Pressure-Stabilized High-Energy-Density Material YN10

Polynitrogen compounds have been intensively studied for potential applications as high energy density materials, especially in energy and military fields. Here, using the swarm intelligence algorithm in combination with first-principles calculations, we systematically explored the variable stoichiometries of yttrium–nitrogen compounds on the nitrogen-rich regime at high pressure, where a new stable phase of YN10 adopting I4/m symmetry was discovered at the pressure of 35 GPa and showed metallic character from the analysis of electronic properties. In YN10, all the nitrogen atoms were sp2-hybridized in the form of N5 ring. Furthermore, the gravimetric and volumetric energy densities were estimated to be 3.05 kJ/g and 9.27 kJ/cm-1 respectively. Particularly, the calculated detonation velocity and pressure of YN10 (12.0 km/s, 82.7 GPa) was higher than that of TNT (6.9 km/s, 19.0 GPa) and HMX (9.1 km/s, 39.3 GPa), making it a potential candidate as a high-energy-density material.

Some Nitrogen Rich Energetic Material Synthesis by Nucleophilic Substitution Reaction from Polynitro Aromatic Compounds

Three new nitrogen-rich energetic compounds, N-(5-chloro-2,4-dinitrophenyl)hydrazine (1), N-(5-chloro-2,4-dinitrophenyl) guanidine (2) and N-(5-chloro-2,4-dinitrophenyl)-4-aminopyrazole (3) prepared by the nucleophilic substitution reaction of 1,3-dichloro-4,6-dinitrobenzene with hydrazine, guanidinium carbonate and 4-aminopyrazole. The compounds were characterized by 1H NMR, 13C NMR, IR and mass spectroscopy. Only compound 2 could be prepared in a suitable crystal and molecular model was determined by X-ray analysis. Compounds were investigated by TG and DSC. Thermal degradation and thermokinetic behavior were investigated by Ozawa–Flynn–Wall and Kissinger–Akahira–Sunose techniques. Compounds were observed to be prone to exothermical thermal decomposition. HOMO and LUMO levels, theoretical formation enthalpy and electrostatic maps were calculated by Gaussian09. The detonation velocity and pressure were calculated by Kamlet–Jacobs equation. The compounds were assayed for antimicrobial properties.

A “Green” Primary Explosive: Design, Synthesis, and Testing

This account presents the synthesis and the characterization of triazine-tetrazine nitrogen heterocyclic compounds. Some compounds were characterized by NMR and IR spectroscopy, mass spectrometry, differential scanning calorimetry (DSC), and single-crystal X-ray diffraction. The physical and chemical properties were obtained by EXPLO5 v6.01, gas pycnometer, BAM Fallhammer, BAM Friction tester, and several detonation tests. The results show that the new metal-free polyazido compound 3,6-bis-[2-(4,6-diazido-1,3,5-triazin-2-yl)-diazenyl]-1,2,4,5-tetrazine (4) with high heat of formation (2820 kJ mol–1/6130.2 kJ kg–1) and excellent detonation velocity and pressure (D = 8602 m s–1, P = 29.4 GPa) could be used as ingredient in secondary explosives. 3,6-Bis-[2-(4,6-diazido-1,3,5-triazin-2-yl)-hydrazinyl]-1,2,4,5-tetrazine (3) can detonate research department explosive (RDX, cyclonite) as a primer (Δf H m = 2114 kJ mol–1/4555.2 kJ kg–1, D = 8365 m s–1, P = 26.8 GPa), whose initiation capacity is comparable to that of the traditional primary explosive Pb(N3)2. Therefore, the metal-free compound 3 can potentially replace lead-based-primary explosives, which would be advantageous for the environment.1 Introduction2 Strategies to Form High-Nitrogen Compounds with High Heat of Formation3 Metal-Free Strategies to Prepare Primary Explosives4 Concluding Remarks

Some nitrogen-rich heterocycles derivatives as potential explosives and propellants: A theoretical study

Four types of nitrogen-rich heterocycles substituted with -NO2, -NHNO2 and -C(NO2)3 explosophoric groups were explored as potential explosives and propellants materials. The calculated crystal density (?0)and the condensed phase heat of formation (?H?0f)for each of the twelve structures investigated shows that all these derivatives possess high (1.834-1.980 g cm-3)(?H?0f) and (605-2130 kJ kg-1) values. Interesting properties such as detonation velocity (D), pressure (P) and specific impulse (Isp) were calculated using the Kamlet-Jacobs method and ISPBKW thermochemical code. Detonation velocity and pressure in excess of 8.44 km s-1 and 32.87 GPa was obtained in all cases. Furthermore, trinitromethyl substituted derivatives shows performance exceeding that of HMX with an estimated D = 9.32-9.72 km s-1 and P = 40.61-43.82 GPa. Some -NO2 and -NHNO2 substituted derivatives were shown to be impact insensitive while retaining good detonation performance and thus are regarded as potential replacement for current RDX -based explosives. Finally, the calculated specific impulse (Isp between 248 and 270 s) of all investigated derivatives indicate that these energetic materials can be considered as possible ingredient in future rocket propellant compositions.

