Modifications of the active sites distribution in the Ziegler‐Natta polymerization of propylene using Lewis acids

Ribour, David; Spitz, Roger; Monteil, Vincent

doi:10.1002/pola.24043

Cited by 15 publications

(12 citation statements)

References 14 publications

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“…It is well known that the use of Lewis bases as external donor could remarkably affect the polymerization kinetics and the activity of Ziegler‐Natta catalysts . The effect of the amount of dicyclopentyldimethoxysilane (D‐donor) on the polymerization yields was summarized in Figure .…”

Section: Resultsmentioning

confidence: 99%

Kinetics of the propylene polymerization with prepolymerization at high temperature using Ziegler‐Natta catalyst

Tan

et al. 2014

J of Applied Polymer Sci

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The bulk polymerization of propylene in liquid monomers with Ziegler-Natta catalyst at 95 C is studied, using alkyl aluminum as the cocatalyst and dicyclopentyldimethoxysilane as the external donor. The highest catalyst activity is shown at the cocatalyst/Ti molar ratio of 300, which keeps relatively constant with the molar ratio increasing from 300 to 800. Besides, the catalyst activity is up to 65 kgPP/(gCat*h) in the range of cocatalyst/donor molar ratio from 12 to 16. The polymerization reaction rate curves with and without catalyst precontacting are similar, while the activity with catalyst precontacting are higher than that without precontacting. Furthermore, the kinetics of polymerization with and without prepolymerization are investigated in the range of the polymerization temperature from 70 to 95 C. It shows that at the high temperature, the polymerization rate increases with prepolymerization. Finally, the influence of prepolymerization at 95 C on the polymerization kinetics and particle properties is also described.

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Section: Resultsmentioning

confidence: 99%

Kinetics of the propylene polymerization with prepolymerization at high temperature using Ziegler‐Natta catalyst

Tan

et al. 2014

J of Applied Polymer Sci

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“…The bulk polymerization of propylene was carried out according to the procedure reported in the literature [36][37][38][39] with the following modifications.…”

Section: Polymerizationmentioning

confidence: 99%

Propylene Polymerization over MgCl₂‐Supported Ziegler–Natta Catalysts Containing Tri‐Ether as the Internal Donor

et al. 2016

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1-Methoxy-2,2-bis(methoxymethyl)butane as a new internal donor was synthesized by the reaction of 1,1,1-tris(hydroxymethyl)propane with sodium hydride as the base and methyl iodide as the alkyl halide. The tri-ether compound was characterized by NMR and FTIR techniques. The MgCl 2 -supported titanium catalysts were incorporated with varying amounts of 1-methoxy-2,2-bis(methoxymethyl)butane as the internal donor (ID) and also without the internal donor were synthesized, and then the prepared catalysts were characterized. The concentration of titanium, magnesium, and chloride were determined by spectrophotometry and by complexometric and argentometric titration, respectively. The polymerization of propylene was carried out with the prepared catalysts in conjunction with triethylaluminum as a cocatalyst and hydrogen as a chain transfer agent, with and without cyclohexylmethyldimethoxysilane as the external donor. The effects of a new internal donor on MgCl 2 -supported Ziegler-Natta catalysts for propylene polymerization were investigated, and then these results were compared to the obtained polypropylenes results, which were obtained using the conventional Ziegler-Natta catalyst containing diisobutyl phthalate as the internal donor. The highest isotacticity, melting temperature, and crystallinity degree of polypropylene were obtained using Cat-D with an ID/Mg molar ratio equal to 0.44, and the highest catalytic activity is related to Cat-B with an ID/Mg molar ratio equal to 0.22. The Ziegler-Natta catalysts incorporated with various ID/Mg molar ratios of 1-methoxy-2,2-bis(methoxymethyl)butane were synthesized. The polymerization of propylene was carried out with the prepared catalysts. The highest catalytic activity is related to Cat-B with an ID/Mg molar ratio equal to 0.22. The catalyst with an optimum ID/Mg molar ratio equal to 0.44 is a favorable catalyst for polymerization of propylene. C

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“…The most typical example was the application of chemically modified silica to Phillips catalyst . ZN and metallocene catalysts were also reported to benefit much from support modification . In this work, we synthesized a series of compounding supports by modifying silica with alumina, zirconia, and titania, respectively.…”

Section: Introductionmentioning

confidence: 99%

“…[43] ZN and metallocene catalysts were also reported to benefit much from support modification. [44][45][46] In this work, we synthesized a series of compounding supports by modifying silica with alumina, zirconia, and titania, respectively. A series of vanadium-oxide-based catalysts supported with the modified and unmodified silica was prepared as well.…”

Section: Introductionmentioning

confidence: 99%

The First Vanadium-Oxide-Based UHMWPE Catalyst Supported on Chemically Modified Silica Gel

Jin

Cheng

et al. 2017

Macromol. Chem. Phys.

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Novel vanadium‐oxide‐based catalysts supported on alumina, zirconia, or titania‐modified silica, which are able to synthesize ultrahigh molecular weight polyethylene (UHMWPE), are successfully developed. Compared with the unmodified silica supported catalyst, the activities of the modified catalysts are substantially enhanced. By changing the polymerization temperature (Tp) from 90 to 60 °C, the molecular weight of the produced UHMWPE can be easily regulated from 2 × 106 to more than 6 × 106 g mol−1. It is the first time that chloride‐free nonsingle site catalysts have been developed to synthesize UHMWPE within such a broad range of Tp. Catalyst characterization by NH3‐temperature‐programmed desorption and pyridine‐Fourier transform infrared spectroscopy reveals that the modified catalysts have increased acidity derived from both Lewis and Brønsted acid sites. The X‐ray photoelectron spectroscopy characterization indicates that the vanadium on the modified catalysts is more electron deficient. Thus, the acidity of the catalysts and the electronic state of the vanadium play a critical role in determining the activity of the vanadium active sites for ethylene polymerization.

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Modifications of the active sites distribution in the Ziegler‐Natta polymerization of propylene using Lewis acids

Cited by 15 publications

References 14 publications

Kinetics of the propylene polymerization with prepolymerization at high temperature using Ziegler‐Natta catalyst

Kinetics of the propylene polymerization with prepolymerization at high temperature using Ziegler‐Natta catalyst

Propylene Polymerization over MgCl₂‐Supported Ziegler–Natta Catalysts Containing Tri‐Ether as the Internal Donor

The First Vanadium-Oxide-Based UHMWPE Catalyst Supported on Chemically Modified Silica Gel

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Modifications of the active sites distribution in the Ziegler‐Natta polymerization of propylene using Lewis acids

Cited by 15 publications

References 14 publications

Kinetics of the propylene polymerization with prepolymerization at high temperature using Ziegler‐Natta catalyst

Kinetics of the propylene polymerization with prepolymerization at high temperature using Ziegler‐Natta catalyst

Propylene Polymerization over MgCl2‐Supported Ziegler–Natta Catalysts Containing Tri‐Ether as the Internal Donor

The First Vanadium-Oxide-Based UHMWPE Catalyst Supported on Chemically Modified Silica Gel

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Propylene Polymerization over MgCl₂‐Supported Ziegler–Natta Catalysts Containing Tri‐Ether as the Internal Donor