近红外光谱法测定HMX中α-HMX杂质晶型的含量

为了快速检测HMX中杂质晶型α-HMX的含量,在制备建模样品的基础上,利用近红外光谱技术,采用偏最小二乘法建立了HMX光谱与其α-HMX杂质晶型含量的计算模型。讨论了建模样品的代表性、模型光谱范围的选择及模型的优化过程。结果表明,模型具有广泛代表性,最佳光谱范围为6 476~6 446cm-1和4 602~4 424cm-1,交互验证决定系数(R2)为0.996,参考值交互验证残差均方根(RMSECV)为0.20%;外部验证的残差均方根(RMSEP)为0.27%;该法误差均小于0.13%,标准偏差为0.1%;近红外光谱法操作简单、快速、无损、绿色环保,可用于HMX中α-HMX杂质晶型含量的检测。     

近红外漫反射光谱法快速测定混合炸药组分含量

研究了近红外漫反射技术快速测定混合炸药组分含量的新方法.以偏最小二乘法建立了混合炸药中HMX(A)、复合黏结剂(氟橡胶B 塑料C)、聚四氟乙烯(D)、石蜡(E)5个组分的定标模型,并对模型进行了内部交互验证和外部检验.结果表明,5种模型准确度和精度较高,交互验证相关系数(R)为0.931 1～0.987 4,交互验证均方根(RMSECV)为0.100 ～0.582,预测标准偏差(SEP)为0.069～0.371;t检验也表明新方法与化学法无显著差异.新方法快速、无损,结果可靠.     

HMX含量实时检测NIRS模型的建立与优化

为实时检测尿素法生产HMX过程中HMX的含量,以生产过程为研究对象,采用偏最小二乘法建立了近红外光谱技术实时检测HMX含量的定量校正模型。通过实验对定量校正模型进行了验证。结果表明,该模型可以用于HMX含量的实时检测。通过用间隔偏最小二乘法初选建模区间,将初选区间及其组合与不同光谱预处理方法优选组合建模,得到最佳建模区间及其匹配的光谱预处理方法。结果表明,近红外光谱技术和光纤探头测试方式可用于实时检测HMX合成过程中HMX的含量。本研究优选出的最佳建模区间为5 000~4 750cm-1,最佳预处理方法为(1st+平滑)预处理法。     

HMX在二甲亚砜、丙酮和硝酸中溶解度的测定及关联

为验证并确定HMX溶解度摩尔分数的对数与对应绝对温度倒数的线性关系,采用常用的测定固体在液体中溶解度的实验装置,用静态平衡法测定293～363 K时HMX在二甲亚砜(DMSO)和质量分数68%硝酸中的溶解度以及273～328 K时在丙酮中的溶解度.然后用最小二乘法对HMX在不同温度下的溶解度数据进行关联,拟合出HMX在3种溶剂中溶解度与温度的线性方程,用其中一方程计算不同温度下HMX在DMSO中的溶解度,并与实测溶解度值进行比较,平均相对误差小于0.5%.此外,列出了溶解-结晶模型并界定了介稳区宽度.     

近红外漫反射光谱法测定硝化棉含氮量的数值模拟及实验研究

通过对107个硝化棉样品的近红外漫反射光谱及其含氮量参比值的研究,采用偏最小二乘法建立了测定硝化棉含氮量的数学模型。用t-对子检验对比了其与化学分析法的结果。结果表明,该模型的交互验证决定系数(R2)为0.998 1,交互验证残差均方根(RMSECV)为0.026%;外部验证的残差均方根(RMSEP)为0.023%。t-对子检验表明,近红外光谱法与化学分析法无显著差异。该方法将分析时间缩短到3min以内,可代替化学分析方法。     

纯度标准物质HMX的制备及均匀性检验

以工业特级品HMX为基体,研究了HMX的纯化工艺,制备出军用纯度标准物质HMX.考察了用不同溶剂重结晶对HMX纯度的影响,选择用两种重结晶方法、分三步操作纯化HMX:首先用二甲基亚砜作溶剂,80℃溶解HMX,趁热过滤除去无机杂质和机械杂质后,用溶剂-非溶剂沉淀技术使HMX结晶析出;第二步以乙腈为溶剂重结晶纯化HMX,HMX的纯度达到99.60%以上;最后用MOS级无水乙醇煮洗,进一步去除有机杂质和溶剂残留.液相色谱分析、X射线粉末衍射分析和均匀性研究结果表明,所制备的纯度标准物质HMX纯度不小于99.70%,晶型为β型并且均匀性良好.     

