莫来石的低温合成

介绍了低温合成莫来石所用的4种起始混合材料:固体混合物、溶胶混合物、硅酸-铝盐混合物、硅醇盐-铝盐混合物或硅醇盐-铝醇盐混合物,总结了用这4种起始混合材料低温合成莫来石的原理、过程和特点,并探讨了在耐火材料中应用的可能性。     

含硅聚氨酯弹性体的合成初探

从酸化的水玻璃中提取活性硅醇 ,然后与聚醚二醇混合 ,再与异氰酸酯反应 ,制得含硅的聚氨酯弹性体。并用固体核磁共振仪和热重分析仪对硅醇与多元醇的混合物的结构进行了分析。结果表明 :当硅醇添加量在一定范围内 ,弹性体的力学性能有所提高 ;在多元醇和硅醇之间没有产生明显的化学结合     

含硅聚氨酸弹性体的合成初探

从酸化的水玻璃中提取活性硅醇，然后与聚醚二醇混合，再与异氰酸酯反应，制得含硅的聚氨酯弹性体。并用固体核磁共振仪和热重分析仪对硅醇的混合物的结构进行了分析。结果表明：当硅醇添加量在一定范围内，弹性体的力学性能有所提高；在多元醇和硅醇之间没有产生明显的化学结合。     

三苯基硅醇与含氢硅油脱氢反应的研究

研究了三苯基硅醇与含氢硅油的脱氢反应,用FTIR、1H NMR谱、29Si NMR谱对产物结构进行了表征.结果表明,三苯基硅醇和含氢硅油在辛酸亚锡或氯铂酸催化下均可发生脱氢反应,相比而言,氯铂酸是较好的催化剂;当三苯基硅醇与含氢硅油的质量比不大于2.20时,在110 ℃下反应2 h后,三苯基硅醇可完全反应.     

酰胺铝鋰法测定硅醇羟基含量

近年来,硅有机化合物已广泛应用于国防和工业各个部门。在以烷基硅醇芳基硅醇为基础的聚硅氧烷等高聚物的生产中,需要使用快速、准确测定硅醇的分析方法。目前,测定硅醇羟基的方法有:气量法     

活性硅醇基聚氨酯水分散体的合成及其防腐性能

水玻璃作为一种廉价的矿物质,经提纯可得到活性硅醇,以其作为内交联剂可应用于聚氨酯的合成中。对不同活性硅醇添加量合成的聚氨酯水分散体粒径及其涂膜的吸水率、接触角、动电位极化曲线、热重和扫描电镜作了测试分析,结果表明当活性硅醇添加量为30%时,水分散体平均粒径最小,为28.83nm;随着活性硅醇添加量的增加,涂膜吸水率增大,接触角反而减小;动电位极化曲线拟合结果表明,当活性硅醇添加量为70%时,涂膜腐蚀电流密度最小且极化电阻最大;红外光谱和扫描电镜分别可以确定水分散体结构中含有Si-O-Si、Si-O-C的基团以及涂膜中含有二氧化硅粒子,说明活性硅醇在体系中不仅参与主链反应,还以无机粒子的形态存在于其中;热重分析表明活性硅醇的引入显著提高了涂膜的热稳定性。     

活性硅醇改性PVC膜的研究

以廉价的水玻璃为原料,用酸化法从水玻璃中得到硅的有机化合物——活性硅醇,并将活性硅醇直接掺杂到PVC膜中。实验结果表明:用活性硅醇掺杂,流涎法制得的PVC膜,硅在PVC膜中的分布均匀,粒径在10μm以下;硅改性后的PVC膜耐热性有了较为明显的改善。活性硅醇改性PVC膜经NaOH浓溶液处理溶去其中的SiO_2粒子后,形成了具有均匀微小孔洞的膜。其孔径与SiO_2粒子的粒径相近。通过控制活性硅醇在PVC膜中的质量分数制备含有不同孔径的PVC膜。     

