首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 15 毫秒
1.
An attempt was made to introduce CL‐20 in a TNT/energetic thermoplastic elastomer (ETPE)‐based melt cast formulation, to obtain an insensitive composition with reduced adverse environmental properties. A loading limit of 42% w/w of CL‐20 in melted TNT was observed, while it should have been around 70%. This paper describes the investigation that was undertaken to understand the observed phenomena. It was demonstrated that CL‐20 undergoes structural alterations in melted TNT. The relative solubility of CL‐20, RDX and HMX in melted TNT was determined and the α‐, β‐, γ‐ and ε‐CL‐20 were prepared and characterized using Raman spectroscopy and DTA. CL‐20 was mixed in melted TNT, as much as 4.2 g of CL‐20 dissolved in 100 g of TNT. This allowed a transformation from ε to β‐CL‐20 and a modification of CL‐20 particle size and distribution. The later modification induced a raise in CL‐20 specific surface and was responsible for the loading limit, while the transformation to β‐CL‐20 caused an increase in sensitivity and a decrease in density. This indicates that the use of CL‐20 in TNT melt cast is not promising. Our study also showed that CL‐20 is sensitive to morphological transformations, which should be taken into consideration in future processing using this compound.  相似文献   

2.
    
The sensitivity of an explosive to detonate due to a shock stimulus is examined using the shock Hugoniots of the condensed material and the detonation products. Explicit equations were developed for the initiation and detonation pressures as a function of the shock parameters, the density, the detonation velocity and the Chapman‐Jouguet pressure which in itself is a function of the heat of detonation. We came upon defining a pressure difference, , between the initiation and detonation pressures which appears to provide a measure of the sensitivity of the explosive to detonate due to a shock loading. For a number of explosives for which reliable shock parameters were available, our results compared very well with widely used and tested small and large scale gap test results. We demonstrated that no one parameter such as the heat of detonation, the Chapman‐Jouguet pressure or even the detonation velocity could be used as a measure of sensitivity to shock detonation but it is the net effect captured by all the parameters that provides the sensitivity of the explosive.  相似文献   

3.
不定形耐火材料用结合剂的发展   总被引：1，自引：0，他引：1  
分析了各种结合剂的使用情况,认为高稠度陶瓷结合剂悬浮液是不定形耐火材料比较理想的结合剂。它不仅有许多优良性能,而且对于节约资源和能源,保护环境,提高经济效益都是有益的。  相似文献   

4.
    
Two new highly stable energetic salts were synthesized in reasonable yield by using the high nitrogen‐content heterocycle 3,4,5‐triamino‐1,2,4‐triazole and resulting in its picrate and azotetrazolate salts. 3,4,5‐Triamino‐1,2,4‐triazolium picrate (1) and bis(3,4,5‐triamino‐1,2,4‐triazolium) 5,5′‐azotetrazolate (2) were characterized analytically and spectroscopically. X‐ray diffraction studies revealed that protonation takes place on the nitrogen N1 (crystallographically labelled as N2). The sensitivity of the compounds to shock and friction was also determined by standard BAM tests revealing a low sensitivity for both. B3LYP/6–31G(d, p) density functional (DFT) calculations were carried out to determine the enthalpy of combustion (ΔcH (1) =−3737.8 kJ mol−1, ΔcH (2) =−4577.8 kJ mol−1) and the standard enthalpy of formation (ΔfH° (1) =−498.3 kJ mol−1, (ΔfH° (2) =+524.2 kJ mol−1). The detonation pressures (P (1) =189×108 Pa, P (2) =199×108 Pa) and detonation velocities (D (1) =7015 m s−1, D (2) =7683 m s−1) were calculated using the program EXPLO5.  相似文献   

5.
    
Thermally stable explosives are becoming more and more important nowadays due to their important role in the oil and mining industry. The requirements of these explosives are constantly changing. Picramate-based compounds are poorly investigated towards their energetic properties as well as sensitivities. In this work, 13 different salts of picramic acid were synthesized as potential energetic materials with high thermal stability in a simple one-step reaction and compared with commercially used lead picramate. The obtained compounds were extensively characterized by e. g. XRD, IR, EA, DTA, and TGA. In addition, the sensitivities towards impact and friction were determined with the BAM drop hammer and the BAM friction tester. Also, the electrostatic discharge sensitivity was explored. Calculations of the energetic performance of selected compounds were carried out with the current version of EXPLO5 code. Therefore, heats of formation were computed and X-ray densities were converted to room temperature. Some of the synthesized salts show promising characteristics with high exothermic decomposition temperatures. Especially, the water-free rubidium, cesium, and barium salts 5 , 6 and 10 with decomposition temperatures of almost 300 °C could be promising candidates for future applications.  相似文献   

6.
    
