Electrical properties of a thermoplastic polyurethane filled with titanium dioxide nanoparticles

In this study we report a nanodielectric system composed of pre-synthesized nanoparticles embedded in an elastomer. Nanoparticles of titanium dioxide were synthesized in an aqueous solution of titanium chloride and polyethylene glycol. The nanoparticles were blended in a twin screw extruder with a thermoplastic, polyurethane (Morthane PS455-203), to form nanodielectrics at three different weight fractions of titanium dioxide. Impedance spectroscopy was employed to study polymer dynamics and the influence of nanoparticles on relaxation. The segmental relaxation associated with the glass transition of the polyurethane matrix, and the local relaxations associated with short range motions of polar groups were investigated at wide ranges of frequency (20 Hz-1 MHz) and temperature (300-20 K). The dielectric breakdown strength of the nanodielectrics was also measured to characterize their insulating properties and their potential for use in high voltage applications.