Fractional Free Volume Dependence of Neutron-Irradiated Polystyrene (PS) Measured by Positron Method
Main Article Content
Abstract
The fractional free volume (Fh) in polystyrene (PS) as a function of neutron -irradiation dose has been measured, using positron annihilation lifetime (PAL) method. The results show that Fh values decreased with increasing n-irradiation dose up to a total dose of 501.03× 10-2 Gy.
A percentage reduction of 2.14 in Fh values is noticed after the initial n-dose corresponding to a percentage reduction in the free volume equal to 42.14/Gy.
The total n-dose induces a percentage reduction of 7.26, corresponding to a percentage reduction of 1.45/Gy. These results indicate that cross -linking is the predominant process induced by n-irradiation.
The results suggest that n-irradiation induces structure changes in PS, causing cross-linking in PS chains, whereas the presence of oxygen during irradiation causes retardness of cross-linking yield, which consequently affects the values of the above mentioned parameter with respect to their values in case the irradiation is performed in vacuum
Article Details
Issue
Section
This work is licensed under a Creative Commons Attribution 4.0 International License.
© 2023 The Author(s). Published by College of Science, University of Baghdad. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International License.