A comparison between the dynamic and static ac conductivity characteristics of barium titanate filled acrylic resin

The ac conductivity characteristics of a polymer can be enhanced through the inclusion of appropriate fillers into the polymer matrix. Previous studies have revealed that the inclusion of ferroelectric fillers, such as barium titanate, allows polymer composites to possess enhanced permittivities at elevated electrical field strengths. At certain filler levels and at certain electrical field strengths, the emergence of harmonics has been observed in the resultant current waveforms. Previous investigations into the static nonlinear conduction characteristics have been performed by measuring the peak current density and electrical field waveforms and calculating the permittivity at a range of peak electric field strengths. An alternative method of evaluating the field dependent permittivity nature of the composite resin is to consider the change in current density with the change in angle of the applied electrical field strength, for a particular peak value of electrical field strength. In this investigation, this dynamic nonlinear conductivity relationship is thus compared with the static nonlinear conductivity relationship, for the acrylic resin system which has been studied, at a variety of filler concentrations.