Department of Electric Power Engineering, Faculty of Electrical Engineering and Informatics, Budapest University of Technology and Economics, Budapest, Hungary
Department of Electrical Devices and High Voltage Technology, Faculty of Electrical Engineering and Computer Science, Lublin University of Technology, Lublin, Poland
Alena Kozakova
VUKI a. s., Electroinsulating resins and varnishes, Bratislava, Slovakia
Tomas Derer
VUKI a. s., Electroinsulating resins and varnishes, Bratislava, Slovakia
Jaroslav Hornak
Department of Technologies and Measurement, Faculty of Electrical Engineering, University of West Bohemia, Pilsen, Czech Republic
The aim of study is addressing the influence of nanoparticles (NPs) on the dielectric properties of polyurethane. In this research, only investigated the effect of Al2O3, MgO and ZnO NPs for concentrations up to 2 wt.% with the temperature range from 25 to 120 °C. During the preparation of nanocomposites, polymer chains bind to NPs, which then limits their mobility. This effect results in a decrease in real permittivity and the course of polarization mechanisms. An increase in permittivity over the entire temperature range only for a 2 wt.% MgO concentration was observed. The decrease in the mobility of polymer chains was confirmed by dynamic-mechanical analysis. This method also results in an increase in the glass transition temperature depending on the type and concentration of NPs. The presence of NPs and the limited mobility of the polymer chains results in a shift of the low-frequency local maximum to lower frequencies.
