Kinetic Study on the Exothermic Decomposition Reaction of 2,4,6,8-Tetranitro-2,4,6,8-tetraazabicyclo[3,3,1]onan-3,7-dione

Introduction 2,4,6,8-Tetranitro-2,4,6,8-tetraazabicyclo[3,3,1]nonan- 3,7-dione (1) is a novel energetic cyclourea nitramine containing four —NO2 groups (Figure 1). The detona-tion velocity corresponding to =1.93 gcm-3 is 9034 ms-1. It is the potential high explosive. Its preparation,1 properties1 and hydrolytic behavior2 have been reported. Thermal behavior is one of the most important aspects of the compound in practical application. However, its kinetic parameters of thermal decomposition…     

Thermal Decomposition Behavior and Non-isothermal Decomposition Reaction of Copper（ll） Salt of 4-Hydroxy-3,5-dinitropyridine Oxide and Its Application in Solid Rocket Propellant

The thermal decomposition behavior and kinetic parameters of the exothermic decomposition reactions of the title compound in a temperature‐programmed mode have been investigated by means of DSC, TG‐DTG and lower rate Thermolysis/FTIR. The possible reaction mechanism was proposed. The critical temperature of thermal explosion was calculated. The influence of the title compound on the combustion characteristic of composite modified double base propellant containing RDX has been explored with the strand burner. The results show that the kinetic model function in differential form, apparent activation energy E_a and pre‐exponential factor A of the major exothermic decomposition reaction are 1‐a,207.98 kJ*mol^?1 and 10^15.64 s^?1, respectively. The critical temperature of thermal explosion of the compound is 312.87 C. The kinetic equation of the major exothermic decomposition process of the title compound at 0.1 MPa could be expressed as: dα/dT=10^16.42 (1–α)e‐2.502×10⁴/T As an auxiliary catalyst, the title compound can help the main catalyst lead salt of 4‐hydroxy‐3,5dinitropyridine oxide to enhance the burning rate and reduce the pressure exponent of RDX‐CMDB propellant.     

Kinetics and Mechanism of the Exothermic First-stage Decomposition Reaction for 1,5-Dimethyl-2,6-bis(2,2,2-trinitroethyl)-glycoluril

ＩｎｔｒｏｄｕｃｔｉｏｎＣｙｃｌｏｕｒｅａｎｉｔｒａｍｉｎｅｓｗｉｔｈＮ ｔｒｉｎｉｔｒｏｅｔｈｙｌｇｒｏｕｐｓｈａｖｅａｇｒｅａｔｅｒｄｅｎｓｉｔｙａｎｄａｈｉｇｈｅｒｄｅｔｏｎａｔｉｏｎｖｅｌｏｃｉｔｙ .Ｓｏｍｅｏｆｔｈｅｃｏｍｐｏｕｎｄｓｃｏｕｌｄｂｅｕｓｅｄａｓｈｉｇｈｅｘｐｌｏｓｉｖｅｓ .1,5 Ｄｉｍｅｔｈｙｌ 2 ,6 ｂｉｓ(2 ,2 ,2 ｔｒｉｎｉｔｒｏｅｔｈｙｌ)ｇｌｙｃｏｌｕｒｉｌ (1)ｉｓａｔｙｐｉｃａｌｃｙｃｌｏｕｒｅａｎｉｔｒａｍｉｎｅ .Ｔｈｅｃｒｙｓｔａｌｄｅｎｓｉｔｙｉｓ1 74ｇ/…     

Thermal Behavior of N,N＇Bis[N-（2,2,2-trinitroethyl）-N-nitro]ethylenediamine

The thermal behavior and kinetic parameters of the exothermic decomposition reaction of N‐N‐bis[N‐(2,2,2‐tri‐nitroethyl)‐N‐nitro]ethylenediamine in a temperature‐programmed mode have been investigated by means of differential scanning calorimetry (DSC). The results show that kinetic model function in differential form, apparent activation energy E_a and pre‐exponential factor A of this reaction are 3(1 ‐α)^2/3, 203.67 kJ·mol^?1 and 10^20.61s^?1, respectively. The critical temperature of thermal explosion of the compound is 182.2 °C. The values of ΔS^≠ ΔH^≠ and ΔG^≠ of this reaction are 143.3 J·mol^?1·K^?1, 199.5 kJ·mol^?1 and 135.5 kJ·mol^?1, respectively.     

