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1

Integrating Moisture Isotherms, Compatibility Assessment, and Model Propellant with ADN as an Eco-Friendly Oxidizer

Yadav Deepak, Ghosh Kavita, Sadavarte Vaibhav, Jawale Lalita, Pawar Rajesh BabanRao, Kurva Ramesh

Central European Journal of Energetic Materials

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2024

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Vol. 21, no. 3

235--254

EN

This study delves into the use of ammonium dinitramide (ADN) as an eco-friendly substitute for ammonium perchlorate (AP) in solid rocket propellants. ADN based novel propellants were formulated with a nitrile butadiene rubber (NBR) based binder system. Employing Dynamic Vapor Sorption (DVS), ADN’s moisture characteristics were investigated at various temperatures (25, 35, 45 and 55°C) and utilized for propellant processing. Two component chemical compatibility assessments, in adherence to STANAG 4147 standard, were performed using Differential Scanning Calorimetry (DSC) and Vacuum Stability Testing (VST). Subsequently, propellant compositions containing ADN were formulated, and their performance was predicted using NASA’s CEC-71 code. The most promising formulation was processed and thereafter underwent testing for physical, ballistic, and mechanical performance against conventional AP-based propellants at a 500 g batch level. Optimal storage (≤ 25 °C, relative humidity (RH) ≤50%) and processing (35-40 °C, RH ≤35%) performance conditions were identified for ADN, contributing to the successful formulation of high-performance ADN/NBR propellant. The developed propellant showed marginal differences compared to AP/NBR in burn rate and density. However, compatibility issues with the bonding agent, hydantoin resin, led to deficiencies in mechanical strength. These findings contribute to the advancement of eco-friendly propellant technology, showcasing ADN’s potential as a transformative substance in aerospace applications.

2

Preparation and Characterization of Porous Carbon/RDX Nanocomposite Energetic Materials

Jiang Ju, Su Jin-Xiao, Liu Zhi-Tao, Du Ping, Liao Xin, Li Xiao-An

Central European Journal of Energetic Materials

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2023

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Vol. 20, no. 3

284--301

EN

A novel energetic material was fabricated by filling porous carbon with 1,3,5-trinitro-1,3,5-triazinane (RDX) via the ultrasonic stirring method. Characterization (TEM, BET, XRD, FTIR, etc.) was performed to determine the micromorphology, crystal structure, and specific surface area. TEM images indicated that the RDX particles were homogeneously distributed in the channels of the porous carbon, FTIR spectra and the XRD curve of the C/RDX composite exhibited the combined characteristics of porous carbon and RDX. The BET test data also confirmed this situation. The thermal decomposition kinetics and thermodynamics of the C/RDX nanocomposite energetic material were investigated at various heating rates (5, 10, 15, and 20 K·min⁻¹). The test results showed that the thermal decomposition temperature and the critical temperature of thermal explosion were lower than for RDX alone by 46.8 and 40.69 ℃, respectively. The activation energy of the C/RDX composite was lower than those of raw RDX and a C/RDX physical mixture, indicating that the C/RDX composite exhibited high thermolysis activity.

3

Anisotropic Interfacial Adhesion between Fluoropolymers and RDX Single Crystal Faces

Liu Jiahui, Zhou Xiaoqing, Qian Wen, Gong Feiyan, Yang Zhijian, Li Hongzheng, Nie Fude

Central European Journal of Energetic Materials

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2022

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Vol. 19, no. 4

409--423

EN

Interfacial interactions have an important influence on the properties of energetic materials. The anisotropy of interfacial adhesive strength between various 1,3,5-trinitro-1,3,5-triazinane (RDX) single crystal faces and a typical binder was studied in this work by experimental and theoretical investigations. An RDX single crystal was prepared and processed into three kinds of orientated crystal faces, including (002), (020) and (210). These crystal slices were used as substrates, and fluorinated polymer F2314 was used as a binder. The surfaces of the RDX slices were analyzed by X-ray photoelectron spectroscopy (XPS) and an atomic force microscope (AFM). The work of adhesion was obtained from direct tensile tests, using designed samples of the sandwich structure of RDX-F2314-RDX, with various RDX single crystal surfaces. The polarity component of the surface energy and the work of adhesion was obtained by Young’s equation and the Fowkes theory, based on surface contact angle tests. The results in this work indicated the anisotropy of the interfacial adhesion of F2314 on various RDX crystal faces.

