Safety and combustion properties of RbNO₃ infrared pyrotechnic composition

The combustion properties of RbNO₃ infrared pyrotechnic composition comprising RbNO₃ as oxidation agent, hexafluoropropenevinylidenfluoride-copolymer(FPM) as binding agent and Mg, Al₃Mg₄, Ti, TiH₂ and B as combustion agent, respectively were studied. DSC was used to analyse the decomposition process of the pyrotechnic composition.The combustion heat and flame temperature were measured and then compared with the results calculated by REAL method. The ingrared radiation intensity of 0.7~1.1 μm and visible light intensity of 0.4~0.7 μm were measured. Results show that the decomposition process of B/RbNO₃/FPM and TiH₂/RbNO₃/FPM pyrotechnic composition is the same. The value of combustion heat of Mg/RbNO₃/FPM pyrotechnic composition is the highest which is 4939 kJ·kg^-1, and then the order is Mg>Al₃Mg₄>TiH₂>Ti>B. The flame temperature of Ti/RbNO₃/FPM is the highest which is over 2700°C and the measured flame temperatures are lower than those of calculation by REAL method. The Ti/RbNO₃/FPM ratio of infrared radiation intensity of 0.7~1.1 μm and visible light intensity is 1.654 which is much higher so that TiH₂/PTFE/FPM can be used as good infrared illuminating composition.