Lightweight epoxy foams prepared with arranged hollow-glass-microspheres/epoxy hollow spheres

The research on lightweight epoxy foams is of great significance to weight reduction for aerospace, aviation, shipbuilding, high-speed railway, and other fields. In this study, a novel lightweight epoxy foam with a macro-sized hollow structure was designed and prepared using arranged hollow glass microspheres/epoxy resin (HGMs/EP) hollow spheres as filler and EP as a matrix by template and molding method. The density and uniaxial compression properties of the prepared hollow spheres could be tuned between 0.14 and 0.27 g/cm3 and 0.30 ± 0.01 MPa to 2.39 ± 0.17 MPa through adjusting the shell thickness, respectively. The bending and compression performance of arranged hollow spheres reinforced epoxy foams were investigated, and the failure mechanism was analyzed as well. The highest specific flexural strength, the specific flexural modulus, the specific compression strength, and the specific compression modulus of obtained epoxy foams was 30.77 ± 3.04 MPa cm3/g, 2.66 ± 0.19 GPa cm3/g, 45.78 ± 1.58 MPa cm3/g, and 1.60 ± 0.26 GPa cm3/g, respectively. This work presents a novel syntactic epoxy foam with low density, good specific flexural strength, and specific compression strength with fewer hollow glass microspheres, which can provide a preparation method for lightweight structural materials.