碱处理丝光沸石的表征及其催化合成乙基叔丁基醚的性能

 研究了碱处理对丝光沸石物相、酸性质和催化合成乙基叔丁基醚(ETBE)性能的影响,并采用XRD,NH3-TPD,吡啶吸附的IR,SEM和N2吸附等方法对其进行了表征. 结果表明,碱处理含有模板剂的丝光沸石的相对结晶度、酸量、比表面积和孔容都增大. 碱处理已脱除模板剂的丝光沸石的相对结晶度、酸量、比表面积和孔容都减小. 碱处理含有模板剂的丝光沸石催化合成ETBE的活性明显高于碱处理已脱除模板剂的丝光沸石,在80 ℃左右即可达到最高活性点,其催化异丁烯的最高转化率为58%,比未经碱处理样品上异丁烯的最高转化率高约13%.     

添加剂对镍系催化丁二烯聚合的影响

对正辛酸一三氟化硼乙酸络合物（n－C_8H_(17)0H－B）预混、乙酸正丁酯一三氟化硼乙醚络合物（CH_3COOC_4H_9－B）预混和稀三氟化硼乙醚络合物（B）单加三种体系的丁二烯聚合行为进行了比较。结果表明；B组分中加入n－C_8H_(17)OH，能在不拓宽三异丁基铝（Al）／B摩尔比范围的情况下，有效地提高聚丁二烯的分子量；B组分中加入CH_3COOC_4H_9，能适当地拓宽Al／B比，但对聚丁二烯分子是不产生影响。对n－C_8H_(17)0H－B在聚合体系中的作用机理进行了探讨，提出了在n－C_8H_(17)0H－B预混体系中存在两种活性中心。     

DMS AND ~(13)C NMR STUDIES ON THE COMPATIBILITY AND DYNAMICS OF LATEX BIDIRECTIONAL IPNS AND LATEX IPN OF PVAc/PBA

The compatibility and dynamics of latex bidirectional/nterpenetrating polymer networks (LBIPNs) and latex IPN(LIPN) of poly(vinyl acetate)(PVAc) and poly (butyl acrylate )(PBA) are investigated by means of dynamic mechanical spectroscopy (DMS) and nuclear magnetic resonance (NMR) techniques. The results of DMS show that the compatibility of the LBIPNs is much better than that of the corresponding LIPN and depends to, a large extent on the distribution of PVAc both in the core and in the shell. The results of NMR measurements indicate that the rotational correlation times of the side- groups of PBA in the LBIPN are longer than those in the LIPN. The relation between the ~(13)C linewidths of PBA and temperature is also discussed.     

大分子ATRP引发剂α-卤烷基聚苯乙烯的合成及其引发的丙烯酸丁酯接枝聚合

通过酰基化、还原、酯化和卤代反应 ,在聚苯乙烯上引入α 卤烷基 ,使用FTIR、1 H NMR、1 3C NMR和GPC对产物进行表征 ,结果表明基团转化可以完全进行 ,整个过程中无交联等副反应 .其中α 溴乙基聚苯乙烯可作为原子转移自由基聚合的多功能度引发剂 ,由此引发丙烯酸正丁酯聚合生成梳状聚 (苯乙烯 g 丙烯酸正丁酯 )     

Reactions of chlorination with tert‐butyl hypochlorite (TBuOCl)

The chlorination reactions of nitrogenous organic compounds (2,2,2‐trifluoroethylamine, benzylamine, glycine, and dimethylamine) by tert‐butyl hypochlorite (^tBuOCl) were studied at 25 °C, ionic strength 0.5 M and under isolation conditions. The kinetic results obtained in the formation processes of the corresponding N‐chloramines in acid medium (pH = 5–7) are summarized in this paper. Kinetic studies showed a first order with respect to ^tBuOCl concentration. The chlorination reactions involving benzylamine, glycine and dimethylamine were all first order with respect to nitrogenous compound concentration and approximately ?1 order with respect to proton concentration. The reaction with 2,2,2‐trifluoroethylamine was more complex, and the order of reaction with respect to the amine varied with pH. Copyright © 2014 John Wiley & Sons, Ltd.     

Preparative enantioseparation of propafenone by counter‐current chromatography using di‐n‐butyl l‐tartrate combined with boric acid as the chiral selector

This paper extends the research of the utilization of borate coordination complexes in chiral separation by counter‐current chromatography (CCC). Racemic propafenone was successfully enantioseparated by CCC with di‐n‐butyl l ‐tartrate combined with boric acid as the chiral selector. The two‐phase solvent system was composed of chloroform/ 0.05 mol/L acetate buffer pH 3.4 containing 0.10 mol/L boric acid (1:1, v/v), in which 0.10 mol/L di‐n‐butyl l ‐tartrate was added in the organic phase. The influence of factors in the enantioseparation of propafenone were investigated and optimized. A total of 92 mg of racemic propafenone was completely enantioseparated using high‐speed CCC in a single run, yielding 40–42 mg of (R)‐ and (S)‐propafenone enantiomers with an HPLC purity over 90–95%. The recovery for propafenone enantiomers from fractions of CCC was in the range of 85–90%.     

