Relaxation phenomenon of poly(vinyl alcohol)/sodium carboxy methyl cellulose blend by thermally stimulated depolarization currents and thermal sample technique

The dipolar relaxation in poly(vinyl alcohol) (PVA), sodium carboxy methyl cellulose (NaCMCs), and their blends were studied using a thermally stimulated depolarization current (TSDC) technique. The mutual effects of polarization conditions such as heating rate, poling temperature, time, and field on the properties of TSDC were investigated. Quantitative analysis of the experimental data is given in terms of dipolar and space charge polarization. A thermal sampling (TS) technique was applied to decompose the complex relaxations in individual polymers and their blend of 0.5/0.5 wt/wt into its normal distribution components. The activation energy of TS-formed electrets was determined by fitting the experimental curve to Bucci and Fieschi equations. Peak parameters such as activation energy and preexponential factor tau(0) were obtained. A linear relationship between the activation energy and logarithm of the preexponential factor was found, thus confirming operation of the compensation law. In addition, by using the Eyring equation of the rate theory, the activation enthalpy Delta/H-not equal and the activation entropy Delta/S-not equal were calculated. (C) 2005 Wiley Periodicals, Inc.