Effect of EPS volume fraction in buoyancy characteristics of expanded polystyrene/epoxy sandwich composites

In this study, the buoyancy characteristics of an expanded polystyrene spheres (EPS) embedded epoxy polymer based sandwich composites with aluminium skin are investigated. Composite which float at the pycnocline layers formulated by three fluids namely refined Helianthus annuus (sunflower) oil, brine solution and water are determined. Four composite samples EPS-22, EPS-29, EPS-36 and EPS-43 vol.% of EPS in the epoxy resin matrix core are fabricated by hand lay-up process. It is observed that the density of the composite is decreasing with increasing EPS volume fractions and the buoyant force acting on the samples at pycnocline layers are increased due to the density gradient. Results show that the sandwich composites with greater than EPS-36 and EPS-43 vol.% float in sunflower oil and composites having EPS-29 vol.% floats at the sunflower oil/fresh water pycnocline layer. Further, it is observed that composite with EPS-22 vol.% floats at the fresh/brine water pycnocline layer.