Dielectric Behavior of Plasticized PVC/Alumina Nanocomposites Influenced With DC Biasing Field

Abstract

Nanocomposites of plasticized poly(vinyl chloride) (PVC) with different content (i.e. 0 to 6 phr) of nano-alumina (Aluminum oxide, n-Al2O3), plasticizer and heat stabilizer were prepared by melt compounding method. Morphological analysis and electrical measurements of p-PVC/n-alumina nanocomposites have been investigated by electron microscopy techniques (i.e. SEM and TEM) and using precision LCR meter technique. The obtained results revealed that degree of dispersion of n-alumina has increased at lower content, which was observed by TEM. The aggregation of nanoparticles and phase discontinuity of samples at the higher content of n-alumina have been observed by SEM and TEM. The frequency dependences of dielectric constant (ε’), dielectric loss (ε”) and loss tangent (tanδ) of p-PVC/n-alumina nanocomposites on different content of n-alumina with variation in DC bias voltage was swept from 0 V to 40 V at room temperature and measured in the frequency range of 20 Hz - 1MHz by applying small AC signal of 1 V. The experimental results showed that the parameters ε’, ε” and tanδ of p-PVC/n-alumina nanocomposites samples are intensely frequency and DC bias voltage dependent. The experimental data of ε’ and ε” are well fitted using the Cole-Cole plot for evaluating the dielectric relaxation parameters.