Development of well-defined olefin block (co)polymers achieved by late transition metal catalysts: Catalyst, synthesis and characterization

Coordination Chemistry Reviews, Год журнала: 2024, Номер 522, С. 216195 - 216195

Опубликована: Сен. 18, 2024

Язык: Английский

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Tandem coordinative chain transfer polymerization for long chain branched Polyethylene: The role of chain displacement

European Polymer Journal, Год журнала: 2023, Номер 190, С. 112008 - 112008

Опубликована: Март 21, 2023

Язык: Английский

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Dearomatized diimines for nickel(ii) and palladium(ii) catalyzed ethylene polymerization and copolymerization

Inorganic Chemistry Frontiers, Год журнала: 2024, Номер 11(5), С. 1394 - 1412

Опубликована: Янв. 1, 2024

Dual steric enhancement was achieved through the combination of a dearomatized acenaphthyl backbone and bulky ortho substituents. The role this in metal-catalyzed ethylene (co)polymerization investigated.

Язык: Английский

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Phosphine–Imidate-Supported Nickel Catalysts for Ethylene/Acrylate Copolymerization

Organometallics, Год журнала: 2024, Номер 43(8), С. 859 - 865

Опубликована: Апрель 2, 2024

Phosphine–imidate-supported nickel catalysts were synthesized and tested for ethylene/acrylate copolymerization activity. Phosphine–amide metalation studies with (pyridine)2Ni(CH2Si(CH3)3)2 (py2Ni(CH2TMS)2) suggest that the proceeds via an intermediate phosphine–amide complex ([P,O–amide]Ni(CH2TMS)2). Subsequent deprotonation of amide N–H gives access to phosphine–imidate-supported ([P,O–imidate]pyNi(CH2TMS)). The imidate form ligand proved be critical polymerization phosphine–imidate described herein capable producing copolymers molecular weights (Mw) from 700 120,000 g/mol acrylate incorporation >2.6 mol % in some cases. It was determined hemilabile alkoxy groups on phosphine aryl necessary achieve high Mw incorporation. These results demonstrate phosphine–amides, a well-studied class, can utilized highly active neutral catalysts.

Язык: Английский

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Synthesis of chain‐end functionalized highly branched polyethylene waxes using sterically open α‐diimine Ni(II) catalysts

Journal of Polymer Science, Год журнала: 2024, Номер 62(17), С. 4051 - 4057

Опубликована: Июнь 6, 2024

Abstract Our previous research showed that bis(benzocyclopentyl) α‐diimine Pd(II) complexes can facilitate chain transfer and polar monomer insertion in ethylene (co)polymerization. In this study, we synthesized two Ni(II) with different backbones. The exhibited high activities (0.63–7.23 × 10 6 g·mol −1 h ) produced low molecular weight (2.7–7.8 kg mol polyethylene waxes branching densities (43–86/1000 C) polymerization. use of a catalyst butyl backbone resulted significantly higher weights. axial substituent restriction strategy employed the nickel allows for sterically open structure, reducing resulting by over orders magnitude, compared to ethyl catalysts without restrictions. This enables production wax grade products improved properties. branched ends were found be aryl‐functionalized according NMR characterization analysis, while double bonds absent. Also, choice solvent affects branching, weight, end composition wax.

Язык: Английский

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Amino‐containing α‐Diimine Nickel Complexes with Adjustable Electronic Properties and their Effective Use in Forming Highly Branched Polyethylene

Macromolecular Chemistry and Physics, Год журнала: 2024, Номер 225(19)

Опубликована: Июль 15, 2024

Abstract A family of ten amino‐containing bis(arylimino)acenaphthene‐nickel (II) bromide complexes varied in the electronic properties para‐substituents (R = Me, i Pr, t Bu, OMe, Cl, F, NO 2 ) as well two amino‐free comparators Cl) are synthesized good yield from their corresponding unsymmetrical N,N’ ‐ligands. All organic compounds characterized by different analysis techniques. On activation with Me AlCl, all nickel exhibit moderate to high activities a maximum activity up 14.19 × 10 6 g (PE) mol −1 (Ni) h and deliver narrow dispersed polyethylene (PDI: 1.85–2.65) adjustable molecular weight values ( M w : 5.27–18.49 5 ). The presence remote fluoro‐ group (4‐amino‐3,5‐dimethylphenyl)(phenyl)methyl has own unique influence on due steric properties. Nevertheless, latter higher hindrance results better thermal stability current catalytic system. Moreover, is highly branched exhibits typical characteristics thermoplastic elastomers, especially mechanical (εb 1175%) elastic recovery rate (up 86%).

Язык: Английский

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Ethylene polymerization with homogeneous catalysts

Elsevier eBooks, Год журнала: 2025, Номер unknown, С. 49 - 72

Опубликована: Янв. 1, 2025

Язык: Английский

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High-Performance Polyolefin Material: Synthesis, Properties, and Application of Poly(4-Methyl-1-pentene)

International Journal of Molecular Sciences, Год журнала: 2025, Номер 26(2), С. 600 - 600

Опубликована: Янв. 12, 2025

As a kind of high-performance thermoplastic crystalline resin, poly(4-methyl-1-pentene) (PMP) is characterized by its low density, dielectric constant, exceptional mechanical and chemical properties, high transparency, gas permeability. PMP has recently received more attention since COVID-19, because it used as hollow-fiber membrane for extracorporeal oxygenation (ECMO) based on permeability excellent biocompatibility. This review summarizes the structure, synthesis, application PMP. The advancements in catalyst systems catalytic synthesis PMP, including Ziegler–Natta, metallocene, post-metallocene, late-transition metal catalysts are emphasized. Furthermore, molecular chain helical conformation, crystallization morphology well properties applications, also introduced detail. Additionally, composites functional materials described promising materials.

Язык: Английский

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Mono- and Trinuclear Phosphine-Phenolate Nickel(II) Complexes as Precatalysts in Ethylene/Acrylate Copolymerization

Organometallics, Год журнала: 2025, Номер unknown

Опубликована: Фев. 3, 2025

Язык: Английский

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Regulation of the Components in Broad Molecular Weight Distribution Polyethylene by C₂‐Symmetric α‐Diimine Nickel Catalysts With Different N‐Aryl Substituents

Applied Organometallic Chemistry, Год журнала: 2025, Номер 39(4)

Опубликована: Фев. 26, 2025

ABSTRACT Among the catalyst design strategies for α ‐diimine nickel systems, C 2 ‐symmetric strategy is an effective and widely used approach. To investigate steric effect of N ‐aryl substitutes on isomerization behavior catalysts properties ethylene polymerization, a series complexes were constructed by introducing phenyl alkyl groups ortho ‐ para ‐positions. From 40°C to 80°C, Ni1 ~ Ni5 exhibited highly polymerization activity (10 7 g mol −1 h ), yielding broadly distributed or bimodal polyethylene dominated high molecular weight component. This attributed rotation bond resulting in presence both anti syn isomers. Increasing temperature decreasing size ‐alkyl results faster conversion rate between It believed that at higher temperatures with larger groups, tends exist more stable conformation. As result, products are component adjustable proportions exhibit good mechanical processing properties, showing great prospects application solar cell package films.

Язык: Английский

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