One-Pack Epoxy Foaming with CO2 as Latent Blowing Agent
Qiang Ren1,2, Shiping Zhu1
1Department of Chemical Engineering, McMaster University, Hamilton, Ontario Canada L8S 4L7.
ACS Macro Letters
|May 21, 2022
Summary
A new method for epoxy foaming uses carbon dioxide (CO2) as a latent blowing agent. This approach creates stable, low-density epoxy foams with good mechanical and thermal properties.
Area of Science:
- Materials Science
- Polymer Chemistry
- Chemical Engineering
Background:
- Epoxy resins are versatile thermosetting polymers widely used in various applications.
- Traditional epoxy foaming methods often involve hazardous blowing agents or complex processing.
- There is a need for simpler, safer, and more sustainable epoxy foaming technologies.
Purpose of the Study:
- To develop a novel one-pack epoxy foaming formulation using carbon dioxide (CO2) as a latent blowing agent.
- To investigate the combined functionality of ammonium carbamate as both a blowing agent and a curing agent.
- To evaluate the properties of the resulting epoxy foams.
Main Methods:
- Blocking active amine groups of an epoxy curing agent with CO2 to form ammonium carbamate.
- Utilizing the thermal decomposition of ammonium carbamate above 100 °C to release CO2 for foaming.
- Employing the liberated amine compound as the curing agent for the epoxy resin.
- Characterizing the storage stability, density, mechanical properties, and thermal stability of the prepared epoxy foams.
Main Results:
- A stable one-pack epoxy foaming formulation with good storage stability was successfully prepared.
- Epoxy foams with low density, good mechanical properties, and thermal stability were produced.
- The ammonium carbamate effectively acted as both a latent blowing agent and a curing agent.
- The developed method demonstrated competitive performance compared to existing epoxy foaming techniques.
Conclusions:
- A novel, simple, environmentally benign, and cost-effective approach for epoxy foaming using CO2 has been developed.
- The one-pack formulation offers practical advantages in terms of storage and application.
- This technology presents a promising direction for the advancement of sustainable epoxy foaming materials.
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