Gamma Ray Induced Modifications in Cellulose Triacetate Polymer used as a Solid-State Nuclear Track Detector

摘要

The effects of gamma radiations from a ~(60)Co source on the easily available overhead projector transparency have been analyzed. FTIR and UV-VIS spectra of the polymer before and after irradiation have been recorded and from the spectral data some modifications in the properties have been investigated. . The band gap energy has been calculated from the UV-VIS spectral data and it was found to remain constant up to a gamma dose of 10~3krad and decreases thereafter. FTIR studies reveal the fact that there is a generation of CO2 and -OH groups at higher doses, which is further confirmed from the decarboxylation mechanism in esters. Aliphatic C-H stretching intensity has also been found to increase with gamma dose. The changes in track registration properties of the polymer alongwith the activation energies for bulk and track etch rates have been observed. The etch rates have been observed to increase, which can accounts for the presence of oxygen. It is found that overhead projector transparency is a highly radiation resistant polymer as it is influenced to a very little extent up to the dose of 10~3krad. The changes are pronounced at higher gamma doses of the order of 5xl0~4 and 10~5krad.