A “rolling ball method” to make glass fiber reinforced hollow epoxy macrospheres used for a three phase epoxy syntactic foam

Abstract

Glass fiber reinforced hollow epoxy macrospheres (GFR-HEMS) and hollow glass microspheres (HGMS) were used to prepare a three phase epoxy syntactic foam (ESF) in this study. An innovative “rolling ball method” was implemented in the preparation of GFR-HEMS where expanded polystyrene (EPS) beads were used as an initiation template. The EPS beads were coated with the epoxy resin and glass fiber using the “rolling ball method”, and these coated EPS beads were later cured and post-cured at high temperature which caused the EPS beads to shrink thus producing a hollow macrosphere structure. The effects of the volume fraction of the GFR-HMES, the wall thickness of the GFR-HEMS and the volume fraction of the HGMS on the compressive properties were discussed to find a comprehensive understanding of the structure–property relationship between the epoxy matrix and sphere fillers. Scanning electron microscopy (SEM) shows that the “rolling ball method” can make glass fibers form a fiber spherical x–y network throughout the macrosphere wall, which can make the GFR-HEMS and three phase ESF have great compressive strength. The ESF (570 kg m⁻³, 27.3 MPa) can withstand 2730 meters water pressure and provide 430 kg m⁻³ buoyancy, which can give some advice to the preparation of buoyancy material used in deepwater oil exploration.