Studies of ziegler-type catalysts for the polymerization of ethylene and propylene—I a highly active catalyst for the polymerization of ethylene

Duck, E.W.; Grant, D.; Butcher, A. V.; Timms, Don G.

doi:10.1016/0014-3057(74)90054-8

Cited by 36 publications

(6 citation statements)

References 13 publications

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“…However, there are no lattice fringes in the interior region. From the consideration of the previous report that the reduction of Mg(OEt) 2 with TiCl 4 produces MgCl 2 , [32] the observed lattice fringes are thought to be crystallites of MgCl 2 formed from the surface region during the preparation procedure of Cat-D. This characteristic microstructure is considered to be closely correlated with the catalyst performance.…”

Section: Resultsmentioning

confidence: 99%

High resolution transmission electron microscope observation of industrial high performance Ziegler catalysts

Mori

Higuchi

Ōtsuka³

et al. 2000

Macromol. Chem. Phys.

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High resolution transmission electron microscopy (HRTEM) was used to directly observe the distribution of crystalline regions in Ziegler catalysts prepared by mechanical plus chemical routes (internal donor; Cat‐A: ethylbenzoate, Cat‐B: dibutylphthalate, Cat‐C: none) and by an entirely chemical route (internal donor; Cat‐D: dibutylphthalate). A comparison of Cat‐A, Cat‐B, and their precursors (ground products of an original MgCl2 with a donor) indicates that MgCl2 crystals are significantly destroyed by the co‐grinding procedure regardless of the kinds of internal donor, and further destruction preferentially occurs in Cat‐B compared with that in Cat‐A. The crystalline lattice of the original MgCl2 is destroyed from the surface into the interior region in the catalysts prepared by the former method. The destruction of the crystals is found to be severe in the following order: Cat‐C ≥ Cat‐B > Cat‐A in the surface area, Cat‐C > Cat‐B > Cat‐A in the central area. On the other hand, Cat‐D shows the different distribution of crystalline regions, which are predominantly present in the near‐surface area, but absent in the central area. These results suggest that the distribution of MgCl2 crystalline regions exhibit a strong correlation with the catalyst preparation procedures and, hence, the catalyst performance.

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Section: Resultsmentioning

confidence: 99%

High resolution transmission electron microscope observation of industrial high performance Ziegler catalysts

Mori

Higuchi

Ōtsuka³

et al. 2000

Macromol. Chem. Phys.

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“…A family of catalysts [119,190], obtained by reduction of TiCl 4 with Grignard reagents at varying ratios between the two components and very active in ethylene polymerization, exhibits a low activity (22.5 -100 g PP (mmol Ti)-I h-I atm-I ) and stereospecificity (I). = 35-55%) in propylene polymerization in the presence of AIR 3 .…”

Section: Isospecijic Polymerization With Supported High Yield Catalystsmentioning

confidence: 99%

“…The presence of H2 however causes a considerable reduction of the polymerization rate which falls by 80% at a 0.18 ratio between H2 and C 2 H 4 partial pressures. e) Catalysts obtained by reaction of transition metal compounds with Mg alkyls Ethylene polymerization by means of catalysts prepared by reaction between TiC4 and Mg organometallic compounds is described by several patents and scientific papers [78,[118][119][120][121][122][123][124][125][126]. Grignard reagents as well as Mg dialkyls and diaryls are employed.…”

Section: High Yield Supported Catalystsmentioning

confidence: 99%

Catalytic Olefin Polymerization

Pasquon

Giannini²

1984

Advances in Comparative and Environmental Physiology

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“…100 A supported version of the Grignard reduced TiCb catalyst can be obtained by treatment of a support with the magnesium alkyl compound, followed by reaction with TiCU. 101 Suitable supports are MgO, ZnO, silica and alumina. Activities of 10 3 -10 5 g polymer (g Ti)" 1 h" 1 atm" 1 were ac~ bved.…”

Section: Other Supported Catalystsmentioning

confidence: 99%