Effect of foaming agent content on the microstructure and macroscopic mechanical properties of epoxy foam

Abstract Epoxy foams have attracted significant attention due to their lightweight nature, excellent physical and mechanical properties, and high specific energy absorption rate. However, there remains a scarcity of work on the preparation of epoxy foams using expandable microspheres. In this study, lightweight epoxy resin foams were fabricated using expandable microspheres as foaming agents, and the impact of foaming agent content (FAC) on the properties of the epoxy foams was systematically explored. The consequences indicate that the density of epoxy foam ranges from 0.33 to 0.55 g·cm −3 , and the compressive strength exceeds 7.5 MPa, demonstrating remarkable lightweight and compressive properties. With the increase of content of the foaming agent, the volume density and compressive strength of the epoxy foam gradually decrease, and the specific compressive strength displays a trend of initially increasing and then decreasing, reaching the maximum when the foaming agent content is 2.3 wt.%. This work provides valuable references for the preparation and performance optimization of epoxy foams.