Synthesis of a new zirconium catalyst for ethylene polymerization

Fim, Fabiana de Carvalho; Machado, Tiago; Sá, Denise Santos de; Livotto, Paolo Roberto; Rocha, Zildete; Basso, Nara Regina de Souza; Galland, Griselda B.

doi:10.1002/pola.22734

Cited by 11 publications

(11 citation statements)

References 21 publications

(15 reference statements)

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“…7a) correspond to redox processes centered on the metallic center, as illustrated in Scheme 2. The proposed electrode process was based on the followed by analogous complexes with pyrone ligands [8,9]. These signals are not present in the DPV profile of 3HF ligand.…”

Section: Electrochemical Behaviormentioning

confidence: 99%

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Flavone complexes of Ti and Zr active in ethylene polymerization

Gheno

Basso

Ceschi

et al. 2013

Applied Catalysis A: General

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a b s t r a c tTwo new complexes of Ti and Zr were synthesized with 3-hydroxyflavone bidentate ligand and investigated in homogeneous ethylene polymerization. Both complexes were characterized by UV-VIS, 1 H and 13 C NMR, and electrochemical studies. The geometries and energies of all possible isomeric species were studied by full unconstrained optimizations performed at Density Functional Theory (DFT) level. The polymerization reactions were performed at different experimental conditions with methylaluminoxane (MAO), as the cocatalyst. Both complexes were active in ethylene polymerization in all the conditions used. However, zirconium complex showed the best activity comparing to the titanium complex at 2500 Al/M ratio. The polymers obtained were high density polyethylene with ultra high molecular weights.

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Section: Electrochemical Behaviormentioning

confidence: 99%

“…Our research group has synthesized various analogs complexes of Ti and Zr based in methylmaltol and ethylmaltol ligands. The synthesized complexes were tested in ethylene polymerization showing activity in homogeneous and heterogeneous conditions [6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Flavone complexes of Ti and Zr active in ethylene polymerization

Gheno

Basso

Ceschi

et al. 2013

Applied Catalysis A: General

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“…Organometallic complexes of Ti and Zr were obtained from bidentate chelator ligands as naphthoquinone, methylpyrone, ethylpyrone and 3-hydroxyflavone. [1][2][3][4][5] All the synthesized complexes were active in homogeneous ethylene polymerization at different reaction conditions. 3-Hydroxy-2-methyl-4-pyrone (methylpyrone or maltol) is a non-toxic compound of natural occurrence in many plants, 6 while 3-hydroxy-2-ethyl-4-pyrone (ethylmaltol) is a synthetic commercial product.…”

Section: Introductionmentioning

confidence: 99%

“…3 However, the dichlorobis(3-hydroxy-2-ethyl-4-pyrone)zirconium(IV) complex from ethylmaltol ligand showed a higher catalytic activity (281 kg PE mol -1 atm -1 h -1 ) 4 than the analogue complex from methylmaltol under the same reaction conditions (Al/Zr: 2500; ethylene: 1.6 atm; temperature: 60 °C; time: 60 min). We concluded that the substitution of the methyl group by the ethyl group in the pyrone ligand structure enhances the catalytic activity of these complexes.…”

Section: Introductionmentioning

confidence: 99%

A New Post-Metallocene-Ti Catalyst with Maltolate Bidentade Ligand: an Investigation in Heterogeneous Polymerization Reactions in Different Mesoporous Supports