Kinetics and Mechanism of the Thermal Decomposition Reaction of 3,3-Bis（azidomethyl）oxetane／Tetrahydrofuran Copolymer

Introduction 3,3-Bis(azidomethyl)oxetane/tetrahydrofuran (BAM- O/THF, marked as B/T) copolymer can be used as an azide binder of high energy propellants with the lower signature, and lower sensitivity to improve the me-chanical properties at lower temperature and the burning rate characteristics. Its decomposition kinetics and the effects of THF on the decomposition kinetics of BAMO copolymers have been reported.1,2 In the present work, we report the kinetic model function and kinetic pa…     

Kinetics and Mechanism of the Exothermic First-stage Decomposition Reaction of Dinitroglycoluril

Introduction Dinitroglycoluril (DINGU) is a typical cyclourea nitramine. Its crystal density is 1.94 gcm-3. The detonation velocity corresponding to =1.94 gcm-3 is about 8450 ms-1. Its sensitivity to impact is better than that of cyclotrimethylenetrinitramine. It has the potential for possible use as high explosive from the point of view of the above-mentioned high performance. Its preparation,1-4 properties1-4 and hydrolytic behavior4 have been reported. In the present paper, we report i…     

Kinetics of the exothermic decomposition of 1-nitro-3-(β,β,β-trinitroethyl)-4,5-dinitroiminoimidazolidine-2-one

The kinetic parameters of the exothermic decomposition of the title compound in a temperatureprogrammed mode have been studied by means of DSC. The DSC data obtained are fitted to the integral, differential, and exothermic rate equations by the linear least-squares, iterative, combined dichotomous, and least-squares methods, respectively. After establishing the most probable general expression of differential and integral mechanism functions by the logical choice method, the corresponding values of the apparent activation energy (E _a), preexponential factor (A), and reaction order (n) are obtained by the exothermic rate equation. The results show that the empirical kinetic model function in differential form and the values of E _a and A of this reaction are (1 − α)^−4.08, 149.95 kJ mol⁻¹, and 10^14.06 s⁻¹, respectively. With the help of the heating rate and kinetic parameters obtained, the kinetic equation of the exothermic decomposition of the title compound is proposed. The critical temperature of thermal explosion of the compound is 155.71°C. The above-mentioned kinetic parameters are quite useful for analyzing and evaluating the stability and thermal explosion rule of the title compound. The text was submitted by the authors in English.     

Syntheses,Crystal Structures,and Thermal Properties of Energetic Semicarbazide Salt,Manganese(II) Salt,and Coordination Compound of 3,5‐Dinitrobenzoic Acid

Nitro compounds have been actively researched as driven by their potential to be high‐performing energetic materials. Herein, three new nitro compounds including semicarbazide 3,5‐dinitrobenzoate, (SCZ)(DNBA), manganese 3,5‐dinitrobenzoate dihydrate, [Mn(DNBA)₂(H₂O)₂]_n, and bis(semicarbazide) manganese(II) 3,5‐dinitrobenzoate, Mn(SCZ)₂(DNBA)₂, were synthesized and characterized by elemental analysis, IR spectroscopy, and single‐crystal X‐ray diffraction analysis. The results indicated that the above mentioned compounds are ionic, polymeric, and molecular in nature, respectively. Moreover, their thermal decomposition properties were assessed by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Their non‐isothermal reaction kinetics parameters, critical temperature of thermal explosion (T_bp), entropy of activation (ΔS^≠), enthalpy of activation (ΔH^≠), and free energy of activation (ΔG^≠) of the exothermic decomposition process were also calculated. Results suggest that there was a relationship between the structure and thermal stability.     

