Polysiloxanes are reviewed for their properties depending on the functionalization of a silicon-oxygen backbone chain. Next, the properties were referred to the requirements that polymers used in ...plastic/polymer-bonded explosive (PBX)-type explosives must meet. Finally, the current state and prospects for the implementation of polysiloxanes in plastic/polymer-bonded explosive (PBX) formulations are presented.
Series of rheokinetic studies involving pure HTPB with high content of 1,2-vinyl groups, binder systems with HTPB, IPDI and DBTDL, and energetic systems containing RDX, HTPB binder system and ...hydantoin-based bonding agent were conducted. Using the viscosity-temperature dependency of pure HTPB the VFT parameters were calculated. Next, pot-life and curing rate constants of HTPB/IPDI binder systems and kinetic parameters of Arrhenius and Eyring equations were determined. The influence of RDX and bonding agent on curing process of energetic systems was examined.
•Viscosity change with temperature of HTPB slows down greatly above 60 °C.•HTPB curing using IPDI in a presence of tin catalyst is a two-stage process.•First stage curing has lower value of Gibbs free energy of activation.•Bonding agent in HTPB system has no significant influence on viscosity.•Bonding agent in RDX/HTPB energetic system causes significant viscosity growth.
The paper presents research on the shock initiation of a melt‐cast insensitive explosive composition containing 3‐nitro‐1,2,4‐triazole‐5‐one (NTO), 2,4,6‐trinitrotoluene (TNT), wax, and aluminum ...powder. The composition was elaborated for steel tubes and initiated with the use of boosters of various configurations. Research systems were made to measure the velocity of detonation wave and to determine the type of response of the composition to shock initiation. A relatively long shock to detonation distances after initiation using the boosters with a steel buffer were found. A method of initiating the composition was indicated to guarantees an immediate achievement of the stationary detonation regime. An attempt was also made to explain the observed processes theoretically. The results obtained can be used in the design of munition filled with melt‐cast insensitive explosives.
Some of the relevant detonation performance parameters of TKX‐50 were re‐determined. The enthalpy of formation was obtained from the measured heat of combustion to be ΔH°f (TKX‐50(s))=+213.4±1.2 kJ ...mol−1. The heat of detonation was measured to be 4650±50 kJ kg−1. The detonation velocity of a TKX‐50/wax mixture (97 : 3) at a density of 1.74 g cm−3 was found experimentally to be 9190 m s−1. Using the experimentally obtained enthalpy of formation for TKX‐50 of +213.4 kJ mol−1 and the experimentally determined solid‐state density at room temperature of 1.887 g cm−3 (TMD), the computed performance parameters for TKX‐50 at its theoretical maximum density at room temperature was calculated to be as follows: VoD=9642 m s−1, pC‐J=37.0 GPa and Qdet=4770 kJ kg−1.
The simplest ligand that can be present in energetic complex compounds is ammonia. It has a lone pair of electrons on the nitrogen atom that can form a coordinate bond with the metal cation. An ...example of such a compound is tetraamminecopper(II) nitrate (TACN). TACN is considered in the literature as an energy material with potential use in ammunition and civil applications. In the work, the physicochemical properties and detonation performance of TACN were investigated. The compound was identified using differential thermal analysis coupled with thermogravimetry (DTA/TG) and infrared spectroscopy (IR). The sensitivity of TACN to mechanical stimuli (friction and impact) was determined. The thermal stability was tested. The critical diameter of the charge with bulk density and the ability to detonation for charges of different densities initiated by an electric detonator were determined. The velocity of detonation was also measured for various diameters and densities of charges and the method of their initiation. The cylinder expansion tests were performed for TACN charges of various densities, and the acceleration ability, detonation pressure and energy as well as the equation of state of detonation products were determined. The calorimetric heats of combustion and detonation were also measured.
New optimized method for the synthesis of 2‐amino‐4,6‐dinitrotoluene (2ADNT) and bis(2‐methyl‐3,5‐dinitrophenyl)diazene N‐oxide (2AzODNT) from 2,4,6‐trinitrotoluene (TNT) was developed. 2AzODNT was ...fully characterized by using nuclear magnetic resonance spectroscopy (1H, 13C), infrared spectroscopy and differential thermal analysis coupled with thermogravimetry. The crystals of 2AzODNT were observed by using scanning electron microscopy (SEM). The heat of combustion and the standard enthalpy of formation for the synthesis product were determined. The detonation parameters of 2AzODNT were calculated with a thermochemical code and experimentally measured. Due to the high detonation performance, the good thermal stability and low sensitivity to mechanical stimuli, 2AzODNT is an attractive low‐sensitivity high explosive. Moreover, the synthesis of 2AzODNT from old TNT can be an effective method of TNT utilization.
