新型后过滤金属烯烃聚合催化剂——镍系烯烃聚合催化剂

镍系烯烃聚合催化剂是近年来受到广泛关注的一类新型催化剂，是配位催化研究的热点之一。这类催化剂具有高催化活性、单活性中心和良好的分子剪栽性，可以在分子层次上实现烯烃聚合的分子设计与组装。本文介绍了镍系烯烃聚合催化剂的发展和研究概况，并评述了聚合特性及最新研究进展。     

新型后过渡金属烯烃聚合催化剂－－镍系烯烃聚合催化剂*

镍系烯烃聚合催化剂是近年来受到广泛关注的一类新型催化剂,是配位催化研究的热点之一。这类催化剂具有高催化活性、单活性中心和良好的分子剪栽性,可以在分子层次上实现烯烃聚合的分子设计与组装。本文介绍了镍系烯烃聚合催化剂的发展和研究概况,并评述了聚合特性及最新研究进展。     

烯烃配位聚合二十年

聚烯烃树脂是消费量最大的合成树脂种类,性能优异,用途广泛。二十多年来,烯烃配位聚合技术取得了突飞猛进的发展,在催化剂、聚合方法、聚合工艺方面都有重大突破。本文综述了二十多年来烯烃配位聚合的研究发展情况,包括Ziegler-Natta催化剂,茂金属催化剂,非茂金属催化剂,配位聚合机理,功能化聚烯烃的制备,原位共聚制备LLDPE,原位聚合制备纳米复合材料,活性配位聚合以及Spherizone工艺等方面的成就。     

Recent progress on olefin polymerization catalysts

Recent progress on metallocene catalysts is reviewed. This consists for the main part of research activities in metallocene catalysts and their polymerization performances (ethylene polymerization, propylene polymerization, styrene polymerization). In addi-tion, the computational design of metallocene catalysts and the commercial status of metallocene technologies in Japan are described.     

A Self-Supporting Strategy for Gas-Phase and Slurry-Phase Ethylene Polymerization using Late-Transition-Metal Catalysts

The polyolefin industry is dominated by gas-phase and slurry-phase polymerization using heterogeneous catalysts. In contrast, academic research is focused on homogeneous systems, especially for late-transition-metal catalysts. The heterogenization of homogeneous catalysts is a general strategy to provide catalyst solutions for existing industrial polyolefin synthesis. Herein, we report an alternative, potentially general strategy for using homogeneous late-transition-metal catalysts in gas-phase and slurry-phase polymerization. In this self-supporting strategy, catalysts with moderate chain-walking capabilities produced porous polymer supports during gas-phase ethylene polymerization. Chain walking, in which the metal center can move up and down the polymer chain during polymerization, ensures that the metal center can travel along the polymer chain to find suitable sites for ethylene enchainment. This strategy enables simple heterogenization of catalysts on solid supports for slurry-phase polymerization. Most importantly, various branched ultra-high-molecular-weight polyethylenes can be prepared under various polymerization conditions with proper catalyst selection.     

烯烃聚合钯催化剂研究进展

综述了烯烃聚合钯催化剂的研究进展,烯烃聚合钯催化剂的配体类型有膦配体、氮配体、碳配体、氧配体、氮-氧配体、膦-氧配体、氮-膦配体等。与齐格勒-纳塔催化剂和茂金属催化剂相比,烯烃聚合钯催化剂具有高催化活性、单活性中心和良好的分子剪裁性等优点,可在分子层次上实现烯烃聚合的分子设计与组装;与铁、钴、镍等后过渡金属催化剂相比,烯烃聚合钯催化剂具有反应条件较温和、催化活性和立体选择性较高的优势。     

A Self‐Supporting Strategy for Gas‐Phase and Slurry‐Phase Ethylene Polymerization using Late‐Transition‐Metal Catalysts

