RDX和HMX机械刺激临界反应阈值试验研究

为了研究RDX和HMX在机械刺激下的临界反应阈值以及丙酮重结晶工艺对它们的影响，采用BAM撞击感度仪和摩擦感度仪测试了不同温度条件下的临界撞击能量和临界摩擦力。结果显示，80、60、40 ℃和25 ℃下，RDX的临界撞击能量分别为5.0、7.5、7.5、7.5 J，HMX的分别为4.0、4.0、5.0、5.0 J；RDX的临界摩擦力分别为120、120、128、144 N，HMX的分别为108、108、108、120 N。丙酮重结晶后，RDX在25 ℃的临界撞击能量和临界摩擦力分别为5.0 J、128 N；HMX在80、60、40 ℃和25 ℃下的临界撞击能量均为7.5 J，临界摩擦力分别为108、108、120、128 N。撞击感度和摩擦感度的结果表明:在25~80 ℃范围内，RDX和HMX的机械感度随着温度的提高呈下降趋势，重结晶工艺对RDX和HMX的机械感度存在着一定的影响。     

溶液法制备四氟硼酸锂的研究

采用溶液法工艺,以氢氟酸、硼酸和碳酸锂为原料,经液相反应、过滤分离、蒸发浓缩、结晶、分离、重结晶等工序,制备四氟硼酸锂。探讨各因素对产物纯度的影响,得到较佳工艺条件:氢氟酸:硼酸:碳酸锂=7.66∶1.85∶1、反应温度7.5℃、溶剂蒸发量70%、重结晶温度15℃。此工艺条件下得到的产物通过红外、XRD、差热和沉淀法分析,四氟硼酸锂纯度为98.84%。     

HMX丙酮溶液在不同升温速率下的热爆炸研究

为了解奥克托今(HMX)热分解过程及其在不同溶剂中热爆炸特性,使用DSC-TG同步热分析仪研究HMX的热分解过程。根据升温速率分别为5、10、15、20K/min的DSC和TG-DTG曲线,利用Ozawa法和Kissinger法计算了动力学参数,求得HMX的分解活化能分别为369.9 k J/mol和379.7k J/mol。用Rogers公式和Arrhenius公式求得指前因子A和速率常数k分别为4.70×1034s-1、7.48×10-16s-1(120℃)。HMX在升温速率为5 K/min时,分解峰值温度的活化焓、活化熵、活化自由能分别为370.2 k J·mol-1、405.39 J·K-1·mol-1、146.04 k J·mol-1;用小容量测试法研究25%质量分数的HMX丙酮溶液在不同升温速率(3、4、5、6℃/min)下的热爆炸特性。结果表明:在试验条件下,HMX丙酮溶液的临界爆炸温度,随着升温速率的增加而升高。     

重结晶制备超细HMX

叙述了溶剂-非溶剂法重结晶制备超细HMX.通过实验研究分析了单一改变重结晶过程中的温度、搅拌速度、溶液过饱和度等因素,对HMX晶体粒径的影响.采用粒度分析仪分析各影响因数水平下结晶体颗粒的大小,结果表明:随着重结晶过程温差越大HMX粒度越小;随着重结晶搅拌速度的增加,结晶晶体的粒径逐渐减小;随着溶液过饱和度的提高结晶体粒度越小,分布均匀;而且与溶剂的化学性质密切相关,其中温度对结晶颗粒粒径的影响最为明显.从而为制备超细HMX,进一步改善HMX化学性能提供相关资料.     

