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International Journal of Spectroscopy
Volume 2011 (2011), Article ID 810936, 7 pages
Research Article

Structural and Optical Investigations of Radiation Damage in Transparent PET Polymer Films

1Department of Chemistry, Uttar Pradesh Textile Technology Institute, 11/208 Souterganj Kanpur 208001, India
2Department of Physics, Presidency College, 86/1 College Street, Kolkata 700 073, India
3Variable Energy Cyclotron Centre, 1/AF Bidhannagar, Kolkata 700 064, India

Received 10 November 2010; Accepted 11 February 2011

Academic Editor: Rolf W. Berg

Copyright © 2011 Shiv Govind Prasad et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Effects of gamma irradiation at different doses up to 135 kGy on polyethylene terephthalate (PET) polymer films have been investigated by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and ultraviolet-visible (UV-VIS) spectroscopy. From XRD analysis, it was found that even at a high dose of gamma irradiation of 135 kGy, crystallinity of the PET samples remain unchanged. However, the FTIR peak at 871 cm−1 (depicting C–H bending mode of out-of-plane vibration) and another at 1303 cm−1 (representing C–H bending mode of in-plane vibration) disappear for gamma-irradiated PET. In this study, it has also been found that γ-irradiation in air enhances the optical absorption in the wavelength region 320–370 nm. This has been attributed to free radicals being produced in the polymer by the γ-radiation. Further, the free radicals react with oxygen of air to form carbonyl group and hydroxyls. With increasing γ-dose, there is a red shift of the UV—near visible cutoff for PET. XRD and FTIR observations on γ-damage have been correlated.