Irradiated polymeric films and its possible application for radiation dosimetry

The aim of the present thesis is the development of a new polymeric films, laboratory prepared by sample uncouthly methods through dying them with different types of dyes. First unit containing three forms were prepared by casting polymeric solution of poly (vinyl chloride). First film was prepared by dying poly ( vinyl chloride ) film with eosin dye. This flexible plastic film dosimeter is bleached when exposed to gamma ray photons at low doses (2-7 kGy) indicating their suitability for eventual application in food irradiation processing. Also, another polyvinyl chloride film contain a Ph indicating dye namely methyl red undergo bleaching in the rang of (20-120 kGy) indicating their suitability for eventual application in sterilization. The third film was a Ph indicating dye cresol red dyed polyvinyl chloride in the presence of CI- containing substance (E.g.Chloralhydrate). This film have the advantage of clear visual in color at high dose gamma radiation. This film was developed using the phenomenon of HCl generation from the CI- containing substance upon irradiation. The produced HCl in turn changes the color of the indicator contained in the polymer. The Dosimetric parameters e.g. dose response, effect of relative humidity and temperature during irradiation on response as well as pre-and post-irradiation stability of all above films are discussed. In second unit, the film was prepared by sandwiching the radiochromic film (nylon 66) containing (Hexa-hydroxyethyl pararosaniline) by two layers of polyvinyl chloride containing UV absorption material namely (2-hydroxy-4n-octoxy-benzophenone) to improve the stability of this famous film towards UV-radiation. Finally, a mixed dyes of ph indicating dyes bromophenol red and cresol red dying a poly vinyl alcohol in the presence of chloral hydrate were prepared. This film exhibit color changes from original color (bagel), yellow to red. The useful dose range of this is (5-50 kGy) indicate its suitability for eventual application as label and dosimeter in sterilization of medical materials