| ABSTRACT
Aim: Tin‑base catalyst is one of the widely used organometallic catalysts in polyurethane technology. The purpose of this study was to
evaluate the effect of tin organometallic catalyst in the radiation response and radiological properties of a new formula of PRESAGE®.
Materials and Methods: In the study, two types of PRESAGE were fabricated. A very little amount of dibutyltindillaurate (DBTDL) (0.07%
weight) was used as a catalyst in the fabrication of new PRESAGE (i.e., PRESAGE with catalyst), which components were: 93.93%
weight polyurethane, 5% weight tetrachloride, and 1% weight leucomalachite green (LMG). For PRESAGE without catalyst, 94%
weight polyurethane, 4% weight tetrachloride, and 2% weight LMG were used. Radiochromic response and postirradiation stability of
PRESAGEs were determined. Also, radiological characteristics of PRESAGEs, such as mass density, electron density, mass attenuation
coefficient, and mass stopping power in different photon energies were assessed and compared with water.
Results: The absorption peak of new PRESAGE compared to PRESAGE without catalyst was observed without change. Sensitivity
of new PRESAGE was higher than PRESAGE without catalyst and its stability after the first 1 h was relatively constant. Also, Mass
attenuation coefficient of new PRESAGE in energy ranges <0.1 MeV was 10% more than water, whereas the maximum difference
of mass stopping power was only 3%.
Conclusions: Tin organometallic catalyst in very low concentration can be used in fabrication of radiochromic polymer gel to achieve
high sensitivity and stability as well as good radiological properties in the megavoltage photon beam. |