The polyolefin industry is dominated by gas‐phase and slurry‐phase polymerization using heterogeneous catalysts. In contrast, academic research is focused on homogeneous systems, especially for late‐transition‐metal catalysts. The heterogenization of homogeneous catalysts is a general strategy to provide catalyst solutions for existing industrial polyolefin synthesis. Herein, we report an alternative, potentially general strategy for using homogeneous late‐transition‐metal catalysts in gas‐phase and slurry‐phase polymerization. In this self‐supporting strategy, catalysts with moderate chain‐walking capabilities produced porous polymer supports during gas‐phase ethylene polymerization. Chain walking, in which the metal center can move up and down the polymer chain during polymerization, ensures that the metal center can travel along the polymer chain to find suitable sites for ethylene enchainment. This strategy enables simple heterogenization of catalysts on solid supports for slurry‐phase polymerization. Most importantly, various branched ultra‐high‐molecular‐weight polyethylenes can be prepared under various polymerization conditions with proper catalyst selection.     

High-performance olefin polymerization catalysts discovered on the basis of a new catalyst design concept

This critical review highlights the "ligand oriented catalyst design concept", a new catalyst design concept for olefin polymerization that has led to the development of high-activity catalysts. The concept has created a series of highly active ethylene polymerization catalysts, many of which show high activities comparable to those of group 4 metallocene catalysts. Moreover, these catalysts display unique polymerization catalysis to produce a wide variety of polymers that possess unprecedented molecular architectures that are either difficult or impossible to achieve using conventional catalysts (98 references).     

后过渡金属催化降冰片烯加成聚合

综述了后过渡金属催化剂催化降冰片烯加成聚合的研究进展。主要介绍了Ni、Pd、Co三种金属催化剂各自的结构以及其催化降冰片烯聚合的特点,同时也阐述了Ni、Pd催化剂催化降冰片烯聚合的机理。     

新型烯烃聚合催化剂研究进展

由于过渡金属催化剂在烯烃聚合方面具有高活性和良好的分子剪裁性,通过调节催化剂的微结构或温度、压力等聚合环境的变化,可以在分子层次上实现烯烃聚合物的分子设计与组装,实现聚合物物理性质的调控,最近引起了人们的广泛关注。本文介绍了过渡金属催化剂的合成及其负载化,水相烯烃聚合及活性聚合等方面的研究进展。     

Ziegler-Natta催化剂催化乙烯气相聚合

本文综述了乙烯气相聚合催化剂研究状况,列举了一些制备气相聚合催化剂有代表性的方法。同时对预聚合的作用及气相聚合与淤浆聚合表观动力学行为的不同性也作了简要介绍。     

Polymerization of acetylenes with rare earth coordination catalysts

The polymerization of acetylene and its derivatives by rare earth coordination catalysts and the characterization of the polymers so obtained in our laboratory are reviewed. Because of the metallic conductivity possessed by doped polyacetylene and the unique properties such as conductivity (semiconductivity), paramagnetism, migration and transfer of energy and chemical reactivity and complex formation ability often shown by acetylenic polymers, which seem promising as specialty polymers, there has been considerable interest in the polymers of acetylene and its derivatives. A wide variety of catalyst systems have been developed for the polymerization of acetylenes. But there has been no information concerning the use of rare earth compounds as catalysts in the polymerization of acetylene and its derivatives. We for the first time in 1981 have succeeded in the polymerization of acetylene with rare earth coordination catalysts, which in turn is a development based upon earlier work on the diene polymerization using rare earth coordination catalysts(Ref. 1). Using rare earth catalysts, acetylene can be polymerized conveniently into high cis polyacetylene films with metallic sheen at room temperature and phenylacetylene can also be polymerized into high molecular weight, high cis polyphenylacetylene films at ambient temperature. Thus new varieties of polyacetylenes have been developed and a novel family of coordination catalysts consisting of a rare earth compound plus trialkyl aluminum for the polymerization of acetylenes has been exploited. This article reviews our studies on the polymerization of acetylene and its derivatives with rare earth coordination catalysts and on the characterization of the polyacetylenes prepared.     

