硝酸脲与黑索今混合炸药的制备及性能研究

为解决黑索今(RDX)生产工厂的废硝酸再利用问题,在RDX生产过程中不分离出RDX,而是直接加入一定量尿素水溶液,废硝酸与尿素反应生成硝酸脲后,使RDX和硝酸脲共同结晶,生成RDX与硝酸脲共结晶的混合炸药。得到两大类型的混合炸药:Ⅰ型混合炸药(含RDX 10%~20%)的综合爆炸性能优于现有的铵梯、乳化及粉状工业炸药;Ⅱ型混合炸药(含RDX 40%)的爆炸性能与TNT相当。该混合炸药的制造工艺简单,RDX生产过程的废酸污染问题得到了改善。     

RDX热分解研究

为了更加全面的探究黑索今(RDX)热安全性,利用绝热加热法及DSC-TG-DTG法两种实验方法分析了RDX的热分解过程。通过对比两种实验方法可以总结出RDX在密闭条件下热分解初始速度比在开放系统中低5.4℃,实验条件对分解过程及相关参数影响较大。     

Condensed combustion products of aluminized propellants. IV. Effect of the nature of nitramines on aluminum agglomeration and combustion efficiency

The condensed combustion products of two model propellants consisting of ammonium perchlorate, aluminum, nitramine, and an energetic binder were studied by a sampling method. One of the propellants contained HMX with a particle size D ₁₀ ≈ 490 μm, and the other RDX with a particle size _{D 10} ≈ 380 μm. The particle-size distribution and the content of metallic aluminum in particles of condensed combustion products with a particle size of 1.2 μm to the maximum particle size in the pressure range of 0.1–6.5 MPa were determined with variation in the particle quenching distance from the burning surface to 100 mm. For agglomerates, dependences of the incompleteness of aluminum combustion on the residence time in the propellant flame were obtained. The RDX-based propellant is characterized by more severe agglomeration than the HMX-based propellant — the agglomerate size and mass are larger and the aluminum burnout proceeds more slowly. The ratio of the mass of the oxide accumulated on the agglomerates to the total mass of the oxide formed is determined. The agglomerate size is shown to be the main physical factor that governs the accumulation of the oxide on the burning agglomerate. __________ Translated from Fizika Goreniya i Vzryva, Vol. 42, No. 4, pp. 78–92, July–August, 2006.     

Fe2O3-Al纳米铝热剂与超细RDX复合物的制备与性能

采用溶胶-凝胶方法,制备出了纳米铝热剂nano-Fe2O3-Al,并获得了其与超细RDX的复合含能材料nanoFe2O3-Al/SFRDX。采用BET法、SEM、XRD综合表征了nano-Fe2O3-Al的结构,采用TG/DSC联用技术测试了nano-Fe2O3-Al的热性能,结果表明气凝胶铝热剂的反应温度更低;nano-Fe2O3-Al的静电火花感度测试结果表明纳米铝热剂对静电十分敏感。对nano-Fe2O3-Al/SFRDX在无约束条件和密闭条件下的燃烧行为进行了研究,高速相机照片法发现在无约束条件下,nanoFe2O3-Al燃烧高达300 m/s,且nano-Fe2O3-Al/SFRDX具有在无约束条件下由燃烧转为爆轰的趋势。     

溶剂对RDX热分解的影响

用布氏压力计研究不同溶剂对溶液中RDX热分解的影响。影响分为加速、抑帛和无影响三种影响三种情况：在苯、萘、异辛烷中RDX热分解速率与熔融态一臻,这类溶剂对RDX热分解无影响;脂肪族芳香化合物,醚,酯,酮及醇能加速RDX热分解,粘度较大的化合物则抑制RDX热分解。     

纳米级RDX颗粒的制备

利用高速撞击法研究了纳米级黑索今(RDX)的制备。结果表明:采用高速撞击法可制备出粒度分布较窄的纳米级RDX颗粒,其粒径d50可细化到46.7 nm左右,其颗粒度分布宽度在0.6 nm范围内。     