单分散聚丙烯酸丁酯-二氧化硅核壳粒子的制备

近年来,有机-无机核壳材料因其具有可调的光、电、磁等特性而备受关注．无机物外壳可以增强粒子的热力学稳定性、机械强度和抗拉性能．高分子乳胶粒内核具有弹性,且易成膜,外部包覆无机物的乳胶粒可结合两者特性并产生协同效应．     

Substituent effects of pyrazine on construction of crystal structures of Zn(II)-benzoate complexes and their catalytic activities (dinuclear,trinuclear, and pentanuclear to 1-D and 2-D)

Several substituted pyrazine ligands (2,3-dimethylpyrazine, 2,6-dimethylpyrazine, 2,5-dimethylpyrazine, quinoxaline) as well as simple pyrazine have been employed to investigate how the bridging pyrazine ligand influences on construction of Zn-benzoate complexes. Simple pyrazine and 2,5-dimethlpyrazine are used as bridging ligands to form two-dimensional and one-dimensional polymeric compounds, respectively. The other quinoxaline and two dimethyl-substituted pyrazine ligands are used only as terminal ligands to form dinuclear, trinuclear, and pentanuclear complexes. This result indicates that the substituents of pyrazine are very important roles for construction of Zn-benzoate complexes. Interestingly, the compounds 1–5 catalyzed efficiently the transesterification of a variety of esters, and among them, the pentanuclear complex 3 showed the most efficient reactivity. The substrates with the electron-withdrawing substituents have undergone faster transesterification, while those with the electron-donating ones have shown slow reaction. In addition, p-nitrophenyl acetate and p-nitrophenyl benzoate, known to be problematic substrates for the transesterification reaction, were also converted quantitatively to the corresponding products. Selectivity test of primary over secondary alcohol protection in the presence of 3 has provided, exclusively, the primary acetate, propyl acetate, suggesting that this catalytic system can be potentially useful in selecting for primary alcohols.     

Preparation and Catalytic Activity of SO42-/TiO-La2O3 in Synthesis of Butyl Butyrate

Butyl butyrate is a very important compound, which is transparent liquid and has the pear,apple flavor. Natural exist is in the fruit, such as apple, pear, banana, grape and strawberry, etc.Primarily used for to prepare the edible spice and is also widely used in industrial intermediate product, solvent and synthetic perfumery. Until now, there are many methods to synthesize it.Conventionally H2SO4 was reported, but it causes many problems, such as the erosion of equipment,easily causes the vice-reaction, difficulty for after-treatment, environment pollution etc. A new environmentally friendly catalyst, SO42-/TiO2-La2O3 was prepared. And catalytic activity of catalyst in esterification of n-butanoic acid and n-butyl alcohol with SO42-/TiO2-La2O3 as catalyst has been no report up to now. Therefore, studying on the synthetic catalyst has theoretical and practical significances. The catalytic activity of catalyst in esterification of n-butanoic acid and n-butyl alcohol was measured.In this paper, we fast reported the preparation of SO42-/riO2-La2O3 and discussed the factors influencing the synthesis catalyst. The catalyst rare earth solid superacid SO42-/TiO2-La2O3 was The precipitate was filtered and washed thoroughly with distilled water until chloride ions were free.furnace at 480 ℃ for 3 h, and finally stored in a desiccator until use.The factors influencing the synthesis were discussed and the best conditions were found out. The experiment indicated that this catalyst has the following advantage. The amount of catalyst was little and getting high yield, its product has a good quanlity and is favour of reducing erosion of equipment, avoiding environment pollution. The optimum conditions are: molar ratio of n-butanoic acid to n-butyl alcohol was 1:1.5, the quantity of catalyst was equal to 1.5% of feed stocks, the reaction temperature was 93-114 ℃, and the reaction time was 1.0 h. Rare earth solid superacid SO42-/TiO2-La2O3 is an excellent catalyst for synthetizing butyl butyrate and its yield can reach over 90.0%.A good catalyst should be able to be used repeatedly. The reusing of the catalyst was studied. We found that the catalytic activities of our catalyst are almost unchanged after it had been used five times. From the above results and discussion, we can see that the synthesis of n-butyl butyrate by SO42-/TiO2-La2O3 instead of H2SO4 has a great prospect of application. It has a good applied foreground.     

K-MnO／y-A1203和Cu／SiO2催化剂应用于苯甲酸甲酯连续加氢合成无氯苯甲醇

以K—MnO／F—Al2O3和Cu／SiO2为催化剂，利用固定床串联反应器实现了苯甲酸甲酯连续加氢合成无氯苯甲醇反应过程．K-MnO/y-Al2O3和Cu／SiO2催化剂对于苯甲酸甲酯连续加氢合成苯甲醇具有良好的加氢活性，反应转化率可达89．2％，苯甲醇的选择性为84．1％．在苯甲酸甲酯加氢连续步骤中的氢醛比得到提高，有效地抑制了副产物甲苯的生成．XRD，SEM和TPR表征结果表明：采用吸附沉淀法制备的Cu／SiO2-C15．2催化剂，氧化铜在载体上具有良好的分散性能，并且易于还原，表现出最佳的苯甲醛加氢活性．