Dielectric Properties and Energy Storage of Hybrid/Boron Nitride/Titanium Carbide/Epoxy Nanocomposites

In this study, hybrid boron nitride (BN)/titanium carbide (TiC)/epoxy resin composite nanodielectrics were manufactured and characterized. Their morphological and structural characterization was conducted via scanning electron microscopy (SEM) images and X-ray diffraction (XRD) patterns, whereas the dielectric behavior was studied by means of broadband dielectric spectroscopy (BDS). Dielectric measurements were carried out from 30 to 160 degrees C and from 10(-1) to 10(6) Hz, respectively. The dielectric results revealed the existence of three relaxation mechanisms, which from high to low frequencies, at constant temperature, refer to re-arrangement of polar-side groups (beta-relaxation) of the macromolecular chains, transition from glassy to rubbery state of the amorphous polymer matrix (alpha-relaxation) and interfacial polarization (IP) between the polymer matrix and the nanofillers. It was found that, in general, nanodielectrics exhibited enhanced dielectric properties mainly due to the high dielectric permittivity of TiC and the fine dispersion of the fillers, confirmed also by the SEM images. Dynamic analysis conducted for the alpha-relaxation showed a Vogel-Fulcher-Tammann dependence on temperature. The ability of energy storing of the nanocomposites was examined via their energy density. Optimum performance is exhibited by the 5 phr TiC/1 phr BN/epoxy nanocomposite, reaching an energy storing ability nine times greater than the unfilled matrix.