RDX和HMX的大气压电喷雾电离质谱分析

用液相色谱-大气压电喷雾电离-质谱（LC-ESI-MS）联用技术分离检测RDX和HMX混合物。由反相高效液相色谱法在C18柱上分离了RDX和HMX,检测在225nm处进行,流动相为甲醇／水（V（甲醇）：V（水）=50：50）,流速为0．2mL／min。分析了影响结果的因素,研究了通过诱导碰撞裂解（CID）电压调节RDX和HMX特征碎片离子的毛细管出口（CapEx）电压、pH值、电离方式和干燥气体温度等对其质谱图的影响。结果表明,用负离子检测模式,当CapEx电压为-100V、pH值为8时,可以得到比较理想的质谱图,可观察到RDX和HMX分子离子峰[M-H]^-、加合离子[M-H＋H2O]、[M-H＋2H2O]^-、[M-H＋NO2]^-、[M-H＋62]^-和其他特征碎片离子。根据CID技术得到的RDX和HMX的分子离子,加合离子和特征碎片离子,易确定RDX和HMX的结构。     

几种多态含能材料构型转变的DFT研究

为了从分子层面上对含能材料不同分子构型间的转变情况有一个直观认识,借助Gaussian 09软件,运用密度泛函理论(DFT),采用TS算法搜寻β-RDX→α-RDX、γ-HMX→β-HMX、ε-CL-20→β-CL-20及β-FOX-7→α-FOX-7在分子构型转变过程中的过渡态结构,确定了它们的构型转变过程;并通过计算吉布斯自由能随构型转变路径的变化,比较多态含能材料分子构型转变的难易程度。结果表明,由亚稳晶型到稳定晶型的转变首先会越过过渡态,克服自由能能垒转变为亚稳态结构,实现β-RDX→α-RDX、γ-HMX→β-HMX、ε-CL-20→β-CL-20及β-FOX-7→α-FOX-7分子构型转变分别需要克服的自由能能垒分别为5.25、22.21、9.69和10.24kJ/mol。因此,常温常压下β-RDX→α-RDX、γ-HMX→β-HMX、ε-CL-20→β-CL-20及β-FOX-7→α-FOX-7构型转变的难度大小排序为:HMX>>FOX-7>CL-20>RDX。     

Removing low ppb level perchlorate, RDX, and HMX from groundwater with cetyltrimethylammonium chloride (CTAC) pre-loaded activated carbon

Perchlorate contaminates vast amounts of groundwater throughout the United States which could potentially be used as potable water. Activated carbon pre-loaded with cetyltrimethylammonium chloride has been shown in this research to be an effective adsorbent for removing perchlorate from three low conductivity (50-66 microS/cm) groundwaters containing perchlorate (ClO(4)(-)) concentrations of 0.85, 1.0, and 5.6 parts per billion (ppb), respectively. In rapid small-scale column tests (RSSCTs), the virgin granular activated carbon (GAC) (used as a control) treated between 20,000 and 40,000 bed volumes (BV) of water. In contrast, the activated carbon that was pre-loaded with CTAC processed 170,000-270,000 BV before perchlorate was detected above 0.25 ppb in the effluent. Though this pre-loading significantly increased the capacity for perchlorate, it also diminished the GAC's capacity to remove organics. The groundwater containing 1 ppb ClO(4)(-) also contained the nitro-organics HMX (0.6 ppb) and RDX (5.5-6.6 ppb). RDX was detected in the effluent from the CTAC-pre-loaded bed after only 8000 BV had been processed whereas 308,000 BV could be processed through the virgin bed before RDX was detected. Likewise, HMX breakthrough was observed after 116,000 BV in the CTAC-pre-loaded bed while the virgin RSSCT exhibited no breakthrough of HMX during a test that was operated for 309,000 BV. However, by combining a CTAC-pre-loaded bed followed by a virgin GAC bed in series, both perchlorate and RDX could be removed for the same length of time.     

膜状RDX/SiO_2传爆药的制备及表征

在SiO_2溶胶向凝胶转变过程中,依次加入RDX的N,N-二甲基酰胺(DMF)溶液和聚乙烯醇(PVA)的水溶液,采用提拉法和手工旋转涂抹法制备了白色、半透明、膜状RDX/SiO_2传爆药.扫描电镜(SEM)分析表明,复合粒子内RDX晶体呈球状、块状和条状,其三维尺寸在0.3~1.0 μm,分散在纳米SiO_2框架内;与相同条件机械掺杂的RDX-SiO_2相比,撞击、摩擦感度均显著降低.爆速测试结果表明,在低密度时,膜的厚度和炸药粒径是影响传爆性能的主要因素.