锆英石的合成

概述了近年来化学法合成锆英石（ＺｒＳｉＯ４）的典型工艺及合成温度,并对合成过程中的晶相变化,影响锆英石合成的因素及锆英石合成机理进行了综述。     

Compressibility and Phase Transition Kinetics of Lanthanide-Doped Zircon

The structure and compressibility of synthetic lanthanide-doped zircon (ZrSiO₄ with a total of 2.0 mol% trivalent Gd, Dy, Er, Yb, and Y, charge-balanced by addition of P⁵⁺) were determined from static compression experiments to 25.9 GPa. The sample bulk modulus, K _{T 0}=189±1 GPa is 5% lower than K _{T 0} for undoped zircon, and the sample transforms from the zircon to the scheelite structure above 22.6 GPa, 3 GPa greater than the transformation pressure in pure ZrSiO₄. A simple model is presented linking compressibility with unit-cell volume for zircon-structured and scheelite-structured ABO₄ compounds, allowing prediction of the compressibility of zircon-structured vanadates and phosphates.     

Kinetics of Barium Titanate Synthesis

Reaction curves were obtained at various temperatures and concentrations for the formation of BaTiO₃ from particulate titania in Ba(OH)₂ solution. Kinetic analyses were performed by constructing mathematical models which took into account the particle size distribution of the reactant titania for both the topochemically-rate-controlled and the diffusion-rate-controlled reactions. At [Ba(OH)₂] > ca. 0.1 M the rate-controlling step is the Ba reaction with TiO₂ at the interface. The measured activation energy is 105.5 kJ/mol. The rates are independent of Ba(OH)₂ concentration, indicating that the TiO₂ interface is saturated. At [Ba(OH)₂] < ca. 0.1 M the rate-determining step shifts to diffusion through the product BaTiO₃ layer, the rates are concentration dependent, and the BaTiO₃ particle sizes are inversely proportional to the Ba(OH)₂ concentrations used.     

Synthesis of Gray Zirconium Silicate Pigments from Zircon Mineral

Zirconium silicate (zircon) pigments in new gray hues have been prepared from mineral zircon as a low-cost raw material. In the first step this material was deocmposed with a waste mixture of NaOH-KOH. In the second step the pigments were synthesized with addition of manganese, especially manganese(II) carbonate, as the chromophore. The optimum conditions for the syntheses of pigments have been estimated and the properties of products (hues, applicability to ceramic glazes) have been evaluated.     

六氯丙烷合成反应动力学研究

以CuCl/CuCl2为主催化剂、正丁胺为助催化剂,对合成六氯丙烷的调聚反应动力学进行了研究,提出了压力为0.6MPa,温度在100～115℃下的反应动力学方程式:(-rA)=4.93×1017exp(-6.84×104/RT)cA0(1-xA)     

Kinetics and Mechanism of Ammonia Synthesis

Synthesis of ammonia on iron catalysts was discovered in 1905. Five years later, an iron catalyst containing two promoters, alumina and potassium oxide, was invented by a team of Badische Anilin und Soda Fabrik (BASF). The first high-pressure ammonia plant went on stream in 1913. Thus it took only 8 years between discovery, invention, and innovation, a remarkable record considering the novelty at the time of high-pressure operation [1]. Also noteworthy is the fact that the original BASF iron catalyst is still in use today although additional promoters are added to the two original ones in various commercial formulations [2]. In fact, recent advances in ammonia manufacture have been largely of an engineering nature [3]. This is so in spite of a very large amount of fundamental and applied work designed to elucidate the mechanism of the reaction and the surface chemistry of commercial or alternative catalysts.     

The Kinetics of the Fischer-Tropsch Synthesis

The literature on Fischer-Tropsch synthesis can be divided into two broad categories: The major portion falls into the category of empirical product distribution studies done with catalyst improvement in mind, while a smaller body of data has been slowly accumulated with the intention of understanding the fundamentals of the reaction. Of this smaller body of mechanistic and kinetic work, only part deals with the quantitative formulation of rate and product distribution phenomena. A vigorous effort has also been made in recent years to contribute to this understanding by surface studies. This approach, however, has at best offered tantalizing views of the various adsorbed species without leading to a quantitative formulation of the kinetics of observable phenomena at reaction conditions.     

