煤温和气化特性的热重研究

用程序升温热重法对煤温和气化特性及反应动力学进行了研究。结果表明：ＣａＯ对煤的裂解具有明显的催化作用。在煤温和气化过程中，减小粒径、提高升温速率有利于煤的裂解反应。煤温和气化反应可分为两段，ＣａＯ的加入明显降低了低温区反应的活化能。低温区与高温区的表观活化能与指前因子呈现良好的线性关系     

The Modulation of Desulphurization Properties of Calcium Oxide by Alkali Carbonates

Kinetics of CaO desulphurization reaction and the effects of alkali carbonates on it have been investigated by thermogravimetric analysis. A grain model was applied successfully to describe the kinetic behavior of the reactions. The activation energy of surface reaction and that of the product layer diffusion were determined by using the model. It was found that the overall desulphurization rate was controlled initially by surface chemical reaction and, in a later stage, by product layer diffusion. Addition of alkali carbonates can decrease the activation energy of the surface chemical reaction, with increasing effectiveness in the order of potassium, sodium and lithium. Such a property of alkali carbonates has also been demonstrated on a raw coal. The process is discussed in terms of a working mechanism of solid-state ionic diffusion. This revised version was published online in August 2006 with corrections to the Cover Date.     

纳米氧化铜的粒度对多相反应动力学参数的影响

本文提出了纳米体系多相反应动力学活化能的模型，并以纳米氧化铜与硫酸氢钠溶液的反应为体系，研究了反应物粒度对动力学参数的影响规律，讨论了表观活化能降低的原因。结果表明：反应物粒度对多相反应的反应级数、速率常数、表观活化能和指前因子均有较大的影响；随着反应物粒径的减小，表观活化能和指前因子减小,而反应级数和速率常数增大，并且速率常数和表观活化能与反应物粒径的倒数呈线性关系；这些影响规律与理论模型是一致的。另外，还发现反应物粒度是通过摩尔表面积、摩尔表面能和摩尔表面熵影响多相反应的动力学参数的。     

Catalysis of the cure reaction of bisphenol A dicyanate. A DSC study

The kinetics of the thermal cure reaction of Bisphenol A dicyanate (BACY) in presence of various transition metal acetyl acetonates and dibutyl tin dilaurate (DBTDL) was investigated using dynamic differential scanning calorimetry (DSC). The cure reaction involved a pregel stage corresponding to around 60% conversion and a postgel stage beyond that. Influence of nature and concentration of catalysts on the cure characteristics was examined and compared with the uncatalyzed thermal cure reaction. The activation energy (E), preexponential factor (A), and order of reaction (n) were computed by the Coats–Redfern method. A kinetic compensation correction was applied to the data in both stages to normalize the E values. The normalized activation energy showed a systematic decrease with increase in catalyst concentration. The exponential relationship between E and catalyst concentration substantiated the high propensity of the system for catalysis. At fixed concentration of the catalyst, the catalytic efficiency as measured by the decrease in E value showed dependency on the nature of the coordinated metal and stability of the acetyl acetonate complex. Among the acetyl acetonates, for a given oxidation state of the metal ions, E decreased with decrease in the stability of the complex. A linear relationship was found to exist between activation energy and the gel temperature for all the systems. Manganese and iron acetyl acetonates were identified as the most efficient catalysts. In comparison to DBTDL, ferric acetyl acetonate proved to be a more efficient catalyst. The activation parameters computed using the Coats–Redfern method agreed well with the results from two other well known integral equations. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1103–1114, 1999     

Study on the reaction kinetics between PBT and epoxy by a novel rheological method

In the present study, the reaction kinetics of polybutylene terephthalate (PBT) and epoxy system was studied by a novel rheological method. The reaction process was determined by rheological test and the results showed that there were three stages in the reaction between PBT and epoxy, which were reaction-controlling stage (stage I), reaction-stagnation stage (stage II) and diffusion-controlling stage (stage III). In addition, the stage I was selected to study the reaction kinetics by the rheological method. The results showed that the reaction between PBT and epoxy could be classified as a pseudo-first-order reaction due to the excessive amount of epoxy group. Furthermore, the reaction apparent activation energy of the stage I determined by the rheological method was 143 kJ/mol. To confirm these results, the reaction kinetics was also evaluated by the endgroup determination method, and the results showed that the reaction could also be classified as a pseudo-first-order reaction. Moreover, the apparent activation energy of the reaction was 116 kJ/mol, which was similar to that of the value obtained by the rheological method.     

