A systematic approach was considered to study the matrix properties by introducing hybrid nanosize TiO2-SiO2 (50-120 nm, 2.5-10% by weight) filler into an epoxy resin. Ultrasonic mixing process was employed to disperse the particles into the resin system. The thermal, flame retardancy, morphology and the viscoelastic properties of the nanocomposite and the neat resin were measured using DSC, TGA, DMTA, and SEM techniques. The curing reaction at four different temperatures was studied for the nanocomposite having 5% nano TiO2-SiO2 and then the reaction rate and conversions were analyzed. The experimental data exhibited an autocatalytic behavior of the reaction that was explained by the model proposed by Kamal. The dependence of the activation energy on the conversion degree was interpreted by isoconversional method. Morphology studies using SEM showed that the nanoparticles were dispersed into the entire volume of the resin, homogeneously. From the experimental data, the nanocomposite exhibited increase in storage modulus, glass transition temperature (T-g), and decomposition temperature from the neat epoxy system. (C) 2010 Elsevier B.V. All rights reserved.