A study of chain-end structures of polypropylene prepared with MgCl2-supported titanium catalyst

Kojoh, Shin-ichi; Kioka, Mamoru; Kashiwa, Norio; Itoh, Masaaki; Mizuno, Akira

doi:10.1016/0032-3861(96)81630-2

Cited by 45 publications

(26 citation statements)

References 6 publications

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“…Mn, Mw/M"' and melting temperature of the obtained polymer were 10400, 9.3, and 155.2°C, respectively. These values were almost the same as those 6 Table I. Proportions of chain end groups Each value was calculated as the ratio of areas in the 13 C NMR spectrum: Et, average of peak areas at ll ppm and 32 ppm: i-Bu, average of peak areas at 23.5 ppm and 25.5 ppm: i-Bu-OH.…”

Section: Resultssupporting

confidence: 49%

“…peak area at 111.5 ppm; Vn, peak area at 115.5 ppm Run No. without molecular oxygen contact were found to be ethyl group (Et) and i-butyl group (i-Bu) at 1: 1, 6 formed by only the reaction as shown in Scheme 1 of Figure 2. Figure 1 shows drastic decrease in the peak assigned to i-Bu and the appearance of the peak assigned to hydroxylated i-Bu (i-Bu-OH) by molecular oxygen contact, indicating hydroxylation at the Al-functionalized chainend group as shown in Scheme 2 of Figure 2.…”

Section: Resultsmentioning

confidence: 99%

“…5 However, such chain-transfer reaction does not occur under the present polymerization conditions. 6 The detection of 4mol% of Vn would be explained by the finding that 8 mol% of P-methyl group of Al-functionalized i-PP may be eliminated as shown in Scheme (4) Polym. J., Vol.…”

Section: Resultsmentioning

confidence: 99%

“…Our previous paper 6 revealed that chain-transfer reaction by Et 3 Al, which formed i-PP having Et 2 Algroups at w-ends, predominantly occurred in isospesific propylene polymerization at lOOoC with the MgCl 2 -TiC14-dioctylphthalate (DOP)/Et 3 Al/diphenyldimethoxysilane (DPDMS) catalyst. The i-PP is suitable for investigation of the reactivity of Al-functionalized i-PP with molecular oxygen and side-reactions, because all w-ends consist of only Al-functionalized i-butyl structure.…”

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confidence: 99%

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Reactivity of Aluminum-Functionalized Isotactic Polypropylene with Molecular Oxygen

Kojoh

Tsutsui

Kioka

et al. 1999

Polym J

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ABSTRACT:The efficiency of the synthesis of terminally hydroxylated isotactic polypropylene (i-PP) through the oxidation of Al-functionalized i-PP was evaluated and side-reactions are discussed. Al-functionalized i-PP was prepared by chain-transfer reaction by Et 3 Al with the MgC1 2 -TiC14 -dioctylphthalate1Et3Alldiphenyldimethoxysilane catalyst. It was oxidized by molecular oxygen and poured into methanol for alcoholysis at chain ends. All chain-end groups of the obtained polymer were identified by 13 C NMR and 52 mol% of Al-functionalized chain ends was found converted to hydroxyl groups. 20mol% vinylidene groups by elimination of f$-hydrogen and Smol% vinyl groups by elimination of P-methyl groups were detected. 20mol% of Al-functionalized chain ends remained unreacted. IR analysis of the resulting i-PPs showed the hydroxyl groups at w-ends to form no hydrogen bond and decrease in reaction time with molecular oxygen to lead to lower conversion to terminally hydroxylated chain ends.

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Section: Resultssupporting

confidence: 49%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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confidence: 99%

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Reactivity of Aluminum-Functionalized Isotactic Polypropylene with Molecular Oxygen

Kojoh

Tsutsui

Kioka

et al. 1999

Polym J

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“…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.

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168

109

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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-

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Factors influencing chain transfer with monomer and with hydrogen in propene polymerization using MgCl2-supported Ziegler-Natta catalysts

Chadwick¹,

Heere²,

Sudmeijer³

2000

Macromol. Chem. Phys.

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A study of chain-end structures of polypropylene prepared with MgCl2-supported titanium catalyst

Cited by 45 publications

References 6 publications

Reactivity of Aluminum-Functionalized Isotactic Polypropylene with Molecular Oxygen

Reactivity of Aluminum-Functionalized Isotactic Polypropylene with Molecular Oxygen

The discovery and progress of MgCl₂‐supported TiCl₄ catalysts

Factors influencing chain transfer with monomer and with hydrogen in propene polymerization using MgCl2-supported Ziegler-Natta catalysts

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A study of chain-end structures of polypropylene prepared with MgCl2-supported titanium catalyst

Cited by 45 publications

References 6 publications

Reactivity of Aluminum-Functionalized Isotactic Polypropylene with Molecular Oxygen

Reactivity of Aluminum-Functionalized Isotactic Polypropylene with Molecular Oxygen

The discovery and progress of MgCl2‐supported TiCl4 catalysts

Factors influencing chain transfer with monomer and with hydrogen in propene polymerization using MgCl2-supported Ziegler-Natta catalysts

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Product

Resources

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The discovery and progress of MgCl₂‐supported TiCl₄ catalysts