多级孔无铝Beta分子筛的合成与表征

研究了氟介质条件下,合成参数对前驱体黏度和无铝Beta分子筛晶化过程的影响.X射线衍射结果表明,高水硅比可降低前驱体的黏度,但抑制分子筛的晶化.当合成体系中加入成核促进剂(二氧化锗)和晶化促进剂(高氯酸根或磷酸根)后,即使水硅摩尔比高达20~30,在150℃水热合成4 d,仍可获得高结晶性、微米级球形或多面体形无铝Beta分子筛.热重和能谱分析结果表明,极少量高氯酸根和磷酸根可进入分子筛孔道,并影响模板剂四乙基铵根离子的热分解过程.氮气吸附-脱附、扫描电子显微镜、透射电子显微镜和选区电子衍射分析结果表明,所得无铝Beta分子筛具有多级孔结构,介孔尺寸在3.4~3.8 nm之间,由纳米晶体或纳米棒堆积而成.     

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.     

Thermochemistry on Coordination Behavior of Praseodymium Chloride Hydrate with Diethylammonium Diethyldithiocarbamate

The complex of praseodymium chloride lower hydrate with diethylammonium diethyldithiocarbamate (D-DDC) has been synthesized conveniently in absolute alcohol and dry N2 atmosphere. The title complex was identified as Et2NH2[Pr(S2CNEt2)4] by chemical and elemental analyses, the bonding characteristics of which were characterized by IR spectrum.The enthalpy of solution for praseodymium chloride hydrate and D-DDC in absolute alcohol at 298.15 K, and the enthalpy changes of liquid-phase reaction of formation for Et2NH2 [ Pr(S2CNEt2)4] at different temperatures were determined by miccocalorimetry. On the basis of experimental and calculated resuits, three thermodynamic parameters (the activation enthalpy, the activation entropy and the activation free energy),the rate constant and three kinetic parameters (the apparent activation energy, the pre-exponential constant and the reaction order) of liquid phase reaction of formation were obtained. The enthalpy change of the solid-phase title reaction at 298.15 K was calculated by a thermochemical cycle.     

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…     

Thermal Decomposition Kinetics of Triethylene Glycol Dinitrate

Introduction Triethylene glycol dinitrate (TEGDN) is a novel en-ergetic material containing two groups of NO2, which can be used as an energetic plasticizer ingredient in propellants because of its excellent proformance.1 It exhibits lower impact sensitivity, better thermostability, weaker poisonousness and volatility, and stronger effec-tiveness of plasticizing cellulose nitrate than nitroglyc-erine (NG). As a new plasticizer TEGDN has good ap-plication prospects in the near future. The…     

油酸包覆纳米铝粉/黑索今复合体系的热行为及非等温分解反应动力学

在氮气气氛下,采用油酸(OA)对纳米铝粉(nmAl)进行了表面包覆处理,采用扫描电镜(SEM)、X射线衍射(XRD)和傅里叶变换红外(FTIR)光谱对其形貌和结构进行了表征.用差示扫描量热(DSC)对油酸包覆前后的纳米铝粉与黑索今(RDX)构成的复合体系[nmAl/RDX和(nmAl+OA)/RDX]的热分解反应动力学进行了研究,得到了动力学参数和动力学方程.结果表明,大量油酸以物理吸附的方式吸附在纳米铝粉表面,少量油酸与纳米铝粉表面铝原子发生了化学反应,以化学键合的形式附着在纳米铝粉表面.与nmAl/RDX复合体系相比,(nmAl+OA)/RDX复合体系在不同升温速率下的分解峰峰温都相对降低,分解反应的表观活化能(Ea)和指前因子(A)分别为141.18kJ·mol-1和1012.57s-1,分解反应机理为三维扩散,服从n=1/2的Jander方程,其动力学方程为dα/dt=1013.35(1-α)2/3[1-(1-α)1/3]1/2e-16981.0/T.     

