β沸石催化剂上丙烯水合醚化反应的原位红外光谱研究

 采用原位红外光谱技术，对β沸石催化剂上的丙烯水合醚化反应过程进行了研究，并结合催化剂的表面酸性进行了讨论．丙烯水合及异丙醇脱水反应主要在催化剂的B酸中心上进行，而丙烯与异丙醇的醚化反应则主要依赖于催化剂的L酸中心．对于丙烯水合醚化反应，催化剂必须具有一定量的B酸中心，合适的B酸／L酸比例是催化剂同时具有高活性和高二异丙醚（以下简称异丙醚）选择性的关键．     

β沸石在丙烯醚化反应中的催化性能

研究了β沸石在不同焙烧温度和加入粘合剂条件下对丙烯与异丙醇合成异丙醚的催化性能。并通过ＸＲＤ、ＸＰＳ、ＮＨ３－ＴＰＤ、ＦＴ－ＩＲ及化学吸附等手段表征了β沸石的物理化学性质。结果表明：焙烧对丙烯醚化反应存在一合适的温度范围；Ａｌ２Ｏ３粘合剂提高了丙烯转化率，降低了异丙醇脱水活性；粘合剂使沸石表面上Ｌ酸中心的比例增加；丙烯醚化反应与Ｌ酸中心存在较好的对应关系，而异丙醇脱水反应与Ｂ酸中心对应；高温焙烧β沸石使骨架铝向表面迁移，粘合剂Ａｌ２Ｏ３能抑制沸石的晶胞收缩。     

丙烯水合醚化反应过程中丙酮生成机理的研究

 在与色－质联用仪相连的微反装置上，考察了Hβ沸石及改性的\r\nHβ沸石催化剂上丙烯水合醚化及异丙醇脱水的反应行为．丙烯水合醚\r\n化反应中有副产物丙酮生成，而异丙醇单独进料时产物中没有发现丙酮\r\n的生成．这表明丙酮并不是异丙醇氧化脱氢的结果，而是一个应予重视\r\n的不利于丙烯水合醚化的副反应．用同位素示踪反应对丙酮的生成机理\r\n进行了探讨，为研制抑制这一副反应的新催化剂提供了参考依据．     

改性对β沸石表面酸性及丙烯水合醚化反应性能的影响

采用浸渍法和离子交换法，制备出一系列改性β沸石催化剂，考察了改性剂对β沸石表面酸性及丙烯水合醚化反应性能的影响。结果表明：硼、锌、铝改性可以提高β沸石的L酸中心，磷、镧、铈改性后β沸石的B酸中心增加。催化剂的B酸和L酸中心与丙烯转化率和异丙醚选择性之间存在着一定的对应关系：B酸量增加有利于提高丙烯转化率，L酸量增加有利于提高异丙醚的选择性。合适的B／L酸比例是催化剂同时具有高活性和高异丙醚选择性的关键。     

丙烯水合醚化催化剂上焦炭前身物的表征

采用热重、红外,高温模拟蒸馏和质谱等分析手段,对丙烯水合醚化失活催化剂上的焦炭前身物进行了表征。焦炭前身物主要是沸程范围在200－400℃的长链饱和烃类化合物,四氯化碳洗液和二氯甲烷萃取液的红外和质谱分析均表明,焦炭前身物中没有烯烃和芳烃类化合物存在,β沸石催化剂具有一定的氢转移反应活性,由丙烯聚合生成的聚合烯烃进一步与焦炭前身物通过氢转移反应生成烷烃和焦炭。     

硼改性对Hβ沸石表面酸性及丙烯与异丙醇醚化反应性能的影响

研究了硼改性的Ｈβ沸石表面酸性变化及其对丙烯与异丙醇醚化反应性能的影响。样品Ｂ２Ｏ３－Ｈβ的酸量随Ｂ２Ｏ３含量增加而增多。含量超过３％时酸量基本不变；对于Ｂ２Ｏ３－Ｈβ－Ａｌ２Ｏ３催化剂，Ｂ２Ｏ３使总酸量明显增大，并以Ｌ酸中心增加为主；Ａｌ２Ｏ３粘合剂的存在促进了Ｂ２Ｏ３与Ｈβ沸石间的相互作用；丙烯转化率及水的产率分别与Ｌ酸和Ｂ酸中心有很好的对应关系。丙烯与异丙醇的醚化反应主要在Ｌ酸中心上进行。     

丙烯二聚催化剂的研究进展

综述了近年来丙烯二聚催化剂的研究进展,讨论了不同催化剂活性中心原子、助催化剂和辅助膦配体对催化反应活性和产物选择性的影响,比较了二聚反应中均相催化剂和非均相催化剂的催化反应机理.与此同时,结合多孔材料择形催化和离子液体的优点,提出了开发离子液体基丙烯二聚复合催化体系的新思路.     