A novel insensitive high explosive 3,4‐bis (aminofurazano) furoxan (BAFF) was prepared using 3‐amino‐4‐acylchloroximinofurazan (ACOF) as a precursor. The molecular and crystal structures of BAFF were characterized by IR, MS, 1H NMR, 13C NMR, elemental analysis, and single crystal X‐ray diffraction. The single crystal structure of BAFF recrystallized from water is monoclinic, space group P 21/c, and ρc=1.745 g cm−3, and that recrystallized from ethanol is triclinic, space group P 1, and ρc=1.737 g cm−3. BAFF has multiple crystal forms. The calculated detonation velocity by BKW code is 8100 m s−1 (ρ=1.795 g cm−3, theoretical density calculated by quantum chemistry) and the experimental value is 7177 m s−1 (ρ=1.530 g cm−3, charge density). The tested values of impact, friction, and electrostatic spark sensitivity show that BAFF is insensitive.  相似文献   

7.
    
This paper reviews the synthesis, properties, performance, and safety of the insensitive explosive 3,3′‐diamino‐4,4′‐azoxyfurazan (DAAF, C4H4N8O3), CAS‐No. [78644‐89‐0], and 18 formulations based on it. Though having a moderate crystal density only, DAAF offers high positive heat of formation and hence superior performance when compared with TATB. It is friction and impact insensitive but is more sensitive to shock than TATB and has an exceptionally small critical diameter and performs very well at low temperatures unlike other insensitive explosives. 39 references to the public domain are given. For Part I see Ref. [1].  相似文献   

8.
    
Using powder X‐ray diffraction in conjunction with a diamond anvil cell (DAC), the unit cell volume of triamino‐trinitrobenzene (TATB) has been measured from ambient pressure to 13 GPa. The resultant isotherm is compared with previous theoretical (Byrd and Rice and Pastine and Bernecker) and experimental (Olinger and Cady) works. While all reports are consistent to approximately 2 GPa, our measurements reveal a slightly stiffer TATB material than reported by Olinger and Cady and an intermediate compressibility compared with the isotherms predicted by the two theoretical works. Analysis of the room temperature isotherm using the semi‐empirical, Murnaghan, Birch–Murnaghan, and Vinet equations of state (EOS) provided a determination of the isothermal bulk modulus (Ko) and its pressure‐derivative (Ko′) for TATB. From these fits to our P–V isotherm, from ambient pressure to 8 GPa, the average results for the zero‐pressure bulk modulus and its pressure derivative were found to be 14.7 GPa and 10.1, respectively. For comparison to shock experiments on pressed TATB powder and its plastic‐bonded formulation PBX 9502 (95% TATB, 5% Kel‐F 800), the isotherm was transformed to the pseudo‐velocity Us–up plane using the Rankine–Hugoniot jump conditions. This analysis provides an extrapolated bulk sound speed, co=1.70 km s−1, for TATB and its agreement with a previous determination (co=1.43 km s−1) is discussed. Furthermore, our P–V and corresponding Us–up curves reveal a subtle cusp at approximately 8 GPa. This cusp is discussed in relation to similar observations made for the aromatic hydrocarbons anthracene, benzene and toluene, graphite, and trinitrotoluene (TNT).  相似文献   

9.
    
The properties of pentaamine (5‐cyano‐2H‐tetrazolato‐N2) cobalt (III) perchlorate (CP), which was first synthesized in 1968, continues to be of interest for predicting behavior in handling, shipping, aging, and thermal cook‐off situations. We report coefficient of thermal expansion (CTE) values over four specific temperature ranges, decomposition kinetics using linear and isothermal heating, and the reaction to three different types of stimuli: impact, spark, and friction. The CTE was measured using a Thermal Mechanical Analyzer (TMA) for samples that were uniaxially compressed at 68.95 MPa and analyzed over a dynamic temperature range of −20 °C to 70 °C. Differential scanning calorimetry, DSC, was used to monitor CP decomposition at linear heating rates of 1–7 °C min−1 in perforated pans and of 0.1–1.0 °C min−1 in sealed pans. The kinetic triplet was calculated using the LLNL code Kinetics05, and predictions for 210 °C and 240 °C are compared to isothermal thermogravimetric analysis (TGA) experiments. Values are also reported for spark, friction, and impact sensitivity.  相似文献   

10.
    