4

Studies on the Properties of a Putty-like Explosive with a Silicone Binder

Zalewski Karol, Chyłek Zbigniew, Trzciński Waldemar A.

Central European Journal of Energetic Materials

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2021

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Vol. 18, no. 1

112--123

EN

In this work a new putty-like explosive containing 1,3,5-trinitro-1,3,5-triazine (RDX) and polydimethylsiloxane (PDMS) was prepared and its properties were studied. The plasticity and the decomposition temperature of the explosive were determined. The sensitivity to friction, impact, shock wave and internal ignition were tested. The heats of combustion and explosion of the formulation were also measured. The diameter and critical layer as well as the detonation velocity of charges of different diameters were determined. The research results obtained were analyzed.

5

Preparation of Insensitive RDX by Suspension Spray Technology and Its Characterization

Yan Xiang, Li Xiao Dong, Zhou Peng, Ji Wei, Shi Xiao Feng

Central European Journal of Energetic Materials

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2019

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Vol. 16, no. 2

216--227

EN

A new insensitive and high energy explosive based on RDX was prepared by suspension spray technology using Estane 5703 as a binder (e-RDX). Scanning electron microscopy was used to characterize the morphology and particle size of the samples. The composite was analyzed by differential scanning calorimetry and X-ray photoelectron spectroscopy. Its impact sensitivity and detonation velocity were determined. For comparison, raw RDX, refined RDX (r-RDX) and solution spray dried RDX/Estane 5703 (e1-RDX) were also tested using these five methods. The SEM results showed that the e-RDX size was 1-3 μm. e1-RDX exhibited a spherical shape with some defects on the surface. The XPS results indicated that Estane 5703 can be successfully coated onto the surface of e-RDX. Compared to raw RDX, the drop height of r-RDX, e1-RDX and e-RDX was increased, being 16.5 cm, 32.9 cm and 58.4 cm, respectively. The activation energy of e-RDX is lower than that of raw RDX, but a little higher than that of e1-RDX. Compared to raw RDX, the detonation velocity of r-RDX, e1-RDX, w-RDX and e-RDX had decreased, being 110 m·s–1, 710 m·s–1, 410 m·s–1 and 210 m·s–1, respectively.

6

High Penetration Performance of Powder Metallurgy Copper-Tungsten Shaped Charge Liners

Elshenawy T., Abdo G., Elbeih A.

Central European Journal of Energetic Materials

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2018

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Vol. 15, no. 4

610--628

EN

Copper tungsten liner manufactured using uniaxial pressing technique has been characterized numerically and experimentally in comparison with a baseline shaped charge copper liner produced by deep drawing technique. The jet properties resulted from these two shaped charges were different according to their liner types and relevant densities which affect the resultant penetration depths into rolled homogeneous armour (RHA) targets. Different copper-tungsten powder liners have been studied and analysed using Autodyn hydrocode, from which an optimum powder design was chosen based on its maximum jet kinetic energy that can be coherent. The compacted liner elastic properties have been measured using SONELASTIC apparatus, whereas its real density is determined using helium gas pycnometer. Baseline copper liner obtained by deep drawing technique of uniform density exhibited lower penetration depth in comparison with the copper-tungsten liner (higher density powder). Besides, the penetration crater resulted from the powder liner showed clean hole without clogging because there was no massive slug as in the case of the copper liners. Experimental field tests of the two liners against (RHA) targets exhibited different penetrations depths, which have been accounted in this research.

