RDX is preferred as explosive in munitions due to its balance of power and sensitivity that is known to be dependent on its particle size and size distribution. In this study, we prepared nano-sized RDX in a silica xerogel matrix using a sol-gel method and investigated its sensitivity for explosive properties. The presence of RDX in composite xerogel was confirmed by TG-DSC and FTIR techniques. Microstructure and porosity were characterized by transmission electron microscopy (TEM), small angle X-ray scattering, and N₂-physisorption techniques. TEM results showed that the size of RDX particles in the RDX-silica composites is in the range of 10–30 nm. The sensitivity to impact and friction was found to be higher for the composites compared to raw RDX. It was also found to be significantly dependent on the acetone/TMOS ratio used in the preparation.

The objective of this study was to determine compositional variables that result in early reaction of aluminum in detonations of pressed high explosive compositions, defined as reaction by 7 volume expansions as measured by 2.54 cm diameter copper cylinder expansion tests. In order to accomplish this in an economical fashion, statistical mixture design of experiments (DOE) was used in conjunction with anaerobic detonation calorimetry. The effect of binder type (e.g. energetic vs. inert), binder content, HMX content, aluminum content, and aluminum particle size was investigated. It was determined an energetic binder must be used to obtain significant aluminum reaction at volume expansions less than 7 V/V₀. Aluminum particle size was only a minor factor. Furthermore, the compositional oxygen balance only provides a general indication of which compositions exhibit more aluminum reaction than others.

The paper reports the energization of Hydroxyl-Terminated Polybutadiene (HTPB) by functionalizing explosophore NO₂ over the HTPB backbone, resulting in the formation of conjugated nitro-alkene derivative of HTPB. A convenient, inexpensive and efficient “one pot” procedure of synthesizing Nitro-Functionalized Hydroxyl-Terminated Polybutadiene (Nitro-HTPB) is reported. The reaction was carried out with sodium nitrite and iodine. To retain the unique physico-chemical properties of HTPB, functionalization by NO₂ group was restricted to 10 to 15 % of double bonds. The Nitro-HTPB was characterized by FTIR, ¹H NMR, VPO, DSC, TGA etc. The polymer has shown good thermal stability for practical applications. The kinetic parameters for the decomposition of Nitro-HTPB at 150–300 °C were obtained from non-isothermal DSC data.

The polynitro imidazole derivative 1,5-dinitro-2,6-bis(trinitromethyl)-3a,4a,7a,8a-tetrahydro-[1,4]dioxino[2,3-d:5,6-d′]diimidazole (DNTNDI) was synthesized through nitration of 2-(dinitromethylene)-1H-imidazol-4-ol in HNO₃/Ac₂O followed by cyclization of the di-enol. It was characterized by NMR, IR, elemental analysis, and single-crystal X-ray diffraction analysis. Compound DNTNDI crystallizes in the orthorhombic space group P2(1)2(1)2(1). The thermal decomposition was studied with thermogravimetry/derivative thermogravimetry (TG/DTG) in a nitrogen atmosphere with a heating rate of 5 K min⁻¹. The TG/DTG analysis indicated that DNTNDI has 97.64 % mass loss between 127 °C and 173 °C by undergoing exothermic decomposition. The density of DNTNDI was determined as 1.906 g cm⁻³ at 293 K with an Ultrapycno 1000 Pycnometer. The denotation velocity and denotation pressure of DNTNDI were calculated as 9325 m s⁻¹ and 40 GPa by applying the LOTUSES (version 1.4) code, respectively. The oxygen balance of DNTNDI is 0 and its oxygen content amounts to 51.78 %, which is superior to that of new generation of chlorine-free oxidizer ammonium dinitramide (ADN).

The microstructures and granularity distribution of different metal particles were investigated and the energy, sensitivity, and combustion properties of fuel rich solid propellants with different metal particles were studied in detail. It was found that the magnesium particles are more uniform than other metal powders, the mean diameter of the magnesium particles d₅₀=67.6 μm is much higher than those of the other ones, which are in the range of 7.1 μm<d₅₀<20.5 μm. Additionally, the preparation process of the Mg-based propellant is easier than those of the other ones. The experimental results showed that the propellant containing magnesium powder was less sensitive to friction and impact (165.1 NM and 21.9 NM, respectively), whereas, the burning rates of propellants with Zr and ZrH₂ particles increased, and the pressure exponents decreased.

Glycidyl azide polymer (GAP) was cured through “click chemistry” by reaction of the azide group with bispropargyl succinate (BPS) through a 1,3-dipolar cycloaddition reaction to form 1,2,3-triazole network. The properties of GAP-based triazole networks are compared with the urethane cured GAP-systems. The glass transition temperature (T_g), tensile strength, and modulus of the system increased with crosslink density, controlled by the azide to propargyl ratio. The triazole incorporation has a higher T_g in comparison to the GAP-urethane system (T_g−20 °C) and the networks exhibit biphasic transitions at 61 and 88 °C. The triazole curing was studied using Differential Scanning Calorimetry (DSC) and the related kinetic parameters were helpful for predicting the cure profile at a given temperature. Density functional theory (DFT)-based theoretical calculations implied marginal preference for 1,5-addition over 1,4-addition for the cycloaddition between azide and propargyl group. Thermogravimetic analysis (TG) showed better thermal stability for the GAP-triazole and the mechanism of decomposition was elucidated using pyrolysis GC-MS studies. The higher heat of exothermic decomposition of triazole adduct (418 kJ ⋅ mol⁻¹) against that of azide (317 kJ ⋅ mol⁻¹) and better mechanical properties of the GAP-triazole renders it a better propellant binder than the GAP-urethane system.

The shelf life of amine based liquid propellant was predicted using Berthelot and Arrhenius approaches and the results were compared. Reduction of the triethylamine concentration to less than 48 wt-% was taken as the end of shelf life. The γ₁₀ parameter and the activation energy of the Berthelot and Arrhenius approaches were determined to be 1.99 and 64.07 kJ mol⁻¹, respectively. According to the experimental data, the fuel shelf life at 293, 303, and 313 K, was predicted to be 5.7, 2.4, and 1.06 years using Arrhenius; and 3.93, 2, and 1 years using Berthelot approach, respectively. Results showed that the results that Berthelot approach gives lower values for fuel shelf life at ambient temperatures but it gives higher values at higher temperatures. Considering the safety aspect, the lower values are recommended as shelf life of the fuel.

Small-angle neutron scattering techniques were used to study the evolution of void morphology with pressed density of the insensitive high explosive, TATB. Samples were studied as a loose powder and as pressed pellets, ranging in density from approx. 1 to 1.804 g cm⁻³. Inter-granular voids in the loose powder were randomly arranged (non-fractal) and had a surface defined mean size of 0.66 μm. Pressing was found to induce a fractal network of voids with fractally rough interfaces. The surface-defined mean void size of the pressed samples was between 0.21–0.33 μm over the range of densities studied and was found to increase with pressed density up to 1.720 g cm⁻³, decreasing thereafter. The volume fractal dimension, indicative of the void arrangement, mirrored the changes in the mean void size. No systematic change in the surface fractal dimension was found. Surface area analysis allowed the average TATB grain size within the pressed samples to be quantified. An initial decrease of the mean grain size followed by an increase with pressed density suggests that the TATB grains behave in a brittle fashion at low densities and ductile at higher pressed densities.