A direct comparison is made between the effectiveness of Al, Mg, and Be powders as additional fuels in model thermobaric compositions containing 20% fuel, 20% ammonium perchlorate, and 60% RDX ...(1,3,5-Trinitro-1,3,5-triazacyclohexane) passivated with wax. Experimentally determined calorimetric measurements of the heat of detonation, along with the overpressure histories in an explosion chamber filled with nitrogen, were used to determine the quasi-static pressure (QSP) under anaerobic conditions. Overpressure measurements were also performed in a semi-closed bunker, and all blast wave parameters generated after the detonation of 500 g charges of the tested explosives were determined. Detonation calorimetry results, QSP values, and blast wave parameters (pressure amplitude, specific and total impulses) clearly indicate that Be is much more effective as an additional fuel than either Al or Mg in both anaerobic post-detonation reactions as well as the subsequent aerobic combustion. The heat of detonation of the RDXwax/AP/Be explosive mixture is over 40% and 50% higher than that of the mixture containing aluminum and magnesium instead of beryllium, respectively. Moreover, the TNT equivalent of the Be-containing composition due to the overpressure in the nitrogen-filled explosion chamber is 1.66, while the equivalent calculated using an air shock wave-specific impulse at a distance of 2.5 m is equal to 1.69. The high values of these parameters confirm the high reactivity of beryllium in both the anaerobic and aerobic stages of the thermobaric explosion.
Investigations of the detonation characteristics of new aluminum‐enriched RDX‐based composites belonging to the enhanced blast explosive formulations were undertaken. Firstly, the explosion heat was ...measured in a calorimetric bomb filled with argon and after the cylinder expansion test was performed. From the cylinder test data the wall velocity, the Gurney energy and the detonation energy of the composites were determined. Then, using simulations, the isentrope exponents of the composite detonation products were estimated and hence the detonation pressures were calculated. Finally the equation of state of the detonation products was determined for each composite from the calorimetric heat and from the cylinder test data. The investigation results are presented and discussed. The effect of the aluminum particle size on the detonation characteristics is also checked. Conclusions about how to use these composite in weapon systems to generate optimal effects are drawn.
Performance of TKX‐50 in thermobaric explosives Klapötke, Thomas M.; Cudziło, Stanisław; Trzciński, Waldemar A. ...
Propellants, explosives, pyrotechnics,
20/May , Letnik:
48, Številka:
6
Journal Article
Recenzirano
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In this study, the behavior of the high‐nitrogen compound TKX‐50 in model thermobaric formulations was investigated. The addition of 10 % Al to TKX‐50 reduces the heat of detonation by approximately ...90 J/g. Despite this, Al reacts with the detonation products of TKX‐50 in an exothermic manner, and the energy contribution was calculated to be approx. 375 J/g. In addition, the overpressure in the explosion chamber filled with argon after detonation of aluminized TKX‐50 charges containing 27 % Al is approx. 20 % higher than in the case of neat TKX‐50. Also the maximum temperature of the TKX‐50/Al explosion products in the argon filled chamber is higher by 370 K than that of measured after detonating TKX only. What is more aluminum oxynitride with a low nitrogen content has been identified in the solid detonation products of aluminized TKX‐50, but only for detonations in argon. Of course, charges made of TKX‐50/Al mixture generate significantly higher overpressure and radiant temperature values in a confined space when they are detonated in an air atmosphere. It all means that burning aluminum in nitrogen provides little energy, and even if the concentration of nitrogen in the post‐detonation products is much higher than that of oxygen, aluminum oxides are preferentially formed.
A direct comparison is made between the effectiveness of Al, Mg, their alloy (Al3Mg4), and Si powders as additional fuels in explosives using the thermobaric effect. The experiment produced ...calorimetric measurements of the detonation heat and a record of the overpressure histories which were used to determine the quasistatic pressure (QSP) in an explosion chamber after the detonation of charges from mixtures containing 30 % fuel and 70 % RDX passivated with wax. The measured heat values indicate that Al−Mg alloy is a more effective additional fuel during anaerobic post‐detonation reactions than Al and Mg separately. Silicon also exothermically reacts with the detonation products, but the released heat only compensates for the lower amount of RDX in the charge. Similar to the calorimetric measurements, the lowest value of QSP was obtained for the mixture with Si powder. In contrast to anaerobic conditions, silicon proved to be an equally effective thermobaric additive as Al, Mg, and Al−Mg powders in air explosions.
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