天然介孔材料负载催化剂的乙烯齐聚反应规律研究

将烯烃齐聚催化剂负载于具有纳米孔道的介孔分子筛上,同均相催化剂进行比较,探索了受限纳米空间内乙烯齐聚反应过程与自由空间内乙烯聚合反应规律的异同点,研究了分子筛载体、反应温度和Al/Fe摩尔比对乙烯齐聚反应的影响,为分子筛负载乙烯聚合催化剂的工业应用提供了有益的基础数据.     

Mesoporous zeolite SBA-15 supported nickel diimine catalysts for ethylene polymerization

The novel mesoporous zeolite SBA-15 is successfully used as the support to immobilize late-transition metal nickel diimine catalyst, both in physical and chemical methods, EA, ICP, FT-IR and XRD are applied to characterizing these supported catalysts. The results of ethylene polymerization reveal that these supported catalysts have high catalytic activity as their homogenous counterpart does,moreover, polyethylene with a fibrous morphology is produced due to the channel effect of support, and both the molecular weight and molecular weight distributions of polymers are increased greatly.     

后过渡金属烯烃聚合均相催化剂的负载化研究进展

综述了后过渡金属烯烃聚合均相催化剂的负载化研究进展.将高活性的后过渡金属均相催化剂负载于SiO2、Al2O3、MgCl2、聚硅氧烷、聚苯乙烯、环糊精等无机和有机载体材料上,所形成的负载催化剂一方面能够充分利用现有的烯烃多相聚合工业化装置(淤浆和气相聚合),另一方面能够发挥均相催化剂高活性的优点.近年来,后过渡金属均相催化剂的负载化日益引起学术界和工业界的重视,具有广阔的发展前景.     

高效催化剂催化乙烯气相聚合的研究─—烷基铝，给电子体和H_2的影响

用ＭｇＣｌ_２负载钛系高活性催化剂进行乙烯气相聚合，考察了分别在预聚合阶段和气相聚合阶段加入不同的烷基铝化合物和给电子体试剂，对气相聚合催化活性的影响。气相聚合催化活性并不受预聚合中烷基铝改变的影响，但随气相聚合中烷基铝改变而变化。气相聚合用不同烷基铝得到的催化活性大小顺序为：Ａｌ（ｉ－Ｂｕ）_３＞ＡｌＥｔ_３＝Ａｌ（ｎ－Ｏｃｔ）_３＞＞ＡｌＥｔ_２Ｃｌ．预聚合中加入给电子体试剂能使气相聚合催化活性有一定程度提高，而在气相聚合中加入给电子体试剂使催化活性下降，同时也研究了Ｈ_２对气相聚合催活性和产物分子量的影响。     

水杨醛席夫碱配体在聚合反应中的研究进展

水杨醛席夫碱配体由于特殊的骨架结构已被广泛应用于制备多种聚合物催化剂,成为金属有机化学研究领域的明星配体。目前水杨醛席夫碱金属配合物几乎涵盖从第三族到第十四族的所有金属,并在多种聚合反应表现出优异的催化性能。本文结合水杨醛席夫碱的相关研究报道,首先简要介绍水杨醛席夫碱的种类,随后重点介绍水杨醛席夫碱配体金属化,及其金属配合物在烯烃配位聚合、CO2聚合和内酯开环聚合等聚合反应的应用。在此基础上,指出了今后水杨醛席夫碱配体在聚合反应研究的发展方向。     

二氧化硅负载磷钨酸催化β-蒎烯阳离子聚合反应

采用浸渍法制备二氧化硅负载磷钨酸催化剂,催化β-蒎烯阳离子聚合合成β-萜烯树脂.运用红外光谱、X射线衍射、透射电镜、比表面积和孔径测定、核磁共振氢谱和凝胶渗透色谱等测试技术对催化剂和聚合产物的结构进行了表征.考察了磷钨酸的负载量、催化剂用量、反应温度、反应时间、原料浓度等因素对产物收率的影响,确定了最佳反应条件：催化剂负载量为60％,用量为0.6g,反应温度为-20℃,反应时间为1h,β-蒎烯的用量为3 ml,1,2-二氯乙烷用量溶剂为7ml时,β-蒎烯树脂收率可达84.8％,数均分子量在1200左右,分子量分布指数为1.72.     