A novel energetic-material detonation and air-blast characterization technique is proposed through the use of a laboratory-scale-based modified “aquarium test.” A streak camera is used to record the radial shock wave expansion rate at the energetic materialair interface of spherical laboratory-scale (i.e., gram-range) charges detonated in air. A linear regression fit is applied to the measured streak record data. Using this in conjunction with the conservation laws, material Hugoniots, and two empirically established relationships, a procedure is developed to determine fundamental detonation properties (pressure, velocity, particle velocity, and density) and air shock wave properties (pressure, velocity, particle velocity, and density) at the energetic materialair interface. The experimentally determined properties are in good agreement with published values. The theory’s applicability is extended using historical experimental test data due to the limited number of experiments able to be performed. Predicted detonation wave and air shock wave properties are in good agreement for a multitude of energetics across various atmospheric conditions.

To improve the safety of HMX, a two-dimensional (2D) graphene oxide (GO) was introduced to HMX by the solventnonsolvent method. The morphology, composition, thermal decomposition characteristic were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetry (TG) and differential scanning calorimetry (DSC). Compared to the previous reports, GO sheets exhibited better desensitizing effect than [60]Fullerene and CNTs. When 2.0 wt-% GO sheets were added, the impact sensitivity of raw HMX decreased from 100 to 10 %, and the friction sensitivity reduced from 100 to 32 %. The DSC results proved that GO sheets were compatible with HMX. In addition, by determining the thermal decomposition kinetic parameters of the samples, it was found that the activation energy (E_a) of HMX with 2.0 wt-% GO increased by 23.5 kJ mol⁻¹, suggesting that GO sheets could improve the thermal stability of HMX.

Insensitive high explosives are being used in military munitions to counteract unintended detonations during storage and transportation. These formulations contain compounds such as 2,4-dinitroanisole (DNAN) and 3-nitro-1,2,4-triazol-5-one (NTO), which are less sensitive to shock and heat than conventional explosives. We conducted a series of four tests on snow-covered ice utilizing 60-mm mortar cartridges filled with 358 g of PAX-21, a mixture of RDX, DNAN, and ammonium perchlorate. Rounds were detonated high- and low-order using a fuze simulator to initiate detonation. Blow-in-place (BIP) operations were conducted on fuzed rounds using an external donor charge or a shaped-charge initiator. Results indicate that 0.001 % of the original mass of RDX and DNAN were deposited during high-order detonations, but up to 28 % of the perchlorate remained. For the donor block BIPs, 1 % of the RDX and DNAN remained. Residues masses for these operations were significantly higher than for conventional munitions. Low-order detonations deposited 10–15 % of their original explosive filler in friable chunks up to 5.2 g in mass. Shaped-charge BIPs scattered 15 % of the filler and produced chunks up to 15 g. Ammonium perchlorate residue masses were extremely high because of the presence of large AP crystals, up to 400 μm in the recovered particles.

The process of rubber composite armor anti-shaped charge jet (SCJ) penetration was divided into four parts based on jet deformation that occurred when the SCJ penetrated the rubber composite armor. Results on the interference speed interval, interference frequency, and surplus penetration capability of the SCJ with the rubber composite armor were derived based on the stress wave and the Kelvin-Helmholtz instability theory. The effects of rubber layer thickness and obliquity of the armor for the composite armor anti-SCJ penetration were studied through theoretical, X-ray, and depth of penetration experiments. The results showed that when the obliquity was at 60° and the rubber layer thickness was in the range of 3 mm to 3.5 mm, the rubber composite armor seriously disturbed the stability of the SCJ. Thus, the rubber composite armor was found to have the best protection capability under these specifications.

Many strobe compositions were discovered in the past but only a few have been studied and none of them were fully understood. This article aimed at introducing the ternary composition of ammonium perchlorate as oxidizer, magnalium as fuel, and barium sulfate as metal salt. Parameters that influence its performances are analyzed. First, the binary compositions ammonium perchlorate/magnesium and ammonium perchlorate/magnalium were studied to observe the differences in behavior by using magnalium instead of magnesium. Next, variations were applied to the ternary composition changing the fuel: oxidizer:metal salt ratio. Finally the effect of potassium dichromate was analyzed. It is often added to the composition because it is known to improve the regularity and sharpness of flashes. The burning behavior was recorded using a high speed camera, together with emission spectra using a Charged-Coupled Device (CCD) camera coupled with a spectrometer and the temporal evolution of the intensity with a photodiode coupled with an oscilloscope. The results of the experiment give first insights into the physical and chemical mechanisms and give directions to the further study on strobe reactions.

Organic gel propellants are promising candidates for a variety of rocket motor and scramjet applications, since they are intrinsically safe and provide high performance. It is well known that organic gel fuel droplets exhibit distinct combustion characteristics compared with conventional liquid fuel droplets, and furthermore an understanding of the ignition delay and lifetime of these droplets is critical to the improvement of combustor design. In this work, investigations of the combustion of unsymmetrical dimethylhydrazine (UDMH) organic gel droplets in different nitrogen tetroxide (NTO) oxidizing atmospheres were conducted using two sets of experimental apparatus. The combustion characteristics under different conditions of temperature and pressure were compared and analyzed based on the flame shapes observed during experimentation. From these trials, an unsteady combustion model was developed and used for the numerical simulation of spray-sized UDMH organic gel droplet combustion in an NTO atmosphere. The hypergolic ignition and burning characteristics of the organic gel droplets under conditions simulating either engine startup or steady state combustion were compared, and changes in ignition delay and droplet lifetime with ambient temperature and pressure were analyzed. The experimental and numerical results show that the UDMH organic gel droplets exhibit periodic swell-burst behavior following the formation of an elastic film at the droplet surface. Each droplet burst results in fuel vapor ejection and flame distortion, the intensity of which declines with increasing ambient pressure. However, the swell-burst period is extended with increasing ambient pressure, which results in potential flameout. Under conditions of low temperature and pressure similar to those at engine startup, the ignition delay and lifetime of spray-sized gel droplets decrease with increasing temperature or pressure, although there is a sharp increase in droplet lifetime when the ambient pressure reaches a critical value associated with flameout. The ignition delay was found to be a rate-limited phenomenon linked to the droplet heating rate. The proportion of ignition delay and droplet lifetime due to droplet heating-up decreased with increasing temperature or decreasing pressure. Conversely, at high temperatures and pressures simulating the engine’s steady state operating conditions, the droplets were observed to flameout after several swell-burst periods and both ignition delay and lifetime decreased monotonically with increasing temperature or pressure. The ignition delay time was determined to be rate-limited by gas phase chemical reactions and contributed very little to the overall droplet lifetime compared with the engine startup condition.