SO(2-)4-Fe2O3-Hβ-Al2O3催化剂制备方法对其表面性质和催化丙烯醚化反应性能的影响

首次以Ｈβ沸石为基础，采用一步浸渍法、机械研磨法、沉积－沉淀法及分步浸渍法制备了ＳＯ＾２－４－Ｆｅ２Ｏ３－Ｈβ－Ａｌ２Ｏ３催化剂，通过ＸＲＤ，ＸＰＳ，ＮＨ３－ＴＰＤ，ＦＴ－ＩＲ及化学吸附等手段对其物理化学性能进行了表征，并对其催化丙烯与异丙醇的醚醚的反应性能进行了评价。     

杂多酸对于二甘醇和乙醇的醚化反应的催化作用

杂多酸对于二甘醇和乙醇的醚化反应的催化作用戚蕴石，刘俊峰，吴海霞，粟小（华东理工大学工业催化研究所，上海２００２３７）关键词醚化反应，杂多酸，二甘醇二甘醇单（双）醚是一种具有广泛用途的重要溶剂，杂多酸（ＨＰＡ）对醚化反应具有很好的催化活性．本文以ＨＰ...     

顺二氨二水合铂(Ⅱ)与膜磷脂及膜蛋白相互作用的荧光光谱研究

用Tb~(3+)分别对用和未用顺二氨二水合铂(Ⅱ)(AAP)处理的红细胞膜和磷酰胆碱(PC)脂质体进行荧光滴定,测Tb~(3+)荧光。用AAP滴定红细胞膜,测蛋白质自身荧光变化。用间接Scatchard法求结合参数。表明蛋白质及磷脂均与AAP结合,蛋白质结合能力较强。     

丙烯环氧化制环氧丙烷Fe-Al-P-O催化剂的研究

用溶胶-凝胶法制得了Fe-Al-P-O催化剂，采用IR、XRD、TEM、BET、TPR和微反等技术研究了催化剂的物化性质和反应性能。实验结果表明，Fe1/2-Al1/2-PO4由10 nm左右 FePO4和AlPO4微晶组合而成，其晶格氧的活泼性大于单纯FePO4，AlPO4在Fe1/2-Al1/2-PO4中起到分散FePO4微晶的作用；Fe1/2-Al1/2-PO4的反应性能与原料气组成密切相关，丙烯与O2的选择氧化产物主要是丙烯醛，原料气中加入H2后，反应产物以环氧丙烷为主，同时还有部分丙烯醛，原料气中引入水蒸气后，可进一步增加环氧丙烷的选择性及减少丙烯醛的产率；在0.1 MPa、200 ℃、C3H6/O2/H2/H2O/N2=1∶1∶1∶1∶6（mol比）和空速1 200 h－1条件下，丙烯的转化率为8.9％，环氧丙烷的选择性为81.0％。     

Effect of solvents on propylene epoxidation over TS-1 catalyst

Solvents have an important effect on the epoxidation of propylene catalyzed by TS-1. The experimental results show that, in different solvents, the catalytic activity of epoxidation is in the following order: methanol > 2-propanol > 2-butanol > acetonitrile > acetone > tetrahydrofuran. Based on the reaction mechanism, the effects of solvents on the epoxidation were studied from eight aspects, which included the electronic effect, the steric effect, the polarity of solvent, the effect of solvent on sorption and diffusion of reactant, the oxidation of alcohol, the etherification of PO, the deactivation of TS-1 and the solubility of propylene in the solvents. The electronic effect, steric effect and the polarity of solvent were considered to be the main aspects. This work may provide theoretical guidance for choosing solvents for these kinds of reactions and also may serve as basis for further industrialization. __________ Translated from Journal of Tsinghua University (Science and Technology), 2007, 47(9): 116–120 [译自: 清华大学学报(自然科学版]     

Supported stereospecific metallocene binary catalyst for propylene polymerization

In this work, propylene was polymerized with isospecific and syndiospecific catalysts in homogeneous and heterogeneous systems. The binary metallocene system of both isospecific and syndiospecific catalysts in the heterogeneous system was also used. Besides the type of catalyst, parameters such as polymerization temperature and pressure were varied to achieve the better conditions for the polymerization. The objective of this work is to investigate the influence of these parameters on the characteristics of the produced polymer. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2979–2986, 2002     

聚醚醚酮酮等温结晶动力学的研究

聚醚醚酮酮等温结晶动力学的研究陈艳，王军佐，曹俊奎，那辉，吴忠文（吉林大学化学系，长春，１３００２３）关键词聚醚醚酮酮，等温结晶动力学，差示扫描量热法聚醚醚酮酮（ＰＥＥＫＫ）是在聚醚醚酮（ＰＥＥＫ）基础上开发成功的一种耐热高分子材料。它保持了ＰＥＥＫ...     

