Methylene-Bridged Tridentate Salicylaldiminato Binuclear Titanium Complexes as Copolymerization Catalysts for the Preparation of LLDPE through [Fe]/[Ti] Tandem Catalysis

Luo, Yani; Li, Jian; Luo, Derong; You, Qingliang; Yang, Zifeng; Li, Tingcheng; Li, Xiandan; Xie, Guangyong

doi:10.3390/polym11071114

Cited by 10 publications

(2 citation statements)

References 61 publications

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“…The branching degrees were effectively adjusted from 4.6 to 39.3/1000C by the change of Al/(Fe+Ti) mole ratio, reaction temperature, Fe/Ti mole ratio and other different reaction conditions. At the same time, in-situ-generated-α-olefins and 2/MMAO copolymerize ethylene can form LLDPE, which has a high activity of increasing to 106g/mol [23].…”

Section: Tandem Iron and Titanium Non-metallocene Bifunctional Catalystsmentioning

confidence: 98%

Preparation and applications of linear low-density polyethylene

Cui²,

Duan³

2022

J. Phys.: Conf. Ser.

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Linear low-density polyethylene (LLDPE) is widely used in many fields like packaging and film due to its chemical resistance and high tensile strength. This review mainly introduces the preparations and applications of LLDPEs produced by Ziegler-Natta catalyst, metallocene-based catalyst, and late transition metal catalyst, respectively. The improved mechanical and conductivity properties of LLDPE by Ziegler-Natta catalysts, higher activity of the metallocene-based catalysts and high performance of LLDPE directly produced by late transition metal were highlighted. The enhancement of the resistance, flexibility, transparency properties, and yield is achieved using those catalysts and mild conditions. This also leads to more applications in electrical, medical, and surgical areas and can reach an industrial scale.

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Section: Tandem Iron and Titanium Non-metallocene Bifunctional Catalystsmentioning

confidence: 98%

Preparation and applications of linear low-density polyethylene

Cui²,

Duan³

2022

J. Phys.: Conf. Ser.

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“…For all the techniques mentioned above, the use of more α-olefin as a raw material is required, which means a higher cost due to the associated production, storage, and transportation of α-olefin. Alternatively, an attractive method with a tandem polymerization integrating oligomerization and copolymerization of ethylene as the only monomer opens a way for eliminating such costs. − …”

Section: Introductionmentioning

confidence: 99%

Engineering Ethylene/1-Hexene Copolymers from Ethylene Stock with a Model-Guided Catalyst Feeding Policy

et al. 2022

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The synthesis of ethylene/α-olefin copolymers with controlled chain composition distribution via tandem polymerization of ethylene is of great challenge because of the complexity of the reaction process involving both ethylene oligomerization and copolymerization. Herein, we report a model-guided oligomerization catalyst feeding approach for tailoring copolymer composition distribution, producing ethylene/1-hexene copolymers with high performance. The copolymers having a cumulative copolymer composition of 5.7 mol % and instantaneous composition distribution in the range of 0–7.3 mol % can be tailored using this strategy, compared to a narrower distribution of 2.8–7.6 mol % under one-time feeding of the oligomerization catalyst. Meanwhile, the model-guided feeding strategy afforded the copolymers having higher contents of [EEE] and [EHH] sequences at 85.93 and 0.33% in comparison with 83.44 and 0.03% for one-time feeding. The lamellar thickness distribution is also increased from 1.16 to 1.33. As a result, the tensile strength of the copolymer increases from 26.3 to 38.1 MPa and the elongation at break increases from 685 to 740%. Tandem polymerization of ethylene with the model-guided feeding of the oligomerization catalyst promises the preparation of high-performance copolymers of ethylene and 1-hexene or other α-olefins.

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Binuclear titanium complexes coordinated by rigid p‐phenylene linked bis‐β‐carbonylenamine: Synthesis, structure, ethylene polymerization and copolymerization with 1,5‐hexadiene

Wang

Qin

et al. 2020

Applied Organom Chemis

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Binuclear complexes for olefin polymerization have attracted great attention due to their unique catalytic properties compared with their mononuclear counterparts. Here a series of p‐phenylene‐bridgedbis‐β‐carbonylenamine ligands and their binuclear Ti complexes Ti2L1–Ti2L3 were prepared and characterized by 1H NMR, 13C NMR, Fourier transform infrared spectroscopy, and elemental analysis. The binuclear complex Ti2L3 bearing an octylthio sidearm was further investigated by single‐crystalX‐ray diffraction, which revealed that the ligand was of β‐imino enol form, with one titanium atom ligated with six other atoms, forming a deformed octahedral configuration. Furthermore, the ligand in Ti2L3 adopted a cis configuration, which was different from the trans configuration of its m‐phenylene‐bridged derivatives. These binuclear complexes (Ti2L1–Ti2L3) could catalyze ethylene polymerization and copolymerization with 1,5‐hexadiene(1,5‐HD) efficiently under modified methylaluminoxane activation. Compared with the mononuclear complex TiL5, the binuclear catalysts were thermally more stable and showed higher activity for ethylene polymerization at higher temperatures. The activity of these titanium complexes for the copolymerization of ethylene with 1,5‐HD were over 106 g/mol Ti.h.atm, almost twice as high as for homopolymerization. Compared with the mononuclear analogue TiL5 and the m‐substituted binuclear derivative Ti2L4, binuclear catalyst Ti2L2 showed higher activity and insertion rate of the comonomer. The activity of Ti2L2 was two to three times higher than that of TiL5 and Ti2L4, indicating that p‐substituted binuclear catalysts generate clear bimetallic synergistic effect for the copolymerization of ethylene and 1,5‐HD. Meanwhile, 1,5‐HD takes 1,3‐cyclopentyl form in the polymer by 1,3‐insertion. The copolymer prepared by binuclear catalysts had higher molecular weight and wider molecular weight distribution than that prepared by the mononuclear catalyst.

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Methylene-Bridged Tridentate Salicylaldiminato Binuclear Titanium Complexes as Copolymerization Catalysts for the Preparation of LLDPE through [Fe]/[Ti] Tandem Catalysis

Cited by 10 publications

References 61 publications

Preparation and applications of linear low-density polyethylene

Preparation and applications of linear low-density polyethylene

Engineering Ethylene/1-Hexene Copolymers from Ethylene Stock with a Model-Guided Catalyst Feeding Policy

Binuclear titanium complexes coordinated by rigid p‐phenylene linked bis‐β‐carbonylenamine: Synthesis, structure, ethylene polymerization and copolymerization with 1,5‐hexadiene

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