Nowadays, the ballistic mortar is the preferred test for the explosive power measurements but there is no reliable method for its prediction. For an energetic compound, the formation of low molecular mass gaseous products and a high positive heat of formation per unit weight of the energetic compound are important parameters to have a high value of power. A novel method was developed to predict the power by the ballistic mortar test for pure and mixture of energetic materials. It can be used for some important classes of energetic compounds including nitroaromatics, acyclic and cyclic nitramines, nitrate esters, and nitroaliphatics. The presented method is based on the molecular structure of the desired compound and there is no need to use experimental data such as the condensed phase heat of formation. For 84 pure and 24 mixtures of energetic compounds, the calculated power relative to 2,4,6-trinitrotoluene (= 100) show good agreement with respect to the measured values.

Urea nitrate (UN) has not found use as a legitimate explosive but is commonly used as an improvised explosive. The dehydration product of UN is nitrourea (NU). Visually both UN and NU are white solids that both melt around 160 °C. Other properties differ markedly as might be expected from an inorganic salt (UN) and an organic molecular compound (NU). An extensive physical characterization of NU and UN is reported. Two reported routes to the NU product are compared and a decomposition mechanism of UN proposed.

In the design of explosive devices, understanding of the behavior of explosively propelled matter is one of the important steps to optimize the performance of the device. In a typical flat, metallic flyer and explosives charge system, the flyer reaches its maximum velocity after a certain degree of expansion of the detonation gas. During this expansion, the flyer is deformed in an arced-shape by the incoming rarefaction from nearby surfaces. In this work, an acceleration/deformation profile of an explosively propelled flat, metallic plate was studied based on the isentropic expansion of detonation gas and subsequent rarefaction intrusion to the center of the flyer. In order to properly describe the arced deformation of the flyer, a rather simplified new term of the pressure release ratio behind the flyer η is introduced based on the expansion of the detonation isentrope behind the flyer. A theoretical model was built to predict the behavior of an explosively driven flyer and the rarefaction intrusion into the center of the explosives charge. The results are compared to a hydrocode simulation and exhibit favorable agreement in a limited application.

The Johnson-Cook parameters for the zirconium material were determined based on the data obtained from the tensile testing of zirconium specimens at different strain-rates and different temperatures. The velocity difference (V_PL) between the particulated jet fragments was calculated for zirconium liners of different thicknesses using Johnson-Cook constitutive equation. A breakup time formula for the zirconium shaped charge was proposed, which demonstrated better ductility performance than the copper shaped charge.

Lead styphnate (LS) and lead azide (LA) must be considered vulnerable to accumulation and discharge of static charge under all conditions. To reduce the risk aroused by static initination hazard in the processing and handling of LS and LA, antistatic modifations of LS and LA are necessary. In this paper, four surfactants were applied to improve the antistatic abilities of lead styphnate and lead azide. The results showed that lauryl dimethylamine betaine (BS-12) is significantly able to reduce the electrostatic accumulation of LS and LA. In addition, possible correlations of electrostatic accumulation with assumption and approximation could be drawn from the surfactant surface concentration. The electrostatic sensitivities, the 5 s delay explosion temperatures, and the thermal decomposition profiles of the compounds were measured. Selected products were additionally investigated by scanning electron microscopy (SEM). For LS the performance of the products with additives was less affected, whereas for LA the sensitivity of the products in the presence of surfactants was distinctly reduced. The surfactants which are preferably compatible with LS and LA do not affect their thermal stability.

A Gurney-type equation was previously corrected for wall thinning and angle of tilt, and now we have added shock wave attenuation in the copper wall and air gap energy loss. Extensive calculations were undertaken to calibrate the two new energy loss mechanisms across all explosives. The corrected Gurney equation is recommended for cylinder use over the original 1943 form. The effect of these corrections is to add more energy to the adiabat values from a relative volume of 2 to 7, with low energy explosives having the largest correction. The data was pushed up to a relative volume of about 15 and the JWL parameter ω was obtained directly. The total detonation energy density was locked to the v=7 adiabat energy density, so that the Cylinder test gives all necessary values needed to make a JWL.

The enthalpies of formation of six 1,2,3,4-tetrazine-based compounds were calculated according to the Density Functional Theory BOP/TNP method and by using homodesmotic reaction designs. Their detonation performances, including detonation velocity and pressure, were predicted in terms of the Stine equations. The 1,2,3,4-Tetrazine-based compounds labeled A, B, C, D, and F are powerful high-energy compounds. The detonation performances of A and B, including detonation velocity, and detonation pressure, are superior to that of the current high-energy explosive CL-20. The detonation velocity, detonation pressure, and oxygen balance of 1,2,3,4-tetrazine related oxo derivatives can be improved by partial oxidation of the nitrogen atoms in the tetrazine ring, but further oxidation causes reduction of the enthalpies and specific impulses of the oxo derivatives. Calculation of the molecular resonance energies indicated that E [C₆N₁₂] and F have more negative values, i.e, the ring strain energies of their configurations are high, whereas the resonance energies of C and D are low, only compound B has a very positive resonance energy. Considering energy and stability, B is a promising compound for practical use with both high energy and low sensitivity.

The combustion behavior of triaminoguanidine nitrate (TAGN) was investigated over a wide pressure range and a detailed combustion mechanism has been proposed. Temperature profiles in the TAGN combustion wave were measured with thin tungsten-rhenium microthermocouples. It was shown that the surface temperature in combustion of TAGN as well as for other onium salts is controlled by the process of dissociation. The burning rate of TAGN is governed by processes in the condensed phase.

Laser ignition experiments were conducted to better understand parameters that influence ignition of energetic materials. A Nd:YAG laser (10 ms, 1.5 J, 3 mm spot diameter) was used to heat the top surface of an energetic powder composed of nanometric aluminum (Al) combined stoichiometrically with an oxidizer (copper oxide (CuO), iodine pentoxide (I₂O₅), polytetrafluoroethylene (C₂F₄), molybdenum trioxide (MoO₃) or iron oxide (Fe₂O₃)). Ignition delay time was calculated as the difference between first light of the laser’s flash lamp and the energetic material. Results show that laser energy required for ignition is dependent on pre-ignition reactions, phase change/decomposition temperatures, confinement, and laser absorbance.

Pyrotechnic smoke compositions for visual obscuration containing boron carbide, potassium nitrate, potassium chloride, and various lubricants are described. Only the waxy lubricants stearic acid and calcium stearate slowed the burning rate into a range suitable for end-burning smoke grenades. For compositions pressed into steel cans, the addition of just 2 wt-% calcium stearate was shown to reduce the burning rate from 0.50 cm s⁻¹ to 0.09 cm s⁻¹. In this system, potassium chloride serves as a diluent that reduces incandesence but also increases slag formation. Compositions containing potassium chloride in the 25–30 wt-% range exhibited both acceptably low incandescense and slag formation upon burning, while also producing copious amounts of white smoke. These experimental compositions were loaded into full-size grenade cans; field and smoke chamber testing revealed that they outperform the US Army’s in-service M83 TA grenade both qualitatively and quantitatively. The photopic mass-based figures of merit for experimental grenades KCl-25, KCl-30, and a production-run M83 TA grenade were 2.51, 2.19, and 1.44 m² g⁻¹, respectively.

