Investigation of flexural strength properties of rubber and nanoclay reinforced hybrid syntactic foams

Highly damage tolerant hybrid syntactic foams are developed by using rubber and nanoclay particles to modify the matrix microstructure in syntactic foams. Four different types of glass hollow particles (microballoons) with different densities are used to fabricate the foam samples. In the rubber hybrid foams, 40 and 75 (mu)m size rubber particles are used by 2% by volume quantity. In nanoclay hybrid foams, volume of nanoclay particles is maintained at 2 and 5%. The total volume of all types of particles is maintained at 65% in all types of plain and hybrid syntactic foams. The plain and hybrid syntactic foams are characterized for flexural properties. An increase in flexural strength is observed with the incorporation of rubber particles in syntactic foams. In nanoclay hybrid foams, flexural strength is observed to depend on the nanoclay volume fraction. The strength of microballoons plays an important role in determining the fracture mode of plain and hybrid syntactic foams. Rubber particles are found to increase the energy absorption under the flexural loading conditions.