Na_2·cis-BNT和G_2·trans-BNT与几种含能材料相互作用的热分析

采用差示扫描量热法(DSC)并结合热重-微商热重法(TG-DTG)研究了双(3-(5-硝基-1,2,4-三唑))的钠盐(Na_2·cis-BNT)和胍盐(G_2·trans-BNT)与黑索金(RDX)、奥克托今(HMX)及3,3-双叠氮甲基氧丁环-聚叠氮缩水甘油醚共聚物(BAMO-GAP)的相容性,及混合物体系的热行为。初步探索了样品制备方法 (研磨法与溶剂法)对混合物体系相容性的影响。结果表明,对Na_2·cis-BNT、G_2·trans-BNT采用干法和湿法制备得到的混合体系相容性结果有一定差异。用干法制备二元体系时,Na_2·cis-BNT/RDX体系相容,Na_2·cis-BNT/HMX体系为轻度敏感,适合短期使用;而G_2·trans-BNT/RDX体系为敏感,不适合使用,G_2·trans-BNT/HMX体系为不相容;用湿法制备二元体系时,Na_2·cis-BNT与RDX、HMX、BAMO-GAP的混合物及G_2·trans-BNT与BAMO-GAP的混合物为相容,而混合物G_2·trans-BNT/RDX、G_2·trans-BNT/HMX为敏感,不适合使用。非均相过程分解的HMX混合体系相容性会受混合方式的影响,因此,由DSC法测定相容性时,制样的混合方法需要明确说明,并应当结合其他方法作最后判定。     

5,5′-偶氮四唑过渡金属含能配合物对RDX和HMX热分解行为的影响

用DSC研究了5种5,5′-偶氮四唑过渡金属配合物MATZ(H2O)n(M=Mn,Ni,Zn,n=6;M=Co,Pb,n=3;ATZ=5,5′-偶氮四唑离子)对RDX和HMX热分解行为的影响。用分解峰温、热爆炸临界温度等特征参数评价了含配合物的二元混合物与纯组分的热分解行为。结果表明,配合物对RDX的影响大于对HMX的。含配合物的二元混合物的热分解行为与纯组分的热分解行为类似,配合物的分解影响了RDX和HMX的热分解特征参数。     

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。     

Research on the Size of Defects inside RDX/HMX Crystal and Shock Sensitivity

Intragranular defects inside RDX/HMX were studied by optical microscopy with matching refractive (OMS), sink‐float method (SFM), and micro‐focus CT (μCT) techniques. OMS results revealed the phenomenon that RDX/HMX had more defects and cracks than RS‐RDX/RS‐HMX. μCT results indicated that RDX/HMX had more defects with larger volume than RS‐RDX/RS‐HMX. The gap test showed that critical shock pressure/gap thickness was 6.4 GPa/19.4 mm for PBX based on RDX, while they were 7.5 GPa/17.5 mm and 8.6 GPa/16.2 mm for PBX based on M‐RDX and RS‐RDX, respectively. Meanwhile, an analysis of the relationship between defects inside RDX/HMX crystal and shock sensitivity was made. Finally, the shock pressure response under impact loading was investigated by discrete element method.     

Determination and correlation solubility of m-phenylenediamine in (methanol,ethanol, acetonitrile and water) and their binary solvents from 278.15 K to 313.15 K

In this study, the solubility of m-phenylenediamine in four pure solvents(methanol, ethanol, acetonitrile and water) and three binary solvent(methanol + water),(ethanol + water) and(acetonitrile + water) systems were determined in the temperature ranging from 278.15 K to 313.15 K by using the gravimetric method under atmospheric pressure. In the temperature range of 278.15 K to 313.15 K, the mole fraction solubility values of m-phenylenediamine in water, methanol, ethanol, and acetonitrile are 0.0093–0.1533, 0.1668–0.5589,0.1072–0.5356, and 0.1717–0.6438, respectively. At constant temperature and solvent composition, the mole fraction solubility of o-phenylenediamine in four pure solvents was increased as the following order:water b ethanol b methanol b acetonitrile; and in the three binary solvent mixtures could be ranked as follows:(ethanol + water) b(methanol + water) b(acetonitrile + water). The relationship between the experimental temperature and the solubility of m-phenylenediamine was revealed as follows: the solubility of mphenylenediamine in pure and binary solvents could be increased with the increase of temperature. The experimental values were correlated with the Jouyban–Acree model, van't Hoff–Jouyban–Acree model, modified Apelblat–Jouyban–Acree model, Sun model and Ma model. The standard dissolution enthalpy, standard dissolution entropy and the Gibbs energy were calculated based on the experimental solubility data. In the binary solvent mixtures, the dissolution of m-phenylenediamine could be an endothermic process. The solubility data,correlation equations and thermodynamic property obtained from this study would be invoked as basic data and models regarding the purification and crystallization process of m-phenylenediamine.     

