fundamental processes that are associated with the γ relaxation. The analysis has shown that the relaxation process can best be described in terms of a thermally assisted tunnelling displacement of a proton, termed activated tunnelling. The parameters derived not only fit the experimental data well, but have a clear physical origin that is shown to be consistent with the network topology as expressed through the glass transition temperature. The maximum temperature for which such behavior is observable has been determined and shown to be consistent with the measurements. The approach proposed here provides a new method for understanding γ relaxations in these and similar systems.
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The nature of the gamma dielectric relaxation in diglycidyl ether Bisphenol-A (DGEBA) based epoxies
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Accepted/In Press date: 13 April 2022
e-pub ahead of print date: 18 April 2022
Published date: 17 May 2022
Additional Information:
Funding Information:
The authors would like to acknowledge the financial support of the Schlumberger Foundation Faculty for the Future.
Publisher Copyright:
© 2022
Keywords:
Barrier energy, Dielectric relaxation, Epoxy resin, Functional network modifiers, Gamma relaxation, Glass transition, Proton tunnelling, vibration frequency
Identifiers
Local EPrints ID: 473703
URI: http://eprints.soton.ac.uk/id/eprint/473703
ISSN: 0032-3861
PURE UUID: a6b75ef0-ed50-407b-a1bf-d6916d4d9d1c
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Date deposited: 27 Jan 2023 17:53
Last modified: 17 Mar 2024 04:06
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Author:
Istebreq Saeedi
Author:
Nikola Chalashkanov
Author:
Leonard Dissado
Author:
Alun Vaughan
Author:
Thomas Andritsch
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