烯烃聚合催化剂的研究

介绍了烯烃聚合催化剂的发展历程,分别讨论了Ziegler-Natta催化剂、茂金属催化剂和后过渡金属催化剂的研究情况,最后,提出了烯烃聚合催化剂的发展趋势。     

烯烃聚合后过渡金属催化剂的研究进展

综述了烯烃聚合后过渡金属催化剂的主要进展,提出了有待研究的问题,展望了后过渡金属催化剂在烯烃聚合中的应用。     

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。     

烯烃聚合催化剂的研究进展

综述了Ziegler-Natta催化剂,茂金属催化剂和后过渡金属催化剂等烯烃聚合催化剂的最新研究进展,特别是前两者负载化的研究,并对Ziegler-Natta 经剂中给电子体作用机理,茂金属催化剂和后过渡金属催化剂应用于开发新型聚烯烃产品的探索做了详尽的叙述。     

铁系催化剂在烯烃聚合中的研究进展

铁系烯烃聚合催化剂具有超高聚合活性,存在易合成、成本低、污染少以及所催化制备的聚烯烃(聚乙烯)具有更宽的相对分子质量分布等优点,显示出良好的工业应用前景.按铁系催化剂用于不同烯烃(单体)聚合的技术进展对铁系催化剂在烯烃聚合中的研究状况进行综述,包括铁系催化剂催化乙烯聚合与齐聚、铁系催化剂用于丙烯聚合、用于苯乙烯原子转移自由基聚合等.     

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。     

非茂金属烯烃聚合催化剂

综述了近年来烯烃聚合用的非茂单中心催化剂(包括非茂体系催化剂和后过渡金属催化剂)的结构特点、技术现状及最新进展情况。结果认为非茂单中心催化剂综合了Z—N催化剂和茂金属催化剂的优点，而且成本低。     

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。     

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。     

新型后过渡金属烯烃催化剂的研究进展

综述了近年来－系列新型α－二亚胺型后过渡金属（Ni、Pd、Fe、Co）催化剂在烯烃聚合、极性单体共聚、烯烃齐聚、环烯烃加成聚合、烯烃活性聚合和聚烯烃纳米复合物等方面的最新进展。系统地阐述了不同的中心过渡金属离子、α－二亚胺骨架、骨架上的取代基和不同的聚合条件（温度、压力）分别对催化剂的聚合活性、聚烯烃支化率、聚合物分子量和分子量分布以及聚合产物的性质等影响，并且简要说明了这一类催化剂的制备方法和新特点。     

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。     

单活性中心络合物均相聚烯烃催化剂

单活性中心络合物均相催化剂是１０多年来烯烃聚合领域研究开发的热点之一。本文综述用于烯烃聚合的单活性中心均相催化剂的研究开发状况,主要包括茂金属催化剂,后过渡金属络合物催化剂以及其他的新型催化剂体系。     

FI Catalysts: A New Family of High Performance Catalysts for Olefin Polymerization

This paper reviews a new family of olefin polymerization catalysts. The catalysts, named FI catalysts, are based on non‐symmetrical phenoxyimine chelate ligands combined with group 4 transition metals and were developed using “ligand‐oriented catalyst design”. FI catalysts display very high ethylene polymerization activities under mild conditions. The highest activity exhibited by a zirconium FI catalyst reached an astonishing catalyst turnover frequency (TOF) of 64,900 s ^–1 atm ^–1, which is two orders of magnitude greater than that seen with Cp₂ZrCl₂ under the same conditions. In addition, titanium FI catalysts with fluorinated ligands promote exceptionally high‐speed, living ethylene polymerization and can produce monodisperse high molecular weight polyethylenes (M_w/M_n<1.2, max. M_n>400,000) at 50 °C. The maximum TOF, 24,500 min ^–1 atm ^–1, is three orders of magnitude greater than those for known living ethylene polymerization catalysts. Moreover, the fluorinated FI catalysts promote stereospecific room‐temperature living polymerization of propylene to provide highly syndiotactic monodisperse polypropylene (max. [rr] 98%). The versatility of the FI catalysts allows for the creation of new polymers which are difficult or impossible to prepare using group 4 metallocene catalysts. For example, it is possible to prepare low molecular weight (M_v∼10³) polyethylene or poly(ethylene‐co‐propylene) with olefinic end groups, ultra‐high molecular weight polyethylene or poly(ethylene‐co‐propylene), high molecular weight poly(1‐hexene) with atactic structures including frequent regioerrors, monodisperse poly(ethylene‐co‐propylene) with various propylene contents, and a number of polyolefin block copolymers [e.g., polyethylene‐b‐poly(ethylene‐co‐propylene), syndiotactic polypropylene‐b‐poly(ethylene‐co‐propylene), polyethylene‐b‐poly(ethylene‐co‐propylene)‐b‐syndiotactic polypropylene]. These unique polymers are anticipated to possess novel material properties and uses.     