The rationale behind using heterocyclic compounds [1], particularly nitrogen heterocycles, as higher energy insensitive high explosives is discussed, including the potential advantages compared with carbocyclic compounds. The types of functional groups used to impart energy to heterocyclic nuclei, whilst maintaining insensitivity, and methodologies for their introduction, are covered. The latter include nitration (by conventional and clean synthetic methods), amination, and oxidation (on ring heteroatoms and of exocyclic amino groups). Strategies for maximising the energetic content of a given heterocyclic nucleus are also examined. The syntheses of specific examples at QinetiQ are described, based on the following nuclei: pyridine, pyrimidine, pyrazine, quinoxaline, quinazoline, pteridine and purine. Strategies for obtaining the desired amino‐nitro derivatives and their heterocyclic N‐oxides are outlined. Optimisation of the synthetic routes for several candidates is discussed. The physical, explosive and thermal properties of the more successful candidates are described, with suggestions for their potential application in military stores.  相似文献   

11.
    
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.  相似文献   

12.
    
In this study HMX was recrystallized from different solvents by a cooling crystallization process to improve the product quality and to produce a more insensitive product. It was found that particles with the best quality were crystallized from propylenecarbonate with a nucleation initiation by dosing a small amount of water as drowning‐out substance. This leads to particles with a very high density (near to the theoretical value) and thus to particles with a small amount of inclusions. GAP tests with this product show less sensitivity against shock. A clear linear dependence of the particle density on the shock initiation pressure was found. The particle density is relatively easy to measure so it will be a useful measure to determine the sensitivity of the material.  相似文献   

13.
    
The rationale behind developing insensitive energetic compounds (IECs) for incorporation into insensitive munition (IM) formulations (rather than the alternative approach of desensitizing higher energy but sensitive compounds) is discussed. With the aim of selecting a maximum of 2–3 IECs suitable for use in insensitive explosive and propellant compositions, a survey of the literature on IECs published in the last 20 years was carried out. From around 50 candidates, a selection was made of eight prime candidates, all heterocyclic compounds (principally monocyclic or fused‐ring bicyclic compounds of the di‐ or triazine, triazole or oxadiazole classes), which displayed explosive performance significantly better than that of the ubiquitous IEC, TATB. The criteria for inclusion of compounds in these listings are described. Screening of the eight candidate compounds against further performance criteria reduced the list to five compounds which were evaluated in detail – these were: CL‐14 (5,7‐diamino‐4,6‐dinitrobenzofuroxan), ANPZ‐i (2,5‐diamino‐3,6‐dinitropyrazine), NNHT (2‐nitrimino‐5‐nitro‐hexahydro‐1,3,5‐triazine), NTAPDO (5‐nitro‐2,4,6‐triaminopyrimidine‐1,3‐dioxide), and PANT [4‐(picrylamino)‐5‐nitro‐1,2,3‐triazole]. A detailed analysis of scale‐up issues associated with each compound was then made, including cost and availability of precursors, hazards (chemical and explosive), effluent streams, and other scale‐up issues (e.g. materials of plant construction). A further downselection using these criteria gave the present short‐list comprising three compounds (the first three listed above) and further evaluation is in progress. The results of this study, funded by UK MOD, comprise the UK contribution to a nine‐nation European research collaboration in the EUCLID Common European Priority Area 14 “Energetic Materials”, as part of a five‐year project which commenced in October 2003.  相似文献   

14.
    
The concept of Insensitive Munitions was developed more than 40 years ago. The challenge for the munition designer was to produce munitions that gave the required performance but did not respond violently when subject to accidents or enemy action. Given that munitions contain metastable energetic materials which are by design able to release large quantities of energy in very short timeframes, coupled with the other constraints of reliability, service life, environmental impact, ease of disposal and cost it is easy to understand that this was and to some extent still is a major challenge. This paper provides a brief summary of the key technologies developed over the last 40 years and provides a set of design principles to facilitate the IM design process.  相似文献   

15.
    
