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Recent Progress on Transition Metal （Fe, Co, Ni, Ti and V） Complex Catalysts in olefin polymerization with High Thermal Stability

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Chinese Journal of Chemistry 2017年第5期35卷 531-540页

作者： Zhifeng Ma Wenhong Yang Wen-Hua Sun Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China

The design and synthesis of transition metal complexes with high thermal stability in olefin polymerization have become more and more important in order to meet the need of industrial *** review focuses on the transition metal complex catalyst with high thermal stability containing different structures,including the backbone of bis（imino）pyridine,a-diimine and other types of *** the catalytic activity,the influence of reaction temperature on the molecular weight and molecular weight distribution of the obtained polymer was also *** plausible mechanism on the stability of catalysts at high temperature was proposed,which may give guidance to design catalyst with good thermal stability.

关键词： thermal stability transition metal complex olefin polymerization homogenous catalysis ligand effects

Benzosuberyl Substituents as a"Sandwich-like"Function in olefin polymerization Catalysis

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Chinese Journal of Polymer Science 2021年第8期39卷 984-993,I0006页

作者： Yu-Yin Wang Chao-Qun Wang Xiao-Qiang Hu Yan Xia Yue Chi Yi-Xin Zhang Zhong-Bao Jian College of Chemistry and Life Science Advanced Institute of Materials ScienceChangchun University ofTechnologyChangchun 130012China Key Laboratory of Advanced Structural Materials of Ministry of Education College of Material Science and EngineeringChangchun University of TechnologyChangchun 130012China State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China

For the rational design of metal catalyst in olefin polymerization catalysis,various strategies were applied to suppress the chain transfer by bulking up the axial positions of the metal center,among which the"sandwich"type turned out to be an eficient category in achieving high molecular weight *** the a-dimine system,the"sandwich"type catalysts were built using the typical 8-aryl-naphthyI *** this contribution,by introducing the rotationally restrained benzosuberyl substituent into the ortho-position of N-aryl rings,a new class of "sandwich-like"a-diimine nickel catalysts was constructed and fully *** rotationally restrained benzosuberyl substituents played a"sandwich-like"function by capping the nickel center from two axial *** to the nickel catalyst Ni1 bearing freely rotated benzhydryl substituent,Ni2 featuring benzosubery|substituent enabled the increase(8 times)of polymer molecular weights from 8 kDa to 65 kDa in the polymerization of *** further increasing the steric bulk of another ortho-site of the N-aryl ring,the polymer molecular weight even reached an ultrahigh level of 833 kDa(Mw=1857 kDa)using the optimized ***,these nickel catalysts could also mediate the copolymerization of ethylene with methyl 10-undecenoate,with Ni3 giving the highest copolymer molecular weight(88 kDa)and the highest incorporation of comonmer(2.0 mol1%),along with high activity of up to 10^(5)g·mol^(-1)·h^(-1).

关键词： olefin polymerization Benzosuberyl substituent Sandwich Nickel catalyst Polar monomer

A Sterically Hindered Zirconocene Complex (1,2-Ph_2C_5H_3)_2ZrCl_2:Synthesis,Structure and Properties as olefin polymerization Catalyst

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Chinese Chemical Letters 2000年第7期11卷 641-644页

作者： Fan ZHANG Ying MU Yue Tao ZHANG Cong Xi CHEN Hui Min ZHAI Han HONG(Department of Chemistry, Jilin University, Changchun 130023Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080) Jilin Univ Dept Chem Changchun 130023 Peoples R China Chinese Acad Sci Inst Chem Beijing 100080 Peoples R China

An unbridged zirconocene complex bis(1,2-diphenylcyclopentadienyl)zirconium dichloride [(1,2-Ph2-C5H3)2ZrCl2] 1 has been synthesized and structurally characterized. When activated by MAO, 1 produces ultra-high molecular weight polyethylene with high melting transition temperature, as well as atactic oligopropylene with average molecular weight of ~1150 g mol-1.