7

Application of the Energetic Complex [Cu(TNBI)(NH3)2(H2O)] in Heterogeneous Solid Rocket Propellants

Bogusz R., Rećko J., Magnuszewska P., Lewczuk R.

Central European Journal of Energetic Materials

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2018

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Vol. 15, no. 2

391--402

EN

This paper presents results from the application of [Cu(TNBI)(NH3)2(H2O)] (CuTNO) to heterogeneous solid rocket propellants based on HTPB/AP, replacing RDX. A series of different compositions of solid heterogeneous rocket propellants based on HTPB and ammonium perchlorate, containing CuTNO or RDX, were prepared and investigated. The ballistic parameters of the examined propellants were determined by combustion in a laboratory rocket motor (LRM). The ballistic properties were evaluated in the pressure range 4-10 MPa and it was found that the linear burning rate at 10 MPa increased by more than 20% for the CuTNO containing propellant, compared to the RDX-based composition. By linear regression of the r = f(p) curves obtained, the burning laws for the investigated propellants were determined. It was found that the CuTNO additive increases the pressure coefficient by over 46%, compared to unmodified propellant. The determination of the sensitivities to friction and impact, the calorific value, hardness and decomposition temperature of the propellants obtained were also investigated.

8

Rapid and simple analysis of trace levels of three explosives in soil by liquid chromatography - tandem mass spektrometry

Yenel G. F., Anilanmert B., Cengiz S.

Acta Chromatographica

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2017

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Vol. 29, no. 1

45--56

EN

The analysis of trace levels of explosives in post-blast debris is critical in homeland security, environmental analysis, and crime scene forensic investigations. A fast and a selective determination method with high recovery was developed for the common explosives 2,4,6-trinitrotoluene (TNT), 3,5-trinitro-1,3,5-triazacyclohexane (RDX), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) in soil, using liquid chromatography - tandem mass spectrometry (LC-MS/MS). An easy and practical sample preparation method was developed using 4.00 mL acidified acetone with 0.25% HCl. After the easy evaporation of acetone extract, 10 min LC-MS/MS analysis provided a clear separation in column. Short duration of the whole procedure allows the use of this method in routine analysis. As a result of the analysis performed in spiked soils in 50.0, 100.0, and 250.0 ng g -1 concentrations, high recoveries such as 100.4 (±8.8)% for RDX, 96.9 (±10.5)% for HMX, and 97.6 (±13.9)% for TNT were obtained. Limit of detection (LOD) and limit of quantification (LOQ) values obtained from the analysis of the spiked soils were 4.3 ng g -1 and 7.00 ng g -1 for RDX, 6.8 ng g -1 and 10.0 ng g -1 for HMX, and 18.9 ng g -1 and 38.0 ng g -1 for TNT, respectively. The Horwitz Ratio (HorRat) calculation was used to evaluate if the inter-day and inter-analyst precisions were in the acceptable limits. The method was successfully applied to three artificial explosion samples for detection of explosives.

9

Thermal Behavior and Decomposition Kinetics of RDX and RDX/HTPB Composition Using Various Techniques and Methods

Abd-Elghany M., Elbeih A., Hassanein S.

Central European Journal of Energetic Materials

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2016

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Vol. 13, no. 3

714--735

EN

In this paper, the thermal behavior and decomposition kinetics of trinitrohexahydrotriazine (RDX) and its polymer bonded explosive (PBX) containing a hydroxyl-terminated polybutadiene (HTPB) based polyurethane binder in the ratio 80% RDX/ 20% HTPB were investigated using various experimental techniques and analytical methods. The HTPB polyurethane matrix contains other additives and was cured using hexamethylene diisocyanate (HMDI). Thermogravimetric analysis (TGA), Differential Scanning Calorimetry (DSC), Vacuum Stability Test (VST) and Ignition Delay Techniques were applied both isothermally and non-isothermally. The kinetic parameters were determined using both the isoconversional (model free) and the model-fitting methods. For comparison, Advanced Kinetics and Technology Solution (AKTS) software was also used. It was found that the addition of an HTPB-based polyurethane matrix to pure RDX decreased its decomposition temperature. It was also found that RDX/HTPB has a lower activation energy than pure RDX. The polyurethane matrix had a significant effect on the decomposition mechanism of RDX resulting in different reaction models. It was concluded that the activation energies obtained using the Ozawa, Flynn, and Wall (OFW) and Kissinger-Akahira-Sunose (KAS) methods were very close to the results obtained via the AKTS software lying in the range 218.3-220.2 kJ•mol−1. The VST technique yielded kinetic parameters close to those obtained using TG/DTG. On the other hand, the Ignition Delay Technique yielded different and inconsistent kinetic parameters.

