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采用热重法(TG)和差示扫描量热法(DSC)测定加巴喷丁(GBP)在氮气氛和空气氛中的热分解过程,测定GBP、热分解过程中不同阶段残余物和气化物的红外光谱,探讨GBP的热分解机理.根据不同升温速率下的热重曲线计算GBP热分解反应的动力学参数,采用Dakin方程推算GBP在各种温度下的预期寿命.结果表明,GBP的热分解过... 相似文献
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聚对苯二甲酸乙二醇酯热降解动力学的研究 总被引:1,自引:0,他引:1
本文用热重法(TGA)研究了聚对苯二甲酸乙二醇酯(PET)的热降解动力学。结果表明:PET的热降解按两个失重阶段进行,每一个失重阶段均为一级热降解反应。另外,还计算出PET的热降解活化能和频率因子。 相似文献
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采用差示扫描量热分析法(DSC)、热重分析法(TG)和微分热重法(DTG),研究了力醇罗抗菌药的热分解动力学过程,计算了其热分解动力学参数一活化能(E),分析了其热分解机理,并剖析了其结构特征。 相似文献
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文章利用DSC TG(差示扫描量热法与热重法)联用技术,在不同的升温速率((10℃/min,20℃/min,40℃/min),下用热分析仪研究了爆炸焊接炸药的热分解动力学规律,求出了混合前后体系的活化能E(kJ/mol),指前因子A(s-1)和动力学机理函数F(a),也给出了各体系在某一特定温度下的热分解速率常数k(s-1)以及热分解起始温度T(K)等。这样我们便得出了该种炸药的热安全性与否。使其能够在工业领域得到合理安全的应用。 相似文献
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利用热重法研究了SIS-甲基丙烯酸甲酯接枝共聚物(SIS-PMMA)在N2气氛条件下以不同升温速率时的热降解动力学及其热寿命。确定了热分解温度与升温速率的关系,求得了热分解过程的表观活化能,得到了不同失重率时的热寿命方程,计算出标题化合物在不同温度下的寿命。 相似文献
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将线型低密度聚乙烯(PE-LLD)与苯氧基环三磷腈(PCPZ)熔融共混,采用热重(TG)法及Freeman-Carroll法分析了PCPZ及PE-LLD/PCPZ共混物的热分解行为。结果表明,PCPZ对PE-LLD的热分解具有催化作用。在PCPZ质量分数为0~10%内,随PCPZ含量的增加,PE-LLD/PCPZ共混物热分解反应的活化能(E)、起始失重温度(T0)、转化率(α)由0增至50%的温度(T50%)、热失重终止温度(Tf)、α由0增至100%的升温幅度(ΔTall)、最大热分解反应速率[(dα/dT)max]、最大热分解反应速率温度(Tmax)、最大热分解反应速率时的转化率(αmax)均下降。同时分别求解了PCPZ及不同PCPZ含量下PE-LLD/PCPZ共混物的热分解反应动力学参数(E、反应级数n、指前因子A),得到了PCPZ阻燃PE-LLD的机理。 相似文献
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不同热分析方法研究B炸药的热分解 总被引:2,自引:0,他引:2
用差示扫描量热仪(DSC)、热重-微熵热重分析仪(TG-DTG)、动态真空安定性技术(DVST)和温度跃升傅里叶变换红外(T-Jump/FTIR)光谱测定法对B炸药在不同试验条件下的热分解行为进行了研究。结果表明,在50~400℃有一个吸热峰和放热峰,吸热峰与主体炸药TNT的熔化峰相一致,放热峰与主体炸药RDX的分解峰一致。在50~400℃有两个失重阶段,第一个失重阶段的失重量与主体炸药TNT的失重量一致,第二个失重阶段的失重量与主体炸药RDX一致,与DSC分析结果相符。B炸药在100℃/48h下的产气量为0.43mL/g,表明B炸药有好的热安定性。B炸药快速热裂解过程的含氮气相产物主要有NO、NH3、HCN和HONO。含碳气体产物主要有CO、CO2、HOCO和HCN。得到了这些产物相对摩尔浓度随时间变化的曲线。 相似文献
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利用红外光谱、X-射线衍射、热重-差热分析-质变联用及透射电镜等分析手段,研究了山嵛酸银的热分解过程。红外光谱、X-射线衍射以及热重-差热分析结果表明,加热山嵛酸银产生了复杂的结构变化,其中有2个明显的热转变过程。在138℃左右,山嵛酸银产生了第1个热转变,即分子中烷基链从有序转变为无序状态;在231℃左右产生了第2个热转变,山嵛酸银发生了结构变化,即山嵛酸热分解。山嵛酸银的主要热分解产物是金属银和山嵛酸。热重-差热分析-质镨联用的分析结果表明,山嵛酸银热分解的气态产物为二氧化碳,水,氢气,乙炔及一些小分子烯烃。 相似文献
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In this study, the thermal decomposition properties of aminonitrobenzodifuroxan are studied using a differential scanning calorimeter (DSC), a thermogravimeter (TG), an X‐ray diffractometer, a mass spectrometer (MS), and a Fourier transform infrared spectrometer (FTIR). The results demonstrate that aminonitrobenzodifuroxan undergoes thermal decomposition in the solid state. Under elevated temperatures, the decomposition primarily involves two steps: separation of nitro group and ring‐scission of the furoxan circles at 198.1 °C, and decomposition of the relatively stable residues (benzofuroxan circle) at 199.1 °C. Moreover, it is found that among the products, nitrogen dioxide undergoes oxidation and catalysis on the host molecule during the whole decomposition. Based on Kissinger and Ozawa functions, we deduce that the activation energies of these two reactions are 167.68 and 204.55 kJ mol−1, respectively. The released energy (ΔH) of CL‐18 is −1781.8 J g−1. 相似文献
