HAN-基凝胶推进剂的热分解反应动力学（英文）

为研究HAN-基凝胶推进剂的热分解特性,利用差示扫描量热仪(DSC)和热重分析仪(TGA)对两种含不同质量聚乙烯醇(PVA)的HAN-基凝胶推进剂样品进行热分析试验,并与一种双基推进剂进行对比。分析了HAN-基凝胶推进剂和双基推进剂的热分解过程,得到热分解反应的动力学参数;采用等转化率法计算了活化能,采用Zhang-Hu-Xie-Li等方法计算出热爆炸临界温度和自加速分解温度。采用Malek法推断出两种HAN-基凝胶推进剂样品的热分解反应的最可几机理函数。结果表明,HAN-基凝胶推进剂的热分解是一个连续的放热过程,热分解较为彻底,残渣较少,活化能约为100kJ/mol。当PVA含量增加时,其热爆炸临界温度和自加速分解温度升高。与双基推进剂相比,HAN-基凝胶推进剂具有较好的热安定性。     

高燃速推进剂GATo的热安全性分析

为研究高燃速推进剂改铵铜(GATo)的热安全性,采用差示扫描量热(DSC)法和热重(TG)法分析了GATo推进剂的热分解过程,计算了其热分解活化能(E_a)、指前因子(A)、分解温度(t_(e0))、热爆炸临界温度(t_0)及热力学参数,并测试了压伸成型管状GATo及含溶剂GATo推进剂药浆的5s延滞期爆发点及热爆发反应参数。结果表明,采用Kissinger法计算得到GATo推进剂的热分解活化能为139.1kJ/mol,指前因子为7.5×10~(15)s~(-1),分解温度为172.0℃;根据Hu-Zhao-Gao法计算得到GATo推进剂的热爆炸临界温度为182.8℃,低于RDX-CMDB推进剂GHT及GHQ;在升温速率为10℃/min时,GATo推进剂分解峰值温度的活化自由能(ΔG~≠)为113.8kJ/mol,活化焓(ΔH~≠)为135.3kJ/mol,活化熵(ΔS~≠)为29.7J/(K·mol)~(-1);压伸成型管状GATo与含溶剂GATo药浆的5s延滞期爆发点分别为231和234℃,热爆发分解反应活化能分别为112和132kJ/mol,表明溶剂对其热爆发分解反应活化能有较大影响。     

一种判定RDX热分解机理函数与热安全性的方法

将DSC、TG数据与Malek法相结合研究了RDX的热分解,得到外延起始温度Le0、拐点温度T、峰顶温度Tp、分解终止温度Tf、分解焓变ΔH、表观活化能E、指前因子A、反应级数n、热爆炸临界温度Tb和自加速分解温度TSADT;利用TG热分析得到RDX热分解的起始分解温度T0、质量损失Δm%、最大质量损失速率及对应的温度...     

二茂铁类衍生物对HAN/PVA热分解影响研究

为了解决硝酸羟铵/聚乙烯醇(HAN/PVA)的点火和燃烧困难问题,采用热重-差示扫描量热-红外光谱-质谱联用技术研究了HAN/PVA的热分解机理,并通过多重扫描速率的非等温法探索了卡托辛、乙基二茂铁、辛基二茂铁和叔丁基二茂铁等对HAN/PVA热分解性能的影响。结果表明,HAN/PVA的热分解主要发生在457.0~485.2K,失重73.7%,放热量为1312.1J/g,活化能Ea为88.8kJ/mol,在加热过程中固体样品基本转变成气态产物;本研究所用二茂铁类衍生物对HAN/PVA的热分解均具有明显的催化效果,催化作用由强到弱依次为叔丁基二茂铁、辛基二茂铁、卡托辛及乙基二茂铁,分别使HAN/PVA的热分解温度降低了42.9、27.5、17.5和12.3K;含辛基二茂铁、卡托辛和乙基二茂铁样品热分解反应的Ea分别为81.2、90.5和77.7kJ/mol;HAN/PVA/卡托辛样品热分解的Ea虽然最高,但指前因子A提高了2个数量级,反应速率常数大幅增加,催化效果最佳。     

