Effect of crumb rubber type on macroballoons towards physical and mechanical properties in syntactic foams

The effect of crumb rubber types on physical and compression properties of macroballoons in syntactic foams was investigated. Expanded polystyrene (EPS) beads were used as initiation material for starting up the macroballoons. The epoxy and hardener system were prepared to be coated with EPS beads and these coated EPS beads were later cured and post-cured to shrink the EPS beads thus producing epoxy macroballoons (EM). The prepared epoxy macroballoons then were coated with different crumb rubber type which is rejected NBR glove crumb (CG-EM) and waste tire rubber crumb (CT-EM). The EM, CG-EM, and CT-EM were then filled in the epoxy mixture to produce syntactic foam. The fabricated syntactic foam was characterized through physical and compression properties, respectively. Results indicated that the syntactic foam embedded with CT-EM shows high density, reduced radius ratio, and high compressive properties. The syntactic foam embedded with CT-EM shows the highest compressive strength and compressive modulus as compared to syntactic foam embedded with CG- EM and EM. The inclusion of the crumb rubber as the coating layer results in high energy absorption and stress transfer in syntactic foam.