分子动力学方法在火炸药研究中的应用进展

概述了国内外分子动力学方法在单体炸药、混合炸药和固体推进剂研究中的应用进展,并分析了在应用中存在的问题以及发展前景,为该领域科研人员利用该方法开展火炸药研究提供参考。     

国外六硝基六氮杂异伍兹烷的发展现状

综述了国外合成六硝基六氮杂异伍兹烷(CL-20)方法及美国、法国、日本等国家的工业化生产能力.介绍了CL-20在高性能炸药、固体推进剂和发射药配方中的应用情况,包括LX-19、PAX-12、PAX-11、PAX-29、DLE-C038和PBXW-16等CL-20基炸药.附参考文献21篇.     

国外六硝基六氮杂异伍兹烷的发展现状

综述了国外合成六硝基六氮杂异伍兹烷（CL-20）方法及美国、法国、日本等国家的工业化生产能力。介绍了CL-20在高性能炸药、固体推进剂和发射药配方中的应用情况，包括LX～19、PAX-12、PAX-11、PAX-29、DLE—C038和PBXW-16等CL-20基炸药。附参考文献21篇。     

金属氧化物对HNIW单元推进剂燃烧的催化研究

对六硝基六氮杂异伍兹烷 (HNIW)的催化燃烧进行了初步的实验探讨 ,实验结果表明 ,HNIW单元推进剂的燃烧速度是 HMX单元推进剂燃烧速度的 2倍左右 ,HNIW单元推进剂的燃烧速度随着压力的增加而直线增加 ,其燃速压力指数为 0 .846 ,通过加入金属氧化物可使 HNIW单元推进剂的燃烧速度发生变化 ,但对其燃速压力指数影响不大     

二硝酰胺铵在火炸药中的应用

综述了新一代氧化剂二硝酰胺铵盐(ADN)在固体推进剂、炸药及发射药中的应用研究进展,认为ADN是替代推进剂中过氯酸铵氧化剂的最佳侯选物。提出了优化工艺、降低成本、改进ADN稳定化和球形化技术以及ADN应用方面的建议。     

六硝基六氮杂异伍兹烷降感技术研究进展

六硝基六氮杂异伍兹烷(HNIW,CL-20)是一种高能量密度新型含能材料,在单质炸药、混合炸药以及推进剂等方面有着广泛的应用前景。但是CL-20感度较高的特点限制了其进一步推广应用,对CL-20晶体进行晶体修饰处理可以有效地降低其感度。概述国内外CL-20晶体修饰降低感度技术研究进展,总结了共结晶和核壳结构包覆两种主要的晶体修饰降感方法,并对不同方法降感机理进行分析。对共结晶和核壳结构包覆这两种降感方法的研究现状进行梳理并对降感效果进行了总结和对比,最后分析该领域的研究趋势。     

含能添加剂对含NNHT的CMDB推进剂能量特性影响

利用能量计算程序计算了含高氮化合物2–硝亚胺基–5–硝基–六氢化–1,3,5–三嗪(NNHT)的复合改性双基(CMDB)推进剂(NNHT–CMDB推进剂)的能量特性,并研究了分别用含能添加剂黑索今(RDX)、六硝基六氮杂异伍兹烷(HNIW)和铝粉部分取代NNHT–CMDB推进剂中的NNHT对推进剂能量特性的影响规律。结果表明:无论推进剂中是否含铝粉,NNHT含量增加,将不同程度地降低原CMDB推进剂的各能量特性参量;与RDX相比,HNIW与NNHT搭配使用效果更佳,原NNHT–CMDB推进剂的标准理论比冲提高十分明显;当m(NNHT)∶m(HNIW)=18∶20时,推进剂的标准理论比冲高于含质量分数26%RDX的RDX–CMDB推进剂;当NNHT与HNIW质量比值不变时,含铝推进剂的各能量特性参量明显高于无铝推进剂;添加HNIW后,10 MPa时,NNHT–CMDB推进剂的标准理论比冲分别可达到253.4 s(无铝)和261.9 s(含铝质量分数5%)。     

