Study on preparation and properties of carbon nanotubes/hollow glass microspheres/epoxy syntactic foam

Abstract Hollow glass microspheres (HGMs)/epoxy syntactic foam reinforced by multiwalled carbon nanotubes (MWCNTs) was prepared in this study. The effect of MWCNTs on the density, mechanical properties and water absorption of HGMs/epoxy syntactic foam was investigated. Because of the low density and low content of MWCNTs, the density of HGMs/epoxy syntactic foam does not change much with adding MWCNTs. In addition, the compression strength of HGMs/epoxy is enhanced by 17–25% when adding 0.3 wt% MWCNTs. The fracture surfaces of specimens were examined with scanning electron microscopy (SEM), and results indicated that the bridging effect of MWCNTs is the reinforcement mechanism. Analyzing the water absorption testing results, it is concluded that MWCNTs may decrease the water absorption content due to the hydrophobicity. Bigger inorganic ions in salt water could prevent the water diffusion, which results in a decrease of water absorption. In addition, the water absorption rate decreases with the extension of testing time.