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Tai-Shung Chung Min Cheng P. K. Pallathadka Suat Hong Goh 《Polymer Engineering and Science》1999,39(5):953-962
The melting and crystallization behavior of Vectratm B950, a random liquid crystalline copoly(ester amide), was studied by differential scanning calorimetry (DSC). Nonisothermal experiments showed the existence of some interesting and peculiar transition behavior, which may depend on the crystallization conditions (cooling rate). In isothermal experiments, both the thermal and crystallization behavior have been studied as functions of annealing temperature and annealing time. Different thermal behaviors were observed, indicating the possibility of multiple states of mesophase aggregation In addition, the thermal decomposition of Vectra B950 was also studied by TGA-FTIR in both nitrogen and air environments. A single-stage decomposition process was found when heating in nitrogen atmosphere, and the decomposition is due to the easter linkage rupture. A double-stage decomposition process was found when heating in air, and the decompositions are mainly due to the ester linkage rupture for the first decomposition step and the oxidative reaction for the second decomposition step. Annealing slightly changes the decomposition composition occuring in the early stage of thermal degradation. 相似文献
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Xiaogang Mu Xuanjun Wang Xiangxuan Liu Youzhi Zhang 《Propellants, Explosives, Pyrotechnics》2012,37(3):316-319
The thermal decomposition behavior of unsymmetrical dimethylhydrazine (UDMH) oxalate was studied using differential scanning calorimetry (DSC), thermogravimetric analysis (TG/DTG), and thermogravimetric analysis combined with infrared spectroscopy (TG‐IR). The endothermic decomposition of UDMH oxalate occurred at temperatures between 180.4 °C and 217.6 °C, the maximum decomposition temperature is 199.2 °C. The kinetic parameters of the decomposition reaction were calculated based on the Kissinger equation. The TG‐IR spectra indicated that the thermal main decomposition products of UDMH oxalate are CO2,H2O and NH3. 相似文献
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Thermal behavior of brominated atactic polypropylene (BAPP), obtained by thermal bromination of atactic polypropylene (APP), was evaluated by thermogravimetric analysis (TGA) and differential thermal analysis (DTA). It was found that the initial decomposition temperature (IDT) and char yield increase with the increase in bromine content while integral procedural decomposition temperature (IPDT) showed a decreasing trend. A comparative study of these value in inert and oxidative atmospheres has been made. DTA study shows that onset decomposition temperature (ODT) and glass transition temperature (Tg) increase with the increase in degree of bromination. The possible reasons for the occurring phenomena have been discussed. 相似文献
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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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HAN-基凝胶推进剂的热分解反应动力学 总被引:2,自引:0,他引:2
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100 kJ/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。 相似文献