POSITRON-ANNIHILATION STUDIES OF POLYETHYLENE-CARBON BLACK COMPOSITES

Results of investigations of the angular correlation of annihilation radiation and positron annihilation lifetime measurements are presented for polyethylene-carbon black composites. The inhibition of positronium formation due to the carbon black introduction is evidenced by a decrease in intensities of the narrow component in angular correlation of annihilation radiation curves and of the longest-lived components in positron annihilation lifetime spectra. A qualitative interpretation of the data in terms of the free-volumes model is proposed.