The dilithium (1), disodium (2), dipotassium (3) and dicesium (4) salt as well as the calcium (5), strontium (6) and barium (7) salt of 5,5′-bis(1-hydroxytetrazole) were prepared and characterized including NMR-, IR- and Raman spectroscopy, mass spectrometry, elemental analysis and differential scanning calorimetry. The crystal structures of 1, 2 and 4–6 were additionally determined by single-crystal X-ray diffraction. The sensitivities of the salts towards impact, friction and electrostatic discharge were determined by means of BAM (Bundesanstalt für Materialforschung- und prüfung) methods. The potential use of 1, 6 and 7 as coloring agents in pyrotechnical mixtures as well as the utilization of 3 and 4 as additives in near infrared (NIR) emitting pyrotechnical formulations was examined.

Polytetrahydrofuran (PTHF) is an effective binder ingredient for improving propellant performance, even though it is not an energetic material. PTHF becomes sufficiently rubbery for use as a binder when a triol material such as glycerin is added as a crosslinking modifier. The cured PTHF/glycerin binder had unsatisfactory mechanical characteristics for use as a propellant binder, so a more appropriate crosslinking modifier than glycerin needs to be found. In this study, glycerol propoxylate (GPO), with a molecular weight of 260, was used as a crosslinking modifier, and the curing behavior, tensile properties, and thermal decomposition behaviors of the PTHF binder using GPO were investigated. The PTHF/GPO blend did not solidify when the PTHF/GPO mole ratio (ξ) was greater than a certain value. The PTHF (M_n=650)/GPO blend with ξ≤5 and the PTHF (M_n=1400)/GPO blend with ξ≤3 were used as propellant binders. From the curing behaviors and tensile properties, it was found that the PTHF/GPO binders ensured optimal mixing of the propellant ingredients and casting of the uncured propellant into the rocket motor case, and the tensile properties of the binders changed more drastically with the variation in ξ than did those of the PTHF/glycerin binders. The thermal decomposition behaviors of the PTHF/GPO binders were hardly dependent on ξ and were almost identical to those of the PTHF/glycerin binders.

Modification of the reactivity of micrometer-sized aluminum through inclusion of low levels of poly(carbon monofluoride) (PMF) using mechanical activation (MA) is reported. Resulting composite particle combustion enthalpy, average particle size, and specific surface area depend on MA intensity, duration, and inclusion level, and range from 18.9 to 28.5 kJ g⁻¹, 23.0 to 67.5 μm, and 5.3 to 34.8 m² g⁻¹, respectively. Differential scanning calorimetry experiments in O₂/Ar indicate that MA reduces the exotherm onset from 555 to 480 °C (70/30 wt-%). Particles are sensitive to electrostatic discharge stimulus (11.5–47.5 mJ) but not to impact (>213 cm) or friction (>360 N) and some low energy MA particles are ignitable by optical flash. With their altered reactivity and high combustion enthalpy, these nanofeatured, micrometer-sized particles may have use as replacements for aluminum in energetic applications.

The energetic material, 3-nitro-1,5-bis(4,4′-dimethyl azide)-1,2,3-triazolyl-3-azapentane (NDTAP), was firstly synthesized by means of Click Chemistry using 1,5-diazido-3-nitrazapentane as main material. The structure of NDTAP was confirmed by IR, ¹H NMR, and ¹³C NMR spectroscopy; mass spectrometry, and elemental analysis. The crystal structure of NDTAP was determined by X-ray diffraction. It belongs to monoclinic system, space group C2/c with crystal parameters a=1.7285(8) nm, b=0.6061(3) nm, c=1.6712(8) nm, β=104.846(8)°, V=1.6924(13) nm³, Z=8, μ=0.109 mm⁻¹, F(000)=752, and D_c=1.422 g cm⁻³. The thermal behavior and non-isothermal decomposition kinetics of NDTAP were studied with DSC and TG-DTG methods. The self-accelerating decomposition temperature and critical temperature of thermal explosion are 195.5 and 208.2 °C, respectively. NDTAP presents good thermal stability and is insensitive.

Information on synthesis methods and properties of N,N′-dinitrourea and its salts, which were reported virtually simultaneously by different authors in different publications, is summarized and systematized. Merits and drawbacks of various approaches for the synthesis of the target products are discussed. The reactivity of N,N′-dinitrourea and its salts in the reactions of nucleophilic substitution and condensation is discussed.

Ammonium nitrate (AN)-based composite propellants have attracted a considerable amount of attention because of the clean burning nature of AN as an oxidizer. However, such propellants have several disadvantages such as poor ignition and a low burning rate. In this study, the burning characteristics of AN-based propellants supplemented with Fe₂O₃ as a burning catalyst were investigated. The addition of Fe₂O₃ is known to improve the ignitability at low pressure. Fe₂O₃ addition also increases the burning rate, while the pressure exponent generally decreases. The increasing ratio (R) of the burning rate of the AN/Fe₂O₃ propellant to that of the corresponding AN propellant vs. the amount of Fe₂O₃ added (ξ) depends on the burning pressure and AN content. R decreases at threshold value of ξ. The most effective value of ξ for increasing the burning rate was found to be 4 % for the propellant at 80 % AN, and the value generally decreased with decreasing AN content. According to thermal decomposition kinetics, Fe₂O₃ accelerates the reactions of AN and binder decomposition gases in the condensed- and/or gas-phase reaction zones. The burning characteristics of the AN-based propellant were improved by combining catalysts with differing catalytic mechanisms instead of supplementing the propellant with a single catalyst owing to the multiplicative effect of the former.

The emission of AlO is commonly observed in tests involving aluminum combustion in propellants and explosives. Such emission has been used as a signature of combustion, as a tool for measuring ignition and reaction times, and as a thermometer. This paper provides a critical review of methodologies exploiting AlO emission spectroscopy as a quantitative tool in energetics testing. Controlled tests involving aluminized explosives, as well as those using added alumina, are conducted, in which AlO emission is quantified and compared to total oxidation in the final residue. Experimental parameters such as optical depth and fireball confinement are systematically varied to examine the effect on AlO emission. We find that thermometry using AlO remains valid, and a new approach to using low resolution spectra is proposed. However, AlO emission spectroscopy or photometry can be quantitatively correlated to ignition and burning time, or used to infer the presence or absence of aluminum combustion, only under a limited set of circumstances. Factors that limit the ability to use AlO emission quantitatively are discussed in depth.

Aiming to solve the problems caused by primary explosives in traditional detonators, a new kind of non-primary explosive detonator based on the principle of flying plate detonator is invented. However, in some special circumstances, such as high temperature, strong radiation, strong magnetic field, overload, high-pressure conditions, the non-primary explosive detonator cannot work well because of the defects of its usual used initiating method like electric hot wire initiating devices, electric exploding bridge wire initiator, and initiating by a shock-conducting tube. In this context, initiation by low energy laser is applied to non-primary explosive detonator. After this combination, the non-primary explosive detonator performs well in resisting high temperature, high pressure, overload, and electric interference.

