Transition metal complex catalysts promoting copolymers of cycloolefin with propylene/higher olefins

Coordination Chemistry Reviews, Год журнала: 2023, Номер 494, С. 215351 - 215351

Опубликована: Июль 27, 2023

Язык: Английский

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Heterogeneous Nickel Catalysts for the Synthesis of Ethylene-Based Polyolefin Elastomers

Macromolecules, Год журнала: 2024, Номер 57(3), С. 1080 - 1086

Опубликована: Фев. 1, 2024

Ethylene-based polyolefin elastomers (EPOEs) represent a novel class of material prepared using ethylene as the only feedstock and bear comparable mechanical elastic properties versus traditional (POEs). EPOEs are from late-transition-metal (nickel or palladium)-catalyzed chain walking polymerization ethylene. However, literature-reported potent catalysts homogeneous systems that operate at relatively low temperatures (<90 °C), while industrial production POE materials requires high (>120 °C). In this contribution, we install some OM (M = H, Na, K) tags in an α-diimine ligand framework, enabling facile heterogenization nickel complexes onto MgCl2-based solid support. The resulting heterogeneous highly active demonstrate much better thermal stability (up to 150 °C) than their counterparts. More importantly, polyethylene products super-stretchability 2160%) maintaining tensile strength 15.4 MPa) elasticity (strain recovery value up 83%). These EPOE can also be used toughen polypropylene, well compatibilize blends polypropylene.

Язык: Английский

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Advances in Nonreactive Polymer Compatibilizers for Commodity Polyolefin Blends

Chemical Reviews, Год журнала: 2024, Номер 124(16), С. 9609 - 9632

Опубликована: Июль 25, 2024

Recycling mixed polyolefin plastics is a significant challenge due to the limitations in sorting and degraded mechanical properties of blends. Nonreactive compatibilization by adding small amount polymeric additive widespread approach restoring performance value recycled plastics. Over past several decades, synthetic advances have enabled access low-cost copolymers precision architectures for deepening understanding mechanisms semicrystalline polyolefins. This review covers design parameters compatibilizer, testing blends, methods producing economically viable additives, surveys literature blends compatibilized HDPE, LLDPE, LDPE, iPP. From this, readers should gain comprehension polymer mechanics, synthesis, macromolecular engineering processable along with field's future directions.

Язык: Английский

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Progress in the catalyst for ethylene/α‐olefin copolymerization at high temperature

The Canadian Journal of Chemical Engineering, Год журнала: 2023, Номер 101(9), С. 4992 - 5019

Опубликована: Янв. 19, 2023

Abstract Ethylene/α‐olefin copolymers are one of the most widely‐used polyolefin materials. With continuous improvement catalysts, high‐performance materials were synthesized by adjusting chain microstructure, changing comonomer type and insertion amount, among which ethylene/α‐olefin random copolymer elastomer (POE) olefin block (OBC) famous well accepted market. The excellent properties POE OBC first depend on their polymer microstructure. microstructure polyolefins is fundamentally determined polymerization conditions, feed policies, reaction engineering. High‐performance elastomers currently prepared high‐temperature solution process, needs to be carried out at a temperature above melting point beneficial speed up rate control However, process launched more stringent requirements for coordination catalyst. Systematic reports catalysts copolymerization ethylene α‐olefins lacking. In this review, we screened some suitable controllable based catalyst's heat resistance, activity, ability, molecular weight, distribution copolymer, including traditional Z–N metallocene post‐metallocene catalysts. And future development olefins, precise microstructures, with polar monomers high envisaged.

Язык: Английский

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Advances in the chemistry of redox-active bis(imino)acenaphthenes (BIAN): A case of transition metal complexes

Coordination Chemistry Reviews, Год журнала: 2024, Номер 514, С. 215845 - 215845

Опубликована: Май 9, 2024

Язык: Английский

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Nickel‐ and Palladium‐Catalyzed Copolymerizations of Norbornene with Polar α‐Olefins

ChemCatChem, Год журнала: 2024, Номер unknown

Опубликована: Март 26, 2024

Abstract Recent progress regarding the copolymerization of norbornene with various polar α‐olefins catalyzed by nickel and palladium catalysts is reviewed here special attention paid to diverse catalyst frameworks, monomer scopes as well polymer microstructures. Both influences steric effect electron property ligand substituents type monomers on catalytic behaviors (activity, stability, polarity tolerance, etc.) microstructures (molecular weight distribution, comonomer contents, have been summarized. The introduction noncyclic‐olefins, such vinyl monomers, higher α‐olefins, styrenes, into rigid cyclic‐based polynorbornene chain resulted in significant modifications polarity, compatibility, thermostability, processibility, transparency, many other properties material, which has also discussed review. contents this review classified according involved copolymerization, each section included bearing different structures, will be meaningful for development new types families norbornene‐based cyclic olefin copolymer materials future.