分子动力学法研究掺杂缺陷对HMX/NQ共晶炸药性能的影响

为了研究掺杂晶体缺陷对HMX/硝基胍(NQ)共晶炸药性能的影响,分别建立了"完美"型与含有掺杂缺陷的HMX/NQ共晶炸药模型;采用分子动力学方法,预测了各种模型的稳定性、感度、爆轰性能和力学性能,得到了不同模型的结合能、引发键键长分布、引发键键连双原子作用能、内聚能密度、爆轰参数和力学参数并与"完美"型模型进行了比较。结果表明,与"完美"型晶体相比,缺陷晶体的结合能减小幅度为1.28%～11.05%,表明分子之间的相互作用力减弱,炸药的稳定性降低;缺陷晶体的引发键键长增大幅度为0.46%～5.29%,而键连双原子作用能减小幅度为0.63%～17.24%,内聚能密度减小幅度为0.83%～10.85%,表明炸药的感度升高,安全性降低;缺陷晶体的密度、爆速和爆压减小幅度分别为0.89%～7.06%、0.68%～5.41%、1.85%～14.18%,表明威力与能量密度降低;由于晶体缺陷的影响,拉伸模量、体积模量和剪切模量减小幅度分别为0.106～4.368GPa、0.086～2.573GPa和0.082～1.835GPa,柯西压增大幅度为0.108～1.787GPa,表明炸药的刚性与硬度降低,延展性增强。因此,晶体缺陷会对HMX/NQ共晶炸药的稳定性、感度和爆轰性能产生不利影响。     

降感HMX的制备及性能测试

为了改善奥克托今(HMX)结晶形态并降低感度,以二甲基亚砜为溶剂,以水为非溶剂,以糊精为晶体控制剂,对普通HMX采用溶剂/非溶剂重结晶法处理,制备降感HMX。使用电子偏光显微镜、液相色谱仪分析测试了HMX重结晶前、后的晶体形貌和质量,表明重结晶后HMX的晶体颗粒更加规整圆滑,近似球形,并且纯度达到99.15%。撞击感度实验表明,重结晶后HMX的撞击感度比普通HMX降低32%。     

NTO包覆HMX的钝感研究

为降低HMX的机械感度并维持其爆炸性能,采用溶液重结晶法用较钝感的3-硝基-1,2,4-三唑-5-酮(NTO)包覆HMX,并测试了其机械感度和爆速。通过SEM观察了包覆HMX的粒径、形貌及包覆钝感的工艺条件。结果表明,包覆HMX的表面形态主要受水与N-甲基吡咯烷酮(NMP)体积比、搅拌速率和冷却速率的影响。当水和NMP体积比为5、搅拌速率为300r/min、冷却速率为6K/min时,包覆HMX的表面形态最好;以水和NMP为溶剂,包覆HMX的H50值提高了14.8cm,撞击感度降低了66%,且摩擦感度从100%降低至50%。包覆HMX的爆速降低了2.8%,基本可以维持爆炸性能不变。     

HMX/AP/Al/HTPB推进剂燃速模拟计算

考察了 HMX/AP/HTPB 推进剂及其组分的热分解特性,当混合氧化剂HMX 和 AP 之质量比为1:1时,其热分解曲线呈现出独特的单峰放热分解特征。考察了十种添加剂对 HMX、AP、HMX/AP 和 HMX/AP/HTPB 热分解性能影响以及对 HMX/AP/Al/HTPB 推进剂燃速的影响。提出了改进的 BDP 模型和燃速模拟计算。     

用LC/APCI/MS方法检测粉尘中的炸药成分

采用高选择性和灵敏度的LC(液相色谱)/APCI(大气压化学电离源)/MS(质谱)方法定量分析粉尘样品中的HMX、RDX、PETN、CE、NQ和TNT。采用ASE萃取,GPC净化浓缩作为前处理方法,在粉尘中分别添加所测炸药组分,用丙酮作为ASE萃取溶剂,乙酸乙酯和环己烷(体积比为1∶1)作为GPC净化时的流动相并抛弃杂质500s,收集1 520s。在LC/MS分析时,通过在流动相中添加1mmol/L甲酸与样品形成[M+HCOO]-的甲酸加合离子。结果表明,HMX、RDX、PETN、CE、NQ、TNT的方法检测限分别为0.78,1.44,1.69,0.77,1.06,1.72ng/mL,回收率为49.0%～88.4%,相对标准偏差为3.5%～10.3%。该方法可以用来系统排查及定量分析爆炸残留物及环境样品中的NQ、RDX、PETN、CE、HMX、TNT成分。     

