A Novel Class of Nitrogen‐rich Explosives Containing High Oxygen Balance to Use as High Performance Oxidizers in Solid Propellants

In this study, density functional theory (DFT) calculations and the best available reliable predictive methods are used to assess performance, thermodynamics, physical and sensitivity of several high nitrogen content energetic tetrazole derivatives. Detonation pressure and velocity of these compounds are greater than 470 GPa and 10.2 km/s, respectively. Furthermore, suitable methods are used to study the condensed phase heat of formation, Gibbs free energy of formation, heat of sublimation, heat of combustion, melting point, enthalpy of fusion, entropy of fusion, specific impulse, Gurney velocity, strength, deflagration temperature, impact sensitivity and shock sensitivity of the novel compounds. The predicted results of the new compounds are compared with the calculated and experimental values of N,N‐bis(1H‐tetrazol‐5‐yl)amine (HTBA), dihydroxylammonium 5,5′‐bistetrazole‐1,1′‐diolate (TKX‐50) and 1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocine (HMX) as high performance energetic compounds.     

呋咱类含能化合物及其在推进剂中的应用

讨论了呋咱类含能化合物的分子结构特点和理化性质,综述了典型呋咱化合物即单呋咱、链状呋咱及大环呋咱、稠环呋咱的合成方法,总结了该类含能化合物在推进剂中的应用情况。认为呋咱类含能化合物由于其优良的性能。在推进剂中有广泛的应用前景。     

新型含能材料呋咱类化合物的研究进展

介绍了几种呋咱类含能化合物3,4–二氨基呋咱(DAF)、3,3′–二氨基–4,4′–氧化偶氮呋咱(DAAF)、3,3′–二氨基–4,4′–偶氮呋咱(DAAzF)、3,4–二硝基呋咱基氧化呋咱(DNTF)、3–硝基呋咱–4–甲醚(NFME)、(3 E,4 E)–二肟甲基氧化呋咱(DPX1)的合成方法和性能。通过与其他含能材料的性能对比,可知呋咱类化合物是一类性能优良、具有广阔应用前景、可应用于推进剂的含能材料。     

呋咱含能化合物的合成及其衍生物反应研究进展

阐述了二肟脱水和氧化呋咱还原2种构建呋咱环的主要方法,以及氨基取代呋咱衍生物、硝基取代呋咱衍生物和氰基取代呋咱衍生物的反应;列举了几种典型的呋咱含能化合物如二硝基呋咱(DNF)、二氨基偶氮呋咱(DAAF)、3,4–双(4′–硝基呋咱–3′–基)氧化呋咱(DNTF)、呋咱醚类化合物(FOF–1,FOF–2,FOF–13)和稠环类呋咱含能化合物(MNOTO、4,5,9,10–四硝基–1,4,5,8–四氮杂氢化萘(2,3,–6,7)并双呋咱)的合成方法及性能。     

Effects of an Organic‐inorganic Nanocomposite Additive on the Combustion and Erosion Performance of High Energy Propellants Containing RDX

A nanocomposite microsphere consisting of solid paraffin, nano‐TiO₂, nano‐BN, zeolitic imidazolate framework‐67 particles and polymethyl methacrylate was prepared and applied as a functional additive for high energy propellants (with about 23 wt % RDX) to reduce the barrel erosion and improve its combustion performance as well. High energy propellants modified with the nanocomposite were manufactured by a solvent extrusion technique. According to the scanning electron microscope and differential scanning calorimetry results, there exists a good compatibility between the nanocomposite and propellant matrix. The energy and combustion performance as well as erosion of the modified propellants were studied by a closed bomb test and an erosion tube device, respectively. Results showed that compared with the unmodified propellant, both the erosion and energy performance of modified high energy propellant gradually decreased with the increase of nanocomposites contents. When the content of nanocomposites was 5.1 %, the erosion mass of the modified propellant reduced to 37.0 % while the propellant force only decreased 5.7 %, indicating that the nanocomposite has enormous ability to improve gun erosion resistance while barely affect energy performance of propellant. Furthermore, the closed bomb burning curves of the samples showed that addition of nanocomposites to propellant matrix could prolong the combustion time, efficiently inhibit the initial generation rate of combustion gas, and further achieve the progressive burning of the propellants.     