工艺参数对HMX基挤注炸药装药质量的影响

以92%(质量分数)高固相含量的HMX(奥克托今)基挤注炸药为研究对象,研究了挤注压力、真空度和水浴温度等对挤注炸药装药质量的影响,采用3因素3水平正交试验进行了影响显著性评价。结果表明,影响的显著性次序依次为:挤注压力真空度水浴温度。得到的最优工艺参数为:挤注压力15MPa、真空度-0.090MPa、水浴温度40℃,采用最优工艺参数制备的ECX-1炸药实际装药密度达到1.711g/cm~3(理论密度的97%以上)。     

基于分子动力学的DNAN基熔铸炸药结合能和热分解反应性能研究

采用Compass力场对DNAN基熔铸炸药的结合能、溶度参数进行分子动力学模拟。计算结果表明:DNAN/RDX混合体系的溶度参数大于DNAN/HMX混合体系的溶度参数;当RDX团簇和HMX团簇的直径均大于15×10^-10 m时,DNAN/RDX混合体系的结合能远大于DNAN/HMX混合体系的结合能。基于ReaxFF-lg力场的分子动力学计算方法,对目标温度为2 000~3 500 K时DNAN/RDX混合炸药的热分解反应进行研究。结果表明:DNAN分子和RDX分子在高温下的初始分解反应路径均会受到影响;除了两种组分的硝基官能团发生脱落形成硝基官能团的初始反应路径不会受到影响之外,DNAN分子生成CH₂O碎片、RDX分子生成HONO和C₃H₃N₃碎片的反应路径均会受到抑制。     

纳米HMX的制备及热性能分析和感度研究

采用机械球磨法批量制备了纳米奥克托今(HMX),用激光粒度仪分析其粒度分布,并用扫描电子显微镜(SEM)观察其大小和形貌;使用热重分析仪(TG)和差示扫描量热仪(DSC)分析其热分解特性和热安定性;同时对纳米HMX的5 s爆发点和感度进行了测试。结果表明,制备的HMX颗粒大部分在100 nm以下;与原料HMX相比,纳米HMX的最大热失重温度降低了3.66℃,表观活化能E a降低了11.19 kJ/mol,自发火温度降低了2.11K;5s爆发点降低了4.9℃,纳米HMX的静电感度和火焰感度与原料HMX相当,纳米HMX的摩擦感度、撞击感度和冲击波感度分别降低了32.5%、20.2%和56.4%。     

3,4-二硝基吡唑合成放大工艺研究

以吡唑为原料,经N-硝化、热重排、C-硝化等反应合成了3,4-二硝基吡唑(DNP)。进行了DNP的放大工艺研究,优化了硝化工艺条件,考察了C-硝化的工艺稳定性及重结晶溶剂苯甲腈的循环利用。研究发现:DNP较佳反应温度为55~57℃,反应时间45 min,收率86. 8%; DNP的放大硝化工艺具有较好的稳定性,重结晶溶剂可以循环利用5次以上,重结晶纯度99%以上。该放大合成工艺得到的DNP具有良好的物理化学性能,有望应用于混合炸药的研制。     

不同比例混合溶剂重结晶黑索金的热性能研究

本文利用超声辅助喷雾重结晶原理,以不同比例的二甲基亚砜和N,N-二甲基甲酰胺为混合溶剂,采用溶剂非溶剂法制备了亚微米RDX粒子.基于Kissinger法,使用差式扫描量热仪(DSC)研究了在不同比例的混合溶剂中细化得到的RDX粒子的热分解性能.结果表明:随着N,N二甲基甲酰胺在混合溶剂中的比例逐渐增加细化后的RDX的表观活化能逐渐降低;当N,N二甲基甲酰胺和二甲基亚砜的比例为4∶1作为溶剂细化的RDX热稳定性最差.     

RDX干燥过程影响因素的综合分析

对黑索今（RDX）干燥过程的影响因素进行了综合分析。通过单因素实验和正交实验,对影响RDX干燥过程的主要因素及其影响显著性进行了研究,得到干燥RDX的最佳干燥条件。干基含水量、真空度、温度对RDX干燥过程有重要影响,影响的显著性顺序为：温度的影响显著性强于真空度,更强于干基含水量。建议RDX的干燥条件是：温度80℃,真空度0．05MPa,干基含水量10％。     

