均相茂金属加合物催化乙烯均聚及乙烯／1—己烯共聚

对均相茂金属加合物催化剂催化乙烯均聚和乙烯与１－己烯共聚进行了研究,采用三异丁基铝（ＴＩＢＡ）部分取代助催化剂甲基铝氧烷（ＭＡＯ）,并对共聚单体投料量对聚合的影响进行了考察。发现共聚活性高于均聚活性;用ＴＩＢＡ部分取代ＭＡＯ可以降低ＭＡＯ用量,而且提高了催化活性;１－己烯的投料量对１－己烯的插入量影响较大。     

介孔材料的形貌控制及其应用

综述了近期介孔材料研究在形貌控制方面取得的成果,着重介绍了在酸性条件下具有孔结构的氧化硅薄膜,薄片,空心球,硬球和纤维的合成。这些特定形貌的介孔材料在催化,纳米材料合成,光学器件和色谱载体等领域具有广泛的应用前景。     

有序介孔材料的形貌调控及应用研究进展

有序介孔材料因具有较大的比表面积、相对大的孔径及孔径可调等优点而被广泛关注,但粉末状的介孔材料由于易发生团聚和难分离而影响了其在很多领域的实际应用,通过形貌调控可以拓展其在吸附、催化、分离等领域的应用.综述了具有薄膜、球体、纤维、管状、棒状等形貌的有序介孔材料的合成及应用.     

不同形貌介孔二氧化硅纳米材料控制制备及应用研究进展

形貌可控的介孔二氧化硅纳米材料具有较大的比表面积、有序可调的介孔结构和稳定的理化性质,在药物输送、吸附、催化转化等领域具有良好的应用前景,近年来得到了广泛的研究.通过综述不同形貌介孔二氧化硅纳米材料的控制制备、形成机制及在不同领域的应用,指出合成过程中模板剂类型、反应温度及反应体系pH值等条件是其形貌控制的关键因素.最后,对不同形貌介孔二氧化硅纳米材料的研究重点和发展方向进行了展望.     

介孔材料的制备及应用

介孔材料的许多优异性能使其成为材料研究的热点。本文综述了近年来介孔材料的制备方法,包括模板法、溶胶一凝胶法、水热法、沉淀法、硬模板法等;同时简要介绍了其在吸附、催化、电极、电客、信息储运和医药基因工程方面的应用。     

介孔碳材料及其负载金属催化剂的制备及应用研究进展

介孔碳材料具有较高比表面积、均一可控纳米孔分布和可调节的表面化学性能,在催化领域具有重要应用前景.综述了介孔碳材料及其负载金属催化剂的制备方法及催化应用进展.     

不同形貌介孔二氧化硅的可控制备与表征

介孔材料由于具有比表面积和孔体积较大、孔径均一、纳米尺寸可调、二氧化硅无生理毒性、热稳定性较好等一系列特点而引起了人们广泛的兴趣和关注．控制介孔二氧化硅的形貌和尺寸可以拓展介孔二氧化硅的应用，尤其是开发介孔二氧化硅在生物医学、     

介孔材料在环境科学中的应用进展

介绍了介孔材料的改性及其在环境科学中的应用，如水中金属阳离子、阴离子、有机污染物的去除及大气中污染物的控制。     

介孔材料的制备与应用进展

综述了模板法、水热法、溶胶-凝胶法、溶剂热法、超声化学法及反胶束法等制备介孔材料的方法,其中模板法介绍了阳离子表面活性剂、阴离子表面活性剂、非离子表面活性剂、混合表面活性剂以及非表面活性剂等作为模板剂在介孔材料制备中的应用.评述了介孔材料的几种典型形貌,并对介孔材料在催化、吸附分离、传感器电极材料的制备以及酶的固定与分离等领域的应用进行了简要介绍.     

限定几何构型茂金属催化剂催化乙烯/1-己烯共聚研究

以自制的限定几何构型茂金属催化剂为主催化剂,甲基铝氧烷为助催化剂,对乙烯/1-己烯共聚性能进行研究,考察溶剂、Al与Zr物质的量比、聚合温度、聚合压力和共聚单体浓度等工艺条件对催化剂活性以及聚合物性能的影响。确定乙烯/1-己烯共聚合的工艺条件为:以正庚烷为溶剂,Al与Zr物质的量比为700~1 000,聚合温度(100~120)℃,聚合压力(1.2~2.0)MPa,优选1-己烯浓度为(0.8~1.8)mol·L~(-1)。     

Kinetic study of olefin polymerization with a supported metallocene catalyst. III. Ethylene homopolymerization in slurry

A kinetic study of ethylene homopolymerization is conducted with a supported unbridged metallocene catalyst in a slurry reactor. The effects of operational parameters such as the reaction temperature and pressure on kinetics are investigated. The kinetic parameters which have been determined for this particular catalyst from previous gas phase studies are used in a slurry reactor model to predict the polymerization behavior under various reaction conditions. The experimental data compare favorably with the predictions from this model. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2901–2917, 2001     

Supported metallocene polymerization catalysis

Zirconocene supported on alumina or magnesium chloride exhibits modest olefin polymerization activity but not when it is supported directly on silica. The surface silanol as well as siloxane groups must be passivated with appropriate reagents. A very active and stereospecific supported catalyst was obtained by first reacting silica with methylalumoxane and bisphenol A before the impregnation of the ansa-zirconocene precursor. The main difference between a homogeneous and supported catalyst is that at the same gross amount of metallocene, the net concentration of it in the pores of a support material is several orders of magnitude greater than it exists in solution thus the rate of deactivation in the former case is correspondingly faster than in the latter. Most other supported metallocene catalysts based on supports such as zeolites, cyclodextrin, polymeric MAO, synthetic polymers, etc., are poor in olefin polymerization for this and other reasons discussed. This revised version was published online in June 2006 with corrections to the Cover Date.     