高固体含量高强度丁羟推进剂工艺调节技术研究

阐述不同燃速的高固体含量高强度丁羟推进剂的工艺调节技术,研制出了中低燃速、中燃速和高燃速3种燃速范围,固体质量分数≥90%、20℃最大抗拉强度≥2.5MPa的丁羟推进剂配方,其工艺性能良好,并成功应用于高性能固体火箭发动机。     

Computational Studies on the Molecular Stability and Detonation Performance of Nitraminebenzene Derivatives as Novel High-Energy Materials

In this article the detonation performance and stability of the benzene derivatives were studied theoretically to facilitate further developments of energetic materials. The gas-phase heats of formation were calculated based on the isodesmic reaction. The solid-phase heats of formation and heats of sublimation were estimated in the framework of the Politzer approach. Molecular stability was calculated by bond dissociation energies and characteristic height. Detonation velocity and pressure were obtained according to Kamlet-Jacobs equations. The results show that all compounds have positive heats of formation, and compounds D1, D2, D3, E, and F have high detonation performance. In addition, the breaking of N?N bond may be initial step in initiation process. Furthermore, theoretical result suggestions that the most of derivatives have good thermal stability. These calculations could provide basic information that may prove useful for the molecular design of novel high-energy density materials.     

耐水抗渗型高性能盾构同步注浆材料性能研究

采用一种新型盾构注浆材料添加剂Z201,配制出耐水抗渗型高性能盾构注浆材料.研究膨润土、硅灰、甲基纤维素和聚丙烯酰胺掺量对盾构注浆材料初始流动度与经时流动度、初凝时间、泌水率、固结收缩率、抗压强度、抗渗性能和耐水性能的影响,并与掺Z201的注浆材料进行性能对比.试验结果表明,外掺10％ Z201的高性能盾构注浆材料流动度经时变化小,初凝时间短、泌水率低、固结收缩率小、抗压强度高、抗渗性能及耐水性能好.     

Study on the Synthesis and Interfacial Interaction Performance of Novel Dodecylamine‐Based Bonding Agents Used for Composite Solid Propellants

An effective pathway was explored to design and select proper bonding agents that could effectively improve the interfacial interactions between bonding agents and solid particles, with three novel synthesized alkyl bonding agents, dodecylamine‐N,N‐di‐2‐hydroxypropyl‐acetate (DIHPA), dodecylamine‐N,N‐di‐2‐hydroxypropyl‐hydroxy‐acetate (DIHPHA) and dodecylamine‐N,N‐di‐2‐hydroxypropyl‐cyano‐acetate (DIHPCA), as examples. Molecular dynamics simulation was applied to compare unit bond energies of these bonding agents with the [110] crystal face of ammonium perchlorate (AP) and the [120] crystal face of hexogen (RDX). The infrared test was used to characterize the interfacial interactions of these bonding agents with AP or RDX. XPS test was applied to calculate the adhesion percentage of the bonding agents on the surface of precoated AP or RDX particles. All of the above results indicated that these three bonding agents have strong interfacial interactions with AP or RDX in the order of DIHPCA>DIHPHA>DIHPA. The prepared three bonding agents were used in HTPB/AP/RDX/Al propellants, and their effects on tensile strength (σ), elongation under maximum tensile strength (ε_m), elongation at breaking point of the propellant (ε_b) and adhesion index (Φ) of the propellant were studied. The results show that the bonding agents improve the mechanical properties of the propellant in the order of DIHPCA>DIHPHA>DIHPA. The methods found from theoretical design, materials synthesis, and mechanistics studies up to practical application show effective guiding significance for choosing the proper bonding agent and improving the interfacial interactions between the solid particles and binder matrix.     

High nitrogen carbon material with rich defects as a highly efficient metal-free catalyst for excellent catalytic performance of acetylene hydrochlorination

In this work,we developed a simple strategy to synthesize a carbon material with high nitrogen and rich carbon defects.Our approach polymerized diaminopyridine(DAP) and ammonium persulfate(APS).Following a range of different temperature pyrolysis approaches,the resulting rough surface was shown to exhibit edge defects due to N-doping on graphite carbon.A series of catalysts were evaluated using a variety of characterization techniques and tested for catalytic performance.The catalytic performance of the N-doped carbon material enhanced alongside an increment in carbon defects.The NC-800 catalyst exhibited outstanding catalytic activity and stability in acetylene hydrochlorination(C_2 H_2 GHSV=30 h~(-1),at 220℃,the acetylene conversion rate was 98%),with its stability reaching up to 450 h.Due to NC-800 having a nitrogen content of up to 13.46%,it had the largest specific surface area and a high defect amount,as well as strong C_2 H_2 and HCl adsorption.NC-800 has excellent catalytic activity and stability to reflect its unlimited potential as a carbon material.     