LLM-105基PBX炸药的热分解反应动力学

通过布氏压力计法获得了普通的和纳米化的LLM-105基PBX炸药在不同温度条件下热分解放气量随时间的变化曲线。基于Arrhenius公式计算了两种PBX炸药分解深度为0.1%时的表观活化能。采用TG-DSC研究了两种LLM-105基PBX炸药的非等温热分解反应动力学。结果表明,由Arrhenius公式得到的普通和纳米化的LLM-105基PBX炸药在分解深度为0.1%时的表观活化能分别为74.67和138.09kJ/mol。利用Kissinger法计算获得两种LLM-105基PBX炸药在最大分解速率(分解深度约50%)下的表观活化能分别为389.26和215.73kJ/mol,与Ozawa法计算结果相吻合。升温速率趋于零时的特征分解峰值温度分别为606.94和586.48K,热爆炸临界温度分别为615.0和600.4K。相对于普通LLM-105基PBX炸药,纳米化LLM-105基PBX炸药热分解具有更高的反应活性,热感度也有所提高。     

低温启动单组元凝胶LLG-1热危险性研究

为了研究运输、贮存过程中低温启动单组元凝胶LLG-1的热危险性,利用差示扫描量热仪DSC及高性能绝热量热仪PHI-TECⅠ对其进行测试。测试结果表明,低温启动单组元凝胶LLG-1的比放热量为2 288.10±53.44 J·g^-1,采用Ozawa法计算得到其活化能为49.05 kJ·mol^-1,利用DSC测试方法及理论计算,得到的热爆炸临界温度过低,有悖于现实,表明该测试方法不适用。后利用加速度绝热量热仪PHI-TECⅠ对该物质进行测试,得到了该物质在实际贮存容器中的活化能为162.67 kJ·mol^-1,长期贮存自加速分解温度SADT=365.4 K。并将其自加速分解温度与相同条件下测试得到的单推-3自加速分解温度进行了对比,结果表明其自加速分解温度高于单推-3自加速分解温度,LLG-1热安全性优于单推-3。     

2,6-二氨基-3,5-二硝基吡啶-1-氧化物基PBX的热安全性研究

为了研究2,6-二氨基-3,5-二硝基吡啶-1-氧化物(ANPyO)基高聚物黏结炸药(PBX)的热安全性,分别以氟橡胶F2311和丁晴橡胶NBR-26为主体设计两种黏结剂体系,采用水悬浮-溶解-蒸馏法制备ANPyO基PBX炸药。利用扫描电子显微镜(SEM)、差示扫描量热法(DSC)和热重法(TG)表征不同黏结剂体系PBX的结构和性能,计算了两种黏结剂体系PBX的热分解动力学参数和热爆炸参数,并获得了被400K气氛环绕的半径为1m的球形、无限圆柱形或无限平板状PBX的热感度概率密度函数S(T)与温度T的关系曲线。结果表明,以丁晴橡胶NBR-26为黏结剂体系主体PBX的活化能E为173.19kJ/mol、指前因子ln(A/s-1)为28.58、自加速分解温度TSADT为550.01K、热点火温度Tbe为565.81K、热爆炸临界温度Tbp为625.06K;以氟橡胶F2311为黏结剂体系主体PBX的活化能E为143.78kJ/mol、指前因子ln(A/s-1)为22.89,自加速分解温度TSADT为539.99K,热点火温度Tbe为560.28K,热爆炸临界温度Tbp为615.55K;球形PBX的热安全性稍高于无限圆柱或平板状PBX,以丁晴橡胶NBR-26为黏结剂体系主体PBX的热安全性高于氟橡胶F2311为黏结剂体系主体PBX。     

Pb-TKX-50燃烧催化剂的合成及热分解性能

以二氯乙二肟、二甲基甲酰胺、叠氮化钠、盐酸羟胺和硝酸铅等为原料,合成了1,1-二羟基-5,5′-联四唑羟胺铅盐(Pb-TKX-50)燃烧催化剂,研究了Pb-TKX-50对推进剂机械感度的影响以及与推进剂组分的相容性;利用差示扫描量热法和热重法研究了Pb-TKX-50在不同升温速率下的热分解过程,计算其表观活化能(E K和E O)和指前因子(A K),得到其热分解动力学参数、热分解机理函数、热爆炸温度和热力学性质。结果表明,在推进剂配方中加入Pb-TKX-50燃烧催化剂,可以改善其撞击感度和摩擦感度,且与推进剂组分的相容性良好;Pb-TKX-50的主峰分解温度相对于TKX-50的主峰分解温度显著提高,说明其热稳定性显著提高。Ozawa法和Kissinger法得到Pb-TKX-50的表观活化能分别为181.45 kJ/mol和182.49 kJ/mol,且热分解过程符合Avrami-Erofeev方程;Pb-TKX-50的自加速分解温度和爆炸临界温度分别为500.53 K和544.33 K,表明其热稳定性良好;Pb-TKX-50催化剂的热分解自由能(ΔG^≠)为158.87 kJ/mol,活化焓(ΔH^≠)为187.03 kJ/mol,活化熵(ΔS≠)为52.98 kJ/mol。     

