Fabrication and mechanical properties of a novel epoxy-hollow glass microsphere composite

According to the demand of deep-sea buoyancy material with high compression strength and low density, a novel epoxy-hollow glass microsphere composite was manufactured and characterized. Firstly, the epoxy resin is modified by chemical modification methods using poly(methyltriethoxysilane) to improve the toughness of epoxy resin. Then, the ammonium bicarbonate is used as the foaming agent to add into the epoxy resin to produce the bubbles. After mixing with a small amount of hollow glass microsphere, the modified epoxy-hollow glass microsphere composite with foams is fabricated. IR spectrum indicates that the silicone has been successfully grafted on the epoxy resin chain, which benefits the toughness of the resin. It can be found that a lot of smaller bubbles exist on the surface of hollow glass microsphere by SEM, which further reduces the density of the modified epoxy-hollow glass microsphere composite. The compression strength has been significantly improved since the bubbles on the surface of glass beads play the role of a buffer balloon and there are few air bubbles in the resin matrix. The coefficient of water absorption for the modified epoxy-hollow glass microsphere composite also increased. The flexural strength of the modified epoxy-hollow glass microsphere composite was slightly reduced at the same time. The results here confirm a promising method for buoyancy materials to promote the compression strength and reduce the density.