Dielectric properties of polymer/clay nanocomposites

Abstract

Intercalated and exfoliated nanocomposites of insulating polymers poly methyl methacrylate and acrylonitrile butadiene styrene with organically modified montmorillonite (OMMT) was prepared by solution casting method. Formation of polymer nanocomposites was confirmed by X-Ray Diffraction. Fourier transform infrared spectroscopy confirmed the interaction between polymers and cations on the surface of OMMT layers. Dielectric properties of these nanocomposites were examined at room temperature in the frequency range of 100 Hz–1 MHz. The findings of dielectric measurements exhibited higher real and imaginary dielectric permittivity values for exfoliated nanocomposites and lesser real and imaginary dielectric permittivity values for intercalated nanocomposites as compared with pure polymers in the same frequency range. The increase in the permittivity values is attributed to Maxwell Wagner polarization in exfoliated nanocomposites because of increased interfacial area between polymer and the clay layers. Decrease in dielectric permittivity in intercalated polymer nanocomposites is attributed to restricted mobility of polymer chains due to nanoscopic confinement of the polymer with the silicate layers.