THERMAL-DECOMPOSITION OF GAMMA-IRRADIATED CALCIUM BROMATE

The thermal decomposition of γ-irradiated Ca(BrO3)2 was studied by dynamic thermo-gravimetry. The reaction order, activation energy, frequency factor and entropy of activation were computed using the Coats-Redfem, Freeman-Carroll and Horowitz-Metzger methods and were compared with those of the unirradiated salt. Irradiation enhances the decomposition and the effect increases with irradiation dose. The activation energy decreases on irradiation. The mechanism for the decomposition of unirradiated and irradiated Ca(BrO3)2 follows the Avrami model equation, 1-(1-α)1/3 = kt, and the rate-controlling process is a phase boundary reaction assuming spherical symmetry. © 1990.