Nitrocellulose (NC) is typically synthesized by nitrating cellulose from cotton linter using a mixed acid of H₂SO₄ and HNO₃. Okara, a soybean-processing byproduct often disposed of as waste, contains approximately 40 wt% of insoluble dietary fiber rich in cellulose, making it a promising alternative raw material for NC. In this study, NC was synthesized from okara under different pretreatment and nitration conditions. Light yellow powder (okara NC) was obtained with a maximum crude yield of 18.0%. Elemental analysis and Fourier transform infrared spectroscopy revealed that the chemical structure of okara NC was comparable to that of the reference NC, with a nitrogen content of approximately 12%. When NaOH-pretreated okara was used as the raw material, the resulting product exhibited a structure that more closely resembled that of the reference NC. In this case, thermal analysis indicated a heat amount of 2.20 kJ･g^-1 and a decomposition temperature of 143.6°C. Hot water washing after nitration increased the decomposition temperature; however, it remained lower than that of the reference NC.

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Miniaturization of exploding foil initiator (EFI) system with micron-sized bridge foil (～200×200 µm²) may provide substantial improvement on detonator reliability and safety as well as manufacturing cost by lowering all-fire operational voltage and relieving many constraints on system design and fireset components. This numerical modeling study presents thermomechanical modeling on plastic flyer acceleration after bridge foil burst by pulsed energy input and high-speed flyer impact detonation initiation of HNS-IV explosive charges in such microscale EFI systems and low-energy fireset circuit. The compensation of deviation from linear bridge vapor expansion is introduced and detonation initiation criteria is recalibrated based on firing test results with thin flyer thickness in present modeling. The computational results on flyer velocity is well validated against the firing test measurements of EFI system with copper bridge foil and polyimide flyer. The influences of bridge and flyer thicknesses on detonation threshold are thoroughly investigated and the combined range of bridge and flyer thicknesses could be suggested for optimal EFI design of micron-sized bridge foil in terms of minimization of threshold charging voltage.

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Carbonates have been used as only pyrotechnic colorants with other oxidisers. But it was considered that the using carbonates which did not contained chloride, nitrogen oxides, and sulfur as oxidiser in pyrotechnics composition is one of the solution methods for reducing of toxic and harmful ingredients and smoke. Calcium carbonate (CaCO₃), which produces an orange flame in fireworks and not typically used as the main component in pyrotechnic compositions, was tested to be used as oxidiser in combination with Ti in this study for developments of carbonates-based pyrotechnics composition. And the substitution of commercial CaCO₃ powder with eggshell, with calcium carbonate as their major component, was tested for making effective use of a food waste product. The mixture between CaCO₃ and Ti was ignited under argon atmosphere as traditional pyrotechnics composition. The reaction products of the mixture which were TiC and CaTiO₃ were determined, and the equation of combustion reaction was summarised. The mixture exhibited continuous combustion and low sensitivity, demonstrating the potential to be used in pyrotechnics. The spark generation was found to be enhanced on substituting CaCO₃ with eggshell powder.

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Trinitrotoluene (TNT) equivalency converts an explosive into the weight of TNT that will result in the same explosive power, which can then be used to calculate its blast parameters. However, the blast parameters of an explosive charge depend on not only its weight but also its shape. In this study, field experiments were conducted using cylindrical emulsion explosive (EMX) charges with weights of 1-80 kg. The height between the center of the EMX charge and ground surface was fixed, and the explosion was initiated from the center of the top face. The blast parameters of the peak overpressure and scaled positive impulse were then used in empirical equations based on hemispherical and cylindrical TNT charges to estimate the explosive power of the EMX charges. The differences of the TNT equivalencies based on the peak overpressure and scaled positive impulse were 18.8% using the hemispherical TNT and 2.5% using the cylindrical TNT, respectively. When the shape, height above the ground surface, and initiation point of the TNT and EMX charges were similar, their blast waves had similar characteristics, and the TNT equivalency of the EMX charge was almost independent of the blast parameter used (i.e., peak overpressure or scaled positive impulse). These results emphasize the necessity of ensuring that the experimental conditions for two types of explosives match as closely as possible to compare their explosive powers.

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Based on the HTPB/IPDI propellant formulation system, the compatibility of three solidifiable catalysts TPB, TEPB and TS-01 with the main component of the propellant, their respective morphological characteristics and rheological properties of the propellant slurry were analyzed by differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and ARES rheometer. Combined with the curing catalytic mechanism, the influence of three curing catalysts on HTPB propellant process and mechanical properties were studied. The result show that the three curing catalysts have good compatibility with the main propellant component. TEPB and TS-01 have higher catalytic activity than TPB, which can accelerate the curing reaction process of propellant system and shorten the curing cycle of propellant. After adding TS-01, the properties of propellant were not much different from those of TPB-containing systems, and the tensile strength of propellant increased by about 0.1 MPa compared with TPB-containing propellant under the same curing conditions. Mechanical properties of TS-01-containing propellant were maintained at virtually a similar level at activity conditions of 50°C, 4 days and 40°C for 5 days as TPB-containing propellant at activity conditions of 60°C, 8 days and 50°C for 10 days.

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