开展高能固体推进剂危险性分级研究的建议

高能固体推进剂中含有大量高能单质炸药，必须充分考虑其在制造、贮存、运输、使用等过程中的安全性。介绍了国外爆炸品的危险性分级方法，分析了国内的有关规定，提出了开展我国高能固体推进剂危险性分级研究的建议。     

无氯氧化剂在洁净固体推进剂中的应用

为满足目前固体火箭推进剂在应用过程中产生的环境相容性要求,对几种无氯氧化剂在洁净固体推进剂中的应用进行了综述。针对固体推进剂燃烧产物中HCl对环境产生的危害,分析了几类推进剂的抑氯机理,并着重从氧化剂的角度介绍多种无氯高能氧化剂在固体推进剂中的应用,分析了无氯氧化剂的特点及在推进剂应用过程中面临的问题,提出了洁净固体推进剂的重点研究方向,促进洁净固体推进剂的广泛应用,降低HCl对环境的危害。     

一种新型含能材料——叠氮有机化合物

介绍叠氮有机化合物作为含能粘合剂、含能增塑剂、高能氧化剂及其它含能添加剂在枪炮发射药、固体推进剂及高能炸药等含能材料中的应用。     

Theoretical Studies on PNMFIW by AM1 and PM3 Methods

AM1 and PM3 semi‐empirical methods were used to conduct theoretical studies on possible polymorphs of pentanitromonoformylhexaazaisowurtzitane (PNMFIW), and a close link between PNMFIW and Hexanitrohexaazaisowurtzitane (HNIW), especially in sensitivity, is shown. The optimized geometries of possible polymorphs of PNMFIW are similar to those of HNIW. PNMFIW in ε‐HNIW prepared from tetraacetyldiformylhexaazaisowurtzitane is predicted to have a D‐form. The average N N bond lengths of PNMFIW computed by AM1 and PM3 methods are shorter than those of HNIW. The differences in energy and thermochemistry values between PNMFIW and HNIW are insignificant except molecular energies 255.75 kJ⋅mol⁻¹ for D‐form PNMFIW and 460.36 kJ⋅mol⁻¹ for ε‐HNIW. Based on a Mulliken population analysis of the N N bonds, the impact sensitivities of A‐, B‐, C‐ and D‐forms of PNMFIW are estimated to be lower than those of the corresponding polymorphs of HNIW. Taking into account all N N bond lengths and overall molecule size, the shock sensitivities of all forms PNMFIW are predicted to be almost the same, and lower than those of HNIW.     

Dissociation Mechanism of HNIW Ions Investigated by Chemical Ionization and Electron Impact Mass Spectroscopy

Chemical Ionization (CI) with Collision‐Induced Dissociation (CID) spectroscopy and Electron Impacting (EI) with metastable Mass analyzed Ion Kinetic Energy (MIKE) spectroscopy have been applied to study ionic dissociations of Hexanitrohexaazaisowurtzitane (HNIW). Similarities and differences between EI/MIKE and CI/CID mass spectra of HNIW were analyzed. In EI mass spectra, the ions [HNIW−n NO₂]⁺ (n=2–5), such as the ion at m/z 347, were less frequent (1–2% relative abundance), but in CI mass spectra, these ions were very abundant. For some ions of large molar mass from HNIW, their dissociations pathways from parent ions to daughter ions were built according to CID and MIKE spectra. Molecular ions of HNIW with a protonated nitro group at five‐member ring seem more stable than at six‐member ring. The HNIW ions losing five of six nitro groups are very stable based on CID spectra, which agrees with some research results for thermal decomposition of HNIW in literature.     

Effects of Additives on ε‐HNIW Crystal Morphology and Impact Sensitivity

Crystals of γ‐HNIW were transformed into crystals of ε‐HNIW by application of a drowning‐out process in the presence of different additives, namely ethylene glycol, triacetin, and aminoacetic acid. They show different effects on the crystal morphology of ε‐HNIW and cause less angular and more regular structures. Investigation of the sensitivities of the different ε‐HNIW crystals shows that their angles and regularity have an influence on the impact sensitivity. Aminoacetic acid selectively inhibits the growth of individual ε‐HNIW crystal faces to modify the morphology into spherical shape, these ε‐HNIW crystals are of much lower sensitivity, even compared with general RDX and HMX explosives.     

