Effect of Particle Size on Dielectric Properties of Polystyrene/TiO2 Composites

In this study composites of Polystyrene (PS) filled with nano- and micro- particles of titania (TiO2) were prepared by solvent assisted mixing technique and filler volume fraction was increased gradually. Dielectric properties and dynamic-mechanical-thermal analysis (DMTA) of the composites were measured as functions of frequency and temperature, respectively. It was found that nano composite had more dielectric permittivity than micro composite at low concentration of filler particles. By increasing volume fraction of fillers, dielectric permittivity of micro composite improved and surpassed the values of nano composites. DMTA results revealed that nano and micro titania, with low concentration, can reduce glass transition temperature of PS matrix. This reduction is more considerable in nanocomposite. By adding more amounts of fillers, Tg improves to the values more than neat PS. Effect of particle size of titania on dielectric properties of PS was explained through dynamics of polymer chains in the interphase region

کلیدواژه ها:

Nano- and micro-Titania ، Polystyrene ، Filler particle size ، Interphase layer ، Dielectric properties