10

Preparation and Properties of RDX-Nitrocellulose Microspheres

Shi X., Wang J, Li X.

Central European Journal of Energetic Materials

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2016

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Vol. 13, no. 4

871--881

EN

A new insensitive explosive based on RDX and with Nitrocellulose (NC) as binder has been prepared using a flash vaporization process. Scanning electron microscopy was used to characterize the morphology and particle size of the resulting RDX-NC microspheres. X-ray photoelectron spectroscopy, Differential Scanning Calorimetry, impact sensitivity, vacuum stability and burning rate of raw RDX, RDX-NC and RDX-1 were also used to characterize the explosive. The RDX-NC microspheres were found to have a fibrous surface. The microspheres ranged in size from 0.5 μm to 4 μm. The NC formed a coat on the surface of the RDX. The activation energies of raw RDX, RDX-1 and RDX-NC were found to be 200.8 kJ·mol−1, 183.9 kJ·mol−1 and 187.2 kJ·mol−1, respectively. The drop heights of raw RDX, RDX-1 and RDX-NC were found to be 21.3 cm, 51.7 cm and 82.9 cm, respectively. The friction sensitivity of RDX-NC was lower than that of raw RDX and RDX-1. In the vacuum stability test, the volumes of evolved gas from raw RDX, RDX-1 and RDX-NC were 0.12 mL·g−1, 0.12 mL·g−1, and 0.09 mL·g−1, respectively. The burning rates of RDX-NC-based propellants were higher than that of RDX-1 and raw RDX based propellants at 5-15 MPa. The burning rate pressure exponent of RDX-NC based propellants is 0.9929 at 40-200 MPa.

11

Plasticization of Submicron-Structured LOVA Propellants by a Linear Dinitramine

Le Brize A., Spitzer D.

Central European Journal of Energetic Materials

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2016

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Vol. 13, no. 3

547--556

EN

Raman spectroscopy is a powerful tool for the analysis of complex energetic materials. In this work, this technique has been used to observe the inter-molecular interactions occurring in nitrocellulose-based propellants containing 1,3,5-trinitro-1,3,5-triazinane (RDX) and plasticized with 2,4-dinitro-2,4-diazahexane (DNDA6). The plasticization mechanism of nitrocellulose by DNDA6 was observed. RDX was found to be markedly uninvolved in chemical interactions in these matrices, hinting at a potential loss of stability in compositions for LOVA (LOw Vulnerability Ammunitions).

12

OPTIMEX: Measurement of Detonation Front Curvature with a Passive Fiber Optical System

Pachman J., Künzel M., Kubát K., Selesovsky J., Maršálek R., Pospíšil M., Kubíček M., Prokeš A.

Central European Journal of Energetic Materials

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2016

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Vol. 13, no. 4

807--820

EN

The ability of a newly developed independent passive optical system OPTIMEX to measure the detonation front curvature is demonstrated on charges of pressed explosive A-IX-1 (RDX/ceresin-stearin mixture with 95/5 wt.%). The charges, with length to diameter ratios of from one to four, were prepared from cylinders with diameters of 21 mm, 30 mm, 40 mm and 50 mm pressed to a density of 1.66 g/cm3. Such charges detonate with a velocity of 8220 m/s. The detonation curvature was obtained using 8 optical fibers and the results were compared with photographs acquired by an ultra-high speed framing camera UHSi 12/24.