LH-1型催化剂催化乙烯聚合的性能

评价了LH-1型催化剂催化乙烯均聚合,乙烯-丙烯、乙烯-1-丁烯共聚合的性能.与国内工业化生产的催化剂进行对比,研究了LH-1型催化剂的粒径分布、催化活性、氢调敏感性.结果表明:LH-1型催化剂的粒径分布均匀,细粉含量少,且具有较高的氢调敏感性;在聚合温度80℃、压力0.8 MPa、氢气分压0.2 MPa的乙烯淤浆聚合工艺下聚合2h,LH-1型催化剂的活性较高,达5.36×104 g/g,优于对比催化剂;用LH-1型催化剂制备的高密度聚乙烯的堆密度较大,达0.350g/cm3,乙烯-丙烯、乙烯-1-丁烯共聚合性能好.     

Study on copolymerization of ethylene/1‐hexene catalyzed by a novel polystyrene‐supported metallocene catalyst

Ethylene/1‐hexene copolymerization was carried out with polystyrene‐supported metallocene catalyst. It was found that the kinetic of the copolymerization was strongly influenced by the steric hindrance of carrier. The influences of 1‐hexene concentration in the feed on catalyst productivity and comonomer reactivity were investigated. The microstructure of resultant copolymer was analyzed by ¹³C NMR. It was found that the different carriers have slight effect on the composite of copolymer. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1574–1577, 2006     

负载茂金属催化剂催化乙烯气相聚合

研究了负载茂金属催化剂(n-BuNeCp)_2ZrCl_2/SiO_2的乙烯气相聚合行为及其催化聚合产品的性能。三乙基铝加入聚合体系后可降低负载茂金属催化剂的初始活性,有利于聚合过程中的温度控制。气相聚合产品聚乙烯的重均分子量为(1 42～2.28)×10~5,相对分子质量分布为2.6～3.1,熔点在135℃以上,结晶度约为60%,聚乙烯产物颗粒形态以球形为主.堆密度大于0.35 g/cm~3。     

茂金属乙烯－辛烯共聚物弹性体的应用

综述了茂金属乙烯－辛烯共聚物作为弹性体系材料的最新应用进展,采用藏属催化剂合成的乙烯－辛烯共聚物是一咎新型热塑性弹性体,可用注射,挤出,吹塑等常用加工方法成型,又可用过氧化物进行化学交联,用橡胶加工方法制成弹性体材料。     

茂金属乙烯-辛烯共聚物用作树脂改性剂的进展

概述了茂金属乙烯－辛烯共聚物在聚丙烯,聚乙烯,聚酯,聚酰胺,苯乙烯基树脂等中的应用进展。     

Highly active ethylene/hydroxyl comonomers copolymerization using metallocene catalysts

Ethylene was copolymerized with 10‐undecen‐1‐ol and 5‐hexen‐1‐ol using stereorigid [rac‐ethylene(Ind)₂ZrCl₂], [rac‐ethylene(H₄Ind)₂ZrCl₂], and the new catalyst systems [rac‐norbornane(Ind)₂TiCl₂] and [mesonorbornane(Ind)₂TiCl₂], activated with methylaluminoxane. The characterization of the copolymers by ¹³C NMR spectroscopy revealed that the polymerization products were copolymers and that the conversion of the polar comonomer was strongly favored in the case of the zirconocene precursors. Very high catalytic activity values, nearly independent on the amount of comonomer in the feed, and comonomer incorporations up to 25.4%‐weight have been found for 10‐undencen‐1‐ol comonomer. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Comparative study of copolymerization and terpolymerization of ethylene/propylene/diene monomers using metallocene catalyst

(Ind)₂ZrCl₂ catalyst was synthesized and used for copolymerization of ethylene and propylene (EPR) and terpolymerization of ethylene propylene and 5‐ethyldiene‐2‐norbornene (ENB). Methylaluminoxane (MAO) was used as cocatalyst. The activity of the catalyst was higher in copolymerization of ethylene and propylene (EPR) rather than in terpolymerization of ethylene, propylene and diene monomers. The effects of [Al] : [Zr] molar ratio, polymerization temperature, pressure ratio of ethylene/propylene and the ENB concentration on the terpolymerization behavior were studied. The highest productivity of the catalyst was obtained at 60°C, [Al] : [Zr] molar ratios of 750 : 1 and 500 : 1 for copolymerization and terpolymerization, respectively. Increasing the molar ratio of [Al] : [Zr] up to 500 : 1 increased the ethylene and ENB contents of the terpolymers, while beyond this ratio the productivity of the catalyst dropped, leading to lower ethylene and ENB contents. Terpolymerization was carried out batchwise at temperatures from 40 to 70°C. Rate time profiles of the polymerization were a decay type for both copolymerization and terpolymerization. Glass transition temperatures (T_g) of the obtained terpolymers were between ?64 and ?52°C. Glass transition temperatures of both copolymers and terpolymers were decreased with increased ethylene content of the polymers. Dynamic mechanical and rheological properties of the obtained polymers were studied. A compounded EPDM showed good thermal stability with time. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011