气相色谱分析碳酸二甲酯与丙醇酯交换合成碳酸二丙酯的反应产物

提出了碳酸二甲酯与丙醇酯交换合成碳酸二丙酯反应产物的气相色谱分析方法.采用SE-54毛细管色谱柱分离了产物碳酸二丙酯及相关化合物,外标法建立了碳酸二丙酯的标准曲线,线性相关系数为0.9979.方法的相对标准偏差RSD为2.2%,回收率为96.2%～103.8%.     

ADSORPTION OF SULFOXIDES ON SOLID FROM AQUEOUS SOLUTIONS Ⅲ.THE ADSORPTION ON CARBON BLACK

The adsorption of decylmethylsulfoxide (DEMS) onto carbon black and the effects of temperature, salt (NaCl) and acid (HCl) have been measured.Typical two plateaux type adsorption isotherms were obtained. Applying the two step model of surfactant adsorption on solid/liquld interface and the general adsorption isotherm equation[9]the experimental results were interpreted qualitatively and quantitatively.     

添加Li+对MgO催化性能的影响

本文以IR、TPD、丁烯异构化及直接脱氢反应为手段,对不同Li⁺添加量的MgO催化剂进行了研究。结果表明,表面低配位氧集团是催化剂的主要活性物种,起碱中心作用;表面金属离子起L酸中心作用。酸、碱中心的数目、强度随Li⁺添加量不同而呈规律性变化。这种变化影响了酸、碱中心的协同作用,从而影响其催化活性。     

氯乙烯-乙酸乙烯酯共聚物组成的控制

本文提出了氯乙烯-乙酸乙烯酯共聚物组成的简化计算法,作出了配比为0.84—0.96克分子分数氯乙烯时的共聚物组成算图和组成分布图。如果对共聚物组成均一性的要求不十分严格,含82—95％(重量)氯乙烯的共聚物可以由一次投料法来生产。简化计算法可以推广于r_1>1、r_2<1而以单体1为主的共聚物组成的计算。     

A Facile Synthesis of Indolizines by 1，3－Dipolar Cycloaddition of Pyridinium and Related Heteroaromatic Ylides with Alkenes in the Presence of TPCD，Py_4Co（HCrO_4）_2

ＡＦａｃｉｌｅＳｙｎｔｈｅｓｉｓｏｆｉｎｄｏｌｉｚｉｎｅｓｂｙ１，３－ＤｉｐｏｌａｒＣｙｃｌｏａｄｄｉｔｉｏｎｏｆＰｙｒｉｄｉｎｉｕｍａｎｄＲｅｌａｔｅｄＨｅｔｅｒｏａｒｏｍａｔｉｃＹｌｉｄｅｓｗｉｔｈＡｌｋｅｎｅｓｉｎｔｈｅＰｒｅｓｅｎｃｅｏｆＴＰ...     

聚乙烯载体催化剂的制备与表征

不同目数的聚乙烯粉末通过辐射方法接枝了4-乙烯基吡啶官能团.经甲基铝氧烷(MAO)预处理后负载了茂金属催化剂Cp₂ZrCl₂.光电子能谱和红外光谱结果表明催化剂通过MAO的作用负载在聚乙烯接枝4-乙烯基吡啶聚合物上.4-乙烯基吡啶的接枝含量、催化剂的负载率以及载体催化剂对乙烯单体的活性均随着聚乙烯粉末的颗粒减小而增大.     

茂钛均相催化剂丁二烯聚合研究

由五甲基单茂钛化合物Cp TiL3 和甲基铝氧烷 (MAO)组成的催化体系进行丁二烯聚合 .考察具有不同辅助配体L的主催化剂Cp TiL3 及外加三异丁基铝 (TIBA)对聚合的选择性 ;讨论了聚合温度、AlMAO Ti摩尔比和催化剂浓度对聚合反应的影响 .发现外加适量TIBA有助于提高催化活性 ,而且随着TIBA用量的增加聚丁二烯分子量增加 .结合钛氧化态分析 ,说明催化体系中Ti(Ⅲ )活性中心更有利于丁二烯聚合     

A New Investigation of Mannich Reaction

Mannich reaction is widely used for the synthesis of many kinds of compounds1. In the synthesis of the derivatives of styryl ketonic Mannich bases, a one-pot method is used, in which ketone, secondary-amine hydrochloride, paraformaldehyde are refluxed together in alcohol2,3. In most cases the normal Mannich product MA is obtained. But when certain amine is used as the reactant, a side-product IM, instead of MA is obtained. MS and 1HNMR data indicate that compound IM is a new type of Man…     

A Novel Zirconium-Based Perovskite-Type Membrane Material for Oxygen Permeation

Zirconia with fluorite structure stabilized by doping rare earth or alkaline earth metal oxides such as Y2O3 and CaO (YSZ and CSZ) is a class of traditional mixed conducting membrane materials, which have been widely investigated for their high oxygen ionic conductivity and excellent chemical and thermal stability1-3. But the electronic conductivity of these materials is very small, unless operated with an internal or external circuitry, the oxygen flux through membranes in usual ranges of …     

聚酰亚胺/二氧化硅纳米尺度复合材料的研究

通过正硅酸乙酯（ＴＥＯＳ）在聚酰胺酸（ＰＡＡ）的Ｎ，Ｎ’ 二甲基乙酰胺（ＤＭＡｃ），溶液中进行溶胶 凝胶反应，制备出不同二氧化硅含量的聚酰亚胺／二氧化硅（ＰＩ／ＳｉＯ２）复合薄膜材料．二氧化硅含量低于１０ｗｔ％的样品是透明浅黄色薄膜；二氧化硅含量高于１０ｗｔ％的样品是不透明棕黄色薄膜．利用红外光谱、扫描电镜、热失重分析、动态力学分析、热膨胀系数测试和应力 应变测试等方法研究了此类材料的结构与性能．结果表明，ＰＩ／ＳｉＯ２纳米复合材料具有较聚酰亚胺更高的热稳定性和更高的模量；线膨胀系数显著降低；拉伸强度和断裂伸长随二氧化硅含量而变化，分别在１０ｗｔ％和３０ｗｔ％附近出现最大值