Stationary phases. Part 39(1): Trace analysis of RDX in HMX on a novel copoly(vinylthiazole-vinylimidazole) stationary phase by HPLC

A method for the HPLC analysis of RDX and HMX on a novel copoly(vinylthiazole-vinylimidazole) stationary phase [P(Th-Im) phase] is described. Special elution order of RDX and HMX on this phase using methanol/water (60/40∼90/10) as mobile phase is HMX > RDX, which is quite different from those on a commercial RP-18 phase. The chromatographic selectivities (α-values) between RDX and HMX are 2.40∼2.55. This advantage can be used to identify the limited impurity of ca. 1 ppm RDX in HMX during the manufacture of HMX.     

Anaerobic biodegradation of RDX and HMX with different co-substrates☆

Simulated wastewater of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) was treated under anaerobic conditions with co-substrates such as ammonium chloride, dex-trose, sodium acetic, sodium nitrate and sulfate. The results showed that with nitrogen compounds such as ammonium chloride added as co-substrate, no significant change was observed, indicating that the molar ratio of N/C for RDX and HMX is sufficient for biodegradation. With the addition of dextrose and acetate to the system, biodegradation efficiency was enhanced greatly. For example, with dextrose as the co-substrate, degradation efficiency of 99.1%and 98.5%was achieved for RDX and HMX, respectively, after treatment for 7 days. When so-dium acetic was used as the co-substrate, the enhancement of degradation percentage was similar, but was not as high as that with dextrose, indicating the selectivity of RDX and HMX to co-substrate during anaerobic degrada-tion. With sodium nitrate as the co-substrate, the degradation efficiency of RDX or HMX decreased with the increase of salt concentration. Sodium sulfate has no significant effect on the biodegradation of RDX and HMX. A wel-selected co-substrate should be employed in applications for degradation of RDX and HMX wastewaters.     

Effect of RDX and HMX on the Efficiency of Catalysts for Double–Base Propellant Combustion

High explosives (RDX or HMX) are added to double–base propellant formulations to improve their energy characteristics. The influence of these HE on the catalysis of propellant combustion practically has not been discussed in the literature. The present paper considers the role of RDX and HMX in the catalysis of double–base propellant combustion. Propellants having various compositions and energy characteristics were studied experimentally. It is established that RDX and HMX decrease the burning rate of double–base propellants (without catalysts) with moderate and high calorific values irrespective of their effect on the energy and combustion characteristic of the propellants. It is shown that if the burning rate of a propellant is affected by catalysts, the addition of RDX or HMX to this propellant (in excess of 100%) does not decrease the relative efficiency of catalysis but even increases it somewhat.     

二苯基亚砜在有机溶剂中的溶解度测定和拟合

在温度288.30～334.32 K、常压条件下,采用合成法测定二苯基亚砜在乙醇、乙酸乙酯、甲苯、丙酮、氯仿以及一系列浓度的乙醇-水混合溶剂中的溶解度。实验结果表明,在相同温度下,5种纯溶剂中二苯基亚砜的溶解度大小顺序如下,氯仿 > 丙酮 > 甲苯 > 乙酸乙酯 > 乙醇;乙醇-水混合溶剂中溶解度随着乙醇浓度下降而迅速降低;该溶解过程为吸热熵增过程,且随着溶解Gibbs斯自由能增大,溶解度减小。数据采用改进的Apelblat方程和van’t Hoff方程进行拟合,在乙醇-水混合溶剂中的溶解度数据还采用Jouban-Acree方程拟合。拟合结果与实验数据基本吻合。测定的固液平衡数据可为二苯基亚砜的合成与提纯等过程的溶剂选择提供依据。     

Solubility study for the purification of hydrogen from high pressure hydrocracker off-gas by an absorption-stripping process

Experiments were carried out to identify a solvent which has a high solubility and selectivity for methane relative to hydrogen at 295 K and pressures from 13.88 to 20.78 MPa. Binary solubilities with pure hydrogen and methane, and ternary solubilities with 73 mol% H₂ and 27 mol% CH₄ were measured at 295 K and for pressures from 6.99 to 20.78 MPa in various organic solvents. This gas mixture simulates hydrocracker and hydrotreater off-gases which are candidates for purification with an absorption-stripper. Of the solvents tested, 2,2,4-trimethylpentane (iso-octane), which showed very high methane solubility and a reasonable selectivity, and methylcyclohexane, which showed a very high selectivity and a reasonable solubility, are the best solvents for methane absorption. Correlations for hydrogen and methane as a function of pressure and solvent solubility parameter were developed with the experimental solubilities. Binary interaction parameters for Peng-Robinson (Peng and Robinson, 1976) and Soave-Redlich-Kwong (Soave, 1972) equations of state were calculated with experimental solubility results. Prediction of gas solubility in a ternary system was compared with experimental and found to be satisfactory when experimental binary interaction parameters were used.     