Gheno¹,

Basso²,

Livotto³

et al. 2016

Journal of the Brazilian Chemical Society

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A new titanium catalyst easily synthesized from ethylmaltol bidentate chelator ligand was studied in homogeneous and heterogeneous ethylene polymerization. The dichlorobis(3-hydroxy-2-ethyl-4-pyrone)titanium(IV) complex was characterized by 1 H and 13 C NMR (nuclear magnetic resonance), UV-Vis and elemental analysis. Theoretical study by density functional theory (DFT) showed that the complex chlorines exhibit cis configuration, which is important for the activity in olefin polymerization. The complex was supported by two methods, direct impregnation or methylaluminoxane (MAO) pre-treatment, in five mesoporous supports: MCM-41 (micro and nano), SBA-15 and also the corresponding modified Al species. All the catalytic systems were active in ethylene polymerization and the catalytic activity was strongly influenced by the method of immobilization of the catalyst and the type of support. Keywords: catalysis, synthesis, mesoporous support, immobilization, polyethylene IntroductionPolyethylene (PE) has a broad application in different segments of the everyday life, from food packaging to resistant pieces for engineering. Due to the polymer industrial demands, continuous development of new technologies and synthetic methods for obtaining this material are necessary. Existing processes, involving polyethylene synthesis in industrial and/or research scale, use Ziegler-Natta, metallocene, and more recently, postmetallocene catalysts. Our research group has studied the synthesis of different post-metallocene catalysts and tested these complexes in ethylene polymerization. Organometallic complexes of Ti and Zr were obtained from bidentate chelator ligands as naphthoquinone, methylpyrone, ethylpyrone and 3-hydroxyflavone. [1][2][3][4][5] All the synthesized complexes were active in homogeneous ethylene polymerization at different reaction conditions. 3-Hydroxy-2-methyl-4-pyrone (methylpyrone or maltol) is a non-toxic compound of natural occurrence in many plants, 6 while 3-hydroxy-2-ethyl-4-pyrone (ethylmaltol) is a synthetic commercial product. These organic compounds are commonly used in food industries as flavor ingredients. Both hydroxypyrones are characterized by their synthetic versatility and they easily coordinate with transition metals of group IV to give L 2 MCl 2 complexes.7 Bis(maltolate) metal(IV) complexes are extensively used in medical studies to assess their therapeutic value as active agents against diabetes, as agents for controlling metal levels in the body and as contrast agents in imaging applications. [8][9][10][11][12] Maltolate complexes appear attractive to catalyze olefin polymerization reaction as well. In 2001, Sobota et al. 13 synthesized and characterized titanium complexes of methylmaltol and verified their catalytic activity in ethylene and propylene polymerization. Subsequently, our research group has synthesized several Ti and Zr complexes Gheno et al. 2083 Vol. 27, No. 11, 2016 analogous based in maltolate ligands. The synthesized complexes were shown to be active in the ethylene...

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“…These studies have shown that the exchange of the methyl substituent by an ethyl in the pyrone ligand exerts a great influence on the catalytic activity, regardless of the metal used, resulting in higher catalytic activities. 10 As part of our studies directed towards organometallics complex synthesis, this paper reports a new synthesis of a maltolato compound, isopropylmaltol, its complexation with TiCl 4 and the use as catalyst in the ethylene polymerization.…”

Section: Introductionmentioning

confidence: 99%

New Isopropylmaltol - Ti Synthesis and its Use as a Catalyst for Olefin Polymerization

Gheno¹,

Basso²,

Ceschi³

et al. 2014

J. Braz. Chem. Soc.

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Este artigo mostra a síntese e caracterização do ligante isopropilmaltol obtido a partir do furfural e também um novo complexo diclorobis-(3-hidroxi-2-isopropil-4-pirona)titânio(IV) com estrutura cis. Dados de ressonância magnética nuclear de 1 H, análise elementar e UV-Vis confirmam a formação do complexo. Este complexo foi estudado em reações de polimerização de etileno utilizando metilaluminoxano (MAO) como co-catalisador. A atividade catalítica deste complexo é baixa, entretanto foram obtidos polietilenos com alto peso molecular que são interessantes para diferentes aplicações.This report describes a new synthesis of isopropylmaltol from furfural. This organic compound was used as ligand to obtain a new complex, the dichlorobis-(3-hydroxy-2-isopropyl-4-pyrone) titanium(IV). 1 H nuclear magnetic ressonance, elemental analysis and UV-Vis analysis confirm the complex formation. This complex was investigated in ethylene polymerization using methylaluminoxane (MAO) as cocatalyst. The catalytic activity was low, however, there were obtained very high molecular weight polyethylenes, which are interesting for various special applications.

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Synthesis of a new zirconium catalyst for ethylene polymerization

Cited by 11 publications

References 21 publications

Flavone complexes of Ti and Zr active in ethylene polymerization

Flavone complexes of Ti and Zr active in ethylene polymerization

A New Post-Metallocene-Ti Catalyst with Maltolate Bidentade Ligand: an Investigation in Heterogeneous Polymerization Reactions in Different Mesoporous Supports

New Isopropylmaltol - Ti Synthesis and its Use as a Catalyst for Olefin Polymerization

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