Enhancement of Dielectric Responses in Cold Curing Polyurethane through Magnesium Oxide Blend Incorporation

We have studied the influence of the presence of various weight percent of MgO nanoparticles in the polyurethane sample on the development of the complex relative permittivity and dissipation factor. The case with weight ≤ 1.0 wt% explicitly showed the real relative permittivity decrease in comparison to the case of 0.0 wt%. The case with weight > 1.0 wt%, on the contrary, showed the opposite effect at frequencies above 1 Hz. To determine the dependence of the dielectric parameters on frequency, the capacitance method was used within the frequency range between 1 mHz and 1 MHz. With the Cole-Cole model and its various parameters, determined at different temperatures, the complex relative permittivity of polyurethane and nanocomposite was analyzed. The a-relaxation and intermediate dipolar effect (IDE) of relaxation processes were observed during temperature measurements.