Morphologies and properties of epoxy resin/layered silicate-silica nanocomposites

A new nanofiller containing layered organo-modified montmorillonite (oMMT) and spherical silica (SiO2) was prepared by an in situ deposition method and coupling agent modification. Fourier transform infrared spectrometry, X-ray diffraction and transmission electron microscopy show that there are interactions between oMMT and SiO2, and the spherical SiO2 particles are self-assembled on the edge of oMMT layers, forming a novel layered-spherical nanostructure. An epoxy resin (EP)/oMMT-SiO2 nanocomposite was obtained by adding oMMT-SiO2 to EP matrix. Morphologies and mechanical and thermal properties of the new ternary nanocomposite were investigated. For purposes of comparison, the corresponding binary nanocomposites, i.e., EP modified with either oMMT or SiO2 were also tested. The results for the mechanical properties show that oMMT obviously improves the strength of EP, and SiO2 enhances the toughness of EP, but oMMT-SiO2 exhibits a synergistic effect on toughening and reinforcing of EP. The toughening and reinforcing mechanism is explained by scanning electron microscopy. In addition, the thermal resistance of EP/oMMT-SiO2 is better than that of EP/SiO2, but it is worse than that of EP/oMMT. (C) 2006 Society of Chemical Industry.