微波作用下的多肽固相缩合反应及动力学研究

分别在微波作用以及传统加热两种方式下, 研究了Fmoc-Val-OH与NH₂-Tyr(t-Bu)-Wang树脂的固相缩合反应及其动力学. 测定了温度变化对反应速率的影响, 并获得了两种方式下的缩合反应的宏观动力学参数: 300 W微波作用下表观缩合反应级数为2.3, 活化能为104.7 kJ/mol; 传统方法中表观反应级数为2.9, 活化能为142.4 kJ/mol. 微波作用将常规条件下的连接率由68%提高到95%, 而所需时间降为常规条件的1/14.     

STUDIES ON APPARENT KINETICS AND RHEOLOGICAL BEHAVIOR OF EPOXY/ACRYLATE IPNS AS VACUUM PRESSURE IMPREGNATION RESINS

The apparent kinetics and cure behavior of novel interpenetrating polymer networks(IPNs) based on cycloaliphatic epoxy resin(CER) and tri-functional acrylate have been investigated by means of differential scanning calorimetry(DSC) and Fourier transform infrared spectroscopy(FT-IR).The results of DSC measurements show that the curing reaction of the TMPTMA component is much earlier than that of the CER component,which can lead to the formation of the IPNs.In contrast to neat anhydride-CER system,the anhy...     

SCRCR'CO重排反应的量子化学研究

用ＭＩＮＤＯ／３方法研究ＳＣＲＣＲ’ＣＯ的热重排反应的机理，给出了活化能和ＩＲＣ途径，讨论了活化能与取代基Ｒ’和迁移基Ｒ的性质之间的内在联系。     

粒度对多相反应动力学参数的影响

以纳米氧化锌与硫酸氢钠溶液为反应体系, 研究反应物粒度对动力学参数的影响规律. 讨论了表观活化能降低的原因. 结果表明：当反应物粒径、反应温度和搅拌速率一定时, 纳米氧化锌与硫酸氢钠溶液的反应速率仅与反应物的浓度有关；反应物粒度对多相反应的反应级数、速率常数、表观活化能和指前因子均有较大的影响；随着反应物粒径的减小, 表观活化能和指前因子减小, 而反应级数和速率常数增大, 并且速率常数和表观活化能与反应物粒径的倒数呈线性关系；反应物粒度是通过摩尔表面积、摩尔表面能和摩尔表面熵三个方面影响多相反应的动力学参数的.     

生物油重质组分模型物热解行为及其动力学研究

采用TG-FT-IR在非等温条件下对生物油重质组分酚、醛和糖类模型代表物(丁香酚、香草醛、左旋葡聚糖)进行热解特性及其热解动力学分析。TG-DTG曲线和FT-IR测试数据显示,重质组分模型物热解的先后次序是酚类、醛类、糖类物质。香草醛、丁香酚均为一个主热解阶段,主要产物为水、烷烯烃、CO₂、CO和小分子酚、芳香醛。左旋葡聚糖热解分两阶段进行,热解发生在较高温区(180~370℃),主要热解产物有CO₂、烷烯烃、醛、酮和环醚,少量的CO和水。混合物热解分为三个阶段,产物与单一模型物热解产物相似,但有少量缩醛低聚物。对比单一组分,混合物中羰基和羟基组分在较高温区(≥300℃)存在相互作用,生成难分解的缩聚物。其中,糖类是影响重质组分热解速率的主要物质。根据热重数据对热解各阶段进行动力学拟合,确定了模型物热解反应动力学三因素。平均表观活化能和反应级数分别为:E_{左旋葡聚糖}第一、第二阶段分别为115.80 kJ/mol(0.5级)、141.19 kJ/mol(2/3级); E_混合物第一阶段为54.46 kJ/mol(1级)、第二阶段为50.67 kJ/mol(2/5级); E_丁香酚为42.29 kJ/mol(0.7级); E_香草醛为36.53 kJ/mol(0.95级)。     

氧化锌颗粒脱硫中固体扩散的动力学分析

用电子探针显微分析 (EPMA)对ZnO基脱硫剂的脱硫颗粒径向硫分布行为进行了考查 ,对颗粒最外层粒子的实验结果分别用未反应收缩核模型及改良收缩核模型进行了动力学处理 ,给出了固体扩散活化能的参数估值。通过与热重研究的比较 ,进一步证实了固体粒子扩散的作用。     