六甲基二硅氧烷中三甲基硅醇含量的定量分析

利用气相色谱和1H NMR核磁共振分析了六甲基二硅氧烷(MM)中三甲基硅醇的含量。配备氢火焰离子化检测器(FID)的气相色谱进行准确定量。结果表明:采用FID气相色谱测定样品中三甲基硅醇的含量为53.15%;采用TCD气相色谱检测样品中三甲基硅醇的含量为55.27%;核磁共振检测出三甲基硅醇的质量分数为51.59%。     

甲基硅醇钠在建筑保温材料中的应用研究

根据中国建筑节能保温的要求,外墙外保温技术被大量使用。而现在广泛使用的保温材料,存在防火或防水的不足,针对其缺点进行了甲基硅醇钠的应用研究。利用甲基硅醇钠能经过反应,缩合成高分子化合物-网状有机硅树酯膜,能在物体表面形成憎水层,起到防水的作用。同时甲基硅醇钠又具有无毒、不燃、不挥发、对环境无污染等优点。     

聚合醇钻井液的研究与应用进展

综述了聚合醇钻井液体系,包括聚合醇-硅盐、聚合醇-钙盐盐水、聚合醇-钾盐、聚合醇-铝盐和聚合醇-聚合物等体系的研究进展;探讨了聚合醇的作用机理以及与盐类物质的协同作用机理;介绍了聚合醇类钻井液在国内外油田钻井中的应用效果;最后展望了聚合醇类钻井液的研究方向。     

Synthesis of biodiesel in supercritical alcohols and supercritical carbon dioxide

Biodiesel was synthesized in supercritical fluids by two routes: non-catalytically in supercritical alcohols and by enzyme catalysis in supercritical carbon dioxide. Two oils, sesame oil and mustard oil, and two alcohols, methanol and ethanol, were used for the synthesis. Complete conversion was observed for synthesis in supercritical alcohols whereas only a maximum of 70% conversion was observed for the enzymatic synthesis in supercritical carbon dioxide. For the synthesis in supercritical alcohols, the activation energies and pseudo-first order rate constants were determined. For the reactions in supercritical carbon dioxide, a mechanism based on ping pong bi-bi was proposed and the kinetic parameters were determined.     

Tandem reactions for streamlining synthesis: enantio- and diastereoselective one-pot generation of functionalized epoxy alcohols

[Reaction: see text] In 1980, Sharpless and Katsuki introduced the asymmetric epoxidation of prochiral allylic alcohols (the Sharpless-Katsuki asymmetric epoxidation), which enabled the rapid synthesis of highly enantioenriched epoxy alcohols. This reaction was a milestone in the development of asymmetric catalysis because it was the first highly enantioselective oxidation reaction. Furthermore, it provided access to enantioenriched allylic alcohols that are now standard starting materials in natural product synthesis. In 1981, Sharpless and co-workers made another seminal contribution by describing the kinetic resolution (KR) of racemic allylic alcohols. This work demonstrated that small-molecule catalysts could compete with enzymatic catalysts in KRs. For these pioneering works, Sharpless was awarded the 2001 Nobel Prize with Knowles and Noyori. Despite these achievements, the Sharpless KR is not an efficient method to prepare epoxy alcohols with high enantiomeric excess (ee). First, the racemic allylic alcohol must be prepared and purified. KR of the racemic allylic alcohol must be stopped at low conversion, because the ee of the product epoxy alcohol decreases as the KR progresses. Thus, better methods to prepare epoxy alcohols containing stereogenic carbinol carbons are needed. This Account summarizes our efforts to develop one-pot methods for the synthesis of various epoxy alcohols and allylic epoxy alcohols with high enantio-, diastereo-, and chemoselectivity. Our laboratory developed titanium-based catalysts for use in the synthesis of epoxy alcohols with tertiary carbinols. The catalysts are involved in the first step, which is an asymmetric alkyl or allyl addition to enones. The resulting intermediates are then subjected to a titanium-directed diastereoselective epoxidation to provide tertiary epoxy alcohols. Similarly, the synthesis of acyclic epoxy alcohols begins with asymmetric additions to enals and subsequent epoxidation. The methods described here enable the synthesis of skeletally diverse epoxy alcohols.     