The ultraviolet absorption properties of a series of ferrocene-modified hyper-branched polyesters (HBPE-Fcs) were analyzed by Ultraviolet/visible spectrometry. HBPE-Fcs were used as burning rate catalyst components added into hydroxyl-terminated polybutadiene (HTPB) based elastomers to investigate their migration behavior. Migration inhibition effects of HBPE-Fcs in different aging conditions were analyzed. The diffusion coefficients (D) of the migration components were calculated according to Fick’s law of diffusion. The catalytic performances of HBPE-Fcs for the thermal decomposition of cyclotrimethylenetrinitramine (RDX) were also investigated by non isothermal measurements using Kissinger method. The incorporation of ferrocenes into hyper-branched polyesters (HBPEs) endows HBPEs with new ultraviolet absorption properties. The migration of HBPE-Fc was minimized by grafting ferrocene on the hyper-branched structures compared to that of simple ferrocene derivatives. HBPE-Fcs present efficient catalytic effects on the thermal degradation of RDX; and, the catalytic reactions were characterized by decreased activation energies and increased rate constants.

Isomers of 4-amino-1,3-dinitrotriazol-5-one-2-oxide (ADNTONO) are of interest in the contest of insensitive explosives and were found to have true local energy minima at the DFT-B3LYP/aug-cc-pVDZ level. The optimized structures, vibrational frequencies and thermodynamic values for triazol-5-one N-oxides were obtained in their ground state. Kamlet-Jacob equations were used to evaluate the performance properties. The detonation properties of ADNTONO (D=10.15 to 10.46 km s⁻¹, P=50.86 to 54.25 GPa) are higher compared with those of 1,1-diamino-2,2-dinitroethylene (D=8.87 km s⁻¹, P=32.75 GPa), 5-nitro-1,2,4-triazol-3-one (D=8.56 km s⁻¹, P=31.12 GPa), 1,2,4,5-tetrazine-3,6-diamine-1,4-dioxide (D=8.78 km s⁻¹, P=31.0 GPa), 1-amino-3,4,5-trinitropyrazole (D=9.31 km s⁻¹, P=40.13 GPa), 4,4′-dinitro-3,3′-bifurazan (D=8.80 km s⁻¹, P=35.60 GPa) and 3,4-bis(3-nitrofurazan-4-yl)furoxan (D=9.25 km s⁻¹, P=39.54 GPa). The NH₂ group(s) appears to be particularly promising area for investigation since it may lead to two desirable consequences of higher stability (insensitivity), higher density, and thus detonation velocity and pressure.

A conventional triaxial confining pressure test was designed to suit the working environment of propellant grain. The mechanical properties of the double-base propellant under varied confining pressure conditions were studied and analyzed. The results show that confining pressures have a pronounced influence on the mechanical properties of propellant materials. The yield value and compressive strength of propellant material increase as the confining pressure increases. The propellant material shows great ductility before it is destroyed, the ductility of propellant material increases with an increase in the confining pressure. The yield values and failure values of the propellant materials show linear relationships with the confining pressures. According to the Mohr-Coulomb theory, the cohesion and internal friction angle of the double-base propellant material were obtained. The influence factors of cohesion and internal friction angle of the double-base propellant material are analyzed. The failure process and mechanism of propellant materials under varying confining pressures were studied. These projects have contributed to the understanding of the innate character of propellant materials and explain the damage and destruction of the structures and components. With this information, measures can be taken to improve the quality and structural performance of propellant grain. The information collected herein may lay the foundation for yield criteria and viscoelastic-plastic constitutive model of propellant materials.

A novel cocrystal explosive composed of 2,4,6,8,10,12-hexanitrohexaazaiso-wurtzitane (HNIW) and 2,4,6-trinitrotoluene (TNT) in a 1 : 1 molar ratio was effectively prepared by solvent/nonsolvent cocrystallization adopting dextrin as modified additive. The structure, thermal behavior, sensitivity, and detonation properties of HNIW/TNT cocrystal were studied. The morphology and structure of the cocrystal were characterized by scanning electron microscopy (SEM) and single crystal X-ray diffraction (SXRD). SEM images showed that the cocrystal has a prism type morphology with an average size of 270 μm. SXRD revealed that the cocrystal crystallizes in the orthorhombic system, space group Pbca, and is formed by hydrogen bonding interactions. The properties of the cocrystal including sensitivity, thermal decomposition, and detonation performances were discussed in detail. Sensitivity studies showed that the cocrystal exhibits low impact and friction sensitivity, and largely reduces the mechanical sensitivity of HNIW. DSC and TG tests indicated that the heterogeneous exothermic decomposition of the cocrystal occurs in the temperature range from 170 °C to 265 °C with peak maxima at 220 °C and 250 °C and significantly increases the melting point of TNT by 54 °C. The cocrystal has excellent detonation properties with a detonation velocity of 8426 m s⁻¹ and a calculated detonation pressure of 32.3 MPa at a charge density of 1.76 g cm⁻³, respectively. Moreover, the results suggested that the HNIW/TNT cocrystal not only has unique performance itself, but also effectively alters the properties of TNT and HNIW. Therefore, the cocrystal formed by HNIW and TNT could provide a new and effective method to modify the properties of certain compounds to yield enhanced explosives for further application.

At present, cis-1,3,4,6-tetranitro-octahydroimidazo-[4,5-d]imidazole (bicyclo-HMX, BCHMX) and ε-2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (ε-HNIW, CL-20) are a topic of interest from the attractive and the potentially attainable nitramines. They were chosen to be studied in comparison with 1,3,5-trinitro-1,3,5-triazinane (RDX) and β-1,3,5,7-tetranitro-1,3,5-tetrazocane (β-HMX). Marginal attention is devoted also to 4,8,10,12-tetranitro-2,6-dioxa-tetraazawurtzitane (Aurora 5). BCHMX, ε-HNIW, RDX, and HMX were studied as plastic bonded explosives (PBXs) with elastic properties based on Composition C4 and Semtex 10 matrices. Also they were studied as a highly pressed PBXs based on the Viton A binder. The detonation parameters and sensitivity aspects of these nitramines and their corresponding PBXs were determined. Relative explosive strengths (RS) of these compositions are mentioned with mutual relationships between the measured RS values and some detonation parameters. These relationships indicate a possibility of changes in detonation chemistry of these mixtures filled mainly by HNIW. A sensitivity of RS-CL20 (HNIW with reduced sensitivity) is reported and the new findings in the friction sensitivity are discussed.

Measurements of consistency and accuracy are standard techniques to assess the performance of a weapon in case of direct fire kill mechanism. It is often determined from the scoring pattern of a witnessing target erected at a known distance in an open range making use of an in-line CCD camera with suitable long-range optics or using an array of acoustic/optical sensors in the close vicinity of the target. In the case of indoor range, acoustic and optical sensors are used to determine the same preferably for small-caliber ammunitions. However, all these indirect methods are subjected to the constraint of triangulation error. In case of high-caliber ammunitions, especially fired from tank guns, witnessing targets and acoustics methods are used although it is time-consuming and labor-intensive in nature. To overcome these difficulties a virtual scoring method is proposed. Herein, a high-speed video camera is used for in-line image acquisition of the projectile at the desired distance using long-range optics. The virtual target is defined making use of an optical detector placed at the target distance and under the trajectory, where a trigger is generated when the projectile passes over it. This hardware trigger is sent to the high-speed video camera and then the spatial coordinates of the projectile in the virtual plane is determined off-line making use of necessary image processing and image analysis. A feasibility study of this technique was performed in a scaled-down model and laid down in greater details.