13

Experimental Studies on Advanced Sheet Explosive Formulations Based on 2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) and Hydroxyl Terminated Polybutadiene (HTPB), and Comparison with a RDX-based System

Jangid S. K., Talawar M. B., Singh M. K., Nath T., Sinha R. K.

Central European Journal of Energetic Materials

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2016

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Vol. 13, no. 1

135--147

EN

The present investigation reports the use of 2,4,6,8,10,12-hexanitro2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) in sheet explosive formulations. In this study, hydroxyl terminated polybutadiene (HTPB) based sheet explosives were prepared incorporating the powerful explosive CL-20 as a partial replacement for hexahydro-1,3,5-trinitro-1,3,5-triazine(RDX). The effects of incorporating CL-20 on the performance, sensitivity, thermal and mechanical properties of the sheet explosive compositions are reported. Sheet explosive formulation containing 80% of RDX and 20% of HTPB-binder was studied as control sample. HTPBbinder consisted of 12% HTPB, 2.9% dioctyl adipate (DOA) and 5.1% dioctyl phthalate (DOP). HTPB was cured with 4,4’-methylene diphenyl di-isocyanate (MDI) to form urethane linkages. The incorporation of 20% of CL-20 in place of RDX led to a remarkable increase in the velocity of detonation (VOD), of the order of 7680 m/s, and to better mechanical properties in terms of tensile strength (1.14 MPa) compared to the control formulation [RDX /HTPB-binder (80/20)]. The 20% CL-20 incorporated sheet explosive formulation also showed remarkable increases in impact and shock sensitivity. Thermal analysis of the sheet explosive compositions has also been carried out using differential scanning calorimetry (DSC).

14

Experimental Studies on a High Energy Sheet Explosive Based on RDX and Bis(2,2-dinitropropyl) Formal/Acetal (BDNPF/A)

Jangid S. K., Singh M. K., Solanki V. J., Pandit G., Nath T., Sinha R. K.

Central European Journal of Energetic Materials

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2016

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Vol. 13, no. 3

557--566

EN

A plastic bonded explosive (PBX) in the form of a sheet explosive was formulated with 1,3,5-trinitro-1,3,5-triazinane (RDX) dispersed in a polymeric matrix of a thermoplastic linear polyurethane and a 50/50 wt.% eutectic mixture of energetic plasticizers, viz., bis(2,2-dinitropropyl)formal (BDNPF) and bis(2,2-dinitropropyl)acetal (BDNPA) was used to increase the performance of the sheet explosive in terms of its velocity of detonation (VOD). The sheet explosives were prepared by a rolling process. Natural rubber (ISNR-5) based sheet explosive was taken as the standard composition. The study showed that the BDNPF/A based sheet explosive has a velocity of detonation of 7850 m/s, which is about 900 m/s higher than the standard composition. Thermal analysis of the sheet explosive formulations was performed using differential scanning calorimetry (DSC).

15

Badania w zakresie oceny zdolności ochronnych układów zabezpieczających przed rażącym działaniem wybuchu

Koślik P., Wilk Z.

Materiały Wysokoenergetyczne

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2015

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T. 7

53--62

PL

W pracy przedstawiono metodykę badawczą związaną z oceną skuteczności oraz optymalizacji układów chroniących przed niszczącym wpływem wybuchu. Skuteczność ochrony zależy od wielu czynników między innymi od struktury i materiału, z jakiego zostały wykonane osłony, grubości poszczególnych warstw oraz ich wzajemnego położenia względem siebie. Wyniki prowadzonych w tym zakresie badań przyczynią się do opracowania konstrukcji osłon poprawiających bezpieczeństwo funkcjonariuszy służb mundurowych i specjalistów stosujących w pracy materiały wybuchowe oraz do ochrony szeroko rozumianej infrastruktury krytycznej.

