Spectroscopic Investigation of Degradation Reaction Mechanism in γ-Rays Irradiation of HDPE
Shiv Govind Prasad, Chhagan Lal, Kriti Ranjan Sahu, Abhijit Saha, Udayan De, A Chapiro, S Dorey, F Gaston, N Girard-Perier, N Dupuy, S Marque, L Delaunay, J Davenas, I Stevenson, N Celette, S Cambon, J Gardette, A Rivaton, L Vignoud, S Prasad, A De, U De, P Singh, R Kumar, A Chapiro, S Aggarwal, M Sajwan, R Singh, I Moise, M Manea, S Vasilca, C Pintilie, M Virgolici, M Cutrubinis, I Stanculescu, V Meltzer, K Burg, S Shalaby, N Ojha, N Pradhan, S Singh, A Barla, A Shrivastava, P Khatua, V Rai, S Bose, A Goulas, K Riganakos, A Badeka, M Kontominas, Q Liu, S Liu, Y Lv, Y Huang, M Kong, Q Yang, G Li, J Suarez, E Da Costa Monteiro, E Mano, A Smedberg, T Hjertberg, B Gustafsson, J Pelto, T Verho, H Ronkainen, K Kaunisto, J Metsjoki, J Seitsonen, M Karttunen, L Amoroso, E Heeley, S Ramadas, T Mcnally, A Nabiyev, A Olejniczak, A Pawlukojc, M Balasoiu, M Bunoiu, A Maharramov, M Nuriyev, R Ismayilova, A Azhibekov, A Kabyshev, O Ivankov, T Vlase, D Linnik, A Shukurova, O Ivanshina, V Turchenko, A Kuklin, K Salasinska, K Mizera, M Celiski, P Kozikowski, M Borucka, A Gajek, H Fouad, R Elleithy, O Alothman
Abstract
Radiation damage and reaction mechanism of product formation due to γ-irradiation in high-density polyethylene (HDPE) have been studied by Fourier transform infrared (FTIR), UV-vis spectroscopic, and x-ray diffraction (XRD) techniques. A Co60gamma source (with a dose rate of 1.707 kGy/hr) has been used up to the total dose of 570 kGy. There are dose-dependent changes in the polymer. The optical band gap decreases with the increase of the γ-irradiation dose. Formations of unsaturation centers have been observed. FTIR observed that a lower dose of γ-irradiation induces the formation of an unsaturated (-C=C-) group and a ketone carbonyl group. Breaking of the C-H bond is more frequent than the breaking of the C-C bond in irradiated HDPE. Crosslinking dominates over chain scission (breaking of C-C bond of the main chain) at a lower dose (100 kGy). There has been no significant influence of γ-irradiation on the crystalline structure, although crystalline size decreases. Mechanisms of the formation of alkyl, allylic, and polyenyl radicals have been investigated.