Delay Mechanism of β→δ Phase Transition of Cyclotetramethylene Tetranitramine in Polymer Bonded Explosive Formulations by Heat Conduction Obstacle

The β→δ phase transition (PT) of cyclotetramethylene tetranitramine (HMX) plays an important role in the safety of explosives when they are exposed to heat. In this work the effect of HMX content on the PT of HMX in Polymer Bonded Explosive (PBX) is reported. Using in situ X‐ray diffraction (XRD) test combined with quantitative analysis, the dependence of the PT temperature and dynamic behavior of HMX in PBX formulations [HMX+triaminotrinitrobenzene (TATB)+Olefin] on the content of HMX is investigated. The results show that the β→δ PT temperature gradually increases with the reduction of HMX content and with the increase of TATB content. Additives of TATB and olefin in high concentration can form compact coatings on the HMX crystals. Such coatings can delay the nucleations of δ‐HMX by inhibiting the volumetric expansion during PT. Moreever, these coatings separate the HMX crystals and build up a heat conduction obstacle. As a result the growths of δ‐HMX are also suppressed by the coatings. In contrast, fewer additives lead to larger free surface area of HMX, which accelerates the PT.     

Encapsulation of Cyclotetramethylenetetranitramine (HMX) by Electrostatically Self‐Assembled Graphene Oxide for Desensitization

To improve the safety of cyclotetramethylenetetranitramine (HMX) particles, a novel strategy was developed for the fabrication of graphene oxide encapsulated HMX (HMX@GO) by electrostatic self‐assembly between graphene oxide and HMX particles. The prepared samples were characterized by optical microscopy, scanning electron microscopy, Raman spectroscopy, X‐ray photon spectroscopy, thermogravimetry, differential scanning calorimetry and water contact angle tests. The results revealed that GO sheets were coated densely and homogeneously on the HMX particles in a HMX@GO composite at a low GO content of about 0.23 wt %. Compared with that of raw HMX, the impact sensitivity of the HMX@GO composite decreased from 100 % to 30 %, and the 50 % probability of required ignition energy (E₅₀) in the electrostatic spark sensitivity test increased from 0.66 J for HMX to 1.12 J for the HMX@GO composite, suggesting that the electrostatically self‐assembled GO coating layer could obviously enhance the safety of HMX.     

HMX/ANPZO共晶炸药的制备及表征

运用分子动力学方法,计算了1,3,5,7-四硝基-1,3,5,7-四氮环杂辛烷(HMX)分子、2,6-二氨基-3,5-二硝基-吡嗪-1-氧(ANPZO)分子以及HMX/ANPZO共晶分子的分子间作用力、结合能和内聚能密度。通过气相扩散法制备了HMX/ANPZO共晶炸药,用红外光谱(IR)、差示扫描量热(DSC)和X射线衍射(XRD)表征了其结构,并测试了其机械感度。结果表明,HMX/ANPZO共晶分子间的相互作用力大于HMX分子间以及ANPZO分子间的相互作用力。与HMX和ANPZO相比,HMX/ANPZO共晶炸药的晶体结构和热分解特性变化较大,特性落高为59cm,与HMX相比提高了96.7%;理论爆速达9 060m/s。     

Effect of Drying Conditions on the Particle Size,Dispersion State,and Mechanical Sensitivities of Nano HMX

Nano HMX was prepared using a bi‐directional rotation mill and dried in different liquids, at various temperatures, and under different conditions. It was revealed that the samples were caked seriously and the particles tend to aggregate with obviously increased size when dried through ordinary drying in different liquids at 70 °C, which also occurred after vacuum drying. The degree of caking and aggregation was enhanced with increasing temperature. The particles were prevented to grow and the samples were fluffy when supercritical drying, particularly freeze drying, was used. The mechanical sensitivities of the samples marked with I‐HMX, O‐HMX, and F‐HMX, which had average sizes of 120.36 μm, 1.18 μm, and 0.16 μm, respectively, were carried out. Compared with I‐HMX, the friction, impact, and shock sensitivities of O‐HMX were slightly lower, and a significant sensitivity decrease for F‐HMX happened with specific values of 28 %, 42.8 %, and 56.4 %, respectively, which demonstrated significant safety improvement.     

