Performance improvement of pentacosa-diynoic acid label dosimeter for radiation processing technology

- Improving the performance 10, 12-pentacosa-diynoic acid label dosimeter.
- The monomer is solid-state polymerized by topochemical reaction under γ-rays.
- Dose range is 5 Gy to 4 kGy depending on PCDA content and wavelength of analysis.
- The effects of environmental conditions were performed for composition 2 at 670 nm.
- Overall uncertainty is lower than 6% at 2σ.

A radiation sensitive material, 10,12-pentacosa-diynoic acid (PCDA), was incorporated into polyvinyl butyral (PVB) films to develop indicators/dosimeters for blood and food irradiation. The present study aims to improve the dosimetric performance of these previously prepared dosimeters and to extend their shelf life by the combination of a radical scavenger, propyl gallate (PG), and a UV absorber, tinuvin-p (TP). The X-ray diffraction (XRD) patterns of the dosimeters were analysed and their dosimetric characteristics were investigated by specular reflectance in the visible spectrum range of 400-700 nm. Upon irradiation, the films turn blue exhibiting two main bands around 670 and 620 nm. Their dose-response functions were fitted by a double exponential growth, 5 parameters, equation. Irradiation temperature influences the dosimeter response at 670 nm without causing thermochromic transition up to 50 °C in poly-PCDA. The useful dose range is 5-4000 Gy depending on the wavelengths of analysis and PCDA content in the films. The overall uncertainty of dose measurement is less than 6% at 2σ.