Ethylene Polymerization Behavior of Tris(pyrazolyl)borate Titanium(IV) Complexes

Murtuza, Shahid; Casagrande, Osvaldo L.; Jordan, Richard F.

doi:10.1021/om010530j

Cited by 124 publications

(82 citation statements)

References 66 publications

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“…On the basis of the powder X-ray diffraction (XRD) analysis, it was observed that the basal spacing of the predried C30B changes from 1.85 nm (2θ = 4.8) to 2.18 nm (2θ = 4.0) indicating that the intercalation of the titanium catalyst into the clay gallery took place (Figure 1). In this case, the increased spacing from predried C30B to 1/C30B is consistent with the 34 The ethylene polymerization behavior of 1/C30B has been evaluated using methylaluminoxane (MAO) as cocatalyst. Representative results are given in Table 1.…”

Section: Resultssupporting

confidence: 76%

“…34 Thus, the predried C30B reacted with toluene solution of Tp Ms* TiCl 3 (1) for 24 h to generate the intercalated titanium catalyst 1/C30B (Scheme 1). The resulting metal content on the clay determined by ICP-OES was 20 µmol Ti g -1 of clay.…”

Section: Resultsmentioning

confidence: 99%

“…Tp Ms* TiCl 3 was synthesized following procedures described in the literature. 34 Cloisite  30B (Southern Clay Products) was dried under vacuum (P < 10 -4 mbar) for 8 hours at 150 °C. Ethylene (polymer grade), provided by White Martins, and argon were deoxygenated and dried through column of BTS (BASF) and molecular sieve (3A) activated prior to use.…”

Section: Methodsmentioning

confidence: 99%

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UHMWPE-layered silicate nanocomposites by in situ polymerization with tris(pyrazolyl)borate titanium/clay catalyst

Junges¹,

Beauvalet²,

Leal³

et al. 2009

J. Braz. Chem. Soc.

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Nanocompósitos de polietileno-MMT foram preparados através da metodologia de polimerização in situ utilizando Tp Ms* TiCl 3 (1) intercalado na galeria da Cloisite  30B (C30B) e na presença de metilaluminoxano (MAO) como ativador. Através da análise de difração de raios-X (DRX) foi observado que o espaçamento basal da argila ativada muda de 1,85 nm (2θ = 4,8) para 2,18 nm (2θ = 4,0) indicando a ocorrência da intercalação do catalisador de titânio na galeria da argila. O sistema catalítico 1/C30B/MAO foi ativo na polimerização do etileno sob diferentes condições reacionais. A morfologia esfoliada do nanocompósito PE-MMT foi confirmada pela análise de difração de raios-X (DRX) e microscopia eletrônica de transmissão (MET). A presença de argila esfoliada (5% em peso) na matriz polimérica confere melhores propriedades mecânicas (módulo de flexão e módulo de armazenamento) quando comparada com aquelas apresentadas pelo polietileno puro produzido exclusivamente por 1.Polyethylene-MMT nanocomposites were prepared by in situ polymerization methodology using Tp Ms* TiCl 3 (1) intercalated into the gallery of Cloisite  30B (C30B) using methylaluminoxane (MAO) as activator. From the powder X-ray diffraction (XRD) analysis it was observed that the basal spacing of the activated organoclay changes from 1.85 nm (2θ = 4.8) to 2.18 nm (2θ = 4.0) indicating that the intercalation of the titanium catalyst into the gallery took place. The catalytic system 1/C30B/MAO was active in the ethylene polymerization under different reaction conditions. The exfoliated morphology of the PE-MMT nanocomposite was further examined and confirmed by X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis. The presence of exfoliated clay (5 wt.%) in the PE matrix confers better mechanical properties (flexural modulus and storage modulus) when compared with the ones displayed by the neat PE produced using exclusively 1. Keywords: clay, UHMWPE, nanocomposites, titanium catalyst IntroductionIn recent years, polymer-clay nanocomposites have attracted much academic and industrial interest because of the anticipated improvements in mechanical properties, stiffness, thermal stability, chemical resistance, high barrier properties, flame retardancy, etc. when the aluminosilicate platelets of clays like montmorillonite are well exfoliated into polymers. [1][2][3][4] Several methods have been adopted to prepare polymerclay nanocomposites, such as self-assembly of exfoliated inorganic layers with polymers, template synthesis of layered crystals in the polymer solution, melting intercalation, and direct ion exchange of polyelectrolyte with hosts. 5 More recently, special attention has been devoted to in situ intercalative polymerization methodology which is frequently also referred to as ''polymerization filling''. In this process, the monomer together with the polymerization initiator or catalyst is intercalated within the silicate layers and the polymerization is initiated either thermally or chemically. In contrast to highly viscous pol...

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Section: Resultssupporting

confidence: 76%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

UHMWPE-layered silicate nanocomposites by in situ polymerization with tris(pyrazolyl)borate titanium/clay catalyst

Junges¹,

Beauvalet²,

Leal³

et al. 2009

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

show abstract

“…Ethylene polymerization behavior using catalysts 3, 4 and 5 were studied under different reaction times (Table 1, entries 20-34) and temperatures (entries [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. The highest activity of catalyst 5 was obtained at 10 °C (31200 Kg PE mol cat -1 h -1 ).…”

Section: Effects Of Polymerization Conditionsmentioning

confidence: 99%

“…In consequence, quite a few highly active catalysts based on both early and late transition metal complexes have been developed [7][8][9][10][11][12][13][14]. There are, however, only a few examples of titanium complexes displaying high ethylene polymerization activities [15][16][17][18][19], though titanium metal is the major player in highly active heterogeneous Ziegler-Natta catalysts. Accordingly, further researches have been conducted on titanium catalysts with the intention of developing the highly active titanium catalysts and applying them to the polymerization of ethylene.…”

Section: Introductionmentioning

confidence: 99%