关键词： Zirconium complex metallocene catalyst olefin polymerization

A New Zirconocene Complex and Its Catalytic Properties for olefin polymerization

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Chemical Research in Chinese Universities 2000年第2期16卷 179-181页

作者： ZHANG Fan MU Ying BU Weiming ZHAO Ligang CHEN Congxi ZHAI Huimin YANG Guangdi Jilin Univ Dept Chem Changchun 130023 Peoples R China Jilin Univ Key Lab Supramol Struct & Spect Changchun 130023 Peoples R China

The synthesis and characterization of a new zirconocene complex, bis(1-methyl-3,4-diphenylcyclopentadienyl)zirconium dichloride (1), and its catalytic properties for ethylene and propylene polymerizations is presented. This compound is the first example of metallocene complexes with 1-alkyl-3,4-diarylcyclopentadienyl as the ligand. Ultra-high molecular weight polyethylenes with high melting transition temperatures are obtained with complex (1) at low Al/Zr molar ratios. This results are attributed to the steric hindrance of the complex. Large steric hindrance prevents the active catalyst from bimolecular deactivation and interaction with methylaluminoxane (MAO), and lower the chain termination rate.

关键词： Zirconium Metallocene olefin polymerization Catalysis Polyethylene Polypropylene

Mathematical Model and Advanced Control for Gas-phase olefin polymerization in Fluidized-bed Catalytic Reactors

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Chinese Journal of Chemical Engineering 2008年第1期16卷 84-89页

作者： Ahmmed S. Ibrehem Mohamed Azlan Hussain Nayef M. Ghasem Department of Chemical Engineering University of Malaya 50603 Kuala Lumpur Malaysia Department of Chemical ＆ Petroleum Engineering UAE University Al-Ain 17555 UAE

In this study, the developments in modeling gas-phase catalyzed olefin polymerization fluidized-bed reactors （FBR） using Ziegler-Natta catalyst is presented. The modified mathematical model to account for mass and heat transfer between the solid particles and the surrounding gas in the emulsion phase is developed in this work to include site activation reaction. This model developed in the present study is subsequently compared with well-known models, namely, the bubble-growth, well-mixed and the constant bubble size models for porous and non porous catalyst. The results we obtained from the model was very close to the constant bubble size model, well-mixed model and bubble growth model at the beginning of the reaction but its overall behavior changed and is closer to the well-mixed model compared with the bubble growth model and constant bubble size model after half an hour of operation. Neural-network based predictive controller are implemented to control the system and compared with the conventional PID controller, giving acceptable results.

关键词： fluidized-bed reactor olefin polymerization mathematical model dynamic studies control system

Asymmetric Cationic [P, O] Type Palladium Complexes in olefin Homopolymerization and Copolymerization

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Chinese Journal of Chemistry 2017年第8期35卷 1209-1221页

作者： Shuoyan Xiong Lihua Guo Shumiao Zhang Zhe Liu Key Laboratory of Soft Matter Chemistry Chinese Academy of Sciences Department of Polymer Science and Engineering University of Science and Technology of China Hefei Anhui 230026 China Shool of Chemistry and ChemtcalEngmeermg Qufu Normal University Qufu Shandong 273165 China

Metal-catalyzed ethylene homopolymerization and ethylene-polar monomer copolymerization to produce new kinds of polyolefins with novel microstructures are of great interest. So far, there are some disadvantages for traditional transition metal catalyst systems. Therefore, it is critical to develop new catalysts or alternative strategies. In recent years, some cationic [P, O] palladium complexes have been demonstrated with the abilities to obtain oligomers and the high molecular weight polymers. Most importantly, these complexes showed high activity and generated polymers with specific microstructures when used for copolymerization of ethylene with industrially relevant polar monomers. This review summarizes several types of high performance cationic [P, O] palladium catalysts in ethylene oligomerization, ethylene homopolymerization and the copolymerization of ethylene with polar monomers Specially, the regulation of steric and electronic effects at specific sites of the metal complexes was focused.

