Exploring the effect of TiO2 and ionic liquid on the dielectric properties of polyurethane and polyaniline blend nanocomposites

Conductive polymer nanocomposites are enormously potent multifunctional lightweight flexible materials used in various electronic devices owing to their excellent dielectric characteristics with interesting relaxation behavior. In this present context, dielectric properties like dielectric permittivity (epsilon '), dielectric loss (epsilon ''), AC conductivity (sigma(ac)), real and imaginary impedance (Z ' and Z ''), Nyquist plots, etc., of thermoplastic polyurethane/polyaniline/TiO2 (TPU/PANI/TiO2) nanocomposite films with 0-2 wt% TiO2 loading level have been studied. The dielectric analysis in the frequency range of 1 Hz to 1 MHz reveals that epsilon', sigma(ac), Nyquist plot as well as the relaxation behavior have been effectively tuned up to 1.5 wt% TiO2 loading level. The very high interfacial polarization of the dipoles at the interface is reflected in the ultrahigh value of epsilon '. The semicircular nature of the Nyquist plots is well explained by the cyclic movement of the charge and the high extent of charge storage. The significant improvement in dielectric properties in 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid (IL)-incorporated nanocomposite system reflects the coupling as well as dispersibility of IL. The reduction in epsilon ' and sigma(ac), and increase in bulk resistance with an increase in temperature indicate the positive temperature coefficient behavior of the developed nanocomposite systems. The adequate interaction between TiO2, TPU and PANI phases has been analyzed using X-ray diffraction. The significant dispersing ability and coupling activity of the IL has been explored from micrographs obtained from a scanning electron microscopy study. (c) 2021 Society of Industrial Chemistry.