过渡金属催化烯烃异构化的研究 Ⅵ.Cp_2TiCl_2/i-C_3H_7MgBr催化4-乙烯基环己烯异构化的研究

近年来我们用 Cp_2 TiCl_2/i-C_3 H_7 MgBr(Cp=η~5-C_5 H_5)催化体系对非共轭双烯烃的异构化进行了一系列的研究.以1,5-环辛二烯和1,5-已二烯为模型化合物的催化异构化反应结果表明,这一催化体系无论是对非共轭的环双烯还是链双烯都具有催化剂活性高,反应条件温和,产物选择性好的特点.本文用同一体系,以4-乙烯基环已烯(1)为代表,研究了     

三氟化硼引发四氢呋喃聚合的研究——Ⅳ.1,4-丁二醇的影响

The molecular weight of polytetramethylene glycol (PTMG) prepared from tetrahydrofu-ran (THF) by using cocatalysts of BF3-etherate and epichlorohydrin (ECH) in the presence of butylene glycol(BG) increased sharply with the polymer conversion, but at yields higher than 80% but could be exactly controlled by the molar ratio of BG to BF₃. The polyether obtained possessed around 70 mol% primaly hydrcxyl end-groups and a hydroxyl end-group functionality of two. The content of ECH derived units in each polymer chain containing 18.2 or 33.8THF derived units is around 1.60 or 2.16 respectively.     

糖类研究（ⅩⅩⅤ）

利用三氟乙酰氧基、三氯乙酰氧基和三氯乙酰亚胺基作为糖端基离去基团，在Ｌｅｗｉｓ酸催化下合成了粘质沙雷氏菌Ｏ４抗原寡糖片段，反应条件温和，收率良好，三氟乙酸酯和三氯乙酸酯法具有很好的立体选择性，运用波谱法方法确定了所有化合物的结构。     

一种含氟丙烯酸树脂的制备及其表面疏水性

在聚合反应的后期阶段,向体系中引入含氟丙烯酸酯单体全氟辛基-(N-乙基-N-丙烯酸乙酯基)磺酰胺(QG-F814)共聚改性的方法制备了一种含氟丙烯酸树脂.接触角测定表明,该树脂具有良好的疏水性能.热重分析表明,该树脂在改性前后的耐热稳定性差别不大.     

聚甲醛自然老化的SEM研究

对户外曝晒3～36个月的聚甲醛(POM)老化形态进行了研究,讨论了老化层厚度,裂纹宽度、裂纹深度及断口形态与老化时间的关系。结果表明:POM的老化导致了材料内部结构由韧性变成脆性而几乎完全丧失物理机械性能。     

LaPO4纳米微粒的制备及表征

Surface-modified LaPO4 nanoparticales were synthesized in the mixture solvent of water-ethanol with the surface modification age of dialkylphosphate. The conditions of synthesis and characterization were discussed. The results indicated that nanoparticle core of LaPO4 and surface-modified layer were formed. The surface-modified nanoparticles of LaPO4 can be dispersed in organic solvent and has better lubricating properties.     

物质数量(或浓度)对化学平衡影响的新描述

外界因素(温度、压力、浓度等)对化学平衡的影响问题,无论从理论上还是从实践上都是化学化工中的重要内容;因为它们启示人们根据化学反应的特点去采取适当措施,以达到增产节约的目的。但是,在目前的《物理化学》教材中仅对温度和压力影响平衡移动给出了定量的描遮。而对于“物质浓度如何影响平衡移动”的问题,有些著作     

聚四氟乙烯纤维辐照接枝制备弱酸性离子交换剂及其对Cu~(2+)的吸附

以聚四氟乙烯纤维为基体通过6 0 Co辐射引发与丙烯酸接枝制备弱酸性阳离子交换纤维 .产物功能基含量为 3 0 6mmol g,在pH =5时该纤维达到对Cu2 + 的最大动态吸附量为 10 7 4 8mg g.使用不同浓度HCl对饱和吸附铜的接枝纤维进行洗脱 ,证实该纤维对铜离子具有优异的解吸性能     

纳米TiO2膜用于光催化氧化测定化学需氧量的研究

A photocatalytic oxidation method for determination of chemical oxygen demand （COD） using nano-TiO2 film, based on the use of a nano-TiO2-Ce（SO4）2 system and electrochemical detection, was proposed. The technique was originated from the direct determination of the Ce（Ⅲ） concentration change resulting from photocatalytic oxidation of organic compounds. Ce（Ⅲ）, which was produced by photocatalytic reduction of Ce（SO4）2, could be measured at a multi-walled carbon nanotubes （MWNT） chemically modified electrode （CME）. The COD values by this method were calculated from the differential pulse voltammetry （DPV） current of Ce（Ⅲ） at the CME. Under the optimal operation conditions, the detection limit of 0.5 mg·L^-1 COD with the linear range of 1-600 mg·L^-1 was achieved. This method was also applied to determination of various COD of ground water and wastewater samples. The resuits were in good agreement with those from the conventional COD methods, i.e., permanganate and dichromate ones.