Polyisoprene Based Composite Layers: Electrical Properties for Stretchable High Storage Energy Materials

In the present work, the dielectric relaxation spectroscopy technique (DRS) is used to investigate the electrical properties of synthetic photoreticulated Polyisoprene films containing conductive particles of core–shell structure. The conduction threshold of these materials is situated below 0.5 wt% of Polyaniline. Such a low percolation threshold is desired to maintain the matrix flexibility. For the 40 wt% loaded film, the conductivity reaches more than 10–5 S/cm. This value is suitable for semi-conductive applications. As expected, the conductivity was found to be thermally activated. The application of Efros-Shklovskii model gives a short localization length of about 4 A°. At low frequencies, the dielectric constant of these composites at room temperature is very high, a jump from nearly 10 to 107 was recorded for the 40 wt% loaded film. This is probably due to the interfacial polarization between the three constituents. Such high values of the dielectric constant allow using these materials as high k dielectrics for energy storage applications.