The storage stability of amine based rocket fuel called Samine was studied over 9 months for the first time. It was found that storage stability significantly depends on fuel oxidation with the air trapped in the storage tanks. A reduction of the triethylamine concentration from 50.2 % (wt) to less than 48 % was taken as the end of shelf life of the propellant. After obtaining experimental data from accelerated storage stability tests, the shelf life of Samine was estimated using the Arrhenius equation. According to the kinetic studies, the oxidation reaction of fuel was a zero order reaction and the shelf lives of Samine in stainless-steel tanks at 20 °C, 25 °C, and 30 °C were obtained to be 5.7, 3.7, and 2.4 years, respectively. Additionally, it was observed that for long time storage of amine based fuels like Samine it is better to use stainless-steel or aluminum tanks, which are charged with an inert gas like nitrogen.

Graphite flake is an electromagnetic interference material of importance for IR screening. In this study, an attempt to improve the performance of graphite flake by coating it with nano-silica using cyclomix (Hosokawa) and hybridizer (Nara) processes was made. Uncoated and coated graphite flakes were examined by scanning electron microscopy (SEM). It was shown that a more uniform coating was obtained using the hybridizer process. Coated graphite flake with a mass ratio of nano-silica equal to 5.25 % exhibited the best hydrophobic properties. The test chamber experiments demonstrated that the deposition velocity of coated graphite flake decreased from 0.227 cm s⁻¹ to 0.187 cm s⁻¹ and its IR interference performance was improved, compared with uncoated graphite flake. The obtained results showed that the coatings on the graphite flake powder with hydrophobic nano-silica enhanced the moisture resistance and electromagnetic interference performance of the graphite flake.

Exothermic reactions between metals and fluorinated polymers are found in a variety of energetic materials, including reactive binder systems and the Magnesium-Teflon-Viton incendiary composition. This paper describes the reactions between a high molecular weight perfluoropolyether, Fomblin Y 140/13, and magnesium in a variety of morphologies including μm-scale powders and nano-scale layered films. Using Temperature Programmed Desorption and Temperature Programmed Reaction we have found that the magnesium-perfluoropolyether interaction is characterized by: (1) competition between Fomblin decomposition and desorption, and (2) magnesium passivation by the formation of magnesium fluoride. Differential Scanning Calorimetry measurements establish a lower-bound estimate of the specific reaction energy of 9.2 kJ g⁻¹. High molecular weight Fomblin (6500 amu) undergoes a competitive reaction/desorption process with desorption occurring at 550 K and decomposition at 610 K. Decomposition becomes more favorable relative to desorption for higher heating rates and thicker films. Perfluoropolyethers produce several characteristic ions in the 70 eV election ionization mass spectra, with the CF₃⁺ ion being the most abundant ion observed during both the molecular desorption and decomposition. Larger fragment ions with masses of 235 and 285 amu are observed in relatively high concentrations during desorption and low concentrations during decomposition. The reaction between magnesium and Fomblin begins at 400 K, producing CF₃⁺, CO⁺, and C₂F₅⁺ in the electron ionization mass spectrum. We propose that these reactions form a passivating layer of magnesium fluoride that protects the remaining metal as it approaches the magnesium melting point. Most of the reaction takes place at 800 K and above when the magnesium fluoride film ruptures.

Recently developed cyclotrimethylene trinitramine (RDX)-based nanostructured explosive compositions were shown to exhibit greatly reduced initiation sensitivity as compared to conventional compositions prepared with coarser, micrometer-scale RDX. In particular, improvements were shown in the sensitivity towards shock and impact stimuli, key sources of inadvertent initiation. Such an improved response to mechanical stimuli is believed to be largely a result of smaller crystal and void sizes. Characterization of these structural parameters is therefore necessary in order to construct a meaningful physical description of these novel explosive compositions. Herein, we report the results of a detailed structural characterization of these novel RDX-based nanocomposites. The analyzed specimens were in pellet form with nominally 10 % porosity. These results constitute an unprecedentedly complete structural picture of this new class of energetic materials.

The decomposition reaction of pentaerythritol tetranitrate (PETN), C(CH₂ONO₂)₄, under static high pressure was examined by conducting observations and infrared measurements up to 5 GPa at around 500 K. The thermal decomposition of PETN proceeded rapidly at around 500 K and formed a fluid consisting of N₂O, CO₂, and H₂O. The rate of the decomposition reaction at 423 K increased as the pressure increased, indicating a negative activation volume. The initial step of the decomposition reaction of PETN under static pressure was presumed to be the elimination of HNO₃.

Shock compression of finely ground CaF₂ crystals embedded into graphite powder in cylindrical recovery ampoules was found to yield single white crystals of 0.1 mm in size within the Mach cone, where the developed temperatures/pressures are exeedingly high. The composition of these crystals CaO ⋅ 3SiO₂ ⋅ SiC is a result of chemical interactions of mixture and SiO₂ due to cumulative eruption of Si from steel walls of ampoules and its reaction with O₂ from sample pores. The atomic structure of crystals was characterized by IR spectroscopy and XRD. The formation of relatively large single crystals can take place only in the melted unloaded material.

With estane as binder, a new nanocomposite energetic material based on 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105) was successfully prepared by the spray drying method. Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), and X-ray diffraction (XRD) was employed to characterize the nanocomposite samples. The impact sensitivity and thermal decomposition properties of the nanocomposites were also measured and analyzed. The results show that the nanocomposite particles are spherical in shape and range from 1 μm to 10 μm in size. The composite is aggregated of many tiny granules with nucleus/shell structure, in which the shell thickness and crystal size of LLM-105 are about 20 nm and 50–100 nm. The crystal type of LLM-105 in the nanocomposite is similar to that of raw LLM-105, however, the diffraction peaks become weaker and wider mainly due to decreasing of particle size. The nanocomposite has lower impact sensitivity and better thermal stability.

This review covers the main applications of conducting polymers in chemiresistor sensors for sensing hazardous hypergolic liquid propellant vapors and toxic exhaust plume acidic vapors of solid rocket motors at explosive (percent), toxic and threshold limit value concentration levels. The First part is focused on vapors of NO₂ and mixed oxides of nitrogen (MON-3). The Second part is focused on vapors of hydrazines such as hydrazine, monomethylhydrazine (MMH) and unsymmetrical dimethylhydrazine (UDMH). Chemiresistor sensors for toxic HCl vapors of exhaust plume of rockets and missiles are reviewed in the third part. Salient features of the sensors such as conducting mechanisms during sensing, thickness of sensing layer, factors that influence conductivity, response time, recovery time, detectable range, and minimum detectable limit are discussed in this review. Advantages and disadvantages of conducting polymer coated fabrics as novel chemiresistor sensors over inorganic substrates are also discussed.

