This study focused on kinetic modeling of a specific type of multistep heterogeneous reaction comprising exothermic and endothermic reaction steps, as exemplified by the practical kinetic analysis of the experimental kinetic curves for the thermal decomposition of molten ammonium dinitramide (ADN). It is known that the thermal decomposition of ADN occurs as a consecutive two step mass-loss process comprising the decomposition of ADN and subsequent evaporation/decomposition of in situ generated ammonium nitrate. These reaction steps provide exothermic and endothermic contributions, respectively, to the overall thermal effect. The overall reaction process was deconvoluted into two reaction steps using simultaneously recorded thermogravimetry and differential scanning calorimetry (TG–DSC) curves by considering the different physical meanings of the kinetic data derived from TG and DSC by P value analysis. The kinetic data thus separated into exothermic and endothermic reaction steps were kinetically characterized using kinetic computation methods including isoconversional method, combined kinetic analysis, and master plot method. The overall kinetic behavior was reproduced as the sum of the kinetic equations for each reaction step considering the contributions to the rate data derived from TG and DSC. During reproduction of the kinetic behavior, the kinetic parameters and contributions of each reaction step were optimized using kinetic deconvolution analysis. As a result, the thermal decomposition of ADN was successfully modeled as partially overlapping exothermic and endothermic reaction steps. The logic of the kinetic modeling was critically examined, and the practical usefulness of phenomenological modeling for the thermal decomposition of ADN was illustrated to demonstrate the validity of the methodology and its applicability to similar complex reaction processes.

The azasydnone unit is a promising explosophoric block for future generations of highly thermostable and dense energetic materials.

A supercritical antisolvent process has been applied to obtain the nitrocellulose nanoparticles with an average size of 190 nm from the nitrocellulose fibers of 20 μm in diameter. Compared to the micron-sized powder, nano-nitrocellulose is characterized with a slightly lower decomposition onset, however, the friction sensitivity has been improved substantially along with the burning rate increasing from 3.8 to 4.7 mm·s⁻¹ at 2 MPa. Also, the proposed approach allows the production of stable nitrocellulose composites. Thus, the addition of 1 wt.% carbon nanotubes further improves the sensitivity of the nano-nitrocellulose up to the friction-insensitive level. Moreover, the simultaneous introduction of carbon nanotubes and nanosized iron oxide catalyzes the combustion process evidenced by a high-speed filming and resulting in the 20% burning rate increasing at 12 MPa. The presented approach to the processing of energetic nanomaterials based on the supercritical fluid technology opens the way to the production of nitrocellulose-based nanopowders with improved performance.

This paper describes a study of boron powders and powder compounds, obtained by various methods, including metallothermal, electrolytic, and borane cracking methods. The crystal state, particle size...

High endothermicity is one of the most important factors in the design of high-performance energetic materials for a new generation of rocket technologies. Taking this into account, in this study, novel highly energetic cage compounds were synthesized by the incorporation of a high-enthalpy N-azidomethyl moiety into the polynitro hexaazaisowurtzitane backbone. All obtained compounds were fully characterized by high-resolution mass spectrometry, IR and multinuclear NMR (¹H, ¹³C, ¹⁴N, ¹⁵N) spectroscopy. For two of them, 4-azidomethyl-2,6,8,10,12-pentanitrohexaazaisowurtzitane and 4,10-bis(azidomethyl)-2,6,8,12-tetranitrohexaazaisowurtzitane, the density and structural features were established by X-ray diffractometry. Enthalpies of formation were determined experimentally by combustion calorimetry. Thermal stability measurements and testing of impact and friction sensitivity were also carried out. The synthesized compounds exhibit a high level of heat resistance (decomposition onset 180–205 °C) and density (1.85–1.93 g cm⁻³). Their enthalpies of formation on a unit of mass (up to 2210 kJ kg⁻¹) are the highest among the known hexaazaisowurtzitane derivatives and are 2–2.5 times that of CL-20. The combination of these attractive properties makes the new materials promising energetic components for propellant compositions.

A computer simulation of cocrystal structures of [1,2,5]oxadiazolo[3,4-e][1,2,3,4]tetrazine-4,6-dioxide (FTDO) with benzotrifuroxan (BTF) in ratios of (1 : 1), (2 : 1) and (3 : 1) was performed, and their thermodynamic stability and physical–chemical characteristics were calculated. According to calculations, the (3 : 1) cocrystal is thermodynamically most stable. Therefore, it is the most preferable for cocrystallization, and we successfully obtained a cocrystal only for the (3 : 1) ratio. The cocrystal was characterized by X-ray diffraction and vibrational spectroscopy. In the vibrational spectra, some new bands were observed compared with the parent compounds spectra. In addition, some bands of pure FTDO and BTF disappeared, which is typical for a molecular complex formation. The thermal decomposition and sensitivity to impact and friction of the cocrystal were investigated. The impact sensitivity (2.8 J) turned out to be equal to the sensitivity of the less sensitive component (BTF). In addition, the sensitivity to friction (14 N) decreased by three times compared with the highly sensitive FTDO, which is unusual for cocrystals of high-energy compounds. The (3 : 1) cocrystal had a high density of 1.888 (calc.) and 1.865 g cm⁻³ (exp.). The calculated detonation velocity (9.14 km s⁻¹) and Chapman–Jouguet pressure (38.08 GPa) are high, and indicate favorable prospects for using this cocrystal.