Barium titanate/polyester resin nanocomposites: Development, structure-properties relationship and energy storage capability

Nanocomposite materials based on two different types of polyester matrix (a commercial type and a laboratory produced one) with embedded barium titanate nano-particles were developed and characterized. Structural and morphological characteristics of the produced composite specimens were studied via X-ray diffraction, Fourier transformation infra red spectroscopy, and scanning electron microscopy. Thermal, mechanical and electrical performance was examined via differential scanning calorimetry, bending and shear strength tests, and broadband dielectric spectroscopy, respectively. Mechanical strength appears to reduce with the increase of filler content. Commercial polyester's composites exhibit brittle behaviour, while laboratory polyester's composites exhibit an elastomeric performance. Dielectric data reveal the presence of four relaxation processes, which are attributed to motion of small parts of the polymer chain (gamma-mode), re-arrangement of polar side groups (beta-mode), glass to rubber transition of the polymer matrix (alpha-mode) and Interfacial Polarization between the systems' constituents. Finally, the energy storing efficiency of the systems was examined by calculating the density of energy.