Dielectric and mechanical properties of polyaniline-grafted sepiolite loaded PVC nanocomposites

Conducting polymers exhibit interesting dielectric properties due to their unique conjugated π-electron backbone. The objective of this study was to examine the dielectric properties of nanocomposites containing a conducting nanohybrid (NH) as a filler. Polyaniline was grafted onto sepiolite by in situ emulsion graft polymerization to synthesize a conducting NH. This NH was blended with poly(vinyl chloride) (PVC) using a melt blending technique. Nanocomposites with variable amounts of nanofiller were prepared and characterized. Fourier-transform infrared (FT-IR) spectra of the NH composites show strong interactions between their individual components. The addition of the nanofiller into PVC increased its thermomechanical properties. Dielectric loss factor and permittivity increased with nanofiller content and decreased frequency, exhibiting strong interfacial polarization in the low frequency range. Incorporation of the nanofiller into the PVC matrix increased conductivity up to 7.9 × 10^-7 S/cm and substantially decreased impedance. The results demonstrate the potential of the nanocomposite for electromagnetic interference shielding, biomedical applications, biosensing, and environmental sensing.