新型后过渡金属络合物聚合催化剂研究进展

概述了后过渡金属催化剂的研究进展,包括催化剂的合成、结构、活化机理以及技术特点,对新型催化剂上的乙烯均聚机理和一氧化碳／乙烯共聚机理作了重点阐述,同时介绍了该研究领域的一些新进展。     

三齿配体过渡金属烯烃聚合催化剂研究新进展

介绍了三齿配体结构、中心金属原子、助催化剂、负载化等对催化剂性能的影响;综述了三齿配体过渡金属烯烃聚合催化剂在乙烯齐聚、乙烯聚合、丙烯聚合以及极性单体聚合方面的应用以及三齿配体过渡金属烯烃聚合催化剂的催化机理方面的研究进展。     

新型烯烃聚合催化剂

从聚合机理出发,综述了后过渡金属ＮｉＰｄ、Ｆｅ、Ｃｏ催化剂的结构、催化机理及其在烯烃、极性单体均聚、共聚中的应用。     

铬系乙烯聚合催化剂研究进展

介绍了铬系乙烯聚合催化剂的类型、改性与发展。指出需对该类型催化剂的聚合反应机理作进一步研究。     

后过渡金属催化剂催化乙烯聚合

考察了不同温度,Ａｌ／Ｆｅ比以及催化剂浓度等条件下后过渡金属ＦｅＭＡ催化剂乙烯常压聚合的催化活性和动力学行为。     

后过渡金属烯烃聚合催化剂的研究进展

综述了以后过渡金属 (Ni,Pd ,Fe和Co)络合物为主催化剂的烯烃聚合催化剂的发现、沿革及研究进展 ,包括催化剂的合成、结构、性能、催化烯烃聚合机理等。     

Ti—Mg催化剂乙烯气相聚合反应研究

研究了乙烯气相聚合Ｔｉ－Ｍｇ催化剂的聚合性能，常压气相聚合催化效率７～１１ｋｇＰＥ／ｇＴｉ，产物表观密度０．３０～０．３３ｇ／ｍｌ，产物颗粒２０～１２０目重量占８９％～９７％，加压搅拌床气相聚合，催化效率６１～８１ｋｇＰＥ／ｇＴｉ，产物表观密度０．３４～０．３５ｇ／ｍｌ，产物颗粒１０～１２０目重量占９１％～９６％。流化床惭烯／１－丁烯共聚合催化效率１００～１６９ｋｇＰＥ／ｇＴｉ，ＭＩ２．１６＝５．     

Ziegler催化剂铝／钛比对乙烯聚合反应的影响

按照乙烯聚合反应机理,论述了Ziegler催化剂铝/钛比降低,对乙烯聚合反应及产品性能的影响,并对所得结果进行了讨论。     

后过渡金属烯烃聚合催化剂的研究进展

综述了以后过渡金属（Ni、Pd、Fe和Co)络合物为主催化剂的烯烃聚合催化剂的发展、沿革及研究进展,包括催化剂的合成、结构、性能、催化烯烃聚合机理等。     

新型高性能Ziegler-Natta催化剂用于乙烯淤浆聚合

A novel high performance MgCl2/TiCl4 catalyst with tetrabutyloxsilicane as electron donor was prepared for ethylene slurry polymerization process. The properties of the catalyst such as particle size distribution, catalytic activity, hydrogen responsibility and copolymerization performance were investigated and compared with commercial catalyst (imported catalyst). Copolymerization of ethylene and 1-butylene using the catalyst was stud-ied in a pilot plant. The composition, structure and property of the copolymer were characterized by 13C nuclear magnetic resonance (13C NMR) and gel permeation chromatography-Infrared (GPC-IR), and compared with those of the copolymer obtained from a commercial catalyst. In comparison with the commercial catalyst, the novel cata-lyst had a higher activity (up to 34.6 kg•g－1) and a better particle size distribution (PSD), and produced polymers having higher bulk density (up to 0.37 g•cm－3) with less fine resin. Meanwhile, the novel catalyst showed a higher hydrogen responsibility and better copolymerization performance. The results indicated that the copolymer obtained from the novel catalyst has a higher branch in the high molecular weight fraction and lower branch in the low mo-lecular weight fraction.     

烯烃聚合后过渡金属催化剂负载化研究进展

综述了后过渡金属催化剂负载化方式和载体的种类及其催化特性,该催化剂载体包括无机载体、聚合物载体、自固载和介孔分子筛等。通过与均相催化剂性能的比较,进一步阐述了负载的目的和必要性。随着这一领域研究深入,将对后过渡金属催化剂工业化发展具有重要的意义。     

