Factors affecting kinetics in slurry type coordination polymerization

Seppälä, Jukka; Auer, Markku

doi:10.1016/0079-6700(90)90018-v

Cited by 20 publications

(10 citation statements)

References 107 publications

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“…In contrast, centers I, II, and III readily copolymerize ethylene with 1-hexene, although their reactivity ratios are also different. This situation mirrors the situation found in the case of ethylene/1-hexene copolymerization reactions with another supported Ti-based catalyst, 21 and it is probably universal for all such heterogeneous catalysts.…”

Section: Hydrogen Effects In Ethylene/1-hexene Copolymerization Kineticsmentioning

confidence: 61%

“…Apparently, active centers in Ziegler-Natta catalysts are activated in ethylene homopolymerization only in the presence of additional ethylene. Our earlier study with a different catalyst 21 showed that centers of this type are selectively poisoned with conjugated dienes such as 1,3-pentadiene or 2,4-hexadiene. We carried out similar poisoning experiments using the current catalyst in a gas-phase polymerization reaction at 80°C at P E ϭ 1.14 MPa.…”

Section: Polymerization Kinetics Of Multicenter Catalystsmentioning

confidence: 98%

“…For example, 1-butene significantly increases copolymerization reactivities of such linear ␣-olefins as 1-decene, 1-dodecene, etc. 18,20,21 4. The overall rate of ethylene homopolymerization with heterogeneous Ti-based ZieglerNatta catalysts has the reaction order n with respect to the ethylene partial pressure, P E , or the ethylene concentration in solution, C E ,…”

Section: Comparison Of Ethylene Homopolymerization and Its Copolymerimentioning

confidence: 99%

See 2 more Smart Citations

Ethylene polymerization reactions with Ziegler-Natta catalysts. I. Ethylene polymerization kinetics and kinetic mechanism

Kissin

Mink

Nowlin

1999

J. Polym. Sci. A Polym. Chem.

153

100

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Section: Hydrogen Effects In Ethylene/1-hexene Copolymerization Kineticsmentioning

confidence: 61%

Section: Polymerization Kinetics Of Multicenter Catalystsmentioning

confidence: 98%

Section: Comparison Of Ethylene Homopolymerization and Its Copolymerimentioning

confidence: 99%

See 1 more Smart Citation

Ethylene polymerization reactions with Ziegler-Natta catalysts. I. Ethylene polymerization kinetics and kinetic mechanism

Kissin

Mink

Nowlin

1999

J. Polym. Sci. A Polym. Chem.

153

100

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“…Sergeev et al observed a similar tendency regarding to stereospecificity in the case of PP obtained with the MgCI2/ EB/TiCI,-TEA/EB catalyst system.23 The influence of temperature on stereospecificity has been also explained by a distribution in the type of active sites and difference in relative temperature dependence for the propylene polymerization rate at isospecific and nonstereospecific sites. 24 The observed cocatalyst effects are due to several simultaneous phenomena: alkylation, reduction, extraction, and catalyst modification reaction. 25 The concentration of alkyl aluminum strongly affects the polymerization rate and also the polymer stereoregularity.…”

Section: Polymerization Conditionsmentioning

confidence: 99%

Propylene polymerization with Mg(OEt)₂/benzoyl chloride/TiCl₄–triethyl aluminum/external donor catalyst systems

