Dyed acrylic-acid grafted polypropylene films for high-dose radiation dosimetry

Gamma radiation-induced polymerization of acrylic acid (AAc) onto polypropy lene (PP) film has been carried out under nitrogen atmosphere. The grafted film of PP-g-PAAc was allowed to react with solutions of two ionic dyes, na mely malachite green (MALG) or methylene green (METG). The Investigations s how that these new dosimeter films of PPMALG and PPMETG may be useful for h igh-close gamma radiation applications. The useful absorbed dose range of t he dyed films extends up to about 400 kGy, with a minimum useful dose of ab out 5 kGy. The radiation-induced colour bleaching has been analyzed with vi sible spectrophotometry, either at the maximum of the absorption band peaki ng at 601 nm (for PPMETG)) or that peaking at 623 nm for (PPMALG). The effe cts of relative humidity during irradiation, shelf-life and post-irradiatio n storage in dark and indirect daylight conditions on dosimeters performanc e are discussed. (C) 1999 Published by Elsevier Science Ltd. All rights res erved.