关键词： palladium olefin polymerization copolymerization cationic metal center substituent effect

The Influence of Bridge Type on the Activity of Supported Metallocene Catalysts in Ethylene polymerization

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Chinese Journal of Polymer Science 2014年第2期32卷 137-142页

作者： Alireza Talaei Faramarz Afshar Taromi Ahmad Arefazar Saeid Ahmadjo Omid Moini Jazani Department of Polymer Engineering and Color Technology Amirkabir University of Technology Department of Catalyst Iran Polymer and Petrochemical Institute (IPPI) Department of Chemical Engineering College of Engineering University of Isfahan

Ethylene polymerization was carried out by immobilization of rac-ethylenebis（1-indenyl）zirconium dichloride （Et（Ind）2ZrCl2） and rac-dimethylsilylbis（1-indenyl）zirconium dichloride （Me2Si（Ind）2ZrCl2） preactivated with methylaluminoxane （MAO） on calcinated silica at different temperatures. polymerizations of ethylene were conducted at different temperatures to find the optimized polymerization temperature for maximum activity of the catalyst. The Me2Si bridge catalyst showed higher activity at the lower polymerization temperature compared to the Et bridge catalyst. The highest catalytic activities were obtained at temperatures about 50 ~C and 70 ~C for Me2Si（Ind）2ZrC1JMAO and Et（Ind）zZrCI2/MAO catalysts systems, respectively. Inductively coupled plasma-atomic emission spectroscopy results and polymerization activity results confirmed that the best temperature for calcinating silica was about 450 ℃ for both catalysts systems. The melting points of the produced polyethylene were about 130 ℃, which could be attributed to the linear structure of HDPE.

关键词： Slurry polymerization olefin polymerization ansa-Metallocene Silica support.

Influence of Backbone and Axial Substituent of Catalyst onα-Imino-ketone Nickel Mediated Ethylene(Co)polymerization

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Chinese Journal of Polymer Science 2022年第5期40卷 469-477页

作者： Yu-Kai Chu Xiao-Qiang Hu Yue Zhang Da-Jun Liu Yi-Xin Zhang Zhong-Bao Jian College of Chemistry and Environmental Engineering Changchun University of Science and TechnologyChangchun 130022China State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 730022China

Theα-imino-ketone nickel catalyst is an emerging versatile platform that is easy to prepare and allows for the production of branched high molecular weight functionalized ***,study on this catalyst system is rare thus *** this contribution,by introducing different backbones,flexible and rigid axial substituents into theα-imino-ketone framework,a family of cationic nickel catalysts were synthesized and fully *** the addition of any activator,systematic studies on ethylene polymerization and copolymerization with polar monomers were performed to explore the influence of both backbone and axial substituent on catalytic activity,polymer molecular weight,branching density and *** particular,owing to the unique semi-opening feature of theα-imino-ketone framework,the preferred nickel catalyst exhibited high activity of 175 kg·mol^(-1)·h^(-1)to produce functionalized polyethylene with molecular weight of 13.4 kg·mol^(-1)and comonomer incorporation of 2.9 mol%.

关键词： olefin polymerization α-Imino-ketone ligand Nickel catalyst Polar monomer

Horizontally and Vertically Concerted Steric Strategy inα-Diimine Nickel Promoted Ethylene(Co)polymerization

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Chinese Journal of Chemistry 2021年第10期39卷 2829-2836页

作者： Xiaoqiang Hu Yixin Zhang Baixiang Li Zhongbao Jian State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesRenmin Street 5625ChangchunJilin130022 China University of Science and Technology of China HefeiAnhui230026 China

Main observation and conclusion Steric bulk plays a significantly paramount role in late transition metal promoted olefin(co)polymerization in terms of polymer molecular weight and catalyst thermal *** sterically encumbered nickel and palladium catalysts have been developed,but they are usually *** this contribution,from a bi-directional side the distinctive horizontally and vertically concerted steric strategy was well-developed and applied toα-diimine nickel *** ethylene polymerization,the increase of vertically steric bulk(H,Ph,Biph)led to an enhanced polymer molecular weight,a slightly ascended branching density;likewise increasing horizontally steric bulk(Ph,Nap,Ant)further resulted in the increase of polymer molecular weight and branching *** a result,in sharp contrast to Ni1(H)without steric bulk,Ni5(Ant)with horizontally and vertically concerted steric bulk was thermally stable,showed very high activities at a level of 107 g·mol–1·h^(–1),and produced polyethylenes with the highest molecular weight of 518.8×10^(4)g·mol^(-1)and the broader range of branching density from 2.4/1000C to 27.8/*** the copolymerization of ethylene with methyl 10-undecenoate,Ni5(Ant)also provided the highest copolymer molecular weight but gave the lowest incorporation of *** work sheds light on the steric effect on olefin(co)polymerization.

关键词： olefin polymerization Steric effect Homogeneous catalysis UHMWPE Nickel