Catalytic effects of nano additives on decomposition and combustion of RDX-, HMX-, and AP-based energetic compositions

Fe-based Fenton-like catalysts for water treatment: Preparation, characterization and modification

Energetic materials have been widely investigated experimentally and theoretically for decades, but there are still many unanswered questions concerning their thermal decomposition mechanisms that ...

Thermal decomposition of energetic materials using TG-FTIR and TG-MS: a state-of-the-art review

Evolution of phosphate coatings during high-temperature annealing and its influence on the Fe and FeSiAl soft magnetic composites

Superthermites or metastable intermolecular composites (MIC) are well-known for their excellent combustion characteristics in propellants. Herein, superthermites with three Fe2O3 morphologies (rod-like, polyhedral, and olivary) were synthesized. The effects of Al/Fe2O3 on the thermal decomposition property of nitrocellulose (NC) were investigated in detail via differential scanning calorimetry (DSC). The results indicate that the catalytic performances of the superthermites are highly relevant to the specific surface area of their corresponding Fe2O3. Al/Fe2O3 containing rod-like Fe2O3 (Fe2O3(r)) shows a much improved performance compared with other morphological samples. The values of apparent activation energy (Ea) and thermal ignition temperature (Tbeo) of NC-Al/Fe2O3(r) were the lowest. This study could provide some directive reference data for the thermal behavior of nitrocellulose-based superthermites.

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Thermal behavior of nitrocellulose-based superthermites: effects of nano-Fe2O3 with three morphologies

Dependence of catalytic properties of Al/Fe 2 O 3 thermites on morphology of Fe 2 O 3 particles in combustion reactions

Nano metal oxides are common combustion catalysts for enhancing the burning rate of solid propellants. Cr2O3 nanoparticles (NPs) are efficient combustion catalysts for the pyrolysis of energetic components. In this study, Cr2O3 NPs were synthesized via a modified sol–gel method and further used for studying the thermal decomposition of nitrocellulose (NC). Differential scanning calorimetry (DSC) and thermogravimetry-Fourier-transform infrared spectroscopy (TG-FTIR) analyses indicate that the Cr2O3 NPs can be safely used with NC and the mechanism of the reaction between Cr2O3/NC and pure NC follows the Avrami–Erofeev equation: f(α) = 3(1 − α)[−ln(1 − α)]1/3/2. The peak temperature and activation energy (Ea) for the thermal decomposition of Cr2O3/NC are lower than those of pure NC. NO2 was detected at a lower temperature after NC was mixed with Cr2O3 NPs; this indicated the catalytically accelerated bond cleavage of NC by Cr2O3 NPs.

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Compatibility and thermal decomposition mechanism of nitrocellulose/Cr2O3 nanoparticles studied using DSC and TG-FTIR

The effect of LaFeO3@MnO2 on the thermal behavior of energetic compounds: An efficient catalyst with core-shell structure

In order to enable the energetic materials to possess a more powerful performance, adding combustion catalysts is a quite effective method. Granular, oval, and polyhedral Fe2O3 particles have been prepared by the hydrothermal method and used to fabricate Al/Fe2O3 thermites. All the Fe2O3 and Al/Fe2O3 thermite samples were characterized using a combination of experimental techniques including scanning electron microsco‐ py (SEM), energy dispersive spectrometer (EDS), X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscope (TEM), and high‐resolution TEM (HRTEM). The non‐isothermal decomposition kinetics of the composites and nitrocellulose (NC) can be modeled by the Avrami‐Erofeev equation f(α)=3(1–α)[–ln(1–α)]1/3/2 in differential form. Through the thermogravimetric analysis infrared (TG‐IR) analysis of decomposition processes and products, it is speculated that Fe2O3 and Al/Fe2O3 can effectively accelerate the thermal decomposition reaction rate of NC by promoting the O‐NO2 bond cleavage. Adding oxides or thermites can distinctly increase the burning rate, decrease the burning rate pressure exponent, increase the flame temperature, and improve the combustion wave structures of the ammonium perchlorate/hydroxyl‐terminated polybutadiene (AP/HTPB) propellants. Among the three studied, different shapes of Fe2O3, the granular Fe2O3, and its corresponding thermites (Al/Fe2O3(H)) exhibit the highest burning rate due to larger surface area associated with smaller particle size. Moreover, Al/Fe2O3(H) thermites have more effective combustion‐supporting ability for AP/HTPB propellants than Fe2O3 structures and the other two as‐prepared Al/Fe2O3 thermites.

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Fengqi Zhao

Papers

Thermal behavior of nitrocellulose-based superthermites: effects of nano-Fe2O3 with three morphologies

Dependence of catalytic properties of Al/Fe 2 O 3 thermites on morphology of Fe 2 O 3 particles in combustion reactions

Compatibility and thermal decomposition mechanism of nitrocellulose/Cr2O3 nanoparticles studied using DSC and TG-FTIR

The effect of LaFeO3@MnO2 on the thermal behavior of energetic compounds: An efficient catalyst with core-shell structure

Combustion Catalyst: Nano‐Fe2O3 and Nano‐Thermite Al/ Fe2O3 with Different Shapes