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

✍ Scribed by M. D. Migahed; N. A. Bakr; M. I. Abdel-Hamid; O. El-Hanafy; M. El-Nimr

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 524 KB
• Volume: 59
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19960124)59:4<655::aid-app11>3.0.co;2-p

✦ Synopsis

The ultraviolet spectra of pure and lead salt-poly(viny1 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 a t 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.