基于 Kissinger 方法的3，4-双（4-硝基呋咱-3-基）氧化呋咱的热分解反应动力学参数和热稳定性研究

采用差示扫描量热法研究了 DNTF和TNT在不同升温速率下的热分解特性；利用Kissinger方法计算和对比分析了DNTF和TNT的热分解反应动力学参数、热爆炸临界温度和热力学参数。结果表明，DNTF的热分解过程不同于TNT ，DNTF的热分解经历了两个阶段，其中第1阶段为主要部分。DNTF的活化能为168．85kJ／mol ，比TNT高约58 kJ／mol ，表明DNTF在低温下有良好的热稳定性。然而，除自由活化能外，DNTF的其他热力学参数均比TNT高。DNTF的热分解峰温和热爆炸临界温度都比 TNT小。因此，与TNT相比，DNTF的热稳定性差。     

基于Kissinger方法的3,4-双(4-硝基呋咱-3-基)氧化呋咱的热分解反应动力学参数和热稳定性研究（英文）

采用差示扫描量热法研究了DNTF和TNT在不同升温速率下的热分解特性;利用Kissinger方法计算和对比分析了DNTF和TNT的热分解反应动力学参数、热爆炸临界温度和热力学参数。结果表明,DNTF的热分解过程不同于TNT,DNTF的热分解经历了两个阶段,其中第1阶段为主要部分。DNTF的活化能为168.85kJ/mol,比TNT高约58kJ/mol,表明DNTF在低温下有良好的热稳定性。然而,除自由活化能外,DNTF的其他热力学参数均比TNT高。DNTF的热分解峰温和热爆炸临界温度都比TNT小。因此,与TNT相比,DNTF的热稳定性差。     

Kinetics of Nano Titanium Dioxide Catalyzed Thermal Decomposition of Ammonium Nitrate and Ammonium Nitrate‐Based Composite Solid Propellant

This study deals with the influence of nanosized titanium dioxide (TiO₂) catalysts on the decomposition kinetics of ammonium nitrate (AN) and ammonium nitrate‐based composite solid propellant. TiO₂ nanocatalyst with an average particle size of 10 nm was synthesized by sol‐gel method using titanium alkoxide as precursor. Formation of nanostructured TiO₂ and presence of its anatase and brookite phases was confirmed by powder X‐ray diffraction (PXRD) and selected area diffraction (SAED) studies. Nano TiO₂ was further characterized by transmission electron microscopy (TEM), infrared (IR) spectroscopy, and thermogravimetry. The catalytic effect of TiO₂ nanocatalysts on the solid state thermal decomposition reaction of AN and nonaluminized HTPB/AN propellant was evaluated. To ascertain the effectiveness of the TiO₂ nanocatalyst, the thermal kinetic constants for the catalytic and non‐catalytic decomposition of AN and AN propellant samples were computed by using a nonlinear integral isoconversional method. Catalytic influence was evident from the lowering of activation energy for the catalyzed decomposition reactions. Apparently, the nanocatalysts provide Lewis acid and/or active metal sites, facilitating the removal of AN dissociation products NH₃ and HNO₃ and thereby enhance the rate of decomposition. The changes in the critical temperature of thermal explosion of AN and AN propellant samples due to the addition of TiO₂ nanocatalyst were also computed and the possible reasons for the changes are discussed.     

Non‐Isothermal Kinetic Study of the Thermal Decomposition of Melamine 3‐Nitro‐1,2,4‐triazol‐5‐one Salt

Study on thermal behavior of 3‐nitro‐1,2,4‐triazol‐5‐one (NTO) salts was required to obtain important data for application purposes. These compounds have been shown to be useful intermediates for gun propellant ingredients, high energetic ballistic modifiers for solid propellants and other potential applications. In this paper, thermal decomposition and non‐isothermal kinetics of melamine 3‐nitro‐1,2,4‐triazol‐5‐one salt (MNTO) were studied under non‐isothermal conditions by DSC and TG methods. The kinetic parameters were obtained from analysis of the DSC and TG curves by Kissinger and Ozawa methods. The critical temperature of thermal explosion (T_b) was 574 K. The results show that MNTO is thermally more stable than NTO when compared in terms of the critical temperature of thermal explosion. Finally, the values of ΔS^#, ΔH^#, and ΔG^# of its decomposition reaction were calculated.     