Partial Reparametrization of the BKW Equation of State for DNAN‐Based Melt‐Cast Explosives

DNAN‐based melt‐cast explosives are a type of new, insensitive munitions (IM) explosives. Quickly determining munitions’ explosive properties is extremely important during the formulation design stage. The aim of this study was to partially reparameterize BKW‐EOS (only β and κ were reparameterized on the basis of the parameters (α , β , κ , and θ ) of classical BKW‐RDX set and BKW‐TNT set) to more accurately predict the properties of DNAN‐based melt‐cast explosives. A new set of parameters β and κ was obtained (β =0.19, κ =9.81) according to measured detonation velocity and detonation pressure for ideal DNAN‐based melt‐cast formulations (DNAN/RDX and DNAN/HMX). For non‐ideal DNAN‐based melt‐cast formulations (DNAN/RDX/Al and DNAN/HMX/Al), aluminum oxidation degree was first determined according to the measured detonation heat; then, another new set of parameters β and κ was obtained in the same way as the ideal formulations (β =0.24, κ =8.5). The predicted detonation properties with BKW reparametrization for DNAN‐based melt‐cast explosives agreed with the measured data.     

热红联用研究AP与RDX和HMX混合体系的热分解

用DSC—TG—FTIR（热红）联用研究了RDX／AP，HMx／AP，RDx／HMx和RDX／HMX／AP混合体系的热分解，测定和比较了它们的热分析特征量和分解气相产物。结果表明，AP与RDX和HMX之间存在强烈的相互作用，尤其是与后者的作用更强烈。在AP（不含碳）分解的温度区间，混合体系的分解也出现CO、CO2和CH2O等碳氧化物，说明体系中RDX和HMX分解的部分产物或残渣与AP同时分解。     

含硝胺和铝粉的少烟改性双基推进剂表面和界面性能

研究了不同含氮量的硝化棉(NC)和不同粒度填料(Al、RDX和HMX)的表面性能,NC与填料之间的界面性能,以及表面和界面性能对含硝胺和铝粉的少烟改性双基推进剂力学性能的影响.结果表明,随着RDX、HMX以及A1粉粒度的减小,其表面张力逐渐增大,RDX、HMX与NC之间的界面张力随着RDX和HMX粒度或硝化棉含氮量的减...     

RDX和HMX的热分解III.分解机理

简述RDX和HM X热分解的各种机理,其热分解的初始过程是N-N和C-N键断裂的竞争反应,试验条件和样品相态等因素影响竞争过程。用DSC-FT IR联用技术和热裂解原位池/FT IR分析了主要分解气相产物和凝聚相中主要官能团的变化。结果表明,RDX和HM X热分解的主要分解气相产物为N2O,CH2O,CO,CO2,H2O和HCN。RDX的分解气相产物CH2O和H2O红外吸收率的温度关系曲线都产生双峰,RDX基团-NNO2的吸收带1 589 cm-1和1 278 cm-1有两个不同速率的变化过程。用N-N键和C-N键竞争断裂的观点解释了RDX与HM X热分析和产物分析的结果。     

Combustion mechanism of nitro ester binders with nitramines

The combustion of binary compositions of nitramines (HMX, RDX, Bi-HMX, and CL-20) with two nitro ester binders, one of which is characterized by gas-phase combustion, and the other by the burning-rate controlling reaction in the condensed phase, was studied in the pressure range 2–15 MPa. It is shown that in compositions with the binder characterized by gas-phase combustion, HMX in concentrations up to 50% acts as an inert additive. Depending on the size and concentration of HMX particles, three types of combustion of the mixtures can be identified: combustion along the binder layers, combustion as a single system, and the model of combustion with a coolant. At higher nitramine concentrations, combustion control passes to nitramine, and the burning-rate controlling reaction occurs in the liquid phase of nitramine. For Bi-HMX and CL-20 nitramines, which are less stable and more fast burning than HMX and in a mixture with a binder characterized by gas-phase combustion, only two combustion models are observed: the model with fast burning additives or combustion as a single unit. In compositions of the nitramines RDX and HMX with a binder burning by the c-phase mechanism, the combustion model with fast burning additives is applicable only in a narrow range of conditions. The compositions mostly burn only as a single unit, and the addition of nitramine increases the burning rate of nitro ester by transferring heat from the overlying zone to the condensed phase.     