Influence of Particle Size and Mixing Technology on Combustion of HMX/Al Compositions

In this work, two widely used components of high‐energy condensed systems – HMX and aluminium – were studied. Morphology, thermal behaviour, chemical purity and combustion parameters of HMX as a monopropellant and Al/HMX as a binary system were investigated using particles of different sizes. It was shown that in spite of the differences in composition and particle size, combustion velocities are almost identical for micrometer‐sized HMX (m‐HMX) and ultrafine HMX (u‐HMX) monopropellants under pressure from 2 to 10 MPa. Replacement of the micrometer‐sized aluminium with ultrafine one in the system with m‐HMX leads to a burning rate increase by a factor of 2.5 and the combustion completeness raise by a factor of 4. Two mixing techniques to prepare binary Al/HMX compositions were applied: conventional and ‘wet’ technique with ultrasonic processing in liquid. Applying wet mixing results in a burning rate increase of 18% compared to the conventional mixing for systems with ultrafine metal. The influence of the component's particle size and the composition microstructure on the burning rate of energetic systems is discussed and analysed.     

Micro Videographic Analysis of the Melt Layer of Self‐Deflagrating HMX and RDX

Micro videographic analysis of the thin molten layer on the surface of HMX (Octahydro‐1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocine) and RDX (Hexahydro‐1,3,5‐trinitro‐1,3,5‐triazine) during self deflagration were performed. This was done to gain a better understanding of the physical structure present in this 100–300 μm layer and give a visual picture for the development of computational models. During steady‐state combustion, RDX had a consistent melt layer with vigorous bubble formation. There was a continuous liquid layer throughout combustion and no foam was formed. The surface of HMX during steady‐state combustion at ambient initial temperatures was an uneven layer of foam. Foam appeared to convect across the surface in undulating waves. At elevated initial temperatures, the HMX molten layer was a consistent foam layer in both time and space. Micro videography was also done with a diagnostic laser sheet as illumination to measure the melt layer thickness. The RDX bubbling layer was about 217±30 μm thick. The HMX foam thickness varied from almost nothing to 660 μm, with an average value of about 234±106 μm.     

超临界水氧化处理HMX废水

实验在400～550℃的反应温度、22～25MPa的反应压力下对HMX炸药废水进行超临界水氧化技术处理,有机物COD去除率在99%以上。采用单因素法分析反应温度、压力、反应时间对超临界水氧化HMX废水的影响,确定超临界水氧化法处理HMX废水的最佳实验运行条件：反应温度500℃,压力为22.4MPa,反应时间为150s。通过液相色谱检测,得出主要污染物的去除率为99.88%。     

Study of the Desensitizing Effect of Different [60]Fullerene Crystals on Cyclotetramethylenetetranitramine (HMX)

Three types of [60]fullerene crystals were obtained. The first one was the direct commercial [60]fullerene, and the other two were recrystallized from the first one in carbon bisulfide and in carbon bisulfide/petroleum ether, respectively. Scanning electron microscopy (SEM), X‐ray powder diffractometry (XRD), and FT‐IR spectrometry were used to study the physical characteristics of the crystals. The thermal stability of the three [60]fullerene crystals was studied by differential thermal analysis (DTA), and the effects of the three [60]fullerenes on the mechanical sensitivity and friction sensitivity of HMX were tested and analyzed. It was found that the three types of [60]fullerenes have different thermal stabilities, and the friction and impact sensitivities of HMX are reduced from 100% to 70% and to 60%, respectively when 1% [60]fullerene 3 was added in HMX.     

Effect of Crystal Quality and Particle Size of HMX on the Creep Resistance for TATB/HMX Composites

Two kinds of reduced sensitivity high explosive 1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocane (RS‐HMX) with different particle sizes were selected to enhance the energy output and the mechanical properties of insensitive high explosive 1,3,5‐triamino‐2,4,6‐trinitrobenzene (TATB). Mechanical sensitivities, dynamic mechanical analysis, and non‐linear time dependent creep behaviors of TATB/HMX composites were investigated and discussed in relation to the structural characteristics. Compared with TATB/conventional HMX (C‐HMX) sample, both the impact and friction sensitivities of TATB/RS‐HMX were reduced. It revealed that TATB/fine grains RS‐HMX composites had the highest storage modulus and minimum steady‐state creep strain rate due to the increased coherence strength and the inhibited slide of the single layer of TATB crystal. The creep resistance also showed clear dependence on the particle size of RS‐HMX. The overall results indicated that RS‐HMX had good potential in high energetic, safe, and load‐bearing material applications.