Thermoanalytical investigation on some boron–fuelled binary pyrotechnic systems

This paper describes the thermochemical properties and ignition characteristics of pyrolants consist of B + KNO3, B + PbO2 and B + Ba(NO3)2 mixtures, where boron is known as fuel and KNO3, PbO2 and Ba(NO3)2 act as oxidant. Differential thermal analysis (DTA) and thermogravimetry (TG) techniques have been employed to elucidate the reaction process of these pyrolants. The results of the experiments suggest that boron particles react exothermally with the gaseous decomposition products of KNO3 at 540 °C. Also, boron particles react exothermally with PbO2 and Ba(NO3)2 at 436 °C and 551 °C, respectively. Furthermore, the effect of heating rate on the thermal decomposition of pyrolants was investigated by DSC. The apparent activation energy (E), ΔG# and ΔS# of the decomposition processes were obtained from the DSC experiments. Based on these kinetic data and ignition temperatures, the relative reactivity of these mixtures was found to obey in following order:B/PbO2 > B/KNO3 > B/Ba(NO3)2