Effect of molecular weight on dielectric properties of polyvinyl alcohol films

Abstract

Impedance analysis is the best technique to reveal the microstructural details of the polymeric material. The dielectric polarization not only depends on physical and chemical properties, but also on the degree of polymerization (DP) of the polymeric material. In the present study, to understand the polarizing mechanism, two different molecular weights of polyvinyl alcohol (PVA) films were used for impedance analysis. Dielectric polarization of PVA film measured at normal temperature and pressure (NTP) condition by using LCR-4282A Impedance analyzer, within the frequency range 20 Hz to 1 MHz. The importance of inves tigation is to know the simultaneous application of DC bias potential from 0 to 40 V with AC signal for measurement of over all electrical parameters. The result shows higher magnitude of dielectric constant for low-molecular weight (LMW) of PVA film in comparison to higher molecular weight (HMW), which is based on Maxwell-Wagner (M-W) theory. © 2006 Wiley Periodicals, Inc.