Analysis for Decomposition Characteristics and Piecewise Thermokinetics of Nitramine Modified Double‐base Propellant with High Solid Content

The thermal stability and decomposition characteristic of nitramine modified double‐base propellant (RDX‐CMDB propellant) with high solid content and its components were investigated under dynamic and isothermal conditions by differential scanning calorimetry (DSC). It was found that the mixture of nitrocellulose (NC) and nitroglycerin (NG) had a promote effect on the decomposition of RDX. The activation energy (E ) and the pre‐exponential factor (A ) of two obviously exothermic processes were obtained by Friedman iso‐conversional method. The screening method suggested by ICTAC was used to determine the most probable mechanism functions and kinetic parameters of the two processes which are corresponding to the deceleration model and the autocatalytic model. The theoretical value was consistent with the experiment result.     

NEPE推进剂热安全性的尺寸效应

为了解NEPE推进剂热安全性的尺寸效应,在不同温度下对不同尺寸的NEPE推进剂药柱进行了热爆炸试验,测得其热爆炸延滞期,并计算得到不同尺寸NEPE推进剂药柱在90、100、110、120℃下的热分解反应速率;通过在药柱内部布置热电偶监测了尺寸为Ф100mm×100mm和Ф150mm×150mm药柱在90℃和100℃环境温度下的内部温度变化。结果表明,当温度高于76.2℃时,NEPE推进剂药柱的尺寸越大,反应速率常数越大;活化能与药柱的比表面积呈线性相关,比表面积越小,活化能越大,当NEPE推进剂药柱的比表面积小于0.02mm-1时,活化能(Ea)为179.3kJ/mol,指前因子(A)为4.62×1019s-1。硝酸酯增塑剂的存在是NEPE推进剂在200℃以下发生热爆炸的主要原因。     

硝酸对硝基苯热稳定性的影响机理

借助C80微量量热仪研究硝酸对硝基苯热稳定性的影响特性,获得含有不同浓度硝酸的硝基苯溶液热流速曲线,并据此求解出混合溶液的化学反应动力学和热力学参数,结合Semenov热爆炸模型,计算并比较了硝基苯混合溶液的自加速分解温度（SADT）。采用GCT气相色谱-飞行时间质谱联用仪研究硝基苯在不同温度下的热分解特性,并结合C80实验结果推测了硝基苯的高温热解反应机理以及硝酸杂质对硝基苯热稳定性的影响机理。     

Study on the influence of ageing on thermal decomposition of double‐base propellants and prediction of their in‐use time

A comparative study of the thermal decomposition of naturally and artificially aged double‐base propellants has been carried out at five different heating rates in a dynamic nitrogen atmosphere using differential scanning calorimetry (DSC) technique. The results show that there is only one decomposition peak on DSC curves, and this decomposition has been accelerated by ageing. The influence of the heating rate on the DSC behaviour of the propellants was verified. The kinetic parameters such as activation energy and frequency factor and the thermodynamic parameters such as the enthalpy of activation, free energy of activation and critical explosion temperature for the compounds were obtained from DSC data using non‐isothermal methods proposed by Kissinger and Ozawa. On the other hand, a prediction of the in‐service period by van't Hoff's equation was performed and compared with the experimental results in order to check the constancy and validity of this method. As a result, the prediction procedure used to obtain the time–temperature profile was achieved with good accordance. Copyright © 2012 John Wiley & Sons, Ltd.     

乙二胺-三乙烯二胺高氯酸盐对高能发射药热分解反应的影响

为了研制一种具有高能高燃速特性的新型发射药,在含有CL-20的高能发射药配方基础上,添加适量高燃速功能材料乙二胺-三乙烯二胺高氯酸盐(SY);利用热重分析法(TG)、差示扫描量热法(DSC)和绝热加速量热仪(ARC)研究了高燃速功能材料SY对高能发射药热分解反应的影响,并计算对比了热分解过程的相关动力学参数。结果表明,高燃速功能材料SY可以明显加快发射药的质量损失速率,使最大质量损失速率提高了43%,主要促进了NC组分的热分解;添加质量分数3%的SY可使高能发射药的绝热分解终止温度由790.4提高到1305.7℃,提高了515.3℃,且最终放热量由1294.72增至2335.22J/g,增加了1040.50J/g,热分解反应更完全;SY的加入降低了高能发射药热分解反应的表观活化能,利用Kissinger法和Ozawa法求得的活化能分别降低40.5和38.5kJ/mol。