The NATO Munitions Safety Information Analysis Center (MSIAC) is a multinational collaboration that collects, stores, and analyses technical information related to Munitions Safety (MS) and Insensitive Munitions (IM). MSIAC supports its member nations through a variety of products and services. In addition to a core responsibility of addressing technical questions related to Munitions Safety posed by members, MSIAC has a diverse programme of work aimed at developing and sharing the related underpinning scientific knowledge. This is applied to support munition safety policy development and implementation. This article provides an overview of some of the current and future areas of work which MSIAC is involved in, with a focus on IM and energetic materials.  相似文献   

16.
进行了耐火浇注料热重分析,热风和微波干燥实验研究,得到了浇注料热风和微波干燥特性曲线。实验结果表明,与热风干燥比较,微波加热极大地降低了耐火浇注料干燥时间、提高了干燥效率和能源效率高,在耐火浇注料干燥过程中有着广阔的应用前景。  相似文献   

17.
李友胜  张唐文  李楠 《耐火材料》2007,41(3):188-190
以电熔白刚玉、镁铝尖晶石、SiC细粉、活性α-Al2O3微粉、球状沥青、Si粉、ρ-Al2O3、氧化硅微粉和铝酸钙水泥为原料制备了Al2O3-MA-SiC-C质浇注料。振动浇注成型后采用静态坩埚法测定了浇注料抗渣侵蚀性,利用X射线衍射、电子探针仪和能谱等手段分析了1500℃埋炭处理3h后试样的物相、显微结构和微区成分,以研究结合剂种类(ρ-Al2O3 氧化硅微粉和铝酸钙水泥 氧化硅微粉)、尖晶石和SiC的加入量对浇注料抗渣性能的影响。结果表明:采用ρ-Al2O3 氧化硅微粉结合的浇注料的抗渣性能明显高于采用铝酸钙水泥 氧化硅微粉结合的,这主要与其在高温下形成的物相有关;随着镁铝尖晶石加入量的增多,浇注料的抗渣性能总体上呈升高趋势;随着SiC加入量的增多,浇注料的抗渣性能显著提高,当SiC加入量(质量分数,下同)为25%时,浇注料的抗渣性能最好;加入过多的镁铝尖晶石和SiC对浇注料的抗渣性能不利,这主要同高温下材料中MgO-Al2O3-SiO2系低熔物的形成有关。  相似文献   

18.
    
A triazolotriazine carbonitrile ( 1 ) was formed by diazotization of 3‐amino‐5‐cyano‐1,2,4‐triazole followed by treatment with nitroacetonitrile. Cyclization of the C≡N bond with sodium azide results in a tetrazolyl triazolotriazine ( 2 ). Formation of the sodium salt of 2 , followed by metathesis with [PPN][Cl] resulted in the organic salt 3 . Compounds 1 , 2 , and 3 were characterized by elemental analysis and infrared, 1H, and 13C{1H} NMR spectroscopy and 1 and 3 were characterized by single‐crystal X‐ray diffraction. Compound 2 has a density of 1.819 g cm−1, is thermally stable up to 305 °C, and is insensitive to impact, friction, and electrical discharge. The detonation pressure and velocity of 2 are calculated to be 27.04 GPa and 8.312 km s−1, respectively, making this a 1,3,5‐triamino‐2,4,6‐trinitrobenzene (TATB) replacement candidate.  相似文献   

19.
    
1,1‐Diamino‐2,2‐dinitroethylene (FOX‐7) is a novel high‐energy insensitive material with good thermal stability and low sensitivity, and exhibits excellent application performance in the field of insensitive ammunitions and solid propellant. Although FOX‐7 is simple in molecular composition and structure, its chemical reactivity is abundant and surprising, including salification reaction, coordination reaction, nucleophilic substitution reaction, acetylate reaction, oxidizing reaction, reduction reaction, electrophilic addition reaction, among other reactions. These reactions are systemically summarized and some reaction mechanisms are analyzed in this review.  相似文献   

20.
    
The continued interest in improving the safety of munitions towards unintentional insults has led to a significant amount of research in the synthesis of new insensitive energetic compounds. This paper discusses various approaches to the synthesis of insensitive energetic compounds, theoretical modeling and correlations of structural properties that contribute to reducing the sensitivity of energetic compounds, and how synthetic chemists integrate theoretical predictions into the design and synthesis of new insensitive energetic compounds.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号