N,N'-二(5,5-二甲基-2-磷杂-2-硫代-1,3-二噁烷-2-基)乙二胺的热分解动力学研究

以TG-DTG为手段, 研究了N,N'-二(5,5-二甲基-2-磷杂-2-硫代-1,3-二噁烷-2-基)乙二胺(DPTDEDA)在氮气气氛中的热分解动力学, 利用 Kissinger法、Flynn-Wall-Ozawa(FWO)法对DPTDEDA进行了动力学分析, 求出了该物质的热分解动力学参数, 同时利用Satava-Sestak法研究了该物质的热分解机理. 结果表明, Kissinger法所求得的表观活化能为137.37 kJ•mol^－1, 指前因子ln A＝28.00; Flynn-Wall-Ozawa法所求得的活化能为139.83 kJ•mol^－1. DPTDEDA的热分解机理为相边界反应, 其动力学方程为G(α)＝1－(1－α)⁴, 反应级数n＝4.     

Kinetic Study on the Exothermic First-stage Decomposition Reaction of 2,4,8,10-Tetranitro-2,4,8,10-tetraaza- spiro[5,5]undecane-3,9-dione

Introduction 2,4,8,10-Tetranitro-2,4,8,10-tetraazaspiro[5,5]udecane- 3,9-dione is a typical cyclourea nitramine (Figure 1). Its crystal density is 1.91 gcm-3. The detonation velocity according to =1.90 gcm-3 is about 8670 ms-1. Its sensitivity to impact is better than that of cyclotrimethy- lenetrinitramine. So it is the potential high explosive. Its preparation,1-3 properties,1-3 hydrolytic behavior4 and electronic structure3 have been reported. In the present work, we report its kinetic pa…     

Non-Isothermal Decomposion Kinetics of Supermolecule Compound [Eu(C_(10)H_9N_2O_4)(C_(10)H_8N_2O_4)(H_2O)_3]_2·phen·4H_2O

Europium(Ⅲ) compound with 2-oxopropionic acid salicyloyl hydrazone (C_(10)H_(10)N_2O_4,H_3L) and 1,10-phenan-throline (C_(12)H_8N_2,phen) has been prepared.A yellow prismatic crystal of the compound was obtained,and themolecule crystallized in the triclinic space group P-1.There are two 9-coordinated complex molecules in everystructure unit,where every Eu atom is coordinated by three water molecules and two tridentate C_(10)H_(10)N_2O_4 ligands,forming two stable pentacycles.The coordination polyhedron around Eu~(3+) was described as a single cap squareantiprism.In the crystal cell,there are one free 1,10-phenanthroline and four water molecules.The thermaldecomposition of the compound and its kinetics were studied by non-isothermal thermogravimetry.The Kissinger'smethod and Ozawa's method were used to calculate the activation energy value of the first-step decomposition.Thestages of the decompositions were identified by TG-DTG-DSC curve.The non-isothermal kinetic data were ana-lyzed by means of integral and differential methods.The possible reaction mechanism and the kinetic equationswere investigated by comparing the kinetic parameters.     

Synthesis,Crystal Structure,Thermal and Explosive Properties of [Cd(SCZ)3(H2O)](PA)2·3H2O (SCZ = Semicarbazide,PA = Picrate)

The heptacoordinate transition metal coordination compound [Cd(SCZ)₃(H₂O)](PA)₂ · 3H₂O ( 1 ) with the ligand semicarbazide (SCZ) and the counteranion picrate (PA) was synthesized and characterized by elemental analysis and FTIR spectroscopy. Single‐crystal X‐ray diffraction analysis revealed that 1 crystallizes in the monoclinic space group P21/c. The Cd²⁺ ion is heptacoordinated by three SCZ groups and a water molecule. SCZ presents typical bidentate coordination modes. The thermal decomposition mechanism of 1 was studied by differential scanning calorimetry (DSC), which revealed that complex 1 exhibits three small endothermic and two large exothermic processes. The non‐isothermal kinetics parameters were calculated by the Kissinger's method and Ozawa‐Doyle's method, respectively. The heat of combustion was measured by oxygen bomb calorimetry. The enthalpy of formation, the critical temperature of thermal explosion, the entropy of activation (ΔS^≠), the enthalpy of activation (ΔH^≠), and the free energy of activation (ΔG^≠) were also calculated. Sensitivity tests revealed that 1 is insensitive to mechanical stimuli.     

