共查询到19条相似文献,搜索用时 78 毫秒
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利用高压DSC研究了三羟甲基丙烷三硝酸酯(TMPTN)的热分解特性.结果表明,尽管TMPTN与硝化甘油(NG)和三羟甲基乙烷三硝酸酯(TMETN)的结构相似,但TMPTN的热分解特性完全不同于NG和TMETN.常压下, TMPTN有两个峰,一个是熔化吸热峰,另一个是分解放热峰,而NG则是一个熔化吸热峰,TMETN是一个分解放热峰,没有熔化吸热峰;在高压下, TMPTN也有一个熔化吸热峰和一个分解放热峰,只是熔化吸热峰相对没有常压下的明显,随着压力的不同,峰形、峰温、放热量都明显不同.同时对TMPTN的分解机理进行了初步分析,并获得了TMPTN的热分解反应动力学参数. 相似文献
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综述了三羟甲基乙烷三硝酸酯(TMETN)的合成方法及其在发射药中的应用,指出TMETN是一种优良的新型含能增塑剂,并对其发展趋势进行了展望。 相似文献
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通过热重分析(TGA)法研究了聚对苯二甲酸丁二醇酯(PBT)在氮气气氛中不同升温速率下的热分解过程,采用不同的动力学数据处理方法研究了PBT的热分解机理。结果表明:采用Kissinger法、FlynnWall-Ozawa法和Friedman法计算PBT的热分解反应活化能分别为179.93,175.83,161.07 kJ/mol,平均值为172.28 kJ/mol,与Coast-Redfern法计算的活化能180.41 kJ/mol接近,取PBT热分解反应活化能为180.41kJ/mol,计算得指前因子为2.68×10~(10)s~(-1);采用Coast-Redfern法和Criado法研究了PBT的固相热分解反应机理,认为PBT的热分解机理属于相边界控制的收缩圆柱体反应机理,反应级数为0.5。 相似文献
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用热分析法研究了阻燃剂聚丙烯酸五溴苄基酯在空气和氮气气氛中的热分解动力学。该阻燃剂在空气气氛中为两步分解,在氮气气氛中为一步分解,利用Friedman法求出聚丙烯五溴苄基酯的第一步分解反应的活化能变化趋势,同时利用Satava-Sestak法研究了其热分解机理。结果表明,在0.10至0.90的转化率范围内,聚丙烯酸五溴苄基酯在空气气氛下的活化能为167.35kJ/mol,在氮气气氛下的活化能为171.94kJ/mol,热分解机理均为Avrami-Erofeev方程,随机成核和随后生长,反应级数分别为n=23和n=12。动力学方程分别为G(a)=[-ln(1-a)]23和G(a)=[-ln(1-a)]12。 相似文献
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碱式碳酸镁的热分解研究 总被引:4,自引:0,他引:4
通过TGA、DSC热分析法,研究了碱式碳酸镁的热分解过程。发现碱式碳酸镁分两个阶段分解,并测得每一阶段的特征温度和吸热值。由Kissinger与Ozawa-Doyle两种方法求得两个阶段热分解反应的表观活化能Ea和指前因子lgA。用常见的固体热分解机理函数拟合了ln[G(α)/T2]~1/T曲线,用Coats-Redfern法确定了碱式碳酸镁热分解过程第一阶段的机理是三维扩散机理D3,第二阶段的机理是随机成核和核生长机理F1,获得其动力学方程。采用DSC方法测试了碱式碳酸镁的比热容,用最小二乘法拟合曲线,获得其比热的表达式为Cp=-3.890 2+0.207 2T-0.002 58T2+1.386 3×10-5T3-2.755 4×10-8T4。 相似文献
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为了解超细六硝基芪(HNS)的热分解性能,通过DSC—TG实验研究HNS—IV的热分解过程,用Kissinger法和Ozawa法计算了HNS-Ⅳ热分解反应动力学参数。结果表明,HNS-Ⅳ的热稳定性与HNS-Ⅱ相当。Kissinger法和Ozawa法得到的HNS-Ⅳ分解表观活化能分别为221.4kJ/mol和220.3kJ/mol,比静态气氛下HNS-Ⅱ热分解反应的表观活化能减小27kJ/mol。 相似文献
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RDX热分解的TG-DSC-QMS-FTIR同步动力学 总被引:6,自引:1,他引:5
采用TG-DSC-QMS-FTIR同步动力学技术对RDX的热分解过程进行了研究,结果表明,RDX在熔融之后发生分解,可以确定RDX的产物有C、H2O、CH2O、N2O、CO、CO2、NO2,可能有CH4和NH3,而几乎没有NO.采用多元非线性拟合技术进行动力学参数计算,结果表明,RDX的分解过程大致可以分为3个连续步骤,第1步反应的活化能为235 kJ/mol,指前因子log(A/s-1)为22,反应级数为0.6,主要气体产物为CO2、NO2和CH2O;第2步反应的活化能为110 kJ/mol,指前因子log(A/s-1)为1.5,反应级数为1.7,主要的气体产物是N2O、H2O、CH4、NH3、C2O+/C3H+4、CN+/C2H+3、CHO+/C2H+;第3步反应的活化能为223 kJ/mol,指前因子log(A/s-1)为20.9,反应级数为4,主要的产物是C和CO. 相似文献
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制备了HNIW热失重分别为91.8%的残余物Res.1和90.1%的残余物Res.2,在氩气气氛下通过热重-差示扫描联用仪(TG-DSC)对残余物Res.1以10℃/min的升温速率加热到300、400、550、600、800℃,得到5种样品,分别为Res.1-300、Res.1-400、Res.1-550、Res.1-600、Res.1-800。结果表明,氩气气氛有利于氰基(-CN)的生成;大气气氛则有利于碳二亚胺的生成。采用原位红外光谱对HNIW在10℃/min升温速率、大气气氛下加热至232.0℃以上的残余物进行研究,结果表明,C-C键与部分C-N键断裂氧化产生活性中间物种-异氰酸酯,异氰酸酯进一步与相关基团反应生成碳二亚胺。探讨了454.7℃的残余物的空间结构,与碳二亚胺两端相联的聚合片段平面是共平面或相互垂直的。 相似文献
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P. K. GALLAGHER D. W. JOHNSON F. SCHREY 《Journal of the American Ceramic Society》1970,53(12):666-670
Conventional thermogravimetry, differential thermal analysis, and evolved gas analysis were used to study the thermal decomposition of reagent-grade FeSO4 ·7H2 O and of freeze-dried FeSO4 ·H2 O in oxidizing and inert atmospheres. The mechanism depends on the atmosphere but is the same for the freeze-dried and conventional materials. In oxygen, iron(II) is converted to iron(III) before the sulfate ion decomposes, whereas in nitrogen this conversion occurs simultaneously with the first step of the sulfate decomposition. The presence of moisture lowers the decomposition temperature. Moess-bauer spectroscopy, X-ray diffraction data, and surface area measurements substantiated the proposed decomposition schemes. 相似文献