The Research of Applied Analysis Method on Shaped Charge Detonation Parameters

For avoid the perforation accident, oil perforating urgent need to calculate accurately shaped charge detonation parameters to guide the design and construction of perforation. According to the charge type and characteristics of shaped charge, based on traditional detonation theory and detonation parameters calculated method, this paper first determining shaped explosive detonation reaction equation, then analysis the shaped charge detonation heat, detonation temperature, detonation tolerance and detonation pressure and detonating velocity, extract the analytical methods of shaped charges detonation parameters suitable for oil at last. The specific practices: determined the reaction equation of shaped charges explosive with a maximum heat release rule; determined detonation heat, detonation temperature and detonation tolerance with law of Hess, internal energy value method and Avogadro law; calculated detonation velocity and pressure by Kamlet law; use engineering calculation method to analyze the detonating velocity as to the non-C-H-N-O composition shaped charges which containing feeling agent, bonding agent, flammable agent, plasticizer and other active agent; by revision Kamlet formula, get detonation pressure calculation formula.

Pressure Measurement of Non-Ideal Detonation in Ammonium Nitrate Based High Energetic Material

In order to know accurate information on the non-ideal detonation pressure, steel tube test was carried out on ammonium nitrate (AN) and activated carbon (AC) mixtures. In this test, detonation velocity and pressure were measured simultaneously by varying thickness of PMMA placed between AN/AC and pressure gauge. The length and the diameter of the steel tube were 350 mm and 35.5 mm. The results showed that shock pressure attenuation in PMMA was not observed for this experimental condition (PMMA gap; 3-5 mm). The averaged measured peak pressure and detonation velocity were 3.4 GPa and 3.2 km/s.

Computational studies on a high density cage compound hexanitrohexaazaisowurtzitane derivative

A newly designed polynitro cage compound with a framework of hexanitrohexaazaisowurtzitane (HNIW) was investigated by density functional theory (DFT) calculations. The molecular structure was optimized at the B3LYP/6-31G** level. IR spectrum, heat of formation (HOF), and thermodynamic properties were also predicted. The detonation velocity and pressure were evaluated by using the Kamlet–Jacobs equations, based on the theoretical density and condensed HOF. The bond dissociation energies (BDEs) and bond orders for the weakest bonds were analyzed to investigate the thermal stability of the title compound. The results show that the first step of pyrolysis is the rupture of the N8–NO2 bond. The crystal structure obtained by molecular mechanics belongs to the P21 space group, with the following lattice parameters: Z = 2, a = 11.10 Å, b = 15.15 Å, c = 10.77 Å, ρ = 1.872 g cm−3. The designed compound has high thermal stability and good detonation properties, and is a promising high-energy-density compound.

Detonation Velocity and Pressure of Ammonium Nitrate and Activated Carbon Mixtures

To obtain a better understanding of detonation properties of ammonium nitrate (AN) and activated carbon (AC) mixtures, steel tube test was carried out for stoichiometric composition of powdered AN and AC mixtures and the detonation velocity and the pressure profile were measured. Based on the results obtained the relation between the detonation velocity and the peak pressure was discussed with the theoretically predicted values which were obtained by the thermohydrodynamic CHEETAH code with the BKWC equation of state. The measured detonation velocity and peak pressure were far below the theoretically predicted values and the non-ideal detonation behaviour was confirmed.

The Performance of Pressure Vessel Using Concentric Double Cylindrical High Explosive

In recent year, it has been hoped to develop a device that generate high pressure in the field of the material consolidation. Therefore a phenomenon of over driven detonation (O.D.D.) [1] that was one of the detonation phenomenons has been researched. The detonation velocity and pressure that is higher than Chapman-Jouguet state generate in the state of O.D.D.. But, in the method of using the flyer plate that has been investigated, it is difficult to apply to the material consolidation since the region where O.D.D. phenomenon generates is very small. Therefore, as a new method of effectively generating O.D.D., the method of combining two kinds of the high explosives was developed. This method is a technique that is generated O.D.D. in the low velocity explosive by making a double cylindrical explosive of the high velocity explosive and low velocity explosive. The detonation pressure of low velocity explosive in a double cylinder was measured by Manganin gauge. The detonation pressure was 2.0 times over higher than the Chapman-Jouguet pressure.