Effect of water absorption, hardness, and acoustic properties on sandwich syntactic foam composite for structural and marine applications

Abstract In this study, a sandwich composite structure was fabricated with core syntactic foam composites (SFC) reinforced with face-sheets of combined kenaf and glass fibers. The core SFC was made from hollow glass microsphere (HGM)/epoxy resin mixture. The focus of this study is to design a suitable material for marine, automobile, and structural applications by investigating the water absorption capacity, hardness, buoyancy, and acoustic resistance level of the sandwich composite. Four sequences of face-sheet reinforcement [e.g. kenaf-kenaf(KK); glass-glass(GG); glass-kenaf(GK), and kenaf-glass(KG)] were adopted. The results show that the KK sandwich absorbed more water, with buoyancy level of 0.329% than other sequence. GK shows the highest sandwich in hardness strength with 58Hv, and 35% more than the KK, while there was no significant difference in the sound pressure level of the sandwich composite.