@article { ISI:000263212700021,
	title = {Effect of gamma-dose rate on crystallinity and morphological changes of gamma-sterilized biomedical polypropylene},
	journal = {Polymer Degradation and Stability},
	volume = {94},
	number = {2},
	year = {2009},
	month = {FEB},
	pages = {272-277},
	publisher = {ELSEVIER SCI LTD},
	address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND},
	abstract = {<p>The present work is aimed to study the changes in crystallinity and morphology of biomedical polyolefins after gamma-sterilization. The isotactic polypropylene (iPP) films were sterilized by gamma-radiation and the changes were characterized by differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD) and atomic force microscopy (AFM) techniques. The effect of dose rate on crystallinity changes also was focused. It was found that crystallinity and morphology significantly changed with gamma-irradiation. There was an increase in crystallinity Lip to 10 kGy accompanied with decrease in viscosity and mechanical properties. The changes in crystallinity mainly depend on gamma-irradiation dose and dose rate. The rise in crystallinity was attributed to chain scission and forming new perfect lamellae. However, the reduction was accompanied by occurrence of gamma- and beta-phases and crosslinking. Possible explanations for transitions in phases are also discussed based on our results. (C) 2008 Elsevier Ltd. All rights reserved.</p>},
	keywords = {Crystallinity, Dose rate, Gamma radiation, mechanical properties, Morphology, polypropylene},
	issn = {0141-3910},
	doi = {10.1016/j.polymdegradstab.2008.10.027},
	author = {Alariqi, Sameh A. S. and Kumar, A. Pratheep and Rao, B. S. M. and Singh, R. P.}
}
@article { ISI:000284374500018,
	title = {Effect of gamma-dose rate on biodegradation of gamma-sterilized biomedical polyolefins},
	journal = {Journal of Polymers and the Environment},
	volume = {18},
	number = {4},
	year = {2010},
	month = {DEC},
	pages = {600-607},
	publisher = {SPRINGER/PLENUM PUBLISHERS},
	address = {233 SPRING ST, NEW YORK, NY 10013 USA},
	abstract = {<p>The aim of the present study is to study the effect of gamma-dose rate on the biodegradation of gamma-sterilized polyolefins. Films of isotactic polypropylene, high density polyethylene and ethylene-propylene (EP) copolymer were sterilized under gamma-radiation with doses of 10 and 25 kGy. Two different (60)Co sources were used with dose rate 600 and 780 Gy h(-1). Neat and sterilized samples were incubated in compost and fungal culture environments. The changes in functional groups, surface morphology and intrinsic viscosity in polymer chains were characterized by FT-IR spectroscopy, SEM and viscometric measurements, respectively. It was observed that both gamma-degradation and biodegradation processes depend on the dose rate of gamma-source. It was found that the biodegradation of gamma-sterilized polyolefins in composting and microbial culture environments increased with decreasing the gamma-dose rate.</p>},
	keywords = {Biodegradation, Composting and fungal culture, gamma-Dose rate, Polyolefins, Sterilization},
	issn = {1566-2543},
	doi = {10.1007/s10924-010-0217-9},
	author = {Alariqi, Sameh A. S. and Singh, R. P.}
}