EN

The paper presents a methodology of research related to the evaluation of the effectiveness and optimization of protection from the damaging effects of explosion and glaring effects of ammunition. The effectiveness of the protection depends on many factors inter alia the material from which the structure was made sheath, the thickness of the individual layers and their relative position to each other. This research will contribute to improving the safety of the uniformed services and professionals at work using explosives and to protect the broader critical infrastructure.

16

Studies on Tungsten Based High Density Cast Polymer Bonded Explosive (PBX) Formulations

Vadhe P. P., Manickam S., Rahujade N., Kondra A., Prasad U., Sinha R. K.

Central European Journal of Energetic Materials

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2015

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Vol. 12, no. 3

497--506

EN

Aluminized melt-cast TNT and PBX (cast/pressed) based compositions have been widely studied and used in different warheads for various applications,such as air blast, underwater blast, thermobaric effects, etc. Tungsten (W) based cast PBX formulations are the least reported in the literature. We have partially replaced RDX or HMX in the control PBX formulation with 15 to 25% W powder and investigated the effect of this on the ease of processing, density, sensitivity, mechanical properties and explosive performance. The viscosity was improved from 9 to 3 kPoise, and the density by about 12 to 25% on the addition of W powder to the PBX formulations. The sensitivity to impact for the RDX/Wand HMX/W based PBX formulations was improved by 12 to 37%. The reinforcing effect of the W powder caused an increase in hardness (Shore A) by 16 to 45%. A decreasing trend in the velocity of detonation (VOD) was observed because of the replacement of the nitramine content (RDX/HMX) with W powder. The approximate detonation pressure of RDX/W/HTPB (65/20/15), roughly calculated by the Kamlet-Jacobs method, is better than the other tungsten based formulations investigated.

17

Concerning the shock sensitivity of cyclic nitramines incorporated into a polyisobutylene matrix

Pelikán W., Zeman S., Yan Q. L., Erben M., Elbeih A., Akštein Z.

Central European Journal of Energetic Materials

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2014

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Vol. 11, no. 2

219--235

EN

Two types of plastic bonded explosives (PBXs) based on ε-2,4,6,8,10,12hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (ε-HNIW, CL-20), and PBXs based on 1,3,5-trinitro-1,3,5-triazinane (RDX), β-1,3,4,7-tetranitro-1,3,5,7-tetrazocane (β-HMX) and cis-1,3,4,6-tetranitro-octahydroimidazo-[4,5-d]imidazole (bicycloHMX, BCHMX) were prepared using a polyisobutylene binder with dioctylsebacate (DOS) as plasticizer, i.e. a C4 matrix. One version of the ε-HNIW PBX is a product with reduced sensitivity (RS-ε-HNIW). All these PBXs, referenced respectively as RS-ε-HNIW-C4, ε-HNIW-C4, RDX-C4, HMX-C4 and BCHMX-C4, were tested using the Small Scale Gap Test according to STANAG 4488. The results of the gap test on the PBXs with RDX, β-HMX and BCHMX correspond to the impact sensitivities of the original crystalline nitramines. This is not entirely valid for ε-HNIW. In other words, PBXs with RS-ε-HNIW cannot achieve as low a shock sensitivity as would be expected from the differences obtained from the impact sensitivities between RDX, β-HMX and BCHMX, on the one hand, and RS-εHNIW on the other. It is shown that the morphological stability of RS-ε-HNIW in the C4 matrix is insufficient. However, further development and use of RS-ε-HNIW as a filler of PBXs would seem to be both desirable and beneficial. Despite the relatively high impact sensitivity of crystalline BCHMX, the shock sensitivity of its analogous C4 PBX is already good, and comparable with that of RS-ε-HNIW.

18

Preparation of Al Nanoparticles and Their Influence on the Thermal Decomposition of RDX

Hou C., Geng X., An Ch., Wang J., Xu W., Li X.