聚氨酯丙烯酸酯齐聚物的合成及其反应动力学

以异佛尔酮二异氟酸酯、丙烯酸羟丙酯和聚乙二醇为原料。采用本体法两步合成聚氨酯丙烯酸酯齐聚物,经光热引发交联成型后可用作聚氨酯弹性体。通过温度、原料、催化剂类型及其用量对反应速率常数影响的实验,研究结果表明;齐聚物的合成是二级反应;温度对反应速率常数影响大;不同反应物的反应速率常数明是不同。由于催化机理的不同。有机锡和叔胺催化剂造成反应速率常数差异较大．并且发现使用三乙胺催化时,催化剂用量对反应速率常数影响明显。     

The Kinetics of the Fischer-Tropsch Synthesis

The literature on Fischer-Tropsch synthesis can be divided into two broad categories: The major portion falls into the category of empirical product distribution studies done with catalyst improvement in mind, while a smaller body of data has been slowly accumulated with the intention of understanding the fundamentals of the reaction. Of this smaller body of mechanistic and kinetic work, only part deals with the quantitative formulation of rate and product distribution phenomena. A vigorous effort has also been made in recent years to contribute to this understanding by surface studies. This approach, however, has at best offered tantalizing views of the various adsorbed species without leading to a quantitative formulation of the kinetics of observable phenomena at reaction conditions.     

对叔丁基苯基五唑的合成及分解动力学

以对叔丁基苯胺为原料,在低温条件下合成出对叔丁基苯基五唑(p-tBPP)。用低温动态核磁分析技术研究了p-tBPP的分解动力学,确定了p-tBPP的分解反应为一级反应;获得了p-tBPP的半衰期t1/2,得出在氘代甲醇中p-tBPP分解反应的活化能及指前因子分别为93.1kJ/mol和3.80×1014s-1,并在此基础上预估了在不同温度区间的稳定性。     

甲基叔丁基醚合成反应动力学研究

本文用新颖的液固相微型反应器对甲基叔丁基醚合成反应动力学作了研究.证明这一可逆过程的正反应在不同醇烯比时会发生反应级数的改变.决定反应级数改变的醇烯比又与温度有关,归纳出描述这一关系的经验方程.考察了逆反应速度,提出合成甲基叔丁基醚反应在两种情况下的可逆反应动力学模型.文中还讨论了反应机理,并为解释反应级数改变提出了部分新的假设.     

锆英石系无机色料的工业搭烧

为了降低锆英石系色料的使用成本,可通过在低温快烧陶瓷辊道窑生产线冷却段预留孔进行色料的搭烧,利用通用色差仪对所得产品进行色调测定,并调整配方和工艺,试验结果表明,以钒锆蓝为例,当复合矿化剂添加量质量分数为14%,烧成温度为950℃并恒温2h,烧成气氛为弱还原性时,能够合成发色纯正的锆英石系无机色料,这也为锆英石系无机色料工业性生产提供了另一条生产途径。     

对苯二甲酸二异辛酯合成的反应机理和动力学

测定了对苯二甲酸(A)与异辛醇(B)在钛酸四丁酯催化下,合成对苯二甲酸二异辛酯(DOTP)反应过程中的产品分布.发现组分浓度随时间的变化符合连串反应的规律.第一步,自A生成单酯(R)是慢反应;第二步自R生成DOTP是快反应.在反应前90min内温度变化在10℃左右,如果粗略地看作等温,可以用两步速率常数的比值等于19拟合实验数据.进而按照第一步是总反应的控制步骤提出了一个二级表观动力学方程式,可以用于反应全过程的生产控制.     

新型非耕地除草剂嘧磺隆合成反应动力学研究

采用间歇玻璃反应釜进行糖精钠与氯甲酸甲酯在丙酮中的缩合反应和Ｎ－（２－甲氯甲酰基苯磺酰）氨基甲酸甲酯与２－氨基－４,６－二甲基啶于抽余油中的缩合反应动力学研究。利用序贯实验设计法安排实验点,用Ｇａｕｓｓ－Ｎｅｗｔｏｎ法进行学微分模型的参数估值,得到了两个反应的动力学方程。     

五氯苯甲腈合成的动力学研究

在五氯苯甲腈制备研究的基础上,通过苯甲腈气固相催化氯化过程的动力学实验研究,对反应机理进行分析和简化,提出了一个宏观反应动力学模型,并进行了参数估计     

六氟环氧丙烷合成反应动力学

针对自主开发的以六氟丙烷（FC-36）为溶剂,六氟丙烯和氧气为原料,合成六氟环氧丙烷的新工艺,考察了原料及溶剂配比、反应温度等条件的影响规律,进而着重研究了该反应的动力学模型。结果表明,该反应在3MPa和110～125℃下为六氟丙烯的一级反应,表观活化能为80．9kJ／mol。     

羟戊醛的合成及其动力学研究

羟戊醛是多种精细化学品合成的重要中间体。采用正交实验设计法考察羟醛缩合制备羟戊醛的反应规律,并对缩合反应的动力学进行了研究。最佳反应条件：碳酸钠催化剂的用量为0.029mol/molHCHO,n（甲醛）∶n（异丁醛）=1∶1,反应时间5h,反应温度66℃。在此条件下产物收率可达97.6%。实验验证了推导出的合成羟戊醛反应的动力学模型,并得出反应速率方程。