Late Transition Metal Catalyst Based on Cobalt for Polymerization of Ethylene

The late transition metal catalyst of [2,6-diacethylpyridinebis(2,6-diisopropylphenylimine)]cobalt(II) dichloride was prepared under controlled conditions and used for polymerization of ethylene. Methylaluminoxane (MAO) and triisobuthylaluminum (TIBA) were used as a cocatalyst and a scavenger, respectively. The highest activity of the catalyst was obtained at about 30°C; the activity decreased with increasing temperature. At polymerization temperatures higher than 50°C not only was a sharp decrease in the activity observed but also low molecular weight polyethylene product that was oily in appearance was obtained. The polymerization activity increased with increasing both of the monomer pressure and [MAO]:[Co] ratio. However, fouling of the reactor was strongly increased with increasing both of the monomer pressure and the amount of MAO used for the homogeneous polymerization. Hydrogen was used as the chain transfer. The activity of the catalyst and the viscosity average molecular weight (M_v) of the polymer obtained were not sensitive to hydrogen concentration. However, the viscosity average molecular weight of the polymer decreased with the monomer pressure. The (M_v), the melting point, and the crystallinity of the resulting polymer at the monomer pressure of 1 bar and polymerization temperature of 20°C were 1.2 × 10⁵, 133°C, and 67%, respectively. Heterogeneous polymerization of ethylene using the catalyst and the MAO/SiO₂ improved morphology of the resulting polymer; however, the activity of the catalyst was also decreased. Fouling of the reactor was eliminated using the supported catalyst system.     

聚烯烃催化剂的研究进展

综述了Ziegler-Natta催化剂，茂金属催化剂和后过渡金属催化剂的研究进展。对Ziegler-Natta催化剂，茂金属催化剂和后过渡金属催化剂的发展前景作了详细的描述。     

负载型单中心催化剂用于烯烃聚合的研究进展

综述了近年来在单中心尤其是负载后过渡金属催化剂的最新研究进展,包括单中心催化剂负载的方法、过程和机理以及在烯烃聚合中的应用。通过与均相单中心催化剂性能的比较,进一步说明了负载的目的和必要性?指出了负载型单中心催化剂目前存在的问题和未来研究的方向。     

Neutral Pd(II) and Ni(II) Acetylide Catalysts for the Polymerization of Methyl Methacrylate

Homogenous polymerization of methyl methacrylate using Pd(II)- and Ni(II)-based acetylide complexes as initiators has been investigated. M(PR'₃)₂(CCR)₂ (M=Pd, Ni; R'=PPh₃, Pn-Bu₃; R=Ph, CH₂OH, CH₂OOCCH₃, CH₂OOCPh, CH₂OOCPhOH-o) were found to be a novel type of effective initiators for the polymerization of methyl methacrylate. Among them, Pd(C CPh)₂(PPh₃)₂ (PPP) shows the highest activity in the MMA polymerization and the PMMA obtained is a syndiotactic polymer with high number-average molecular weight (M _n) of 14.1 × 10⁴. Some features and kinetic behavior of MMA polymerization initiated by PPP were studied in detail. The polymerization reaction is first-order with respect to both [PPP] and [MMA]. Radical polymerization mechanism is proposed.