HMX based enhanced energy LOVA gun propellant

Efforts to develop gun propellants with low vulnerability have recently been focused on enhancing the energy with a further improvement in its sensitivity characteristics. These propellants not only prevent catastrophic disasters due to unplanned initiation of currently used gun propellants (based on nitrate esters) but also realize enhanced energy levels to increase the muzzle velocity of the projectiles. Now, in order to replace nitroglycerine, which is highly sensitive to friction and impact, nitramines meet the requirements as they offer superior energy due to positive heat of formation, typical stoichiometry with higher decomposition temperatures and also owing to negative oxygen balance are less sensitive than stoichiometrically balanced NG. RDX has been widely reported for use in LOVA propellant. In this paper we have made an effort to present the work on scantily reported nitramine HMX based LOVA gun propellant while incorporating energetic plasticizer glycidyl azide polymer to enhance the energy level. HMX is known to be thermally stable at higher temperature than RDX and also proved to be less vulnerable to small scale shaped charge jet attack as its decomposition temperature is 270 degrees C. HMX also offers improved impulse due to its superior heat of formation (+17 kcal/mol) as compared to RDX (+14 kcal/mol). It has also been reported that a break point will not appear until 35,000 psi for propellant comprising of 5 microm HMX. Since no work has been reported in open literature regarding replacement of RDX by HMX, the present studies were carried out.     

The fate and transport of RDX, HMX, TNT and DNT in the volcanic soils of Hawaii: a laboratory and modeling study

The adsorption and degradation behavior of RDX, HMX, TNT and DNT and the impact of pH, ionic strength and dissolved organic matter on sorption were examined for two volcanic soils of a former military training area on Hawaii Island, Hawaii, USA. The transport of these chemicals in the soil was also studied in small packed columns and simulated using a water-flow and solute-transport model, HYDRUS_1D. The results show that HMX and RDX are both significantly more mobile than TNT and DNT. The adsorbability of the four chemicals was ranked as: RDXRDX>DNT>TNT. No significant trend was observed for the effect of ionic strength, pH and dissolved organic carbon (DOC) on the adsorption of explosive compounds within the concentrations and pH ranges evaluated. The simulation results show that TNT and DNT would not leach beyond a depth of 30cm soil profile whereas a significant amount of HMX and RDX would pass the 30cm depth. It seems that the risk for contamination of groundwater is much higher for both HMX and RDX than for DNT and TNT as the substratum in this area consists of highly permeable lavas.     

DFTNAN/DNTF二元相图及低共熔物熔融动力学研究

通过测定3,5-二氟-2,4,6-三硝基苯甲醚（DFTNAN）/3,4-二硝基呋咱基氧化呋咱（DNTF）二元混合体系熔融过程的差示扫描量热（DSC）特征量数据,建立了T-X和H-X二元相图,并获得了该混合体系低共熔物的组成和熔点。然后,研究了低共熔物以及熔点为80 ℃时混合物的黏度、机械感度和理论爆炸性能。分析了不同的升温速率和添加剂对低共熔物熔融过程的影响,并通过Sˇatava-Sˇesták、Coats-Redfern和通用积分方程获得了低共熔物熔融过程的动力学参数Ea、A和最概然机理函数。结果表明,由T-X相图和H-X相图计算得到的DFTNAN/DNTF低共熔物的组成m(DFTNAN)∶m(DNTF)分别为62.94∶37.06和62.88∶37.12,低共熔温度为63.84 ℃。调节DFTNAN和DNTF的比例,可使混合体系既达到熔铸工艺要求的工艺温度（≥80 ℃）,又能保持较高的能量水平和较低的感度。随着升温速率的提高,熔融反应起始温度和峰温发生相应的延后;添加HMX或RDX后,熔融起始温度发生较明显的后移;DFTNAN/DNTF低共熔物的熔融动力学参数Ea和lgA分别为32.95 kJ/mol和2.81,最概然机理函数为f(α)=(1-α)^2/3。     

Aqueous solubility and alkaline hydrolysis of the novel high explosive hexanitrohexaazaisowurtzitane (CL-20)