Three HTPB-based rocket propellant formulations containing ammonium perchlorate and aluminum particles, with different aluminum content and particle size, have been manufactured. The study has focused on the change of mechanical properties with aging time by using dynamic mechanical analysis (DMA). Therefore, propellant formulations underwent an accelerated aging program, in air (RH<10 %), between 60 °C and 90 °C with aging time adjusted to a thermal equivalent load of 15 to 20 years at 25 °C. DMA investigations revealed distinct changes in the shape of the loss factor curve. These curves were modeled with three exponentially modified Gaussian (EMG) functions in order to get the molecular interpretation of the involved aging phenomena by separating the binder fractions with different mobility. Aging of propellant formulations can be followed by considering only two parameters: the areas of the second and third loss factor transition peaks (A₂, A₃), and the corresponding maximum temperature values of the assigned Gauss peaks (Tc₂, Tc₃).

An experimental study was conducted to determine the dependence of the burning rate coefficient of gel fuel droplets on the pressure at different ambient oxygennitrogen mixtures. Experiments were conducted using a pressure chamber, in which the droplet was suspended and the combustion process was video-photographed by a high-speed digital video camera. The tests were conducted at pressures between 0.1–4 MPa at different ambient oxygennitrogen compositions (air, 40 % O₂ – 60 % N₂, and 60 % O₂ – 40 % N₂). The fuel was a compound of 95 % kerosene and 5 % gellant. At sub-critical pressure conditions, the burning rate coefficient was found to increase with increasing ambient oxygen mass fraction. At supercritical conditions, no dependence of the burning rate coefficient on the ambient mixture was found. The results indicate that the burning rate coefficient depends on the oxygen partial pressure, at least at low pressures.

Two-dimensional axisymmetric interior ballistics simulations in projectile acceleration systems that use granular or long slotted tubular solid propellants are performed using the solid/gas two-phase fluid dynamics code of the Euler-Lagrange approach. For validation, the simulation results are compared with experimental data for tubular solid propellants. In the series of the interior ballistics simulations, the propellant grain size and shape effects on the firing performance of 50 mm gun are numerically investigated. The propellant grain size and shape affect the energy release rate of the solid propellant charged in the chamber, the projectile kinetic energy at the muzzle, and even the fluctuations of the chamber pressure history. An appropriate burning surface area of the propellant grain exists, so that the projectile can achieve the maximum kinetic energy from the released energy of the solid propellant. Based on the simulation results, guidelines are proposed for the grain size design that enables the propellant energy to be used efficiently.

A thermal-mechanical model for the ignition of a layer of cyclotetramethylene tetranitramine (HMX) particles under drop-weight impact was developed. Considering the micro-particle plasticity, frictional heating, melting, fracture, and chemical reaction at particle level, effects of loading parameters and sample characteristics on ignition and mechanical responses were discussed. The threshold values for ignition to occur under different loading conditions and various material parameters can be predicted. The model was validated by comparing experimental measured and calculated mean pressure-strain curves, which showed two turning points due to localized fragmentation and melting. Relationships between thermal and mechanical responses at the particle level were examined.

Considering that the sound velocity of concrete is lower than that of metal, this study discusses the effect of stationary shocks and compression during the process of shaped charge jet penetration into concrete when the penetration velocity is greater than sound velocity. The linear relationship between shock velocity and particle velocity is used to describe concrete materials. The state parameters of concrete under shock loading are calculated using Rankine-Hugoniot jump conditions. Moreover, a combination of these relations with the Bernoulli equation yields a supersonic penetration equation across the shock. A cavity growth equation based on the Szendrei-Held equation is presented when supersonic penetration occurs. Predictions from the supersonic penetration model are in good agreement with the depth and cavity diameter of experimental results for shaped charge jet penetration into concrete for charge diameters of 60, 142, 200, and 400 mm.

A formula to predict the radial distribution of the fragment velocities of the Velocity Enhanced Warhead (VEW) is proposed. Not only the maximum velocity gains, but also the velocity gains with azimuth angle can be calculated using this formula. Its predictions are in good agreement with the experimental data from the previous literatures. This formula applies a correctional function in consideration of the directivity and initiation characteristics of the warhead fragments. The correlation between the coefficient k in the correctional function and the warhead property in terms of the ratio β of charge mass to metal casing mass is discussed. The fragment energy distribution can also be obtained from the formula and the results show that when β is equal to 1.0, half of the fragment energy is concentrated within the range of 63° in the target direction.

A series of plastic bonded explosives (PBXs) based on Viton A and Fluorel binders were prepared using four nitramines, namely RDX (1,3,5-trinitro-1,3,5-triazinane), β-HMX (β-1,3,5,7-tetranitro-1,3,5,7-tetrazocane), BCHMX (cis-1,3,4,6-tetranitro-octahydroimidazo-[4,5-d]imidazole), and ε-HNIW (ε-2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane). The detonation velocities, D, were determined. Detonation parameters were also calculated by means of modified Kamlet & Jacobs method, CHEETAH and EXPLO5 codes. In accordance with our expectations BCHMX based PBXs performed better than RDX based ones. The Urizar coefficient for Fuorel binder was also calculated.

Conditions, which result in the formation of triacetone triperoxide (TATP) or diacetone diperoxide (DADP) from acetone and hydrogen peroxide (HP, were studied for the purposes of inhibiting the reaction. Reaction of HP with acetone precipitates either DADP or TATP, but the overall yield and amount of each was found to depend on (1) reaction temperature, (2) the molar ratio of acid to HP/acetone, (3) initial concentrations of reactants, and (4) length of reaction. Controlling molar ratios and concentrations of starting materials was complicated because both sulfuric acid and hydrogen peroxide were aqueous solutions. Temperature exercised great control over the reaction outcome. Holding all molar concentrations constant and raising the temperature from 5 to 25 °C showed an increase of DADP over TATP formation and a decrease in overall yield. At 25 °C a good yield of TATP was obtained if the HP to acetone ratio was kept between 0.5 : 1 and 2 : 1. At constant temperature and HP-to-acetone held at one-to-one ratio, acid-to-HP molar ratios between 0.10 : 1 and 1.2 : 1 produced good yield of TATP. Plotting the molality of HP vs. that of sulfuric acid revealed regions, in which relatively pure DADP or pure TATP could be obtained. In addition to varying reaction conditions, adulterants placed into acetone were tested to inhibit the formation of TATP. Because there is much speculation of the relative stability, sensitivity, including solvent wetting of crystals, and performance of DADP and TATP, standard tests (i.e. DSC, drop weight impact, and SSED) were performed.

Environmental and health considerations have encouraged the development of ammunition with substitutes for lead and other heavy metals. In general, the emission products from munitions containing nitro-based propellants are highly complex mixtures of gases, vapors, and solid particles. The major combustion products are H₂O, CO, CO₂, H₂, and N₂. In addition, compounds including hydrogen cyanide (HCN), ammonia (NH₃), methane (CH₄), nitrogen oxides, benzene, acrylonitrile, toluene, furan, aromatic amines, benzopyrene, and various polycyclic aromatic hydrocarbons are detected in minor concentrations. Many of the identified chemical species have severe toxicological properties, and some of the compounds do even have mutagenic effects. Gun smoke emission is a concern because its exposure to humans may be substantial during military and civilian police training, as respiratory protection equipment is not routinely worn. In this work we study the compositions of some of the main decomposition products, experimentally as well as theoretically. The concept of frozen equilibrium at around 1500–2000 K appears to apply for CO, CO₂, and H₂. However, the trace species in the combustion mixtures appear theoretically to be present in negligible concentrations. Our measured results are many orders of magnitude higher than theoretical results in open space. We forecast that future development of gun powder will focus on reducing the amount of toxic trace species.

