Structure-Properties Relationships Involved in the Embrittlement of Epoxies
Romain Delannoy1,2, Vincent Tognetti2, Emmanuel Richaud1
1Laboratoire PIMM, Arts et Metiers Institute of Technology, CNRS, Cnam, HESAM Universite, 151 Boulevard de l'Hopital, 75013 Paris, France.
Polymers
|November 11, 2022
Summary
Thermal oxidation of epoxy amine networks forms amides, increasing elastic modulus while significantly reducing failure strain and energy. These findings correlate amide concentration with mechanical property degradation.
Area of Science:
- Polymer Science
- Materials Science
- Chemical Engineering
Background:
- Epoxy amine networks are widely used thermosets.
- Understanding their degradation mechanisms is crucial for material longevity.
- Thermal oxidation is a primary degradation pathway.
Purpose of the Study:
- To investigate the effects of thermal oxidation on epoxy amine networks.
- To correlate molecular changes with macroscopic mechanical property alterations.
Main Methods:
- Fourier Transform Infrared (FTIR) spectroscopy for molecular analysis.
- Tensile testing to evaluate mechanical properties (elastic modulus, ultimate strain, failure energy).
Main Results:
- FTIR confirmed significant amide formation during oxidation.
- Tensile tests revealed a ~0.5 GPa increase in Young's modulus.
- Ultimate strain and failure energy decreased by over 50%.
Conclusions:
- Thermal oxidation induces molecular changes (amide formation) in epoxy amine networks.
- These molecular changes directly lead to substantial degradation of mechanical performance.
- Established linear correlations between amide concentration and mechanical property changes.
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