ZnTiO3/epoxy resin nanocomposites: Development, dielectric behaviour and functionality

The dielectric response and functionality of zinc titanate/epoxy resin nanocomposites was investigated with parameters the reinforcing phase content, temperature and the frequency of the applied field. Morphological studies of the prepared nanocomposites were conducted via scanning electron microscopy and X-ray diffraction spectra. Differential scanning calorimetry and broadband dielectric spectroscopy were employed for determining the thermal response and electrical behaviour of the produced nanocomposites. Data analysis revealed the presence of four relaxation processes, which with descending relaxation time are attributed to: interfacial polarization, glass to rubber transition (alpha-process), rearrangement of polar side groups of the polymer chain (beta-process) and local motion of small segments of the polymer chain (gamma-process). The functionality of the systems and their energy storing efficiency was examined in terms of energy density and dielectric reinforcing function. Nanocomposites exhibit several times higher energy storing efficiency than the unfilled matrix, varying with frequency, temperature and filler content.