Development and Mechanical Characterization of HGMS-EHS-Reinforced Hollow Glass Bead Composites

Hollow glass microsphere-reinforced epoxy hollow spheres (HGMS-EHSs) were prepared by a "rolling ball method" using expanded polystyrene beads, HGMSs, and epoxy resin (EP). The three-phase epoxy syntactic foam (epoxy/HGMS-EHS-HGMS composite) was fabricated by combining HGMS-EHS as a lightweight filler with EP and HGMS by a "molding method". The HGMS-EHS and epoxy curing agent systems were well mixed by scanning electron microscopy. Experiments show that higher HGMS-EHS stack volume fraction, lower HGMS-EHS layer number, higher HGMS-EHS diameter, lower HGMS-EHS density, higher HGMS volume fraction, and lower HGMS density result in a decrease in the density of the three-phase epoxy syntactic foam. However, the above factors have the opposite effect on the compressive strength of the three-phase epoxy syntactic foam. Therefore, in order to obtain the "high-strength and low-density" three-phase epoxy syntactic foam, the influence of various factors should be considered comprehensively to achieve the best balance of compressive strength and density of the three-phase epoxy syntactic foam. This can provide some advice for the preparation of buoyancy materials for deep sea operations.