On the Promotion of TKX‐50 Thermal Activity with Aluminum

Abstract

It is significant to investigate the effect of aluminum (Al) on the thermal activity of Dihydroxylammonium 5, 5'-bistetrazole-1, 1'-diolate (TKX-50) for the application of TKX-50-based composite solid propellant. In this work, TKX-50/Al composites with different particle sizes and contents of Al were blended, and the thermal decomposition and combustion properties were investigated by differential scanning calorimetry (DSC), thermal decomposition kinetic methods, laser ignition experiments, and constant-volume combustion cell test. The results showed that the exothermic peak temperatures for thermal decomposition of TKX-50 were gradually advanced with the decrease of Al particle size. With the increase of Al nanoparticles (nAl) content, the peak temperatures of TKX-50 first decreased and then increased. As the content of nAl was 50 %, the activation energy of TKX-50 changed from 226.51 kJ • mol À 1 to 215.23 kJ • mol À 1 , and the critical temperature of thermal explosion decreased by 13.54 °C after the addition of nAl. In addition, a small amount of nAl could promote the combustion of TKX-50 that is reflected on the accelerated burning rate, increased maximum combustion pressure and pressurization rate. Overall, nAl with high specific surface area and high reactivity is a great thermal activity enhancement additive for TKX-50.

An Overview on Synthesis, Explosion, Catalysis, Modification, and Application of Dihydroxylammonium 5,5′-Bistetrazole-1,1′-diolate (TKX-50)

“…Research found that the introduction of metal in the thermal decomposition process of TKX-50 can improve its thermal decomposition performance. − Ju et al studied the decomposition process of the TKX-50 molecule on the surface of Al (111) by using the DFT method, to explore the decomposition mechanism of the pyrolysis of TKX-50 by Al. The activation energy of TKX-50/Al is lower than that of TKX-50 due to the formation of N–Al, O–Al, and OH–Al bonds on the surface of Al.…”

“…It can be considered that aluminum atoms promote the fracture of the tetrazole ring of TKX-50 and accelerate the thermal decomposition process. Based on this simulation study, Guo et al carried out corresponding experiments on the pyrolysis process of TKX-50 catalyzed by Al. The thermal decomposition process of TKX-50/Al composites with different aluminum particle size and content was investigated by thermal analysis.…”

“…(a) DSC Curves of Different Particle Sizes of Al Participating in the Thermal Decomposition of TKX-50. (b) DSC curves of different contents of nAl involved in the thermal decomposition of TKX-50 . (Reprinted with permission from ref , 2022 John Wiley & Sons, Inc.)…”

Direct Visualization of Aluminum Particle Wetting on Carbon Using In Situ Laser Heating TEM

“…Aluminum particles are utilized in a wide variety of industrial and military applications, such as nanocomposites, surface coatings, and explosives. − For instance, in metal–matrix composites, understanding the wetting behavior is critical for manufacturing and processing composites. Since carbon is a common material to be used as reinforcement in composites, many studies have been performed on the aluminum–carbon system to understand its wetting behavior. − However, most research studies focused on contact angle measurement via the sessile drop method under isothermal conditions.…”

Characterization of thermal decomposition mechanism and combustion performance of 4,4’‐azobis(1,2,4‐triazole)**

“…Combustion is a form of reaction with a faster rate of energy release than thermal decomposition [21][22][23]. The thermal analysis and combustion behaviors of new polynitrogen compounds is of great significance for the qualitative description of their reaction laws in the combustion process, the establishment of mathematical models, the calculation of kinetic parameters, thermodynamic parameters, and the development and application of new polynitrogen compounds [24][25][26][27].…”