The Decomposition of some RDX and HMX Based Materials in the One‐Dimensional Time to Explosion Apparatus. Part 1. Time to Explosion and Apparent Activation Energy

A One‐Dimensional Time to Explosion (ODTX) apparatus has been used to study the times to explosion of a number of compositions based on RDX and HMX over a range of contact temperatures. The times to explosion at any given temperature tend to increase from RDX to HMX and with the proportion of HMX in the composition. Thermal ignition theory has been applied to time to explosion data to calculate kinetic parameters. The apparent activation energy for all of the compositions lay between 127 kJ mol⁻¹ and 146 kJ mol⁻¹. There were big differences in the pre‐exponential factor and this controlled the time to explosion rather than the activation energy for the process.     

Degradation of TNT,RDX, and HMX Explosive Wastewaters Using Zero‐Valent Iron Nanoparticles

The high‐energy explosives 2,4,6‐trinitrotoluene (TNT), hexahydro‐1,3,5‐trinitro‐1,3,5‐triazine (RDX), and the high melting explosive octahydro‐1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocine (HMX) are common groundwater contaminants at active and abandoned munitions production facilities causing serious environmental problems. A highly efficient and environmentally friendly method was developed for the treatment of the explosives‐contaminated wastewaters using zero‐valent iron nanoparticles (ZVINs). ZVINs with diameters of 20–50 nm and specific surface areas of 42.56 m² g⁻¹ were synthesized by the co‐precipitation method. The explosives degradation reaction is expressed to be of pseudo first‐order and the kinetic reaction parameters are calculated based on different initial concentrations of TNT, RDX, and HMX. In addition, by comparison of the field emission scanning electron microscopy (FE‐SEM) images for the fresh and reacted ZVINs, it was apparent that the ZVINs were oxidized and aggregated to form Fe₃O₄ nanoparticles as a result of the chemical reaction. The X‐ray diffraction (XRD) and X‐ray absorption near edge structure (XANES) measurements confirmed that the ZVINs corrosion primarily occurred due to the formation of Fe₃O₄. Furthermore, the postulated reaction kinetics in different concentrations of TNT, RDX, and HMX, showed that the rate of TNT removal was higher than RDX and HMX. Furthermore, by‐products obtained after degradation of TNT (long‐chain alkanes/methylamine) and RDX/HMX (formaldehyde/methanol/hydrazine/dimethyl hydrazine) were determined by LC/MS/MS, respectively. The high reaction rate and significant removal efficiencies suggest that ZVINs might be suitable and powerful materials for an in‐situ degradation of explosive polluted wastewaters.     

EAK基熔铸分子间炸药的能量和撞击感度

通过水下爆炸试验研究了RDX和HMX对EAK基熔铸分子间炸药水下能量的影响。结果表明,RDX和HMX对EAK基混合炸药起到明显的增能作用,但对含铝和非含铝体系有不同的作用效果。爆速和撞击感度测定表明,EAK—RDX混合炸药爆轰的理想化程度和稳定性及撞击感度随RDX含量的增加而增加。从能量和撞击感度两个方面综合考虑,RDX的较佳加入量应为20％～30％。     

Optical Properties of Energetic Materials: RDX,HMX, AP,NC/NG,and HTPB

Optical properties of RDX, HMX, AP, HTPB/IPDI and a catalyzed NC/NG propellant (N5) were obtained from 2.5 μm to 18 μm using FTIR transmission spectrometry. Scattering-corrected KBr pellet methodology was used for the crystalline materials. Absorption index (k) was measured directly and refractive index (n) was deduced using dispersion theory. At 10.600 μm the absorption coefficients were AP, 190 cm⁻¹ (240 cm⁻¹ at 10.6036 μm); HTPB/IPDI, 360 cm⁻¹; N5, 510 cm⁻¹; RDX, 2800 cm⁻¹; and HMX, 5670 cm⁻¹.     

Measurement and correlation of solubility of xylitol in binary water+ethanol solvent mixtures between 278.00 K and 323.00K

The solubility of xylitol in ethanol+water solvent mixtures was measured at temperatures ranging from 278.00 K to 323.00 K at atmospheric pressure by using a laser technique. The results of these measurements were correlated by the combined nearly ideal binary solvent CNIBS/Redlich-Kister equation. The experimental solubility and correlation equation in this work can be used as essential data and models in the purification process of xylitol. The variant 2 in the CNIBS/R-K models was confirmed to be more adaptable to predict solubility of xylitol in binary ethanol +water system. Using the experimentally measured solubilities, the thermodynamic properties of dissolution of xylitol, such as Gibbs energy, molar enthalpy of dissolution, and molar entropy of dissolution, were calculated.