含能配合物[Mn（BTA）（phen）2·5H2O]n的合成、结构与性质研究

以N,N′-二（5-四唑基）胺为含能配体设计合成了一个含能配合物[Mn（BTA）（phen）2·5H2O]（1）（BTA=N,N′-二（5-四唑基）胺,phen=1,10-phenanthroline）,利用元素分析,X射线单晶衍射,红外光谱以及热重分析等手段对标题化合物进行了表征,并研究了配合物1对固体推进剂主要组分HMX热分解行为的影响,结果表明配合物1可以降低HMX的分解峰温．晶体学数据：单斜晶系,P2（1）／c空间群,a=1．0752（6）nm,b=2．6913（14）nm,c=1．0965（6）nm,β=107．953°,V=3．019（3）nm^3,Z=4,S=1．010,最终残差因子[I〉2σ（I）]R1=0．0420,wR2=0．1084,对于全部数据R1=0．0608,wR2=0．1207．     

氧化锰纳米管及其超级铝热剂:制备及对环三亚甲基三硝胺热分解的影响

采用水热法制备了MnO₂纳米管,以其与纳米铝粉为原料,采用超声分散复合的方法,制备了超级铝热剂Al/MnO₂.利用粉末X射线衍射(XRD)、扫描电子显微镜(SEM)及能量散射光谱仪(EDS)对产物的物相、组成、形貌和结构进行分析表征,并运用差示扫描量热法(DSC)研究了MnO₂纳米管及其超级铝热剂对环三亚甲基三硝胺热分解特性的影响.结果表明,水热法制备的纳米MnO₂呈管状均匀分布,球形纳米Al与管状纳米MnO₂相互依附,分散较均匀;MnO₂纳米管及其超级铝热剂的加入均改变了环三亚甲基三硝胺的热分解行为及分解历程,使原有占主导的液相分解变为二次的气相反应加剧,使环三亚甲基三硝胺主分解峰形发生了明显的改变.     

4-氨基-1,2,4-三唑苦味酸盐的晶体结构、比热容和热力学性质

利用4-氨基-1,2,4-三唑与苦味酸的甲醇溶液制备了4-氨基-1,2,4-三唑苦味酸盐,并于室温下培养出单晶。通过X射线单晶结构分析法测定其晶体结构,晶体属于正交晶系,空间群为Pbcn,晶胞参数为:a=0.9207(3)nm,b=1.9874(6)nm,c=1.3304(4)nm,β=90°,V=2.434(5)nm3,Dc=1.709g/cm3,Z=8,F(000)=1280,R1=0.0584,wR2=0.1840。运用DSC测得配合物在298.15K时的标准摩尔比热容为484.39J/(mol.K),比热容与温度的关系式为:Cp(J/(g.K))=0.4435+3.6997×10-3T。     

3,6-双(1-氢-1,2,3,4-四唑-5-氨基)-1,2,4,5-四嗪银盐的热分解反应动力学及热安全性

利用两步合成法,得到标题化合物3,6-双(1-氢-1,2,3,4-四唑-5-氨基)-1,2,4,5-四嗪(BTATz)银盐（Ag2(BTATz)·2H2O）,并用元素分析、X荧光和红外光谱分析对其进行了结构表征。 采用DSC和TG-DTG技术对化合物进行热分解行为及非等温热分解动力学研究。 结果表明,其热分解过程是由1个吸热阶段和2个放热阶段组成,主放热阶段的非等温热分解反应动力学方程为:dα/dt=1014.29×{3(1-α)[-ln(1-α)]1/4/4}exp(-2.10×104/T)。 计算得到化合物的自加速分解温度(TSADT)、热爆炸临界温度(Tb)、热点火温度(TTIT)和绝热至爆时间（tTIAD）分别为517.10 K、580.12 K、531.00 K和90.32 s ,以此来评价其热安全性。