Polymerization of Ethylene by Trialkylaluminum-Lewis Base-Peroxide Catalyst

Yatsu, Tadao; Ohno, Takao; Maki, Hiroshi; Fujii, Hiroyasu

doi:10.1021/ma60056a006

Cited by 11 publications

(6 citation statements)

References 3 publications

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“…This spectrum was found to have the same g value and hyperfine splitting constants as exhibited by the anilino radical II from A1Et 3 as well as by the anilino radical 'g (1) .., ~-,.. VI from AlisoBu3 • Therefore, the adduct thus observed was assigned to N-(2-substituted)ethoxy-2,4,6-tri-tert-butylanilino radical (X) resulting from the trapping of the propagating end of ethylene (g=2.003, aN=l0.6 G, aHrµ 1=aHrmi= 306 2.3 G).…”

Section: Behavior Of Coordinated Radical In Presence Of Ethylenementioning

confidence: 74%

“…Our preceding paper showed that a mixture solution of the three catalyst components is capable, without the use of any additives, of generating up to one ethyl radical per A1Et3 molecule. 1 Furthermore, this ethyl radical, to be discussed later, has been shown to behave quite differently from the usual free radical under the polymerization conditions. These facts suggest that the steric-298 ally hindered state of the ethyl radical presents, in other words, a state in which the ethyl radical finds itself coordinated to, say, the aluminum atom in the catalyst system, or a state in which it can be regarded as virtually so coordinated.…”

Section: Detection Of Coordinated Alkyl Radicalmentioning

confidence: 98%

“…1 For further clarifying the behavior of the alkyl radical, the admixture system of A1Et 3-BLtert-butyl peroxyisobutyrate was subjected to ESR analysis where a spin-trapping agent was employed. For the spin-trapping agent 2,4,6-tritert-butylnitrosobenzene was used and it is reported to be a bifunctional reagent because the steric effect it exerts on the oncoming radical leads to the formation of two different spin adducts.…”

Section: Detection Of Coordinated Alkyl Radicalmentioning

confidence: 99%

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Mechanism of Ethylene Polymerization by Trialkylaluminum—Lewis Base—Peroxide Catalyst

Yatsu

Moriuchi

Fujii

1977

Polym J

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ABSTRACT:Studies were conducted on the mechanism of ethylene polymerization by the ternary catalyst system consisting of certain specific combinations of trialkylaluminum, Lewis base, and peroxide. Comparison of the polymerization product by the ternary system of triethylaluminum (AlEta)-r-butyrolactone (BL)-tert-butyl peroxyisobutyrate with those products brought about by two low-temperature free-radical initiators suggested that two different active sites were formed in the ternary system, i.e., one responsible for the formation of solid polyethylene, and the site of the usual free-radical polymerization responsible for oily oligomers. The ESR analysis employing a bifunctional spin-trapping agent, 2,4,6-tri-tert-butylnitrosobenzene, disclosed that the sterically hindered alkyl radical which can be regarded as being in the coordinated state was formed along with the usual free alkyl radical from the trialkylaluminum. Participation was suggested on the part of the coordinated alkyl radical, as we propose to call it, in the initiation reaction for the solid polyethylene, since cyclopentene added to the ternary system showed only the coordinated ethyl radical quantitatively transformed into the cyclopentyl radical. IR and NMR measurements of AlEta-BL complex in the presence of cyclopentene suggested possible activation of ethylene monomer by the complex in the polymerization system. The analysis for the ternary system both in the absence and presence of 4-methyl-1-pentene showed a possibility of the coordinated radical taking part in the propagation reaction with the coordinated state retained. Further direct support was obtained upon introduction of ethylene monomer to the ternary system containing trimethylaluminum when the coordinated methyl radical was found to be transformed into the coordinated methylene growing-end radical. These facts suggest that the formation of the solid polyethylene should rest solely on the mechanism of the coordinated radical polymerization, i.e., the mechanism in which the coordinated alkyl radical formed from trialkylaluminum attacks the ethylene molecules which are in the activated state causing the initiation reaction followed by the propagation reaction, with the coordinated state retained throughout.

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Section: Behavior Of Coordinated Radical In Presence Of Ethylenementioning

confidence: 74%

Section: Detection Of Coordinated Alkyl Radicalmentioning

confidence: 98%

Section: Detection Of Coordinated Alkyl Radicalmentioning

confidence: 99%

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Mechanism of Ethylene Polymerization by Trialkylaluminum—Lewis Base—Peroxide Catalyst

Yatsu

Moriuchi

Fujii

1977

Polym J

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“…The amount of the free-radical initiator was so determined as to make the isopropyl radical formed from its decomposition equal in quantity to that of the ethyl radical from the ternary system AlMeg-BL-acetyl peroxide 2.0-2.0-1.0 of AlEta-BL-tertbutyl peroxyisobutyrate during the period of the polymerization time. 1 The results are listed in Table I. The activity was higher in the copolymerization performed by the ternary system than in the free-radical copolymerization.…”

Section: Resultsmentioning

confidence: 97%

Copolymerization of Ethylene with Vinyl Acetate by Trialkylaluminum-Lewis Base-Peroxide Catalyst

Yatsu¹,

Moriuchi²,

Fujii³

1977

Macromolecules

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“…The remarkable alternating copolymerizations of ethylene with vinyl acetate reported recently by Yatsu et al (13,14) may be an actual example of this type. These copolymerizations were initiated by triethylaluminum and peroxides in the presence of y-butyrolactone.…”

Section: Copolymerization Of Vinyl Monomersmentioning

confidence: 86%

A proposed propagation mechanism involving π^* and σ^* radical ions

Hall

1980

J. Polym. Sci. B Polym. Lett. Ed.

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Polymerization of Ethylene by Trialkylaluminum-Lewis Base-Peroxide Catalyst

Cited by 11 publications

References 3 publications

Mechanism of Ethylene Polymerization by Trialkylaluminum—Lewis Base—Peroxide Catalyst

Mechanism of Ethylene Polymerization by Trialkylaluminum—Lewis Base—Peroxide Catalyst

Copolymerization of Ethylene with Vinyl Acetate by Trialkylaluminum-Lewis Base-Peroxide Catalyst

A proposed propagation mechanism involving π^* and σ^* radical ions

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Polymerization of Ethylene by Trialkylaluminum-Lewis Base-Peroxide Catalyst

Cited by 11 publications

References 3 publications

Mechanism of Ethylene Polymerization by Trialkylaluminum—Lewis Base—Peroxide Catalyst

Mechanism of Ethylene Polymerization by Trialkylaluminum—Lewis Base—Peroxide Catalyst

Copolymerization of Ethylene with Vinyl Acetate by Trialkylaluminum-Lewis Base-Peroxide Catalyst

A proposed propagation mechanism involving π* and σ* radical ions

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A proposed propagation mechanism involving π^* and σ^* radical ions