Publication Date:
2015-09-25
Description:
We report a novel time-resolved photoacoustic-based technique for studying the thermal decomposition mechanisms of some secondary explosives such as RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine), picric acid, 4,6-dinitro-5-(4-nitro-1 H -imidazol-1-yl)-1 H -benzo[ d ] [ 1 – 3 ] triazole, and 5-chloro-1-(4-nitrophenyl)-1 H -tetrazole. A comparison of the thermal decomposition mechanisms of these secondary explosives was made by detecting NO 2 molecules released under controlled pyrolysis between 25 and 350 °C. The results show excellent agreement with the thermogravimetric and differential thermal analysis (TGA–DTA) results. A specially designed PA cell made of stainless steel was filled with explosive vapor and pumped using second harmonic, i.e., λ = 532 nm, pulses of duration 7 ns at a 10 Hz repetition rate, obtained using a Q-switched Nd:YAG laser. The use of a combination of PA and TGA–DTA techniques enables the study of NO 2 generation, and this method can be used to scale the performance of these explosives as rocket fuels. The minimum detection limits of the four explosives were 38 ppmv to 69 ppbv, depending on their respective vapor pressures.
Print ISSN:
0946-2171
Electronic ISSN:
1432-0649
Topics:
Physics
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