Effects of Functionalized Nano-TiO₂ on the Molecular Motion in Epoxy Resin-Based Nanocomposites

Epoxy resin-based nanocomposites have been widely researched for being potential insulating materials in high voltage power equipment. In this paper, nano-TiO₂ particles were chosen and surface-modified by a silane coupling agent containing an epoxy group. The effect of functionalized nano-TiO₂ doping on the physical properties of epoxy resin was studied. The results of differential scanning calorimetry show that T_g increased significantly and can be increased by up to 35 °C. Therefore, it is believed that the suppression of molecular motion by the addition of nanofillers works effectively in the case of this functionalized nano-TiO₂ and a strong interaction between the epoxy resin and the nano-TiO₂ was formed after surface modification. Consequently, dynamic mechanical properties, thermal conductivity, electrical conductivity, and trap characteristics of epoxy resin are all adjusted after introducing functionalized nano-TiO₂. All of these physical properties were analyzed from the perspective of suppression of molecular motion, and it is of significance to establish the theory of a nanocomposite dielectric. Besides, the results show that the epoxy/TiO₂ nanocomposite is expected to be applied in the insulation system of electrical equipment.