Lee

Jeong

Soga

et al. 1993

J of Applied Polymer Sci

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SYNOPSISMg( OEt).Jbenzoyl chloride ( BC)/TiC14 catalyst has been prepared by the chemical reaction method, and the chemical composition and X-ray structure of the catalyst were studied. The effect of various conditions on catalyst activity and isospecificity were also examined. With 13C-NMR analysis, it was found that aluminum carbinolate is formed during polymerization by reaction of triethyl aluminum cocatalyst with BC remaining in the prepared catalyst. The formed aluminum carbinolate acts as an additional donor to increase the isotactic index of polypropylene (PP) . The morphology of the prepared catalyst and PP was also observed. 0 1993 John Wiley & Sons, Inc. INTRODUCTIONMany modern Ziegler-Natta catalysts for stereospecific olefin polymerization employ the high-surface-area support matrices for active transition metal catalyst sites. The first significant results were obtained in the early 1960s by using the reactive Mg compounds such as Mg( OH) C1,l hydroxylated MgO or MgS04.' In the past 20 years, there have been many reports about the various supports for TiC14 catalysts including such magnesium compounds as Mg0,3 Mg ( OH ) 2 , MgC12, Grignard compounds, and Mga l k y l~.~ Among these supports, in the early of 1970s, it was discovered that MgC12 was a good support for stereospecific catalysts. The discovery of active magnesium chloride as an ideal support for the fixation of titanium chloride and its derivatives opened a new era in the field of Ziegler-Natta catalysis, and then the preparation and characterization of MgC12-supported high-active titanium catalysts were studied inten~ively.8~~ But MgC12-supported catalysts have high chlorine content and dealing with MgC12 is not easy due to its high hygroscopicity. From these reasons, magnesium alkoxides were reported as efficient supports in some patients."Recently, Mg ( OEt )2-supported TiC14 catalysts including an organic chloride and/or an internal donor prepared by the physical milling method were studied and it was found that Mg( OEt)2 is converted to MgC12 by reaction with TiC14 and that organic chloride is necessary to promote the conversion of Mg( OEt)2 to MgCl,." In addition, the polymerization activity and isospecificity of polypropylene with the catalyst prepared by the chemical reaction method showed almost the same results as those corresponding to the physical milling method."In this paper, the Mg( OEt)2/benzoyl chloride (BC ) /TiC14 catalyst was prepared by the chemical reaction method and the chemical compositions of the prepared catalysts were examined in detail. The polymerization behaviors of the prepared catalysts were studied for various polymerization conditions. The chemical reaction of triethyl aluminum cocatalyst and BC remaining in the prepared catalyst has also been examined in detail. In addition, the morphology of the catalyst and polymer was observed. Ind. Co. and dried by passing through two columns of preactivated molecular sieve 4A. Nitrogen of extrapure grade, 99.999%, was dried by passing through the molecular sieve ...

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“…This is why industrial polymerization processes are often preceded by catalyst prepolymerization under mild conditions. [2] Recently, propene polymerization kinetics data for high activity Ziegler-Natta MgCl 2 -supported catalysts have been published for periods shorter than 1 s, based on a stoppedflow method. [3,4] Similar information about the kinetics in the seconds and minutes of polymerization that follow is scarce.…”

Section: Introductionmentioning

confidence: 99%

Diffusion Interface Technique for Determination of Initial Polymerization Kinetics

Skoumal

Cejpek

Chêng³

2005

Macromol. Rapid Commun.

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Summary: A new procedure for the investigation of initial kinetics in a slurry olefin polymerization with a Ziegler‐Natta catalyst has been developed. It is based on the accurate timing of short polymerizations that result from the immediate start of a reaction between a catalyst separated in an oil phase and the remaining components of the system upon their being mixed together. The polymer samples are suitable for 13C NMR analysis and the number of active sites could be calculated.

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Factors affecting kinetics in slurry type coordination polymerization

Cited by 20 publications

References 107 publications

Ethylene polymerization reactions with Ziegler-Natta catalysts. I. Ethylene polymerization kinetics and kinetic mechanism

Ethylene polymerization reactions with Ziegler-Natta catalysts. I. Ethylene polymerization kinetics and kinetic mechanism

Propylene polymerization with Mg(OEt)₂/benzoyl chloride/TiCl₄–triethyl aluminum/external donor catalyst systems

Diffusion Interface Technique for Determination of Initial Polymerization Kinetics

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Factors affecting kinetics in slurry type coordination polymerization

Cited by 20 publications

References 107 publications

Ethylene polymerization reactions with Ziegler-Natta catalysts. I. Ethylene polymerization kinetics and kinetic mechanism

Ethylene polymerization reactions with Ziegler-Natta catalysts. I. Ethylene polymerization kinetics and kinetic mechanism

Propylene polymerization with Mg(OEt)2/benzoyl chloride/TiCl4–triethyl aluminum/external donor catalyst systems

Diffusion Interface Technique for Determination of Initial Polymerization Kinetics

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Product

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Propylene polymerization with Mg(OEt)₂/benzoyl chloride/TiCl₄–triethyl aluminum/external donor catalyst systems