γ-Ray-driven degradation of robust epoxy thermosets
Zhen Hu1, Ningdi Xu1, Ziqiang An1
1School of Chemistry and Chemical Engineering, MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, Harbin Institute of Technology, Harbin 150001, China. huangyd@hit.edu.cn.
Materials Horizons
|March 22, 2022
Summary
This study introduces a new method for controlled polymer degradation using gamma rays. Stable conjugated linkages enable precise cleavage of epoxy thermosets, offering a sustainable alternative for material recycling.
Area of Science:
- Polymer Chemistry
- Materials Science
- Radiation Chemistry
Background:
- Gamma (γ) ray irradiation is a cost-effective and eco-friendly method for polymer degradation.
- Simultaneous cross-linking and degradation limit controlled irradiation degradation of thermosets.
- Developing controllable degradation technologies for thermosets is a significant challenge.
Purpose of the Study:
- To design and synthesize γ-ray-responsive epoxy networks.
- To achieve controllable polymer chain cleavage using γ-ray irradiation.
- To develop a sustainable method for thermoset material degradation and recycling.
Main Methods:
- Exploitation of stable conjugated linkages, specifically phenyl imine conjugated N-N bonds, for γ-ray-induced polymer chain cleavage.
- Design of epoxy networks incorporating these responsive linkages.
- Irradiation of epoxy networks at a dose of 40 kGy at room temperature.
- Incorporation of radical scavengers to mitigate uncontrolled recombination.
Main Results:
- The designed γ-ray-responsive epoxy networks exhibit controllable degradation at 40 kGy.
- The degraded epoxy thermosets maintain mechanical, thermal, and chemical resistance properties comparable to conventional epoxy resins.
- Radical scavengers accelerate degradation by reducing uncontrolled recombination of degradation segments.
Conclusions:
- Stable conjugated linkages provide a mechanism for γ-ray-induced controllable polymer degradation.
- This approach offers a promising route for the development of recyclable epoxy thermosets.
- The technology presents a sustainable solution for managing thermoset waste.
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