Effect of an external donor upon chain-transfer reactions in propylene polymerization with a MgCl2-supported titanium catalyst system

Kojoh, Shin-ichi; Tsutsui, Toshiyuki; Kashiwa, Norio; Itoh, Masaaki; Mizuno, Akira

doi:10.1016/s0032-3861(97)10220-8

Cited by 25 publications

(21 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We confirmed that regio-irregular insertions of the monomers led to dormant sites that could be reactivated by chain transfer by molecular hydrogen. 29,30 It innovated the PP production process by dispensing with the facilities and energy for removing the catalyst Figure 5. Influences of EB/Ti molar ratio in the MgCl 2 -supported TiCl 4 catalyst system on the yields of overall polymer, iso-PP and ata-PP.…”

Section: 12mentioning

confidence: 99%

The discovery and progress of MgCl₂‐supported TiCl₄ catalysts

Kashiwa

2003

J. Polym. Sci. A Polym. Chem.

Self Cite

168

109

View full text Add to dashboard Cite

Polyolefins represented by polyethylene (PE) and polypropylene (PP) are indispensable materials in our daily lives. TiCl 3 catalysts, established by Ziegler and Natta in the 1950s, led to the births of the polyolefin industries. However, the activities and stereospecificities of the TiCl 3 catalysts were so low that steps for removing catalyst residues and low stereoregular PP were needed in the production of PE and PP. Our discovery of MgCl 2 -supported TiCl 4 catalysts led to more than 100 times higher activities and extremely high stereospecificities, which enabled us to dispense with the steps for the removals, meaning the process innovation. Furthermore, they narrowed the molecular weight and composition distributions of PE and PP, enabling us to control the polymer structures precisely and create such new products as very low density PE or heat-sealable film at low temperature. The typical example of the product innovations by the combination of the high stereospecificity and the narrowed composition distribution is highperformance impact copolymer used for an automobile bumper that used to be made of metal. These process and product innovations established these polyolefin industries. The latest MgCl 2 -supported TiCl 4 catalyst is very close to perfect control of isotactic PP structure and is expected to bring about further innovations. Keywords: MgCl 2 -supported TiCl 4 catalysts; polyolefins; stereospecific polymers; copolymerization; polyethylene (PE); poly(propylene) (PP) Dr. Norio Kashiwa is a senior research fellow of Mitsui Chemicals, Inc., who is offering that position only to him. He graduated from Osaka University (Japan) in 1964 and received his masters degree in engineering from the same university in 1966. Then, he joined Mitsui Petrochemical Industries in the same year. He discovered MgCl 2 -supported TiCl 4 catalysts in 1968. It brought about process and product innovations in polyolefin industries, and now those catalysts constitute the majority of global polyolefin production. Since then, he has been in the front line of olefin polymerization catalyst research including not only MgCl 2 -sup-

show abstract

Section: 12mentioning

confidence: 99%

The discovery and progress of MgCl₂‐supported TiCl₄ catalysts

Kashiwa

2003

J. Polym. Sci. A Polym. Chem.

Self Cite

168

109

View full text Add to dashboard Cite

show abstract

“…In general, the addition of an external donor in polymerization of propylene causes the molecular weight of the polypropylene obtained to increase, 41 and therefore the hydrogen response of catalyst decreased. It has also been reported that the effect of hydrogen on the molecular weight of polypropylene depends upon the nature of the external donor.…”

Section: Effects Of the Tri-ether Internal Donor On Average Molecularmentioning

confidence: 99%

“…It has also been reported that the effect of hydrogen on the molecular weight of polypropylene depends upon the nature of the external donor. 41 Alkoxysilanes as the external donor giving high isospecificity also give high molecular weight polypropylene. 42 It should be noted that, due to the adhesive polypropylene particles with high xylene solubility produced using Cat-ZN (without the external donor), and Cat-0 (with and without the external donor), it was not possible to measure the MFI values of related polypropylenes.…”

Section: Effects Of the Tri-ether Internal Donor On Average Molecularmentioning

confidence: 99%

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

et al. 2016

View full text Add to dashboard Cite

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

show abstract

“…The estimated dormant sites were 20% in the former system and 50% in the latter system. Furthermore, Kojoh et al 32 investigated the type of chain transfer without H 2 in the MgCl 2 /TiCl 4 /dioctyl phthalate (DOP)-diphenyldimethoxysilane (DPDMS)/ TEA system. They reported that 2,1-insertion was easily observed without DPDMS but not observed with DPDMS.…”

Section: Figurementioning

confidence: 99%

Kinetic study of a highly active MgCl₂‐supported Ziegler–Natta catalyst in liquid pool propylene polymerization. II. The influence of alkyl aluminum and alkoxysilane on catalyst activation and deactivation

Shimizu

Pater

Swaaij

et al. 2002

J of Applied Polymer Sci

View full text Add to dashboard Cite

ABSTRACT:The influence of alkyl aluminum and alkoxysilane on the kinetics in liquid pool propylene batch polymerization was investigated with a highly active ZieglerNatta catalyst system that consisted of MgCl 2 /TiCl 4 /diester-alkoxysilane/AlR 3 . In this study, diethyl phthalate and t-BuEtSi(OMe) 2 were used as a diester and an alkoxysilane, respectively. The catalyst activity depended on the concentration of the alkyl aluminum when it came into contact with the catalyst. In addition, alkoxysilane as an external donor had a role in activating the catalyst. With respect to activity decay, the overreduction of Ti did not seem to be the cause. Instead, the decay rate decreased with an increasing alkoxysilane/catalyst ratio. This implied that activity decay was caused by the formation of dormant sites after 2,1-misinsertion of propylene.

show abstract

Effect of an external donor upon chain-transfer reactions in propylene polymerization with a MgCl2-supported titanium catalyst system

Cited by 25 publications

References 13 publications

The discovery and progress of MgCl₂‐supported TiCl₄ catalysts

The discovery and progress of MgCl₂‐supported TiCl₄ catalysts

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

Kinetic study of a highly active MgCl₂‐supported Ziegler–Natta catalyst in liquid pool propylene polymerization. II. The influence of alkyl aluminum and alkoxysilane on catalyst activation and deactivation

Contact Info

Product

Resources

About

Effect of an external donor upon chain-transfer reactions in propylene polymerization with a MgCl2-supported titanium catalyst system

Cited by 25 publications

References 13 publications

The discovery and progress of MgCl2‐supported TiCl4 catalysts

The discovery and progress of MgCl2‐supported TiCl4 catalysts

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

Kinetic study of a highly active MgCl2‐supported Ziegler–Natta catalyst in liquid pool propylene polymerization. II. The influence of alkyl aluminum and alkoxysilane on catalyst activation and deactivation

Contact Info

Product

Resources

About

The discovery and progress of MgCl₂‐supported TiCl₄ catalysts

The discovery and progress of MgCl₂‐supported TiCl₄ catalysts

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

Kinetic study of a highly active MgCl₂‐supported Ziegler–Natta catalyst in liquid pool propylene polymerization. II. The influence of alkyl aluminum and alkoxysilane on catalyst activation and deactivation