Central European Journal of Energetic Materials

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2013

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Vol. 10, no. 1

123--133

EN

Aluminum (Al) nanoparticles were prepared by the DC arc plasma method in order to study the influence of Al nanoparticles on the thermal decomposition of cyclotrimethylenetrinitramine (RDX). The Al powder was characterized by TEM, BET, XRD, and LSA, and the thermal decomposition of RDX and RDX/nanometer Al were examined by DSC. Based on the DSC curves, the thermal decomposition parameters of the samples were calculated and compared. The results showed that the particles of Al are homogeneous and fine, and that the surface is smooth. The TEM results showed that the nanoparticles are spherical, with an average diameter of approximately 60 nm. The peak temperature of RDX decomposition decreased by 4.36 K at the heating rates of 5, 10, and 20 K/min after the addition of nano-Al powder, and the activation energy for decomposition decreased by about 11 kJ/mol. Furthermore, the critical explosion temperature was also reduced. These observable changes indicate that Al nanoparticles act as catalysts for the thermal decomposition of RDX.

19

Effect of Different Polymeric Matrices on the Sensitivity and Performance of Interesting Cyclic Nitramines

Elbeih A., Zeman S., Jungova M., Akstein Z.

Central European Journal of Energetic Materials

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2012

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Vol. 9, nr 2

131-138

EN

Different polymeric matrices, based on butadiene-styrene rubber, polymethyl-methacrylate and silicone binders, were investigated for their ability to decrease the sensitivity of explosives to different mechanical stimuli. A series of plastic explosives based on four different nitramines, namely RDX (1,3,5-trinitro- 1,3,5-triazacyclohexane), β-HMX (β-1,3,5,7-tetranitro-1,3,5,7-tetrazacyclooctane), BCHMX (bicycloHMX, 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, ε-CL-20), bonded by the selected polymeric matrices were prepared. Sensitivity to impact of all of the plastic explosives prepared as well as of the pure explosives, was measured using the fall hammer test. Sensitivity to friction was determined using the BAM friction test. The performance was studied using the ballistic mortar test and the results were recorded relative to TNT (trinitrotoluene) as reference. By comparing the results of impact and friction sensitivities, it is obvious that the mechanism of transfer of the friction force to the reaction center of the nitramine molecule should be different from that of impact energy transfer. The silicone binder appeared to be the best polymer for decreasing the sensitivity of explosives. The results of the ballistic mortar proved that the performance of the plastic explosives prepared is affected by the type and weight percentage of the binder in each sample.

20

Thermal Stability and Detonation Characteristics of Pressed and Elastic Explosives on the Basis of Selected Cyclic Nitramines

Elbeih A., Pachmáň J., Zeman S., Trzciński W. A., Akstein Z., Sućeska M.

Central European Journal of Energetic Materials

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2010

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Vol. 7, nr 3

217-232

EN

Bicyclo-HM X (cis-1,3,4,6-tetranitro-octahydroimidazo-[4,5-d] imidazole or BCHM X) was studied as a plastic explosive bonded with the C4 matrix and with Viton A. Also a series of nitramines namely RDX (1,3,5-trinitro-1,3,5=triazinane), HM X (1,3,5,7-tetranitro-1,3,5,7-tetrazocane) and HNIW (ĺ-2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane, ĺ-CL-20) were studied for comparison with the same types of binders. The detonation velocity, D, of all prepared mixtures was measured. Their thermal stability was determined using non-isothermal differential thermal analysis (DTA). While the C4 matrix lowers the thermal stability of the resulting explosives, Viton A enhances this stability. Approximate relationships between the peaks of exothermic decomposition and the D values were found. The detonation parameters were also calculated by means of Kamlet & Jacobs method, CHEETAH and improved EXPLO5 code for all the mixtures. From the measured D values and the calculated detonation parameters, it is obvious that the detonation parameters of BCHM X-mixtures are very close to HM X-explosives and better than those of RDX-mixtures. It was found that the C4 matrix reduces the difference between the values of energy of detonation in the studied C4 mixtures. As expected, the pressed HNIW-Viton A mixture has the highest detonation parameters of all of the prepared mixtures.