Язык: Английский

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Unveiling the mutual effects of hydroxyl and dibenzhydryl groups in α‐diimino‐nickel precatalysts for direct synthesis of polyethylene elastomers

Applied Organometallic Chemistry, Год журнала: 2024, Номер 38(4)

Опубликована: Фев. 18, 2024

The properties and practical applications of polyethylene are closely associated with the polymer molecular weight, polydispersity, degree branching, type branches its arrangement within microstructure. In this study, a set structurally diverse unsymmetrical 1‐(2,6‐dibenzhydryl‐4‐hydroxylphenylimino)‐2‐(2,6‐(R)‐4‐(R 1 )phenylimino)acenaphthene‐nickel dibromide precatalysts (where Ni 2Me [R = Me, R H], 2Et Et, 2iPr iPr, 3Me [R, Me], 2Et,Me Me]) has been prepared studied for ethylene polymerization. Molecular structure analysis complexes revealed distorted tetrahedral geometries at nickel. polymerization activities extremely high all upon activation either EASC or MMAO aluminum reagents, trend notably pronounced in case EASC‐activated systems, entering activity range 10 million g mol −1 h 30°C. demonstrated exceptional performance higher temperatures, achieving an 2.4 × 6 100°C generated weight ( M w 5 ) narrow dispersity across reaction temperatures Ð ≈ 1.5). High temperature 13 C NMR spectra identified 97–142/1000C resulting polyethylene, feature significantly dependent on temperature. terms mechanical properties, stress–strain indicated that synthesized lower displayed superior tensile strength compared produced while reverse was observed strain recovery analysis. (up to 72%) these highlights characteristic thermoplastic elastomers.

Язык: Английский

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Ultrahigh Molecular Weight Ethylene–Acrylate Copolymers Synthesized with Highly Active Neutral Nickel Catalysts

Angewandte Chemie International Edition, Год журнала: 2025, Номер unknown

Опубликована: Март 6, 2025

Molecular weight is a crucial parameter in catalytic olefin polymerization to determine the thermomechanical properties of polymers. Elevating molecular ethylene-acrylate copolymer, typical polar polyolefin has been persistent challenge. This study presents direct synthesis ultrahigh (UHMW) copolymers using highly active, neutral, single-component phosphine-phenolate nickel catalyst under mild conditions. The coordination-insertion copolymerization ethylene and various acrylates, such as methyl acrylate, n-butyl t-butyl can yield with UHMWs (Mn) ranging from 1000 2700 kDa, exceptional activities up 4.03 × 106 g mol-1 h-1. A relatively large-scale (30-50 g) UHMW was notably achieved. these were comprehensively evaluated, demonstrating that retained bulk polyethylene (UHMWPE) while exhibiting improved surface dyeing properties. In particular, tensile strength significantly increased higher weights, reaching 44 MPa (147 after predrawing ratio 3.1), which comparable UHMWPE.

Язык: Английский

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Tuning 2,3-Bis(arylimino)butane-nickel Precatalysts for High-Molecular-Weight Polyethylene Elastomers

Molecules, Год журнала: 2025, Номер 30(8), С. 1847 - 1847

Опубликована: Апрель 20, 2025

The catalytic performance of α-diiminonickel complexes is highly sensitive to structural modifications in their ligand frameworks. In this study, a series unsymmetrical 2,3-bis(arylimino)butane-nickel featuring ortho-2,6-dibenzhydryl groups as sterically demanding motifs and para-methyl electron-donating enhancers were proposed synthesized. These nickel thoroughly characterized using FTIR, elemental analysis, single-crystal X-ray diffraction (for Ni4 Ni5), revealing deviations from ideal tetrahedral geometry. Upon activation with Et2AlCl, these demonstrated exceptional ethylene polymerization activity, achieving remarkable value 13.67 × 106 g PE mol-1 (Ni) h-1 at 20 °C. Notably, even 80 °C, the maintained high activity 1.97 h-1, showcasing superiority compared previously reported complexes. resulting polyethylenes exhibited ultra-high molecular weights (Mw: 3.33-19.47 105 mol-1) tunable branching densities (84-217/1000C), which effectively controlled by temperature. Moreover, mechanical properties polyethylenes, including tensile strength (σb = 0.74-16.83 MPa), elongation break (εb 271-475%), elastic recovery (SR 42-74%), finely tailored optimizing weight, crystallinity, degree. prepared displayed outstanding recovery, hallmark high-performance thermoplastic elastomers, making them promising candidates for advanced material applications.

Язык: Английский

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High-Performance α-Diimine Nickel Complexes for Facile Access of PE Elastomers with Exceptional Material Properties

Chinese Journal of Polymer Science, Год журнала: 2023, Номер 42(5), С. 620 - 635

Опубликована: Дек. 26, 2023

Язык: Английский

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