The recently developed polycyclic nitramine CL-20 is considered as a possible replacement for the monocyclic nitramines RDX and HMX. The present study reports aqueous solubility data for CL-20, as well as the kinetic parameters for its alkaline hydrolysis with sodium hydroxide below and above its solubility limits. Aqueous solubility of CL-20 was measured in the temperature range of 4–69 °C and the data were fitted to a generalized solubility model. Alkaline hydrolysis experiments were conducted at 15, 20, 30 and 40 °C, with hydroxide concentrations ranging from 0.25 to 300 mM. Like RDX and HMX, alkaline hydrolysis of CL-20 follows second-order kinetics. CL-20 alkaline hydrolysis was found to proceed at a significantly faster rate than RDX. The temperature dependency of the second-order rate constants was evaluated using the Arrhenius model. The activation energy for CL-20 was found to be within close range of the activation energies reported for RDX and HMX.     

二硝基乙腈钾与火药组分相容性的DSC法评估

为了了解二硝基乙腈钾(DNCK)与火药常用组分之间的相容性,采用差示扫描量热法（DSC）研究了DNCK与这些组分之间的相互作用。结果表明:DNCK与DAGR吸收药、DA吸收药、硝化棉（NC）、硝基胍（NQ）、叠氮硝胺（DIANP）、1,3-二甲基-1,3-二苯基脲（C2）、2-硝基二苯胺（2-NDPA）相容性良好;与六硝基六氮杂异戊兹烷（CL-20）和N 甲基-4-硝基苯胺（MNA）轻微敏感;与黑索今（RDX）、三羟甲基乙烷三硝酸酯（TMETN）和间苯二酚（Res）敏感;DNCK与奥克托今（HMX）和N-丁基硝氧乙基硝胺（BUNENA）混合体系的分解峰温较HMX和BUNENA单质组分分别提前了35.2 ℃和17.4 ℃,因此,与HMX和BUNENA不相容。     

不同加载压力下HMX基含铝炸药的冲击起爆特性

为了研究HMX基含铝炸药的冲击起爆特性,对其进行了两种加载压力下的冲击起爆试验。结果表明,加载压力为14.68 GPa时,其到爆轰距离为12.04~15.38 mm;加载压力为15.55 GPa时,到爆轰距离为10.23~12.01 mm;稳定爆轰后的爆轰压力约为25 GPa。基于圆筒试验确定了HMX基含铝炸药的JWL状态方程参数,结合两种加载压力下的冲击起爆试验结果进行数值模拟,标定并验证了点火增长模型反应速率方程参数。计算结果与试验结果一致。得到14.68 GPa加载压力下HMX基含铝炸药到爆轰时间为2.5 μs,到爆轰距离为13.70 mm;15.55 GPa加载压力下的到爆轰时间为1.9 μs,到爆轰距离为10.60 mm。计算结果表明,加载压力增大,前导冲击波速度增长变快,波阵面压力增长变快,炸药到爆轰时间与到爆轰距离减小,爆轰成长阶段同一时刻下的波阵面压力增长速率也随之增大。     

Evaluation of a TiO2 photocatalysis treatment on nitrophenols and nitramines contaminated plant wastewaters by solid-phase extraction coupled with ESI HPLC–MS

Nitration reactions of aromatic compounds are commonly involved in different industrial processes for pharmaceutical, pesticide or military uses. For many years, most of the manufacturing sites used lagooning systems to treat their process effluents. In view of a photocatalytic degradation assay, the wastewater of a lagoon was investigated by using HPLC coupled with mass spectrometry. The wastewater was highly concentrated in RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine), HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) and two herbicides Dinoterb (2-tert-butyl-4,6-dinitrophenol) and Dinoseb (2-sec-butyl-4,6-dinitrophenol). First of all, an analytical method using solid-phase extraction (SPE) combined with HPLC ESI MS/MS was put in work for identification and titration of RDX, HMX and the two dinitrophenols in a complex natural matrix. Then, the UV/TiO₂ treatment was investigated for pollutants removal. Dinitrophenolic compounds were significantly degraded after a 8-h-exposition of the wastewater/TiO₂ suspension, whereas RDX and HMX were poorly affected.