The synthesis of potassium dinitramide (KDN), an intermediate in the ammonium dinitramide (ADN) synthesis, was optimized to reduce the costs of the ADN synthesis in order to facilitate competitiveness of this oxidizer with ammonium perchlorate (AP). The optimal conditions for the synthesis of KDN like feedstock molar ratio, nitration time, and temperature were determined. KDN was obtained in ca. 48 % yield. The modifications introduced allowed to reduce feedstock consumption and energy intensity of the process.

Fire and explosions in the processing of matchhead compositions are reported due to the friction sensitivity of materials used. This investigation is aimed at investigating the influence of different types of contact materials and their surface roughness on the friction sensitivity of a matchhead composition. The friction sensitivity of the matchhead composition was found to be dependent on the contact materials and their roughness. The results demonstrated that the contact materials and their surface roughness imparted variations to the sensitivity, ranging from 108 to 360 N. The sensitivity response of the energetic mixture was quicker in case of aluminum plate-aluminum pin combinations than those when steel plate-steel pin and brass plate-brass pin combinations were used. For the first time, the experimental investigation identified a new value based on the material’s surface roughnesses called critical surface roughness, at which the matchhead composition ignited at a minimum frictional load. The matchhead composition was found to be highly hazardous at the critical surface roughness values of 1.09, 1.01, and 1.05 μm for aluminum, brass, and steel surfaces, respectively. Based on the experimental results this paper also discusses mechanism of ignition caused by the frictional load.

Analysis of ammonium dinitramide (ADN), the advance rocket propellant oxidizer, in pure form as well as in mixtures was carried out by ion chromatography (IC). The purity of ammonium dinitramide was directly determined by estimating the dinitramide ions and indirectly by estimating the impurities. Both methods gave results comparable with those determined by Differential Scanning Calorimetry and UV spectroscopy. The chemical composition of ADN in mixtures containing nitrate, chromate, chlorate, perchlorate, and thiocyanate ions was quantitatively estimated in the same solution without any interferences or prior separation of analyte ions. The newly developed ion chromatographic methods for the analysis of ADN are simple and fast with good accuracy and precision when compared to other analytical techniques. The IC methods are found to be highly suitable for quality control analysis of ADN containing compositions and for the online process monitoring of the formation of ADN in the reaction mixture.

The compatibility of tetraethylammonium decahydrodecaborate (BHN) with some energetic components and inert materials of solid propellants was studied by DSC method, where glycidyl azide polymer (GAP), cyclotrimethylenetrinitramine (RDX), cyclotetramethylenetetranitroamine (HMX), lead 3-nitro-1,2,4-triazol-5-onate (NTO-Pb), hexanitrohexaazaisowurtzitane (CL-20), 3,4-dinitrofurzanfuroxan (DNTF), N-guanylurea-dinitramide (GUDN), aluminum powder (Al, particle size=12.18 μm) and magnesium powder (Mg, particle size: 44–74 μm) were used as energetic components and polyoxytetramethylene-co-oxyethylene (PET), polyethylene glycol (PEG), addition product of hexamethylene diisocyanate and water (N-100), hydroxyl terminated polybutadiene (HTPB), cupric adipate (AD-Cu), cupric 2,4-dihydroxy-benzoate (β-Cu), lead phthalate (ϕ-Pb), carbon black (C. B.), aluminum oxide (Al₂O₃), 1,3-dimethyl-1,3-diphenyl urea (C₂), di-2-ethylhexyl sebacate (DOS) and potassium perchlorate (KP), were used as inert materials. It was concluded that the binary systems of BHN with NTO-Pb, CL-20, aluminum powder, magnesium powder, PET, PEG, N-100, AD-Cu, β-Cu, ϕ-Pb, C. B., Al₂O₃, C₂, DOS, and KP are compatible, and systems of BHN with GAP and HMX are slightly sensitive, and with RDX, DNTF, and GUDN are incompatible. The impact and friction sensitivity data of BHN and BHN in combination with the energetic materials under present study were obtained, and there was no consequential affiliation between sensitivity and compatibility.

Micrometer-sized aluminum is widely used in energetics; however, performance of propellants, explosives, and pyrotechnics could be significantly improved if its ignition barriers could be disrupted. We report morphological, thermal, and chemical characterization of fuel rich aluminum-polytetrafluoroethylene (70–30 wt-%) reactive particles formed by high and low energy milling. Average particle sizes range from 15–78 μm; however, specific surface areas range from approx. 2–7 m² g⁻¹ due to milling induced voids and cleaved surfaces. Scanning electron microscopy and energy dispersive spectroscopy reveal uniform distribution of PTFE, providing nanoscale mixing within particles. The combustion enthalpy was found to be 20.2 kJ g⁻¹, though a slight decrease (0.8 kJ g⁻¹) results from extended high energy milling due to α-AlF₃ formation. For high energy mechanically activated particles, differential scanning calorimetry in argon shows a strong, exothermic pre-ignition reaction that onsets near 440 °C and a second, more dominant exotherm that onsets around 510 °C. Scans in O₂-Ar indicate that, unlike physical mixtures, more complete reaction occurs at higher heating rates and the reaction onset is drastically reduced (approx. 440 °C). Simple flame tests reveal that these altered Al-polytetrafluoroethylene particles light readily unlike micrometer-sized aluminum. Safety testing also shows these particles have high electrostatic discharge (89.9–108 mJ), impact (>213 cm), and friction (>360 N) ignition thresholds. These particles may be useful for reactive liners, thermobaric explosives, and pyrolants. In particular, the altered reactivity, large particle size and relatively low specific surface area of these fuel rich particles make them an interesting replacement for aluminum in solid propellants.

The demilitarization of ammunition that has reached the end of life (or become obsolete) has to be carried out with minimum energy and environmental impacts. The Portuguese Armed Forces have significant amounts of ammunition that need to be eliminated. In order to assess and improve ammunition demilitarization, a life-cycle approach must be adopted. The main goal of this article is to present a comprehensive life-cycle assessment (LCA) of the ammunition demilitarization performed by the Portuguese company IDD (Industria de Desmilitarização e Defesa). A life-cycle model was developed for the entire demilitarization process, which involves ammunition dismantling, discharging, the incineration of energetic material, and the subsequent flue gas treatment. A detailed inventory was based on data collected from the IDD. A life-cycle impact assessment was carried out, based on three complementary methods used to assess a total of ten impact categories: cumulative energy demand (primary energy); CML 2001 (six environmental impact categories) and USEtox (three toxicological categories). The results show that the main contributor in nine out of the ten impact categories is the incineration and gas treatment process, due to the high energy requirements (electricity and propane). Nevertheless, equipment manufacture also has a significant impact in the Human Toxicity (non-cancer) category, mainly related to the manufacture of the static kiln. These findings enhance our understanding of demilitarization using a static kiln, showing that the associated impacts are significant and should be reduced.