Effect of nanoclay on the mechanical, dynamic mechanical and thermal properties of cyanate ester syntactic foams

Nanoclay reinforced, cyanate ester-based syntactic foams with varying nanoclay loadings were processed and evaluated for mechanical, dynamic mechanical and thermal properties. The volume percentage of the filler (microballoon + nanoclay) was kept constant at 70. X-ray diffraction studies showed intercalated morphology of the nanoclay particles in the foam composites. The properties of the nanoclay reinforced syntactic foams were compared with those of bare cyanate ester syntactic foams containing the same filler concentration. A considerable improvement in the mechanical properties viz. tensile, flexural and compressive strengths and corresponding moduli was observed for the foams on incorporation of nanoclay. The corresponding specific properties also showed substantial improvement. Nanoclay improved the toughness of the foam composites. The storage moduli were higher for the foam composites containing nanoclay. However, nanoclay diminished the Tg of the syntactic foams due to the plasticizing effect of the organic moiety of the nanoclay. The thermal properties of the syntactic foams were not significantly influenced by the addition of nanoclay.