乙二醇辅助浸渍法制备Cu-NiO@Al2O3吗啉催化剂及其催化性能

【目的】开发催化活性高和热稳定性好的吗啉合成催化剂。【方法】以铜、镍为主要活性组分,活性氧化铝为载体,采用乙二醇辅助浸渍法制备具有高活性的Cu-NiO@Al_2O_3吗啉催化剂(IC-CN),再分别采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、程序升温还原(TPR)和N2-吸附脱附测试(BET)等手段对IC-CN和常规浸渍法制备的催化剂(IM-CN)的晶体结构、孔结构和氧化还原能力等性能进行表征。【结果】IC-CN在高空速条件下(0.7mL·g~(-1)·h~(-1))的吗啉收率高达93.1%,远高于IM-CN(56.2%)。高温热稳定性测试结果表明,经290℃反应3h后(空速为0.4mL·g~(-1)·h~(-1)),IC-CN仍能保持90.1%的吗啉收率,而IM-CN的吗啉收率仅为57.6%。【结论】乙二醇辅助浸渍法制备的催化剂活性要明显优于常规浸渍法所制备的催化剂。     

Recent progresses of late-transition metal complexes with nonsymmetric diimine ligands in ethylene polymerization and oligomerization

Researches of late-transition metal complexes for ethylene polymerization and oligomerization have attracted a lot of attention in the last two decades. A large number of late-transition metal complexes with symmetric diimine ligands have been extensively studied. Although the research of unsymmetric diimine late-transition metal complexes was still in the initial stage, some superior performances were observed in olefin polymerization. Recent developments in the research of ethylene poly- merization and oligomerization catalyzed by late-transition metal complexes with unsymmetric diimine ligands were summarized in this review, with the influence of complex structure on the catalytic performance of the catalyst analyzed.     

高分散Pt／MOM-41催化剂的制备及其萘加氢活性

关注环保、降低排放已成为世界各国发展的共同趋势．芳烃加氢催化剂的开发已成为清洁柴油研究的热点。本文采用乙二醇化学还原法和沉淀法制备了Pt／MCM－41、Pt－0．4PVP／MCM－41和Pt－5PVP／MCM－41催化剂。通过BEI、、XRI）、TEM等技术对催化剂的结构进行了表征,并考察了不同催化剂对萘加氢的催化活性。实验结果表明,勺Pt／MCM－41和Pt－0．4PVP／MCM－41催化剂相比,Pt－5PVP／MCM－41催化剂表现出较高的催化活性,这归因于适量PVP的加入导致催化剂Pt粒子的平均粒径较小和高度分散在载体上。     

Bimodal PE prepared with combined iron (II) and nickel (II) olefin polymerization catalysts

Iron (II) and nickel (II) complexes based on bis (imine) ligands are typical late-transition olefin poly- merization catalysts. As usual, nickel (II) catalysts can produce branched polyethylene (PE) even super branched PE of narrow molecular weight distri…     

环氧乙烷四氢呋喃共聚醚P（E－CO－T）的研制（Ⅱ）

研究了高ＥＯ含量、高相对分子质量产品的制备方法．采取提高后期反应温度，反应一定时间后再补加催化剂，延长聚合时间等措施，用本体聚合法可制备高ＥＯ含量Ｍｎ≤４０００的二官能度共聚醚；延长聚合时间，用溶液聚合法可制备高ＥＯ含量Ｍｎ＞４０００的二官能度共聚醚；用活性氧化铝吸附可除去高ＥＯ含量粗产品中的酸性催化剂．     

Ni(Ⅱ)/PNP催化体系催化乙烯齐聚的研究

合成了3种PNP配体,与Ni(Ⅱ)形成催化剂,在助催化剂甲基铝氧烷(MAO)存在的条件下,催化乙烯齐聚.试验结果表明:镍系催化剂催化活性最高可达4.65×105g/(mol.h),α-烯烃选择性达76.40%.利用核磁共振氢谱、元素分析及质谱对配体及催化剂进行了结构表征.     

聚苯乙烯/聚吡咯复合微球催化剂性能

采用种子乳液聚合制备了聚苯乙烯/聚吡咯(PS/PPY)复合微球,以其为载体负载钼活性中心制备了PS/PPY复合微球负载钼系催化剂,系统研究了载体性质对负载型催化剂催化环辛烯环氧化反应的催化活性.结果表明:亲水性的负载型催化剂在以过氧化氢为氧源的催化体系中催化活性较高;聚合物的掺杂离子对催化剂的催化性能具有重要影响,以硝酸铁为氧化剂制备的负载型催化剂的催化活性最高,催化环辛烯环氧化的转化率可以达到90%.     

MgCl_2-n-BuOI-SiCl_4-TiCl_4/AlR_3体系的EPR考察

考察了不同载 Ti量的 TiCl_4/MgCl_2-n-BuOH-SiCl_4 与烷基铝相互作用产生的EPR 谱、不同作用时间形成的 EPR 谱的特征变化,以及它们与催化剂催化烯烃聚合活性的关联。结果表明,不同载Ti 量催化剂的 EPR主要是暴露于催化剂表面的孤立 Ti~(3+)离子贡献。表征催化剂中处于不同畸变配体场Ti~(3+)物类的g=1.95与g=1.97信号强度比值随载 Ti量增加而减小;g=1.99 信号的形成和增长与催化剂聚合活性有一定对应关系。     

