Highly Efficient Supported Diimine Ni(II) and Iminopyridyl Fe(II) Catalysts for Ethylene Polymerizations

Bahuleyan, Bijal Kottukkal; Oh, Jae Min; Chandran, Deepak; Ha, Ju Young; Hur, A Young; Park, Dae‐Won; Ha, Chang Sik; Suh, Hongsuk; Kim, Il

doi:10.1007/s11244-010-9478-8

Cited by 10 publications

(3 citation statements)

References 25 publications

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“…The method of preparation of the silica-supported complexes (incipient wetness, or mixing with excess solvent volume and drying in vacuum) has no observable effect on the catalyst activity or the PE microstructure. Further, it appears that the catalyst precursor is adsorbed well on the silica substrate and does not leach easily in toluene because repetitive washing of the substrate with toluene after immobilization does not reduce activity in a subsequent polymerization experiment (entry [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19].…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…Compatibility with the electrophilic metal center is achieved only by a prior passivation, often by an excess of aluminum cocatalyst, which functions as a scavenger here. Even for late transition metals, supported catalysts were activated with excess aluminum alkyls. − This also prohibits polar monomer insertion polymerization, because of the reaction of the cocatalyst with the monomer.…”

Section: Introductionmentioning

confidence: 99%

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Solid-Supported Single-Component Pd(II) Catalysts for Polar Monomer Insertion Copolymerization

2014

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Heterogenized representatives of neutral phosphine sulfonato Pd(II) complexes for polar monomer insertion polymerization were prepared by two different approaches.[{κ 2 -(P,O)-(2-anisyl) 2 PC 6 H 4 SO 2 O}Pd(Me)L] (L = pyr, dmso, or Cl) complexes were physisorbed on inorganic substrates, namely, clay or silica. In addition, new phosphine sulfonato complexes bearing hydroxyl linker groups at the nonchelating P-aryl moiety were prepared. These complexes were covalently tethered to cross-linked polystyrene. All immobilized palladium complexes are active in ethylene polymerization and ethylene/MA copolymerization without any additional cocatalyst. In addition, separation from the polymer solution formed and reutilization for another polymerization were demonstrated for polystyrene-bound complexes.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Solid-Supported Single-Component Pd(II) Catalysts for Polar Monomer Insertion Copolymerization

2014

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“…In contrast, the heterogenization of homogeneous α-diimine complexes on supports presents an efficient strategy. It can improve the polymer products morphology, increase the polymer molecular weight, 2 of 17 prolong the catalyst lifetime, and meet the requirements of industrial gas-phase or slurry polymerization [23][24][25][26][27][28][29][30][31][32][33].…”

Section: Introductionmentioning

confidence: 99%

Synthesis of α-Diimine Complex Enabling Rapidly Covalent Attachment to Silica Supports and Application of Homo-/Heterogeneous Catalysts in Ethylene Polymerization

Zhao,

Hou,

et al. 2023

IJMS

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For covalent attachment-supported α-diimine catalysts, on the basis of ensuring the thermal stability and activity of the catalysts, the important problem is that the active group on the catalyst can quickly react with the support, anchoring it firmly on the support, shortening the loading time, reducing the negative impact of the support on the active centers, and further improving the polymer morphology, which makes them suitable for use in industrial polymerization temperatures. Herein, we synthesized a α-diimine nickel(II) catalyst bearing four hydroxyl substituents. The hydroxyl substituents enable the catalyst to be immobilized firmly on silica support by covalent linkage in 5–10 min. Compared with the toluene solvent system, the homogeneous catalysts show high activity and thermal stability in hexane solvent at the same conditions. Compared with homogeneous catalysts, heterogeneous catalysis leads to improvements in catalyst lifetime, polymer morphology control, catalytic activity, and the molecular weight of polyethylene (up to 679 kg/mol). The silica-supported catalysts resulted in higher melting temperatures as well as lower branching densities in polyethylenes. Even at 70 °C, the polyethylene prepared by S-CatA-2 still exhibits dispersed particle morphology, and there is no phenomenon of reactor fouling, which is suitable for industrial polymerization processes.

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Ethylene Polymerization Catalyzed by Pyrene‐Tagged Iron Complexes: The Positive Effect of π‐Conjugation and Immobilization on Multiwalled Carbon Nanotubes

Zhang¹,

Zhang²,

Serp³

et al. 2014

ChemCatChem

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2‐[1‐(2,6‐Diisopropylphenylimino)ethyl]‐6‐[1‐(pyren‐1‐ylimino)ethyl]pyridine (L1) and 2,6‐bis[1‐(pyren‐1‐ylimino)ethyl]pyridine (L2) were synthesized and used to prepare the corresponding Fe complexes Fe1 and Fe2 from FeCl2. All new compounds were characterized, and single‐crystal XRD analysis of Fe1 was performed. The π‐conjugated pyrenyl substituent enhanced the catalytic activity of the Fe complexes, which display high activity in ethylene polymerization up to 107 gPE molFe−1 h−1 (PE=polyethylene). These Fe complexes were easily immobilized on multiwalled carbon nanotubes (MWCNTs) through noncovalent π–π interactions. The supported precatalysts showed better ethylene polymerization activity than their homogeneous counterparts to produce well‐dispersed MWCNT/PE composite materials.

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Highly Efficient Supported Diimine Ni(II) and Iminopyridyl Fe(II) Catalysts for Ethylene Polymerizations

Cited by 10 publications

References 25 publications

Solid-Supported Single-Component Pd(II) Catalysts for Polar Monomer Insertion Copolymerization

Solid-Supported Single-Component Pd(II) Catalysts for Polar Monomer Insertion Copolymerization

Synthesis of α-Diimine Complex Enabling Rapidly Covalent Attachment to Silica Supports and Application of Homo-/Heterogeneous Catalysts in Ethylene Polymerization

Ethylene Polymerization Catalyzed by Pyrene‐Tagged Iron Complexes: The Positive Effect of π‐Conjugation and Immobilization on Multiwalled Carbon Nanotubes

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