有机金属烯烃配位聚合催化剂

有机金属烯烃配位聚合催化剂具有高催化活性和良好的分子剪裁性,通过调节催化剂的微结构,如配体的取代基?配位原子以及配位中心的电子与立体环境等,可以在分子层次上实现烯烃聚合物的分子设计与组装;实现聚合物物理性质的调控,从而得到各种具有新型功能和立体异构的聚合物。本文综述了金属烯烃聚合催化剂研究进展,并展望该领域的发展趋势。     

均相铬系催化剂的合成与催化α－烯烃聚合的进展

铬系多相催化剂已广泛应用于工业聚乙烯的生产中。近年来，探明多相铬催化 剂的本质，并进一步开发新一代铬系均相催化剂成为人们追求的热点。综述了近年 来有关均相铬催化剂的合成与催化α－烯烃的报道。     

水相配位催化烯烃聚合的新进展*

水相催化研究已经成为近年来化学反应研究的热点课题.烯烃聚合领域中水相自由基乳液聚合和悬浮聚合等方法早已工业化,而前过渡金属烯烃聚合催化剂对水气敏感,水相烯烃配位聚合发展缓慢.低亲氧性、高活性的后过渡金属烯烃聚合催化剂的出现使水相催化成为可能.本文综述了后过渡金属催化剂水相催化烯烃配位聚合的一些新进展,内容包括乙烯、α-烯烃、环烯烃、二烯烃的聚合反应和环烯烃的开环聚合反应以及CO/烯烃的共聚反应等方面.     

Gas Phase Polymerisation of Ethylene with Supported Titanium-Nickel Catalysts

Olefins gas phase polymerization uses generally supported titanium catalyst systems inindustrial production. The polymerization of olefins with late transition metal catalysthas recently attracted considerable interestl-2. The new catalyst family shares many ofthe advantages of metallocene catalysts in terms of activity and control of polymerproperties and, in addition, the new catalysts yield homopolymer of ethylene with veryhigh branching degrees and branching degree can be controlled.A new …     

Polymerization of ethylene with supported zirconium organic compounds

The polymerization of ethylene was studied with supported catalysts prepared by the reaction of Zr(benzyl)₄ and Al₂O₃. The influence of the preparation of the catalysts and the reaction conditions on the overall rate of the polymerization was established. The rate exhibits a maximum which depends on the thermal pretreatment of the support and the quantity of the fixed Zr(benzyl)₄. The concentration of the active centres of the catalysts was determined by quenching the polymerization with labelled butanol. The catalysts possess active centres which have different rates of propagation for ethylene. The decrease of the polymerization rate is caused by chemical reaction. The higher the concentration of free hydroxyl groups on the catalyst, the higher the rate of deactivation. Hydrogen in the monomer feed produces a decrease or an increase of the polymerization rate depending on the preparation of the catalysts.     

丙交酯开环均聚合

生物可降解脂肪族聚酯--聚丙交酯由可再生资源获得.聚丙交酯独特的物理性质使得它在包装、涂层、纤维、薄膜等方面有着广泛的应用.聚丙交酯低成本、大规模的生产及应用将极大地减轻对石油产品的依赖.高分子量的聚丙交酯主要由丙交酯开环聚合制备.本文总结了催化丙交酯开环聚合的3大类催化剂及其反应机理;综述了近年来国内外在丙交酯均聚合催化剂开发上的研究进展,并重点论述了稀土催化剂在丙交酯开环聚合中的优势及由其催化合成的聚丙交酯在生物学应用中的优点.     

合成聚(丙交酯-co-ε-己内酯)的催化剂研究进展

综述了合成聚(丙交酯-co-ε-己内酯)的催化剂的研究进展;针对几种不同类型催化剂的活性、安全性及其对单体催化反应的影响等进行了评述;指出催化剂在内酯开环聚合中所起的关键作用.     

稀土催化剂在高分子合成中的开拓应用

综述了40多年来我国在高分子合成领域中开拓应用稀土催化剂,在双烯烃、炔烃、环氧烷烃、环硫烷烃、二氧化碳共聚、丙交酯、己内酯和环碳酸酯等聚合方面取得的主要进展。