Thermochemical Properties and Non-isothermal Decomposition Reaction Kinetics of N-Guanylurea Dinitramide （GUDN）

Introduction N-Guanylurea dinitramide (GUDN) is a new ener-getic oxidizer with higher energy and lower sensitivity. Its crystal density is 1.755 g·cm-3. The detonation velocity is about 8210 m·s-1. Its specific impulse and pressure exponent are 213.1 s and 0.73, respectively. It has the potential for possible use as an energy ingredient of propellants and explosives from the point of view of the above-mentioned high performance. Its preparation,1 properties2 and hygroscopocity2 have been …     

1，1－二氨基2，2－二硝基乙烯（DADE）的热化学性质、热行为和热分解机理

The constant-volume combustion energy, △cU （DADE, s, 298.15 K）, the thermal behavior, and kinetics and mechanism of the exothermic decomposition reaction of 1,1-diamino-2,2-dinitroethylene （DADE） have been investigated by a precise rotating bomb calorimeter, TG-DTG, DSC, rapid-scan fourier transform infrared （RSFT-IR） spectroscopy and T-jump/FTIR, respectively. The value of △cHm （DADE, s, 298.15 K） was determined as （-8518.09±4.59） j·g^-1. Its standard enthalpy of combustion, △cU （DADE, s, 298.15 K）, and standard enthalpy of formation, △fHm （DADE, s, 298.15 K） were calculated to be （-1254.00±0.68） and （- 103.98±0.73） kJ·mol^-1, respectively The kinetic parameters （the apparent activation energy Ea and pre-exponential factor A） of the first exothermic decomposition reaction in a temperature-programmed mode obtained by Kissinger＇s method and Ozawa＇s method, were Ek=344.35 kJ·mol^-1, AR= 1034.50 S^-1 and Eo=335.32 kJ·mol^-1, respectively. The critical temperatures of thermal explosion of DADE were 206.98 and 207.08 ℃ by different methods. Information was obtained on its thermolysis detected by RSFT-IR and T-jump/FTIR.     

A Novel Stable High‐Nitrogen Energetic Compound: Copper(II) 1,2–Diaminopropane Azide

The multi‐ligand coordination compound copper(II) 1,2‐diaminopropane (pn) azide, [Cu(pn)(N₃)₂]_n ( 1 ), was synthesized using pn and azido groups. It was characterized by X‐ray single crystal diffraction, elemental analysis, and FT‐IR spectroscopy. The crystal structure of 1 belongs to the monoclinic system, space group C2/c. The copper(II) cation is six‐coordinated by one pn molecule and four azido ligands with μ‐1 and μ‐1,1,3 coordination modes. Thermogravimetric investigations with a heating rate of 10 K · min^–1 under nitrogen showed one main exothermic stage with a peak temperature of 215.7 °C in the DSC curve. The non‐isothermal kinetics parameters were calculated by Kissinger and Ozawa methods, respectively. The heat of combustion was measured by oxygen bomb calorimetry, and the enthalpy of formation, the critical temperature of thermal explosion, the entropy of activation (ΔS^≠), the enthalpy of activation (ΔH^≠), and the free energy of activation (ΔG^≠) were calculated. The measurements showed that 1 has very high impact, friction, and flame sensitivities.     

Thermal Behavior of 2‐(Dinitromethylene)‐1,3‐diazacyclopentane

A new compound, 2‐(dinitromethylene)‐1,3‐diazacyclopentane (DNDZ), was prepared by the reaction of 1,1‐diamino‐2,2‐dinitroethylene (FOX‐7) with 1,2‐diaminoethane in N‐methylpyrrolidone (NMP). Thermal decomposition of DNDZ was studied under non‐isothermal conditions by DSC, TG/DTG methods, and the enthalpy, apparent activation energy and pre‐exponential factor of the exothermic decomposition reaction were obtained as 317.13 kJ·mol^?1, 269.7 kJ·mol^?1 and 10^24.51 s^?1, respectively. The critical temperature of thermal explosion was 261.04°C. Specific heat capacity of DNDZ was determined with a micro‐DSC method and a theoretical calculation method, and the molar heat capacity was 205.41 J·mol^?1·K^?1 at 298.15 K. Adiabatic time‐to‐explosion was calculated to be a certain value between 263–289 s. DNDZ has higher thermal stability than FOX‐7.     

