Preparation and dose response of PVC film coated with methyl red for routine dosimeter

This research aimed to prepare the film dosimeter from polyvinyl chloride (PVC) and methyl red. For the PVC film preparation, 0.05 g of PVC powder was dissolved in a solvent solution of cyclohexanone and dioctyl phathalate by solution casting technique. The PVC film was dyed by methyl red for the radiation indicator. The PVC film dosimeter was irradiated by gamma ray with a difference dose in the range of 0 - 30 kGy. The chemical structure of the PVC film dosimeter before and after irradiation was investigated by Fourier transform infrared spectroscopy. The results showed that the peak of C-H and C-Cl clearly showed after irradiation. The color changing of the PVC film dosimeter was increased with increasing the radiation dose. The color change of the PVC film dosimeter after irradiation was clearly observed by UV-Vis spectrophotometer. The results showed that the absorption intensity was increased with increasing irradiation dose. The wavelength at 525 nm of all samples exhibited the highest accuracy. In addition, the absorbance intensity during the seven days was not changed indicating that the PVC film dosimeter had high stability. From this experiment, the PVC and methyl red film can develop and use as a routine dosimeter.