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纳米HMX基PBX的热分解特性 总被引:1,自引:0,他引:1
采用溶液-水悬浮法,通过控制水料比、反应温度、搅拌速度等因素制备了纳米HMX基PBX。使用热重(TG)/差示扫描量热(DSC)同步热分析仪研究了其热分解特性。结果表明,纳米HMX基PBX热分解反应的DTG峰温、活化能和放热量分别为557.5K、270.5kJ/mol和816.3J/g;与微米HMX基PBX相比,纳米HMX基PBX的DTG峰温延后3.7K,活化能提高86.9kJ/mol,放热量增加158J/g。在558.3K以下,纳米HMX基PBX的安定性优于微米HMX基PBX。 相似文献
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V. V. Nedelko N. V. Chukanov A. V. Raevskii B. L. Korsounskii T. S. Larikova O. I. Kolesova F. Volk 《Propellants, Explosives, Pyrotechnics》2000,25(5):255-259
The thermal decomposition kinetics of different polymorphs of CL‐20 (α, γ and ε) has been investigated by thermogravimetry, IR spectroscopy and optical and electronic microscopy. The reactions proceed with self‐acceleration and can be described by a kinetic law of first order with autocatalysis. Already at the earliest stages of decomposition (≤1%) phase transitions take place from αγ and from εγ. For this reason the observed decomposition is related to the decomposition of γ‐CL‐20. On the other hand, the kinetics of decomposition depends on the initial polymorphic state, so that the thermal decomposition increases in the series: α<γ<ε. Experiments with different samples of α‐CL‐20 demonstrate that different rates of decomposition are observed for the same polymorph depending on the mean size and the size distribution of the crystals and their morphological features. In some cases the thermal stability of α‐CL‐20 can be increased by previous annealing. It is concluded that the thermal decomposition of CL‐20 is purely a solid‐state process. Microscopical and spectroscopical analysis of the condensed CL‐20 decomposition product (formed after prolonged heating at high temperature) show that it has a network structure and consists mainly of carbon and nitrogen. 相似文献
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F. Azimfar I. Kohsari S. M. Pourmortazavi 《Journal of Inorganic and Organometallic Polymers and Materials》2009,19(2):181-186
Data on thermal stability of metallocene catalysts such as bis(n-butyl cyclopentadienyl) zirconium dichloride and bis(t-butyl
cyclopentadienyl) zirconium dichloride is required because of their application in high temperature polymerization process.
In the present study, the thermal stability of the bis(n-butyl cyclopentadienyl) zirconium dichloride and bis(t-butyl cyclopentadienyl)
zirconium dichloride was determined by differential scanning calorimetry (DSC) and simultaneous thermogravimetry-differential
thermal analysis (TG-DTA) techniques. The results of TG analysis revealed that the main thermal degradation for the bis(n-butyl
cyclopentadienyl) zirconium dichloride and bis(t-butyl cyclopentadienyl) zirconium dichloride occurs in the temperature ranges
of 194–360 °C and 195–350 °C, respectively. On the other hand, TG-DTA analysis indicated that bis(n-butyl cyclopentadienyl)
zirconium dichloride melts (about 98.7 °C) before it decomposes. However, the thermal decomposition of the bis(t-butyl cyclopentadienyl)
zirconium dichloride was started simultaneously with its melting. Also, the kinetic parameters such as activation energy and
frequency factor for both compounds were obtained from the DSC data by non-isothermal methods proposed by Kissinger and Ozawa.
Based on the values of activation energy obtained by Kissinger and Ozawa methods, the following order for the thermal stability
was noticed: bis(t-butyl cyclopentadienyl) zirconium dichloride >bis(n-butyl cyclopentadienyl) zirconium dichloride. Finally,
the values of ΔS#, ΔH# and ΔG# of their decomposition reaction were calculated. 相似文献