Comparative thermal research on tetraazapentalene-derived heat-resistant energetic structures

Abstract

Organic inner salt structures are ideal backbones for heat-resistant energetic materials and systematic studies towards the thermal properties of energetic organic inner salt structures are crucial to their applications. Herein, we report a comparative thermal research of two energetic organic inner salts with different tetraazapentalene backbones. Detailed thermal decomposition behaviors and kinetics were investigated through differential scanning calorimetry and thermogravimetric analysis (DSC-TG) methods, showing that the thermal stability of the inner salts is higher than most of the traditional heat-resistant energetic materials. Further studies towards the thermal decomposition mechanism were carried out through condensed-phase thermolysis/Fourier-transform infrared (in-situ FTIR) spectroscopy and the combination of differential scanning calorimetry-thermogravimetry-mass spectrometry-Fourier-transform infrared spectroscopy (DSC-TG-MS-FTIR) techniques. The experiment and calculation results prove that the arrangement of the inner salt backbones has great influence on the thermal decompositions of the corresponding energetic materials. The weak N4-N5 bond in “y-” pattern tetraazapentalene backbone lead to early decomposition process and the “z-” pattern tetraazapentalene backbone exhibits more concentrated decomposition behaviors.

Comparative Thermal Research on Energetic Molecular Perovskite Structures

“…Non-isothermal kinetics of the thermal decompositions of (C 6 H 14 ON 2 )[NH 4 (ClO 4 ) 3 ] and (C 6 H 14 N 2 )[Na(ClO 4 ) 3 ] were investigated through DSC experiments under different heating rates of 2, 5, 10, and 20 • C/min with their thermal decomposition peaks compared with those of (C 6 H 14 N 2 )[NH 4 (ClO 4 ) 3 ] as shown in Figure 3a-c. Similar to many energetic materials' thermal decomposition behaviors under different heating rates [23][24][25], the decomposition peaks of the three molecular perovskites shifted toward high temperatures with the increase of heating rate, meanwhile, both the peak shape and heat release were very close under different heating rates, indicating that the thermal decompositions of (C 6 H 14 ON 2 )[NH 4 (ClO 4 ) 3 ], (C 6 H 14 N 2 )[Na(ClO 4 ) 3 ] and (C 6 H 14 N 2 )[NH 4 (ClO 4 ) 3 ] were probably one-step reactions. Kinetic parameters and mechanism functions of these thermal decomposition reactions were then calculated with NETZSCH Thermokinetics Software [26].…”

On-Line Thermally Induced Evolved Gas Analysis: An Update—Part 1: EGA-MS

“…Detailed thermal decomposition behaviors and kinetics were investigated through thermoanalytical methods, showing that the thermal stability of the inner salts is higher than most of the traditional heat-resistant energetic materials. Further studies on the thermal decomposition mechanism were carried out through the analysis of the evolved gases by coupling both mass spectrometry and Fourier-transform infrared spectroscopy [ 282 ].…”

A π-stacking highly stable insensitive energetic inner salt and its insensitive energetic salts

“…The strong ionization and electrostatic and hydrogen bond interactions will reduce the gap between molecules, and the crystal will be packed closer, resulting in a denser energetic material. 30–32 Energetic salts sometimes exhibit properties that are quite different from those of their parent molecules, such as stacking patterns, to improve their safety and stability. For some acidic ligands, their ammonium salts, hydroxylamine salts, and diammonium salts have good detonation performance and safety and have been widely studied.…”