Preparation,crystal structure,and thermal decomposition of an azide energetic compound [Cd(IMI)2(N3)2]n (IMI = imidazole)

Cadmium(II) imidazole (IMI) azide [Cd(IMI)₂(N₃)₂]_n (1) was synthesized using imidazole and azide, and was characterized by the elemental analysis and FTIR spectrum. The crystal structure was determined by X-ray single crystal diffraction, and the crystallographic data show that the crystal belongs to orthorhombic, Pba2 space group, α?=?10.780(4) Å, b?=?13.529(5) Å, and c?=?3.6415(12) Å. Its crystal density is 2.080?g·cm^–3. Cd(II) is a six-coordinate with six nitrogens from four imidazoles and two azides with μ–1,1 coordination. The thermal decomposition mechanism was determined based on differential scanning calorimetry (DSC) and thermogravimetry-derivative thermogravimetry (TG-DTG) analysis, and the kinetic parameters of the first exothermic process were studied using Kissinger’s method and Ozawa’s method, respectively. The energy of combustion, enthalpy of formation, critical temperature of thermal explosion, entropy of activation (ΔS ^≠), enthalpy of activation (ΔH ^≠), and free energy of activation (ΔG ^≠) were measured and calculated. In the end, impact sensitivity was also determined by standard method.     

Evaluating the Thermal Hazard of Double-Base Propellant SQ-2 by Using Microcalorimetry Method

The thermal decomposition behavior of double‐base rocket propellant SQ‐2 was studied by a Calvet microcalorimeter at four different heating rates. The kinetic and thermodynamic parameters were obtained from the analysis of the heat flow curves. The critical temperature of thermal explosion (T_b), the self acceleration decomposition temperature (T_SADT), the adiabatic decomposition temperature rise (ΔT_ad), the time‐to‐explosion of adiabatic system (t), critical temperature of hot‐spot initiation (T_cr), critical thermal explosion ambient temperature (T_acr), safety degree (SD) and thermal explosive probability (P_TE) were presented to evaluate the thermal hazard of SQ‐2.     

鬼臼毒素及其衍生物热分解反应的动力学研究

The thermal behavior and thermal decomposition kinetic parameters of podophyllotoxin （1） and 4 derivatives, picropodophyllin （2）, deoxypodophyllotoxin （3）, fl-apopicropodophyllin （4）, podophyllotoxone （5） in a temperature-programmed mode have been investigated by means of DSC and TG-DTG. The kinetic model functions in differential and integral forms of the thermal decomposition reactions mentioned above for first stage were established. The kinetic parameters of the apparent activation energy Ea and per-exponential factor A were obtained from analy- sis of the TG-DTG curves by integral and differential methods. The most probable kinetic model function of the decomposition reaction in differential form was （1- a）^2 for compounds 1-3,2/3·a^-1/2 for compound 4 and 1/2（1-a）·[-In（1-a）]^-1 for compound 5. The values of Ea indicated that the reactivity of compounds 1-5was increased in the order： 5〈4〈2〈1〈3. The values of the entropy of activation △S^≠, enthalpy of activation △H^≠ and free energy of activation △G^≠ of the reactions were estimated. The values of △G^≠ indicated that the thermal stability of compounds 1-3 with the samef（a） was increased in the order： 2〈3〈1.     

3,7-二硝基亚氨基-2,4-二氮杂双环[3,3,0]辛烷的放热分解反应动力学

The kinetic parameters of the exothermic decomposition reaction of the title compound in a temperature-programmed mode have been studied by means of DSC. The DSC data obtained are fitted to the integral, differential and exothermic rate equations by linear least-squares, iterative, combined dichotomous and least-squares methods, respectively. After establishing the most probable general expression of differential and integral mechanism functions by the logical choice method, the corresponding values of the apparent activation energy (Ea), pre-exponential factor (A) and reaction order (n) will be obtained by the exothermic rate equation. The results show that the empirical kinetic model function in differential form and the values of Ea and A of this reaction are (1-α)0.44, 230.4 kJ/mol and 1018.16 s-1, respectively. With the help of the heating rate and obtained kinelic parameters, the kinetic equation of the exothermic decomposition reaction process of the title compound is proposed. The critical temperature of thermal explosion of the compound is 302.6℃. The above-mentioned kinetic parameters are quite useful for analyzing and evaluating the stability and thermal change rule of the title compound.