以温度为函数的硝仿系炸药的爆发分解反应动力学参数

用爆发点试验装置测定了6种硝仿系炸药:2,2,2-三硝基乙基-N-硝基-甲胺(TNMA)、二(2,2,2-三硝基乙基-N-硝基)乙二胺(BTNEDA)、4,4,4-三硝基丁酸-2,2,2-三硝基乙酯(TNETB)、二(2,2,2-三硝基乙醇)缩甲醛(BTNF)、1,1,1,3-四硝基丙烷(TETNP)和二(2,2,2-三硝基乙基)硝胺(BTNNA)在不同温度下的爆发延滞期.依据谢苗诺夫方程lnt_(lag,i)=E_α/RT_i-lnA_α,由lnt_(lag,i)对1/T_i的关系,用作图法和最小二乘法计算了爆发分解反应的表观活化能(E_α)、指前因子(A_α)和5 s爆发点.用非线性等转化率积分法所得的表观活化能(E_α)校验了由lnt_(lag,i)～1/_Ti关系得到的Eα值.借助热力学关系式,计算了爆发分解反应的活化热力学参数[活化自由能(ΔG≠),活化焓(ΔH≠)和活化熵(ΔS≠)].结果表明: (1) E_α和作图法所得E_α间的相对误差在±5%以内; (2) E_α与最小二乘法所得E_α相等的事实佐证了不同温度下爆发分解反应延滞期内的分解深度是相等的,所得E_α和A_α值是可接受的,谢苗诺夫方程推导过程中采用A_α>>G(α)的假设是合理的; (3) 以5 s爆发点和ΔG~#为判据,6种硝仿系炸药对热抵抗能力的次序为:TNETB＞BTNF＞BTNEDA＞TETNP＞TNMA＞BTNNA.     

2,5,7,9-四硝基-2,5,7,9-四氮杂双环[4,3,0]壬酮-8的放热分解反应动力学

在程序升温条件下,用DSC研究了2,5,7,9-四硝基-2,5,7,9-四氮杂双环[4,3,0]壬酮-8的放热分解反应动力学参数.表明该反应的微分形式的动力学模式函数、表观活化能(Ea)和指前因子(A)分别为3(1-α)[-ln(1-α)](2)/(3), 204.7 kJ/mol 和 1020.89 s-1.该化合物的热爆炸临界温度为188.81℃.反应的活化熵(ΔS≠)、活化焓(ΔH≠)和活化自由能(ΔG≠)分别为141.6 J/(mol*K), 200.9 kJ/mol 和136.8 kJ/mol.     

Studies on the critical temperature of thermal explosion for 3-Nitro-1,2,4-triazol-5-one (NTO) and its salts

The critical temperature of thermal explosion for 3-nitro-1,2,4-triazol-5-one (NTO) and its ethylenediammonium salt (ENTO), potassium salt (KNTO), copper salt (CuNTO) and lead salt (PbNTO) were obtained using the stationary theory of thermal explosion, the calculation formula of estimating the critical temperature of thermal explosion under non-isothermal DSC condition, and the determination method for the critical temperature of thermal explosion of small-scale solid explosive and its data treatment method. The results of the four methods are agreeable to each other, whose differences are within 5%. The results indicate that the heat-resistance ability of NTO and its salts and of the common explosives, cyclotetramethylenetetranitramine (HMX), cyclotrimethylenetrinitramine (RDX), pentaerythritoltetranitrate (PETN) and tetryl decreases in the order HMX > NTO > ENTO > KNTO > RDX > PETN > tetryl > PbNTO > CuNTO.     

高聚物粘结炸药平面应变断裂韧度实验研究

介绍了高聚物粘结炸药平面应变断裂韧度 K1c的测试方法 ,对三种高聚物粘结炸药 JOB- 90 0 3、JO- 915 9、JB- 90 14在常温下的K1c值进行了测试。测试结果分别为 :0 .2 4± 0 .0 1MPa·m1/ 2、0 .17± 0 .0 1MPa· m1/ 2、0 .37± 0 .0 1MPa·m1/ 2 ,显示出 JB- 90 14具有相对较强的抗裂纹扩展能力。文章同时讨论了三种高聚物粘结炸药 K1c值与其常规力学性能如拉伸应力应变曲线、蠕变曲线测试结果的一致性 ,还从材料组成的角度 ,分析揭示了 JB- 90 14具有较大 K1c值的主要原因在于 JB- 90 14所用粘结剂为 F2 314     

含能配合物的研究进展

含能配合物是开发具有钝感、含能、环保材料的一个重要发展方向。概述了以高能多氮直链化合物如碳酰肼,富氮杂环化合物如三唑、四唑类为配体的配合物的合成、热行为以及性能的研究情况,同时简要地从分子或原子结构描述了一些其他多氮含能配体如肼、肼基甲酸甲酯等所形成的配合物的晶体结构以及热分解行为,并对含能配合物的发展方向进行了展望。     

NTO及其盐的制备、表征与应用(续)

2．2．2晶体结构 杨利等人、冯长根等人、马海霞等人对制备的NTO胺盐的晶体结构进行了研究,确定了它们的分子结构和晶体学参数,李加荣对一些早期的研究成果进行了概述,结果见表12。研究表明：目前制备出的NTO胺盐全部为离子型化合物,除ANTO和GNTO各含1分子结晶水外,其他NTO胺盐均不含结晶水。     