馏分油浆态床加氢处理研究: II FCC柴油加氢工艺条件及动力学研究

对FCC柴油在浆态床柴油加氢催化剂SP25上的加氢工艺条件进行了优化,并考察了加氢脱硫（HDS）和加氢脱氮（HDN）动力学。结果表明,提高反应温度、提高反应压力、增加催化剂的加入量、延长反应时间都能提高催化剂的加氢精制活性,最佳的FCC柴油浆态床加氢工艺条件为,温度350℃、压力6MPa、催化剂加入量6%、反应时间2h。催化剂循环使用性能的考察结果表明,SP25催化剂具有良好的活性稳定性。动力学研究结果表明,FCC柴油的加氢脱硫反应过程可以分为两个阶段。第一阶段为较易脱除的苯并噻吩类（BTs）硫化物的加氢脱硫反应,反应活化能为70.00kJ/mol;第二阶段为较难脱除的二苯并噻吩类（DBTs）硫化物的加氢脱硫反应,反应活化能为85.65kJ/mol。FCC柴油HDN反应的活化能为79.91kJ/mol。烷基取代的二苯并噻吩类硫化物（特别是DMDBTs）是加氢精制反应中最难脱除的含杂原子（S或N）烃类化合物。     

Radiation-induced heterogeneous polymerization of methyl methacrylate in precipitants

The radiation-induced heterogeneous polymerization of methyl methacrylate in various precipitants, mainly methyl alcohol, was carried out, and the effects of reaction conditions on the polymerization behavior and the molecular weight distribution of polymer were studied. Bimodal molecular weight distributions were found for the polymer produced by the heterogeneous polymerizations in methyl alcohol and in tert-butyl alcohol. The apparent activation energy is 1.0 and 4.5 kcal/mole, respectively, for the polymerization at a monomer concentration of 10 vol-% in methyl alcohol above and below 35°C. The polymerization at a monomer concentration lower than 40 vol-% in methyl alcohol proceeded with the precipitation of polymer. The dose rate exponent of the mean rate of heterogeneous polymerization decreased from 0.5 to a smaller value as the polymerization progressed. The ratio of the two peaks in the bimodal molecular weight distributions of polymer produced in methyl alcohol was affected by the reaction conditions. These results show the coexistence in the polymerizations of two different physical states of propagating chain, a loose state and a rigid one. The reaction scheme is discussed in connection with the physical factors which affect the solubility or the mobility of propagating chains, and the rate of elementary reactions, which influences the degree of propagating chains.     

Effects of Aluminum on Thermal Decomposition of Hexogen/Ammonium Perchlorate

Thermogravimetry-differential scanning calorimetry-mass spectrometry-Fourier transform infrared spectrometry（TG-DSC-MS-FTIR） simultaneous analysis was used to study the effects of 10.7 μm and 40 nm Al on the thermal decomposition of the Hexogen/ammonium perchlorate（RDX/AP,1/2,mass ratio） mixture.TG-DSC results show that there are two mass loss processes for the thermal decomposition of RDX/AP/Al.The first one is mainly ascribed to the thermal decomposition of RDX.The reaction rate of RDX/AP/10.7 μm Al is so fast that the apparent activation energy,calculated by model-free Friedman method,is negative,which is the same as that of RDX/AP.30％（mass fraction） 40 nm Al added in RDX/AP change the activation energy from negative to positive value.The second mass loss process of the RDX/AP/A1 mixture is ascribed to the thermal decomposition of AP.This process can be divided into three stages for RDX/AP with and without Al.The kinetics model is not changed in the presence of micro-sized Al,while it is changed from CnB/D1/D1 to CnB/D1/D4 after the addition of 40 nm Al to RDX/AP.The reaction rate constant of the first stage and the end temperature of the second stage decrease,while the end temperatures of the third stage increase in the presence of 40 nm Al.The MS-FTIR results show there is a competition between the formation reactions of HNCO,N2O and NO2 during the second mass loss process.     

SCRCR′CO重排反应的量子化学研究

用MINDO／3方法研究SCRCR′CO的热重排反应的机理，给出了活化能和IRC途径，讨论了活化能与取代基R′和迁移基R的性质之间的内在联系．     

多官能度炔烃与叠氮化物的固化研究

采用差热扫描量热仪 (DSC)研究了不同分子量的端叠氮基聚乙二醇 (ATPEG)与N ,N ,N′,N′ 四炔丙基乙二胺及 1 ,1 ,1 三 (炔丙氧甲基 )丙烷的固化反应动力学 ,并利用FT IR跟踪了固化反应过程中特征基团的变化 .结果表明 ,ATPEG与N ,N ,N′,N′ 四炔丙基乙二胺固化反应的峰温及反应活化能均高于与 1 ,1 ,1 三 (炔丙氧甲基 )丙烷的固化反应 .增加ATPEG的分子量 ,升高了与多官能度炔烃的固化峰温 ,却降低了固化反应的活化能 .而采用扩链剂仅降低固化反应活化能 .     

