This work investigated a new thermite formulation consisting of Fe2O3, metal or alloy (Al, Mg, Ti or MgAl) and polyoxymethylene (POM), with potential applications as a propellant in fireworks. Thermal analysis (TG/DSC) data indicated that all mixtures underwent a mass loss on heating, although only the Fe2O3/Mg and Fe2O3/MgAl systems generated exothermic peaks due to an oxidation-reduction reaction. Ignition activation energies of vigorously and lightly mixed Fe2O3 were determined as 32.6 and 47.8 kJ mol-1, respectively. Also, ignition activation energies of Fe2O3/Mg,Fe2O3/Ti and Fe2O3/MgAl were determined as 48.8, 52.5 and 29.4 kJ mol-1, respectively. These combinations of Fe2O3 with various metals were found to undergo intense combustion in air when ignited, thus confirming that the thermite reaction has occurred. The maximum pressures of vigorously and lightly mixed Fe2O3/Al/POM, Fe2O3/Mg/POM, Fe2O3/Ti/POM and Fe2O3/MgAl/POM were obtained as approximately 2100, 1200, 1100 and 250 kPa, respectively. A vigorously mixed Fe2O3/Al/POM (5/5/20) composition generated a particularly high gas pressure, greater than those of the other mixtures and comparable to the pressures generated by black powder, CuO/Al/POM and CaO2/Al/POM systems.
composition, thermite, fireworks, pressure, energy