α-二亚胺镍溴化物/凹凸棒黏土负载催化剂催化乙烯聚合研究

A nickel-diimine catalyst [N, N'-bis(2,6-diisopropylphenyl)-1,4-diaza-2,3-dimethyl-1, 3-butadiene nickel dibromide, DMN] was supported on palygorskite clay for ethylene slurry polymerization. The effect of supporting methods on the catalyst impregnation was studied and compared. Pretreatment of the support with methylalumi-noxane (MAO) followed by DMN impregnation gave higher catalyst loading and catalytic activity than the direct impregnation of DMN. Catalyst activity as high as 5.42×105g PE·molNi-1·h-1 was achieved at ethylene pressure of 6.87×105 Pa and polymerization temperature of 20℃. In particular, the morphological change of the support during MAO treatment was characterized and analyzed. It was found that nano-fiber clusters formed during the support pretreatment, which increased the surface area of the support and favored the impregnation of the catalyst. The investigation of polymerization behavior of supported catalyst revealed that the polymerization rate could be kept at a relatively h     

A new iron‐based catalyst for ethylene polymerization

A new iron‐based catalyst, 2,6‐bis[(1‐naphthanylimino)ethyl]pyridine iron(II) chloride I, has been successfully synthesized and characterized. Ethylene was polymerized by I/methylaluminoxane to give branched, low‐density polymers with good activity. The result shows that the new diimino ligand has improved the characteristics of the resulting polyethylene. © 2000 Society of Chemical Industry     

气相法铬系聚乙烯催化剂QCP-01的改进

从催化剂配方和制备工艺条件方面对QCP-01气相法铬系聚乙烯催化剂进行了改进,达到了适当降低催化剂聚合活性并提高聚合物熔融指数的目的。     

一种新型非茂负载催化剂应用于乙烯聚合催化的研究

研究开发了一种新型非茂聚烯烃催化剂CpTi(dbm)Cl2，考察了该催化剂在均相以及负载条件下对乙烯聚合的催化行为。此催化剂在均相条件下对乙烯聚合的催化活性较低，但用MgCl2和MgCl2／高岭土复合双载体对催化剂进行负载后，催化乙烯聚合具有非常好的催化活性。MgCl2和MgCl2／高岭土双载体用甲基铝氧烷（MAO）预处理后，可以在铝钛摩尔比较低时发挥出高的催化活性，也可以用烷基铝代谢MAO做助催化剂。采用负载催化剂后，不仅提高了催化活性，而且也提高了聚合物的堆密度。用BET法测孔结构，发现当非茂催化剂负载到经MAO处理的双载体上，催化剂的比表面积增加了3．5倍，孔体积增加了4倍，大孔所占比例较负载前有显著提高。     

Integrating Catalyst and Co‐Catalyst Design in Olefin Polymerization Catalysis: Transferable Dianionic Ligands for the Activation of Late Transition Metal Polymerization Catalysts

Treatment of nickel and palladium α‐diimine catecholate complexes with alkylaluminum catecholates leads to active ethylene polymerization catalysts. Comparison of the catalytic activities achieved with combinations of α‐diimine catecholate or halide complexes as catalyst precursors with different activators (MMAO or alkylaluminum catecholates) reveals that the presence of the catecholate ligand in both catalyst components is beneficial for achieving high activity levels at very low M/Al ratios.     

负载复合后过渡金属烯烃聚合催化剂研究进展

综述了负载和复合型后过渡金属烯烃聚合催化剂的研究进展。把后过渡金属催化剂负载化,可以适合现有工业生产的工艺要求,改善聚合物产品的形态结构、抑制粘釜现象等。用后过渡金属催化剂与其他过渡金属催化剂(如Ziegler-Natta催化剂、茂金属催化剂等)进行复合的目的主要是制备具有某些特定性能聚烯烃产物及使单一乙烯单体聚合制备支化聚乙烯。后过渡金属催化剂进行负载和复合后在改善聚烯烃产物性能、降低生产成本等方面有突出的优势．具有十分广阔的工业应用前景。     

过渡金属催化剂加氢脱硫作用机理研究

从过渡金属催化剂的活性相结构和反应物在催化剂表面活性位上的吸附—催化反应机理两个方面阐述了过渡金属催化剂的催化作用研究进展,并对过渡金属催化剂催化机理研究存在的争议和未来的研究方向进行了分析。     

Zeolite MCM-22 Supported Heterogeneous Chromium Catalyst for Ethylene Polymerization

The chromium alkyl complex Cp*Cr(py)Me₂ (Cp* = ⁵-pentamethylcyclopentadienyl, py = pyridine, Me = methyl) has been affixed to the surface of zeolite MCM-22 via methane elimination. The resulting composite material has been characterized by a variety of physical methods. The results are consistent with the presence of isolated organometallic fragments linked to the solid support by a covalent chromium–oxygen bond. Activation of this material with methylaluminoxane (MAO) yielded a highly active catalyst for the polymerization of ethylene. The polyethylene thus formed featured high molecular weights (M_w 4 × 10⁶) and narrow molecular weight distributions (M_w/M_n 3.5).     

过渡金属改性HZSM-5催化乙醇脱水制乙烯

分别考察了过渡金属铁、锰和钴改性HZSM-5对乙醇脱水制乙烯的影响,并对催化效果最好的催化剂进行了反应条件的优化.结果表明:Co/HZSM-5的催化性能最好,使用该催化剂在220℃、质量空速2.5 h-1、乙醇体积分数为60%的反应条件下,乙醇的转化率和乙烯的选择性分别高达99.6%和99.3%.