Studies on Energetic Compounds Part 27: Kinetics and Mechanism of Thermolysis of Bis(Ethylenediamine)Metal Nitrates and Their Role in the Burning Rate of Solid Propellants

Four bis(ethylenediamine)metal(II) nitrate (BEMN) complexes, i.e. [M(EDA)₂](NO₃)₂, where M=Cu, Co, Ni and Zn, have been prepared and characterized. Thermolysis of these complexes induced by heat and drop‐weight impact has been investigated by TG‐DTG, DTA, explosion delay (D_E), explosion temperature (T_E) and impact sensitivity measurement. The kinetics of early thermolysis reaction prior to fast decomposition have been evaluated. Contracting area (CA, n=2) and contracting cube (CC, n=3) equations were found to give the best fits in isothermal TG data among all tested nine mechanism‐based kinetic models. The values of activation energy (E_a), T_E, D_E and activation energy for explosion (E*) have been found to be quite lower for the copper complex as compared to cobalt, nickel and zinc complexes. A mechanism of thermolysis has also been proposed. All these complexes were found to be insensitive towards impact of 2 kg weight up to the height of 110 cm. These complexes were used as energetic burning rate modifiers in the combustion of hydroxy‐terminated polybutadiene (HTPB)‐ammonium perchlorate (AP) composite solid propellants. A two‐fold increase in burning rate was observed with copper and cobalt complexes at low concentration (2% by wt.). The in situ freshly formed metal oxides with large number of active sites in their crystallites seem to be better additives for combustion of propellants.     

MIR/NIR/FIR Characterization of Poly‐AMMO and Poly‐BAMO and their Precursors as Energetic Binders to be Used in Solid Propellants

To establish the relation between structure and properties of composite solid propellants it is important to know the structure of the elastomeric binder that has been used in the system. Therefore this study is focused on the characterization of polymers containing energetic groups that has been synthesized at ICT. The characterization uses the wide spectral band of infrared, NIR/MIR/FIR. This gives an identification of the analytical bands and allows quantitative and kinetic studies of these compounds.     

高效液相色谱法同时测定牙膏中的维生素B_2、维生素B_3和维生素B_6

建立了同时测定牙膏中维生素B_2、维生素B_3和维生素B_6的检测方法。样品经水分散溶解后,用丙酮沉淀杂质,采用Waters T3色谱柱分离,HPLC测定,实验优化了沉淀剂的选择及用量等条件。结果表明,待测维生素在各自浓度范围内线性良好,相关系数均大于0.999,方法检出限在0.60~1.20 mg/kg之间,在高中低三个添加水平的平均回收率为95.0%~103.7%,相对标准偏差为1.67%~6.96%。该方法具有前处理简单、定量准确、灵敏快速的特点,适用于牙膏中维生素B_2、维生素B_3和维生素B_6的定量分析检测。     

甲型肝炎灭活疫苗(MRC-5细胞)中乙二胺四乙酸二钠残留量HPLC检测方法的建立及验证

目的 建立检测甲型肝炎(hepatitis A,HA)灭活疫苗(MRC-5细胞)中乙二胺四乙酸二钠(EDTA-2Na)残留量的HPLC 法,并进行验证.方法 色谱条件:选用反相色谱柱;流动相为水相-有机相,水相为四丁基氢氧化铵的磷酸盐溶液,有机相为乙腈;流速为1.0 mL/min;检测波长为257 nm;进样量为20 ...     

Analysis of Fluorescent Ceramide and Sphingomyelin Analogs: A Novel Approach for in Vivo Monitoring of Sphingomyelin Synthase Activity

A novel sensitive high‐performance liquid chromatography‐fluorescence detection (HPLC‐FLD) method was developed for real‐time monitoring of relative sphingomyelin synthase (SMS) activity based on the measurement of a fluorescent ceramide (Cer) analog and its metabolite, a fluorescent sphingomyelin (CerP Cho) analog, in plasma. Analyses were conducted using HPLC‐FLD following a protein precipitation procedure. The chromatographic separations were carried out on an Agilent C18 RP column (150 × 4.6 mm, 5 μm) based on a methanol—0.1 % trifluoroacetic acid aqueous solution (88:12, by vol) elution at a flow‐rate of 1 mL/min. The limit of quantification in plasma was 0.05 μM for both the fluorescent Cer analog and its metabolite. Significant differences in the fluorescent Cer analog and its metabolite concentration ratio at 5 min were found between vehicle control group and three D2 (a novel SMS inhibitor) dose groups (P < 0.05). Dose‐dependent effects (D2 doses: 0, 2.5, 5, 10 mg/kg) were observed. Our method could be used to detect relative SMS activity in biochemical assays and to screen potential SMS inhibitors in vivo. D2 was found to be a potent SMS inhibitor in vivo, and may have a potential antiatherosclerotic effect, which is under further study. D609 was also selected as another model SMS inhibitor to validate our newly developed method.