Dielectric relaxation and electric modulus behavior in poly(vinyl alcohol)-based composite systems

Abstract

The ultraviolet spectra of pure and lead salt-poly(vinyl alcohol) (PVA) composite films were studied at room temperature. Blending of PVA with lead acetate and lead nitrate cause a considerable change in the UV spectrum, indicating electronic structure modifications. The complex permittivity (c*) and the complex electric modulus (M*) of the pure PVA and the PVA-based composite films were investigated between 300 and 400 K in the 100 Hz-100 kHz frequency range. The frequency dependence of the permittivity is influenced by the space-charge polarization. The interfacial polarization is manifested at high temperature and becomes important only above the PVA glass transition temperature and below 1 kHz. Dielectric properties of PVA-lead nitrate composite revealed that the salt is complexed with PVA through hydrogen bonding. © 1996 John Wiley & Sons, Inc.