Anionic polymerization of propylene oxide: Isomerization of allyl ether to propenyl ether end groups

The isomerization of allyl ether to propenyl ether end group in anionically-polymerized poly (propylene oxide) was monitored by ¹H NMR spectroscopy. It was confirmed that the reaction followed a simple second-order rate law: ?d[allyl]dt = k₂[allyl] [O^?]. Values of k₂ determined over the 90–130°C temperature range, indicated an activation energy of 116 kJ mol^?1. © 1994 John Wiley & Sons, Inc.     

聚醚醚酮微结构及反应特性的量子化学研究

利用AM1对聚醚醚酮重复单元进行条件优化,得出了此分子的最优构型,明确了聚醚醚酮分子链的微观构象,并在此构象基础上进行量子化学计算,给出了健序、净电荷、前线轨道等信息,从理论上研究了聚醚醚酮的磺化反应及热分解反应的一些特性.     

含联苯结构聚醚醚酮酮共聚物和共混物的制备及性能研究

聚醚醚酮（PEEK）是八十年代初投入市场的全芳香结构热塑性耐高温特种工程塑料，它的7’。一143“C，Tm一334C“‘，最大结晶度为48％，典型制品结晶度为20％～30％［”．PEEK可用通常的设备成型，其制件、纤维、涂料及复合材料在电子电器、机械设备、交通运输、宇航、原子能工程、军事等领域有广泛的用途［’j．聚醚醚酮酮（PEEKK）是继PEEK之后，由德国Hoechst公司开发出来的又一种全芳香结构热塑性耐高温特种工程塑料［‘j．为了研究该类聚合物的结构和性能的关系，我们在实验室中合成了PEEKK和含联苯结构聚醚醚酮酮（PE－＊…     

Studies on cellulose acetate and sulfonated poly(ether ether ketone) blend ultrafiltration membranes

New ultrafiltration membranes based on chemically and thermally stable arylene main-chain polymers have been prepared by blending the sulfonated poly(ether ether ketone) with cellulose acetate in various compositions in N,N^′-dimethylformamide as solvent by phase inversion technique. Prepared membranes have been subjected to ultrafiltration characterizations such as compaction, pure water flux, water content, and membrane hydraulic resistance. The pore statistics and molecular weight cut-off (MWCO) of the membranes have been estimated using proteins such as trypsin, pepsin, egg albumin and bovine serum albumin. The pore size increased with increasing concentrations of sulfonated poly(ether ether ketone) in the casting solution. Similarly, the MWCOs of the membranes ranged from 20 to 69 kDa, depending on the various polymer compositions. Surface and cross-sectional morphologies of membranes were analyzed using scanning electron microscopy. The effects of polymer compositions on the above parameters were analyzed and the results are compared and discussed with those of pure cellulose acetate membranes.     

气相色谱法探究聚醚醚酮的热降解及热氧化降解（英文）

Poly(ether ether ketone)(PEEK)was synthesized via polycondensation of hydroquinone with 4,4′-difluorobenzophenone at 320℃for 5 h.Thermal and thermo-oxidative degradation of PEEK was studied over a wide range of temperatures.In an inert medium,decomposition of the polymer occurred in one stage,with the formation of a coke residue accounting for approximately 50%of the original polymer mass.In air,the mass loss curve exhibited two distinct stages.The first stage involved breakdown of the main polymer chain,the speed of which indicated a radical chain failure mechanism.In the second stage,the rate of mass loss clearly decreased,indicating a transition from the radical chain failure mechanism to simple combustion reactions(wherein the polymer combusted completely).To further investigate the nature of the processes occurring during the pyrolysis of PEEK,the investigations were carried out using gas chromatograph under isothermal conditions.It was concluded that during thermal degradation,the decomposition of the polymer starts with the rupture of ketone and ether bonds and proceeds to destruction of the benzene ring at higher temperatures,which is accompanied by the formation of H2O and CH4.Above 500℃,the polymer degradation further involved thermohydrolysis.The thermo-oxidation of PEEK,which was accompanied mainly by the formation ofH2,was noticeable beginning at 325℃.The total yield of the latter indicated oxidation of fragments of the benzene ring.