含氮有机碱活化CO2分子及合成碳酸乙烯酯的催化活性研究

合成五种４－氨基－３，５－二取代－１，２，４－三唑及四种与对羟基苯甲醛缩的Ｓｃｈｉｆｆ碱，作为含氮有机碱催化剂，用来催化由二氧化碳与环氧乙烷合成碳酸乙烯酯的反应，通过结构特点和碱性强弱碱解释评价其催化活性，并且对反应机理进行了初步探讨，实验结果表明，催化活性顺序：三唑Ｓｃｈｉｆｆ碱〉４－氨基－３，５－二取代－１，２，４－三唑，这与含氮有机物碱性大小是一致的。     

Ethylene polymerization by novel highly active iron/acetyl（imino）pyridyl complex

In recent years, significant developments have oc- curred in olefin polymerization with late-transition- metal catalyst systems, in particular, the discovery of exceptionally active catalysts based on penta- coordi- nate iron and cobalt bearing bis(imino)pyridyl triden- tate ligands with substituted aryl groups, reported in- dependently by the groups of Brookhart[1] and Gibson[2]. Following this discovery, a considerable amount of efforts have been dedicated to investigate the nature of the ac…     

合成乙二醇单烷基醚乙酸酯的催化剂研究

详细介绍了评述了阳离子交换树脂、分子筛负载TiO2/SO42-、稀土盐、层柱状粘土等不同催化剂催化合成乙二醇单烷基醚乙酸酯的方法。探讨了用硫酸氢钠催化合成乙二醇单甲醚乙酸酯的最佳条件。结果表明，硫酸氢钠是催化合成乙二醇单甲醚乙酸酯的良好催化剂，用量少、收率高、操作简便。     

LLDPE/TiO2 nanocomposites produced from different crystallite sizes of TiO2 via in situ polymerization

Nano-TiO2 particles with a range of crystallite sizes were synthesized by a conventional sol-gel method,and then used as nanoparticle substrates in the synthesis of LLDPE/TiO2 nanocomposites via in situ polymerization of ethylene/1-hexene with zirconocene/MMAO catalyst.It was found that the size of the nano-TiO2 crystallite nanoparticles can influence the catalytic activity in the polymerization system.The larger nano-TiO2 crystallites provided better catalytic activity in the polymerization system due to more space for monomer attack.In addition,by thermo-gravimetric analysis,it can be seen that the larger nano-TiO2 crystallites also exhibited lower interaction with available MMAO.Consequently,the MMAO reacted more efficiently with the zirconocene catalyst during the activation process,and enhanced polymerization catalysis.All the polymer nanocomposites products did not have well defined melting temperature indicating non-crystalline polymers.This is due to the high amount of hexene incorporation(based on 13C NMR).The difference in crystallite sizes of the nano-TiO2 also affected how 1-hexene became incorporated into the polymer nanocomposites.The smaller crystallite size of nano-TiO2 allowed greater 1-hexene incorporation due to depression of the reactivity of the ethylene.The contribution of this work helps develop a better understanding of the role of nano-TiO2 in the catalytic activity of the polymerization system and in the microstructure of the polymer composite product.However,this study only considers work on the laboratory scale,so for commercial application of these results,it is necessary to scale up the polymerization process.It is only at this stage,that other physical properties,such as the mechanical properties of these materials can be sensibly determined.     

超支化聚酰胺负载铂纳米簇杂化膜催化剂在苯加氢反应中的活性寿命

采用溶液缩聚合成了超支化聚酰胺,制备了超支化聚酰胺负载铂纳米簇杂化膜催化剂,对比新鲜和使用11次后的杂化膜催化剂,考察了催化剂在苯加氢反应中的活性寿命问题,并结合了透射电流(TEM)、X-射线衍射(XRD)、X-射线能谱(XPS)等手段对催化剂表征.结果表明:杂化膜型催化剂比传统粉末型催化剂寿命更长、活性更好;在杂化膜型催化剂中,使用超支化聚合物作为贵金属的载体,比线性聚合物作载体时苯的转化率高.起主要催化作用的可能是杂化膜表面的铂纳米颗粒.     

Study on the distribution of active centers in novel low Ti-loading MgCl2-supported Ziegler-Natta catalyst

Novel MgCl2-supported Ziegler-Natta (Z-N) catalysts prepared using a new one-pot ball milling method can effectively control the amounts of Ti-loading in the catalysts. Complex GPC data on polypropylene synthesized by these novel catalysts were analyzed using the method of fitting the molecular weight distribution (MWD) curves with a multiple Flory-Schulz function. It was found that multiple active centers exist in these novel catalysts. Detailed study of the effects of the Ti-loadings in the catalysts on the distribution of the active centers showed that the Ti-loadings in the novel MgCl2-supported Z-N catalysts might affect the proportion of each type of active centers; and might be the main factor responsible for the effect of the Ti-loadings on the microstructure, the molecular weight and molecular weight distribution width of the resultant polymer, the catalytic activity and polymerization kinetics.