Supported hybrid early and late transition metal catalysts for the synthesis of polyethylene with tailored molecular weight and chemical composition distributions

Choi, Yiyoung; Soares, João B. P.

doi:10.1016/j.polymer.2010.08.030

Cited by 24 publications

(13 citation statements)

References 25 publications

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“…In chain‐walking ethylene polymerization on diimine nickel and palladium complexes (Brookhart catalysts) the catalytically active transition metal travels up and down the polymer main and side chain during ethylene polymerization and enables alkyl‐branching . The co‐immobilization of early and late transition‐metal catalysts on an methylaluminoxane (MAO)‐tethered silica support affords control of branching using ethylene as the exclusive feedstock . The absence of 1‐olefin comonomers contributes to energy savings and reduced costs related to the production, transportation, and feed of 1‐olefin in LLDPE manufacturing.…”

Section: Tailoring Resource‐ and Energy‐efficient Hydrocarbon Polymersmentioning

confidence: 99%

Tailoring Hydrocarbon Polymers and All‐Hydrocarbon Composites for Circular Economy

Hees

Zhong

Stürzel

et al. 2018

Macromol. Rapid Commun.

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The world population will rapidly grow from 7 to 9 billion by 2050 and this will parallel a surging annual plastics consumption from today's 350 million tons to well beyond 1 billion tons. The switch from a linear economy with its throwaway culture to a circular economy with efficient reuse of waste plastics is therefore mandatory. Hydrocarbon polymers, accounting for more than half the world's plastics production, enable closed‐loop recycling and effective product‐stewardship systems. High‐molar‐mass hydrocarbons serve as highly versatile, cost‐, resource‐, eco‐ and energy‐efficient, durable lightweight materials produced by solvent‐free, environmentally benign catalytic olefin polymerization. Nanophase separation and alignment of unentangled hydrocarbon polymers afford 100% recyclable self‐reinforcing all‐hydrocarbon composites without requiring the addition of either alien fibers or hazardous nanoparticles. Recycling of durable hydrocarbons is far superior to biodegradation. The facile thermal degradation enables liquefaction and quantitative recovery of low molar mass hydrocarbon oil and gas. Teamed up with biomass‐to‐liquid and carbon dioxide‐to‐fuel conversions, powered by renewable energy, waste hydrocarbons serve as renewable hydrocarbon feedstocks for the synthesis of high molar mass hydrocarbon materials. Herein, an overview is given on how innovations in catalyst and process technology enable tailoring of advanced recyclable hydrocarbon materials meeting the needs of sustainable development and a circular economy.

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Section: Tailoring Resource‐ and Energy‐efficient Hydrocarbon Polymersmentioning

confidence: 99%

Tailoring Hydrocarbon Polymers and All‐Hydrocarbon Composites for Circular Economy

Hees

Zhong

Stürzel

et al. 2018

Macromol. Rapid Commun.

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show abstract

“…AS in the polymerization reactor stopped the degradation by neutralizing the metal in the catalyst, because of its acid scavenging nature which resulted in a higher activity of the AS compared to AO‐1 and AO‐2. However, in the hybrid of catalysts due to the complex interaction between the catalysts, the MgCl 2 support and antioxidant showed different behaviors …”

Section: Resultsmentioning

confidence: 99%

“…The results suggested that the different antioxidants did not have a notable effect on the thermal properties of polymers when the single catalyst was used in the polymerization reactor, however, when the hybrid of two catalysts (Cat 3) was used in the polymerization reactor, the X c % changed from 43 to 60. This is probably due to difference in the structures of the catalysts used …”

Section: Resultsmentioning

confidence: 99%

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Effect of different additives and their mixtures on thermal stability of polyethylene synthesized using iron and titanocene hybrid catalysts

Fayegh

Ahmadjo

Mortazavi

2017

J of Applied Polymer Sci

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Traditionally, additives are introduced into a polymer matrix via extrusion process which consumes a high amount of energy. In this study, the use of different additives including antioxidants for the in‐reactor stabilization of polyethylene has been investigated in order to provide an energy saving system. Particular attention was dedicated to the efficiency of antioxidant influencing the catalysts activity and properties of polymers. The effect of the addition of Irganox 1330 and Irgafos 168 antioxidants and zinc stearate on the activities of metallocene, post‐metallocene, and their supported hybrid were studied. In addition, the effect of different additives on the thermal characteristics of the synthesized polymers and oxidative induction time (OIT) was evaluated. Our polymerization results exhibited that the factors such as chemical structure of antioxidant and its steric hindrance, type of catalysts, and their hybrid could affect the catalyst performance and OIT contents. The use of antioxidants mixture and hybrid of catalysts is a way that can increase oxidation resistance of polymers considerably. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45482.

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“…Up to now various types of hybrid catalysts including Ziegler–Natta/metallocene, metallocene/metallocene, metallocene/LTM, and finally LTM/LTM have been studied in polymerizing different types of monomers and comonomers for producing polymeric reactor alloys; however to the best of our knowledge, no report could be found on the application of any kind of Ziegler–Natta/LTM hybrid catalyst in polymerization of alpha‐olefins. In the present article, a Ziegler–Natta/LTM hybrid catalyst of the type forth generation ZN catalyst pretreated with triethylaluminum (TEA) before combining with the late transition metal (LTM) catalyst (I) (Scheme ).…”

Section: Introductionmentioning

confidence: 99%

Thermal Behavior of Polyethylene Reactor Alloys Polymerized by Ziegler–Natta/Late Transition Metal Hybrid Catalyst

Ahmadjo

Dehghani

Zohuri

et al. 2014

Macro Reaction Engineering

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Polyethylene reactor alloys are synthesized through heterogeneous ethylene polymerization with a new type of Ziegler-Natta (ZN)/late transition metal (LTM) hybrid catalyst. The effect of various parameters including catalyst composition (LTM/ZN ¼ 0.01, 0.02, 0.04), polymerization temperature (TP ¼ 30, 30-60, 60 8C) and loading temperature (TL ¼ 30, 60 8C) on catalyst activity, chain's vinyl content, viscosity average molecular weight (M v ) and thermal properties are investigated. Two distinct melting peaks were observed in the ranges of 110-140 8C and 60-90 8C, indicating presence of two different lamellar structures. LTM/ZN ratio shifted melting peaks toward lower values. Rheological properties confirmed homogeneity of polymer blend's microstructure as they follow time temperature superposition.Macromol. React. Eng. 2015, 9, 8-18 wileyonlinelibrary.com PolymerizationCatalyst component handling and polymerization procedures were carried out as previously described. [47] Polymerization reactions were performed in a 150 ml steel reactor equipped with controlling Scheme 1. Structure of late transition metal catalyst.

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Supported hybrid early and late transition metal catalysts for the synthesis of polyethylene with tailored molecular weight and chemical composition distributions

Cited by 24 publications

References 25 publications

Tailoring Hydrocarbon Polymers and All‐Hydrocarbon Composites for Circular Economy

Tailoring Hydrocarbon Polymers and All‐Hydrocarbon Composites for Circular Economy

Effect of different additives and their mixtures on thermal stability of polyethylene synthesized using iron and titanocene hybrid catalysts

Thermal Behavior of Polyethylene Reactor Alloys Polymerized by Ziegler–Natta/Late Transition Metal Hybrid Catalyst

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