Co/AC催化剂对F-T合成醇产物的影响

以活性炭为载体,采用真空浸渍法制备Co/AC催化剂,在浆态床反应器中考察反应温度、反应压力和空速等条件对F-T合成醇产物的影响。结果表明,升高反应温度对长链烃和醇的生成有利,醇类的选择性随着反应压力的增大而提高,但反应压力增至3.0 MPa后,继续增加反应压力对醇类选择性变化不大;随着空速的增大,液相产物中醇含量虽然增加,但醇的分布无变化。     

Biokatalytische Synthesen tertiärer Alkohole

Tertiary alcohols are found as a motif in many pharmaceuticals and natural products. Elucidation of their biosynthesis is thus a good starting point for the identification of enzymes for the synthesis of chiral tertiary alcohols. To date, however, relatively few enzymatic methods for such syntheses have been established in biotechnological processes. Whereas secondary alcohols can be efficiently synthesized via the (asymmetric) reduction of ketones, a generally applicable method for the enzymatic synthesis of tertiary alcohols has been more difficult to identify. Herein, a survey of the biocatalytic methods for the synthesis of (chiral) tertiary alcohols is presented. Advantages and disadvantages of the respective methods are discussed from a synthetic point of view.     

Development of a new low-temperature methanol synthesis process

A new reaction route of methanol synthesis at low temperature from CO₂-containing syngas with Cu/ZnO catalyst and the aid of alcohols has been developed in a batch and a flow-type semi-batch reactors. The use of alcohols as catalytic solvents realized methanol synthesis at 443 K with formate as an intermediate. The activity of methanol synthesis depends on types and structures of alcohols. Among all alcohols, 2-alcohol exhibited the highest activity. With the aid of 2-butanol, the one-pass 47.0% conversion and 98.9% selectivity were achieved at a mild condition, 443 K and 50 bar. The new reaction route of methanol synthesis is a practical method for near future technology.     

全氟烷基醇的合成

全氟烷基醇是重要的含氟中间体,广泛用于织物整理剂、表面活性剂、含氟树脂和医药中间体等领域。本文综述了其主要的合成方法：电解氟化法,调聚法和酯化水解法,重点介绍了以酯化水解法合成全氟烷基乙醇,并指出各种合成方法的优缺点。对其市场状况及研究发展进行分析展望,为实现其工业化研究提供必要的技术支持。     

Nickel and manganese co-modified K/MoS2 catalyst: high performance for higher alcohols synthesis from CO hydrogenation

Mn and Ni co-modified K/MoS₂ catalyst for higher alcohols synthesis from syngas was prepared by co-precipitation, and its performance in CO hydrogenation was tested. The results indicated a synergistic effect between Mn and Ni on co-modified K/MoS₂ catalyst, which led to high performance for higher alcohols synthesis.     

L型沸石合成过程中的晶型控制

综述了原料、凝胶组成、晶化条件及添加剂等合成变量对L型沸石晶型调控的影响。选择不同的硅源和铝源,得到的晶粒尺寸和形貌有所差别;凝胶中水含量越高,碱度越低,晶化温度越高,晶粒的长径比越大,呈长圆柱体;添加导向剂和金属导致晶粒尺寸变小,添加醇类化合物可使晶粒长径比减小,添加模板剂促进晶粒变大,提高晶型的完好性。     

Synthesis and modification of epoxy‐ and hydroxy‐functional microspheres

This article describes the synthesis and surface modification of epoxy‐ and hydroxy‐functional polymeric microspheres. The functionalized microspheres were synthesized using aqueous and nonaqueous cationic suspension photopolymerizations using multifunctional silicon‐containing epoxy monomers with iodonium salt photoinitiators. Although generally solid microspheres were obtained using these techniques, macroporous spheres could be obtained though the use of porogens. Various rapid and facile acid‐ and base‐catalyzed ring‐opening addition reactions were performed on the epoxy‐functional microspheres. These reactions include the additions of mercaptans, acid chlorides, isocyanates, amines, sodium azide, water, and alcohols. Similar functionalization reactions were performed on the hydroxy‐functional microspheres. The particle size and size distribution were determined using scanning electron microscopy. Fourier transform infrared spectroscopy was used to monitor the functionalization reactions. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1574–1585, 2005