An Investigation on Decomposition Kinetics and Thermal Properties of Copper-Fueled Pyrotechnic Compositions

Thermal properties of pyrotechnic mixtures containing copper powder as fuel and NH4ClO4, KClO3, and KClO4 as oxidants are reported. The thermogravimetry (TG) differential thermal analysis (DTA) results for pure components and corresponding pyrotechnic mixtures showed that melting point, decomposition temperature, and rate of oxygen releasing of the oxidants have dominant effects on decomposition reaction of the pyrotechnic mixtures. Although NH4ClO4, KClO3, and KClO4 as pure oxidants are found to decompose at 321, 472, and 592 degrees C, respectively, the pure fine copper powder oxidized at 271.5 degrees C. On the other hand, the pyrotechnic systems Cu+NH4ClO4, Cu+KClO3, and Cu+KClO4 possessed decomposition temperatures of 283, 400, and 510 degrees C, respectively. Based on the decomposition temperatures obtained and the resulted kinetic data (E, G#, H#, and S#), obtained from differential scanning calorimetry (DSC), the thermal reactivity of the pyrotechnic mixtures found to decrease in the order Cu+NH4ClO4 Cu+KClO3 Cu+KClO4.