Thermal Decomposition of NTO: An Explanation of the High Activation Energy

Burning rate characteristics of the low‐sensitivity explosive 5‐nitro‐1,2,4‐triazol‐3‐one (NTO) have been investigated in the pressure interval of 0.1–40 MPa. The temperature distribution in the combustion wave of NTO has been measured at pressures of 0.4–2.1 MPa. Based on burning rate and thermocouple measurements, rate constants of NTO decomposition in the molten layer at 370–425 °C have been derived from a condensed‐phase combustion model (k=8.08⋅10¹³⋅exp(−19420/T) s⁻¹. NTO vapor pressure above the liquid (ln P=−9914.4/T+14.82) and solid phases (ln P=−12984.4/T+20.48) has been calculated. Decomposition rates of NTO at low temperatures have been defined more exactly and it has been shown that in the interval of 180–230 °C the decomposition of solid NTO is described by the following expression: k=2.9⋅10¹²⋅exp(−20680/T). Taking into account the vapor pressure data obtained, the decomposition of NTO in the gas phase at 240–250 °C has been studied. Decomposition rate constants in the gaseous phase have been found to be comparable with rate constants in the solid state. Therefore, a partial decomposition in the gas cannot substantially increase the total rate. High values of the activation energy for solid‐state decomposition of NTO are not likely to be connected with a sub‐melting effect, because decomposition occurs at temperatures well below the melting point. It has been suggested that the abnormally high activation energy in the interval of 230–270 °C is a consequence of peculiarities of the NTO transitional process rather than strong bonds in the molecule. In this area, the NTO molecule undergoes isomerization into the aci‐form, followed by C3‐N2 heterocyclic bond rupture. Both processes depend on temperature, resulting in an abnormally high value of the observed activation energy.     

三唑类抗真菌药-氟康唑的研究进展

氟康唑是三唑类抗真菌药物,对于治疗深部真菌感染有显著疗效,毒副作用小,临床应用广泛。本文从氟康唑的抗真菌作用机制,药物动力学,临床应用范围,不良反应及氟康唑衍生物的合成等方面的研究进展进行了综述。     

基于顶盖举起试验的炸药内爆炸性能评估

为了评估炸药在密闭/半密闭结构内的爆炸性能,通过自建的顶盖举起试验装置对5种典型炸药装药进行了内爆炸试验,利用冲击波超压和顶盖的举起位移评估了其内爆炸威力。结果表明,冲击波超压高的炸药,内爆炸性能不一定好,炸药的空中爆炸性能与内爆炸性能具有显著的差异;顶盖举起最大位移与炸药的非同步自氧化燃烧热具有线性关系,关系式为xmax=17.717ΔHas-5.322,相关系数R2=0.991 7;内爆类炸药应具有高燃烧热、高非同步自氧化燃烧热和适中的爆速。     

Influence of experimental variables on thermally stimulated recovery results: analysis of simulations and real data on a polymeric system

Thermally stimulated recovery (TSR) is a low frequency mechanical spectroscopy technique that allows investigation of conformational mobility in polymeric systems. In this study the effect of initial parameters chosen to perform experiments on the TSR response of a material in the thermal sampling mode is investigated. The studied experimental parameters are creep time (t_σ) recovery time (t_r) and window width (ΔT_w); all are independently changed at one constant creep temperature. A simple model, able to describe global TSR and TS measurements, is used to evaluate the influence of each of the different parameters. The simulations are conducted for a system with a uniform distribution of activation energies and a fixed pre‐exponential factor. These simulation results are qualitatively compared with some experimental data obtained for semicrystalline poly(ethylene terephthalate) under different conditions in the glass transition region. The tendencies resulting from the influence of the studied parameters on the intensity, the position of the TS peaks and the corresponding activation energies are found to be the same for the experimental and simulated results. Only the variation of the activation energy with t_σ is opposite to that observed with the modelling results; this feature is explained on the basis of structural relaxation effects. © 2002 Society of Chemical Industry     

Thermal Decomposition,Kinetics and Compatibility Studies of Poly(3‐difluoroaminomethyl‐3‐methyloxetane) (PDFAMO)

The thermal decomposition of poly(3‐difluoroaminomethyl‐3‐methyloxetane) (PDFAMO) with an average molecular weight of about 6000 was investigated using thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). The kinetics of thermolysis were studied by a model‐free method. The thermal decomposition of PDFAMO occurred in a two‐stage process. The first stage was mainly due to elimination of HF and had an activation energy of 110–120 kJ mol⁻¹. The second stage was due to degradation of the polymer chain. The Fourier transform infrared (FTIR) spectra of the degradation residues showed that the difluoroamino groups decomposed in a two‐step HF loss at different temperatures. The remaining monofluoroimino groups produced by the incomplete elimination of HF were responsible for the two‐stage thermolysis process. The compatibility of PDFAMO with some energetic components and inert materials used in polymer‐bonded explosives (PBXs) and solid propellants was studied by DSC. It was concluded that the binary systems of PDFAMO with cyclotrimethylenetrinitramine (RDX), 2,4,6‐trinitrotoluene (TNT), 2,4‐dinitroanisole (DNAN), pentaerythritol tetranitrate (PETN), ammonium perchlorate (AP), aluminum powder (Al), aluminum oxide (Al₂O₃) and 1,3‐diethyl‐1,3‐diphenyl urea (C₁) were compatible, whereas the systems of PDFAMO with lead carbonate (PbCO₃) and 2‐nitrodiphenylamine (NDPA) were slightly sensitized. The systems with cyclotetramethylenetetranitroamine (HMX), hexanitrohexaazaisowurtzitane (CL‐20), 3‐nitro‐1,2,4‐triazol‐5‐one (NTO), ammonium nitrate (AN), magnesium powder (Mg), boron powder (B), carbon black (C. B.), diphenylamine (DPA), and p‐nitro‐N‐methylamine (PNMA) were incompatible. The results of compatibility studies fully supported the suggested thermal decomposition mechanism of PDFAMO.