Studies of the Positron Lifetime and Doppler Broadening Annihilation Radiation of Polyvinyl Chloride Doped with Al<sub>2</sub>O<sub>3</sub>

Abstract

Positron annihilation lifetime and Doppler broadening of annihilation radiation studies of pure and doped polyvinyl chloride (PVC) with Al2O3 reflect the effect of concentration on free volume. Therefore, variations of the relative fractional free volume, which is extracted from positron annihilation parameters, have been correlated with changes in the dielectric properties (dielectric constant and a.c. conductivity) of the pure and doped PVC with Al2O3 from 10 to 50 %. The o-Ps lifetime and its intensity show a linear dependence with a discontinuity at 30 % concentration of Al2O3. A correlation between the relative fractional free volume and the dielectric parameters has been achieved.