Open AccessSpectroscopic Investigation of Degradation Reaction Mechanism in γ-Rays Irradiation of HDPE
Publication year - 2020
Publication title -
biointerface research in applied chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.216
H-Index - 11
ISSN - 2069-5837
DOI - 10.33263/briac112.94059419
Subject(s) - high density polyethylene , irradiation , fourier transform infrared spectroscopy , degree of unsaturation , radical , photochemistry , alkyl , reaction mechanism , chemistry , polyethylene , ketone , polymer chemistry , polymer , materials science , organic chemistry , catalysis , chemical engineering , physics , nuclear physics , engineering
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.