ESR dosimetry and radical kinetics of gamma-irradiated propyl gallate

• Polycrystalline propyl gallate was γ-irradiated at room temperature and studied using ESR spectroscopy.
• Irradiated PG were present almost a singlet ESR spectra.
• Two different radical species were identified from the ESR spectra and simulation calculation.
• Kinetic features of the radicals were investigated at high and room temperatures, and the activation energies were calculated.

Propyl gallate (PG) is one of the most effective synthetic antioxidant. In the present work, the effects of gamma radiation on powder PG were investigated by Electron Spin Resonance (ESR) spectroscopy. The experimental spectra of irradiated PG were found to be consisted of two different overlapped spectra that originated for different radical species. Structural and kinetic features of the radicals which are responsible for experimental ESR spectrum were explored through the variations of the signal intensity with applied microwave power, variable sample temperature, and high-temperature annealing studies. Activation energies of the radical species were determined using the data derived from annealing studies. The dosimetric potential was also investigated in the range of 0.5–25.0 kGy. It was found that the G value of PG is about 0.35.