Pyro and Kinetic Studies of Barium Oxalate Crystals Grown in Agar Gel

摘要

Single crystals of barium oxalate have been grown using gel method at ambient temperature. Thermal characteristics and kinetic parameters of barium oxalate crystals were determined by thermo-gravimetric (TG) analysis under non-isothermal heating conditions. The pyrolysis experiments were performed with increasing temperature up-to 600℃ at heating rate of 5℃, 7℃ and 10℃ in nitrogen gas atmosphere. The pyrolysis curve showed that loss of mass took place mainly in the range of 220℃ - 400℃. At higher temperature there was a significant mass loss due to decomposition of oxalates. Ozawa and Coats & Redfern methods were used to determine the apparent activation energies of material degradation. The apparent activation energies for barium oxalate crystals were obtained 187.42 KJ·mol-1 and 185.4 KJ·mol-1 for the respective methods.