Kinetic studies on the deamination of [Co(en)3](NCS)3

The loss of ethylenediamine from [Co(en)₃](NCS)₃ has been studied using isothermal weight loss methods. The reaction has been found to be catalyzed by NH₄SCN and piperidine hydrothiocyanate, and the reaction appears first order in catalyst. However, the reaction proceeds so slowly without a catalyst present that a reliable activation energy could not be obtained. For the catalyzed process, the activation energy appears to decrease slightly as the amount of catalyst used is increased, although the results are inconclusive when NH₄SCN is the catalyst. When piperidine hydrothiocyanate is the catalyst, the activation energy appears to decrease from 37.7 kcal mole^?1 to 29.4 kcal mole^?1 as the amount of catalyst increases from 0.5 to 8.0 mole percent. In all cases, the product turned dark after a few hours indicating some reduction as a complicating feature.     

Theoretical studies on the electrocyclic reactions of bis(allene) and vinylallene. Role of allene group

The reaction mechanisms of the electrocyclic ring closure of bis(allene) and vinylallene were studied by ab initio MO methods. The conrotatory and disrotatory pathways of the electrocyclic reactions from bis(allene) to bis(methylene)cyclobutene were determined by a CASSCF method. The transition state on the conrotatory pathway is 26.8 kcal/mol above bis(allene) and about 23 kcal/mol lower than that on the disrotatory pathway at a MRMP calculation level. The activation energy on the conrotatory pathway is lower by 23 kcal/mol than that of the electrocyclic reaction of butadiene. This lower energy barrier comes from the interactions of the "side pi orbitals" of the allene group. The interaction of the "vertical pi orbitals" of the allene group is predominant at the early stage of the reaction. The activation energy of the electrocyclic reaction of vinylallene is about 8.5 kcal/mol higher than that on the conrotatory pathway of bis(allene).     

聚甲基丙烯酸甲酯热氧化降解的化学动力学研究

使用质谱、热分析手段研究了PMMA热解反应.结果表明,在氮气中,PMMA-CH=CH2有两个失重阶段,分别对应于主链末端双键引发的断链和主链无规则断链反应,转折点的失重率约为26%.其中,第一阶段的失重速率受扩散过程控制,平均表观活化能E为158.5 kJ/mol, lnA为27.69;第二失重阶段为1.5级化学反应,平均表观活化能E为214.79 kJ/mol, lnA为40.46.在空气中, PMMA也有两个失重阶段,反应机理为1级化学反应,转折点处的失重率约为70%.其中在第一失重阶段平均表观活化能E为130.32 kJ/mol, lnA为24.81,在此阶段中, 过氧化基团的分解反应对PMMA的失重速率有重要影响; 在空气中第二失重阶段平均表观活化能E为 78.25 kJ/mol, lnA为13.97.     

Kinetics of thermo-oxidative degradation of polypropylene/aluminum trihydroxide/organo Fe-montmorillonite nanocomposites

In the article, the thermal oxidative degradation kinetics of pure polypropylene/aluminum trihydroxide (PP/ATH) and PP/ATH/organo Fe-montmorillonite (Fe-OMT) nanocomposites were investigated using Kissinger, Friedman and Flynn–Wall–Ozawa methods. The results showed that thermal oxidative degradation of PP/ATH/Fe-OMT nanocomposites to PP/ATH were complex reaction: the whole process of thermal oxidative degradation were composed with the decomposition of ATH, the cracking and charring of the backbone chains of PP, and the oxidative degradation of char, which the curses of energy mutative with the process of thermal oxidative degradation. The control steps were different in each degradation stage. The activation energy was high in the original degradation stage. It was due to the molecular structure and may closely relate with onset temperature. In the intermediate process, the activation energy was low. In the last stage of the degradation, the activation energy was graveled because the carbon may be oxidized. In the whole process of thermal oxidative degradation, the activation energy of PP/ATH/Fe-OMT nanocomposite was higher than that of PP/ATH.