Thermal Stability and Dynamic Mechanical Properties of Nano and Micron-TiO2 Particles Reinforced Epoxy Composites: Effect of Mixing Method

This research work focuses on the performance optimization of composites containing both micron and nano size TiO2 particles separately in various concentrations and to understand the role of each on the thermal stability and moduli of the composites. Thermal stability of the particle-reinforced composites increased on increasing the concentration of TiO2, both in nano and micron filled cases, except for the 2.5 wt% nano-filled composite. Storage modulus (E') increased on adding micron-TiO2 to the epoxy hardener resin system from 1 - 2.5 - 5 wt% respectively and decreased dramatically on further increasing the micron TiO2 content to 7.5 and 10 wt% respectively. Nano TiO2 particle-reinforced composites showed an increasing trend of storage modulus for 2.5 - 5 - 7.5 wt% TiO2 filled composites with respect to the neat resin system. Presence of both micron and nano TiO2 particles increased the Tg of the composites. Also, the effect of sonication on the modulus and Tg is discussed. As a whole, composites in which the TiO2 particles were dispersed through the resin matrix by glass rod revealed better results (higher storage moduli and Tg) than those mixed by sonication, due to high viscosity of the epoxy resin used.