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Ionic liquids (ILs) can function as "green" solvents owing to their stability and low vapor pressure. These features help prevent the ignition of a reaction and therefore ensures its safety. In this study, the application of ILs in the synthesis of energetic materials was examined; this was accomplished using nitration reactions in an IL, i.e. 1-butyl-3-methylimidazolium trifluoromethanesulfonate [BMIM][OTf] to determine its effect on runaway reactions. In this study, the nitration process generated o-, m-, and p-nitrotoluene (NT) with by products; the major by-product was benzoic acid (BA), and the ratio of the weight of the NTs to the BA was ~90 %. Furthermore, the presence of oxygen facilitated the production of BA. The amount decreased to 0.45 % under nitrogen atmosphere in a closed instrument. This investigation showed that oxygen was one of the key factors to the generation of BA, which was considered a characteristic feature of the nitration in [BMIM][OTf]. The presence of BA reduces the temperature required to initiate the exothermic reaction of the NTs. However, neither the benzoic-acid-induced temperature decrease nor the heat-of-reaction-induced adiabatic temperature increase facilitated the attainment of a temperature that triggered the decomposition of NTs or IL. [ABSTRACT FROM AUTHOR]

The deterioration of chemicals contained in safety devices is an important issue because such devices must be ready for emergencies and should remain functional for a long period of time, even when exposed to degrading environments. In this study, we focused on the influence of ozone disinfection on chemicals present in safety devices as ozone can be used for virus inactivation in compartments housing these devices. Specifically, we conducted accelerated deterioration tests to evaluate the effects of ozone exposure on guanidine nitrate (GN). Under the experimental conditions of this study, ozone-containing water deteriorated GN, whereas no change was observed in GN exposed to dry ozone. The ion chromatography (IC) analysis of the deteriorated product suggested that GN decomposed into nitrate ions, while capillary electrophoresis (CE) revealed a transformation of guanidine ions into ammonium ions. These results imply that GN deterioration produces ammonium nitrate. Additionally, ultraviolet-visible spectroscopy revealed the reaction products between GN and ozone, which were considered electrically neutral because of their absence in the results of IC and CE analyses. In a differential accelerating rate calorimeter, decomposition started at a lower temperature for the deteriorated GN than for the pristine sample. This indicates that the deterioration products affected the thermal decomposition behavior of GN. This change in exothermic and pressure-release behavior is considered to have an impact on the performance of pyrotechnics using GN. [ABSTRACT FROM AUTHOR]

Pyrotechnics, which include magnesium powder, produce bright flames, but magnesium is easily aged by water. To prevent the aging problem, which decreases the burning performance and increases the risk of spontaneous combustion, it is necessary to use a stabiliser. In this study, we observed the stabilisation effect of surfactants on the aging of magnesium with ammonium perchlorate and water. The effect of sodium stearate, a straight-chain carboxylate, on the aging of magnesium with ammonium perchlorate and water, was analysed. The results showed an increase in the apparent activation energy of the exothermic reaction of magnesium when sodium stearate was used as a stabiliser. Furthermore, our experiments revealed the stabilising capability of sodium laurate, sodium behenate, and sodium dodecylbenzenesulfonate. But sodium propionate did not exhibit a pronounced stabilisation capability. The experimental results revealed that the stabilisation effect of straight-chain carboxylates increased with increasing length of their hydrocarbon chains. The relationship between the stabilisation effect and the hydrophilic-lipophilic balance was evaluated and revealed that the stabilisation effect of the surfactant on the aging of magnesium with ammonium perchlorate and water depends on its hydrophilicity. [ABSTRACT FROM AUTHOR]

In order to change the energy release properties of energetic materials by altering the electronic state, the electrolytic oxidation of azoles with sodium perchlorate was carried out at conditions determined by linear sweep voltammetry. The change in electronic state due to the electrolytic oxidation was verified using ultraviolet spectroscopy. The thermal stability of products was investigated using sealed cell differential scanning calorimetry and thermogravimetric-differential thermal analysis. The electrolytic oxidation provided products whose onset temperatures of peaks differed from those of reactant azoles. The electrolytic oxidation destabilized 1,2,4-triazole (TA) and 4-amino-1,2,4-triazole (4ATA), but increased the stability of 3-amino-1,2,4-triazole (3ATA). However, distinct exothermic peaks were observed and Q DSC significantly increased for all triazole products. The gasification rates increased by more than 50 % due to electrolytic oxidation. In particular, electrolytic oxidized TA with perchlorate reached 99.5 % of gasification rate. These results confirmed that electrolytic oxidation is a promising method for developing new energetic materials with favorable energy release properties. [ABSTRACT FROM AUTHOR]

Degradation decreases the quality and safety of pyrotechnic compositions. To reduce pyrotechnic degradation, a better understanding of the mechanism of degradation is required. Previously, our work revealed that exposure to water caused degradation of a guanidine nitrate (GN) and basic copper nitrate (BCN) mixture, a major component for gas-generating agents in pyrotechnics. Our previous study detected only one degradation product: copper oxide (CuO). Herein, we aim to identify other degradation products and reveal the degradation mechanism of BCN. We also study the effect of GN/BCN degradation on thermal stability. Modified accelerating aging tests and X-ray powder diffraction analysis revealed two degradation products: CuO and copper nitrate trihydrate [Cu(NOs)2-3H2O, CuNite]. CuNite was not observed in experiments involving heating or contact with CuO during drying. CuO was detected in each degradation. Degradation behavior in water was observed using UV-Vis spectroscopy. Quantitative spectroscopic analysis revealed a ratio of Cu24- to NO3" of 1:2 in water during the accelerating aging test with BCN, consistent with CuNite but not with BCN. Differential thermal analysis of simulated aged GN/BCN revealed the effect of aging on thermal stability. Two degradation products, CuO and CuNite, decreased the thermal stability of GN. GN/CuO showed higher thermal stability than GN/BCN. The thermal stabilities of GN/CuO/CuNite and GN/BCN were the same, but the former showed a decrease in mass at around 100 °C due to dehydration. These results indicate thermal stability changes in GN/BCN due to aging. [ABSTRACT FROM AUTHOR]

This study investigated effects of aluminum powder in a melting experiment and ignition experiment using an electric furnace for microcrystalline wax fuel with 30 m aluminum powder added. Melting experiment results show that the melting time of the solid fuel decreases. Therefore, the aluminum powder promotes the phase change of WAX from solid to liquid near the surface of the solid fuel in the boundary layer combustion. Ignition experiment results show that adding aluminum powder reduced the time to ignition. By adding aluminum powder to microcrystalline wax, solid fuel ignites easily due to the ignition heat quantity per unit mass decreased. However, the aluminum powder was not ignited. Nevertheless, by adding aluminum powder to microcrystalline wax, the thermal conductivity increases, which promotes solid fuel melting and ignition. [ABSTRACT FROM AUTHOR]