Preparation and Performance of a HNIW/TNT Cocrystal Explosive

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.     

Attractive Nitramines and Related PBXs

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.     

不同结晶体系中PNMAIW对HNIW转晶影响的理论研究

为了从理论上揭示五硝基-乙酰基六氮杂异伍兹烷(PNMAIW)对六硝基六氮杂异伍兹烷(HNIW)转晶的影响,采用分子模拟的方法,设计了PNMAIW的稳定构型,分别研究了硝酸-水体系、乙酸乙酯-正己烷体系和乙酸乙酯-三氯甲烷体系中PNMAIW对HNIW转晶的影响.结果表明,PNMAIW存在4种稳定构型;由于PNMAIW与HNIW各面的键合能远大于溶剂和非溶剂与HNIW各面的键合能,因此,如果转晶体系中存在杂质PNMAIW,PNMAIW更容易接近HNIW的晶面,从而阻碍HNIW在溶液中的转晶.     

高能量密度化合物——六硝基六氮杂异伍兹烷合成研究最新进展

１９８７年由美国Ａ．Ｔ．Ｎｉｅｌｓｅｎ首次合成的六硝基六氮杂异伍兹烷（ＨＮＩＷ）,是当前密度和能量水平最高的高能量密度化合物（ＨＥＤＣ）,被誉为明天的高能炸药,并受到世界各国的普遍关注。本文综述近３年ＨＮＩＷ合成研究的最新进展,包括六苄基六氮杂异伍兹烷（ＨＢＩＷ）的合成、ＨＢＩＷ的脱苄、ＨＮＩＷ的合成及ＨＮＩＷ的转晶等几方面。目前制造ＨＮＩＷ的工艺已日趋成熟,且多有创新,ＨＮＩＷ的生产成本已大幅度下降。     

笼形含能化合物HNIW的结构与性能研究

根据Ｘ射线单昌衍射测定六硝基六氮杂异伍北钾种晶型的结构数据,在ＲＨＦ水平上,分别应用ＡＭ１和ＰＭ３量子化学半经验分子轨方法,对这四种晶型进行行全参数优化,并从计算的生成热,偶极矩,ＨＯＭＯ和ＨＵＭＯ轨道能级之间的差值△Ｅ,预测ＨＮＩＷ的某些性能和电子结构。     

Preparation of ε‐HNIW by a One‐Pot Method in Concentrated Nitric Acid from Tetraacetyldiformylhexaazaisowurtzitane

ε‐HNIW was prepared by a one‐pot method in concentrated nitric acid from tetraacetyldiformylhexaazaisowurtzitane (TADFIW). γ‐HNIW was firstly obtained, then γ‐HNIW was directly transformed to ε‐HNIW in the solution in which nitration reaction occurred. The acid number of ε‐HNIW prepared by the method mentioned above is less than 0.2‰, yield of ε‐HNIW is up to 91%, and the purity of ε‐HNIW is up to 99.5%. Because steps of filtration and drying of γ‐HNIW were omitted, the process by which ε‐HNIW was prepared simplified greatly.     

Quantitative Determination of ε‐phase in polymorphic HNIW using X‐ray Diffraction Patterns

An X‐ray diffraction method was applied for the quantitative determination of the ε‐Hexanitrohexaazaisowurtzitane (HNIW) in polymorphs of HNIW. The XRD patterns of four polymorphs illustrate the unique nonoverlapping peak at 19.9° which belongs to ε‐HNIW. The intensity ratio of the peak at 19.9° of ε‐HNIW to the peak at 79.6° of α‐Al₂O₃ is proportional to the weight ratio of standard ε‐HNIW to the internal standard of α‐Al₂O₃, which enables the internal standard method. When the particle size of the sample is less than 10 μm, the content of ε‐HNIW ranging from 70 to 100 wt.‐% can be determined with an absolute error below 2.0%.