Cationic Polymerization of Isobutyl Vinyl Ether: Livingness Enhancement by Dialkyl Sulfides

Chang Gi Cho; Ben Ami Feit; Owen W. Webster

doi:10.1021/ma00209a006

Cationic Polymerization of Isobutyl Vinyl Ether: Livingness Enhancement by Dialkyl Sulfides

Chang Gi Cho, Ben Ami Feit^*, Owen W. Webster

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

Abstract

The synthesis of well-defined living polymers of isobutyl vinyl ether (IBVE) has been accomplished with trifluoromethanesulfonic (triflic) acid or Lewis acids plus proton sources as initiators. Excess alkyl sulfides were used to stabilize the carbocationic chain ends. The number-average molecular weight (M_n) of the polymers obtained was directly proportional to monomer conversion. The molecular weight distribution (MWD) was narrow. As the sulfide concentration was increased, the rate of polymerization decreased and a nearly monodisperse polymer was obtained. With triflic acid initiator living conditions were observed at -40 and -15 °C. With EtAlCl₂ initiator the living polymer is obtained even at 0 °C. When the bulkiness of the sulfide was increased, the rate of polymerization increased but the system deviated from living behavior. Mechanistic studies indicate that alkyl sulfides reduce the concentration of active propagating species via reversible sulfonium ion formation.

Original language	English
Pages (from-to)	1918-1923
Number of pages	6
Journal	Macromolecules
Volume	23
Issue number	7
DOIs	https://doi.org/10.1021/ma00209a006
State	Published - 1990
Externally published	Yes

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title = "Cationic Polymerization of Isobutyl Vinyl Ether: Livingness Enhancement by Dialkyl Sulfides",

abstract = "The synthesis of well-defined living polymers of isobutyl vinyl ether (IBVE) has been accomplished with trifluoromethanesulfonic (triflic) acid or Lewis acids plus proton sources as initiators. Excess alkyl sulfides were used to stabilize the carbocationic chain ends. The number-average molecular weight (Mn) of the polymers obtained was directly proportional to monomer conversion. The molecular weight distribution (MWD) was narrow. As the sulfide concentration was increased, the rate of polymerization decreased and a nearly monodisperse polymer was obtained. With triflic acid initiator living conditions were observed at -40 and -15 °C. With EtAlCl2 initiator the living polymer is obtained even at 0 °C. When the bulkiness of the sulfide was increased, the rate of polymerization increased but the system deviated from living behavior. Mechanistic studies indicate that alkyl sulfides reduce the concentration of active propagating species via reversible sulfonium ion formation.",

author = "Cho, {Chang Gi} and Feit, {Ben Ami} and Webster, {Owen W.}",

year = "1990",

doi = "10.1021/ma00209a006",

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T2 - Livingness Enhancement by Dialkyl Sulfides

AU - Cho, Chang Gi

AU - Feit, Ben Ami

AU - Webster, Owen W.

PY - 1990

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N2 - The synthesis of well-defined living polymers of isobutyl vinyl ether (IBVE) has been accomplished with trifluoromethanesulfonic (triflic) acid or Lewis acids plus proton sources as initiators. Excess alkyl sulfides were used to stabilize the carbocationic chain ends. The number-average molecular weight (Mn) of the polymers obtained was directly proportional to monomer conversion. The molecular weight distribution (MWD) was narrow. As the sulfide concentration was increased, the rate of polymerization decreased and a nearly monodisperse polymer was obtained. With triflic acid initiator living conditions were observed at -40 and -15 °C. With EtAlCl2 initiator the living polymer is obtained even at 0 °C. When the bulkiness of the sulfide was increased, the rate of polymerization increased but the system deviated from living behavior. Mechanistic studies indicate that alkyl sulfides reduce the concentration of active propagating species via reversible sulfonium ion formation.

AB - The synthesis of well-defined living polymers of isobutyl vinyl ether (IBVE) has been accomplished with trifluoromethanesulfonic (triflic) acid or Lewis acids plus proton sources as initiators. Excess alkyl sulfides were used to stabilize the carbocationic chain ends. The number-average molecular weight (Mn) of the polymers obtained was directly proportional to monomer conversion. The molecular weight distribution (MWD) was narrow. As the sulfide concentration was increased, the rate of polymerization decreased and a nearly monodisperse polymer was obtained. With triflic acid initiator living conditions were observed at -40 and -15 °C. With EtAlCl2 initiator the living polymer is obtained even at 0 °C. When the bulkiness of the sulfide was increased, the rate of polymerization increased but the system deviated from living behavior. Mechanistic studies indicate that alkyl sulfides reduce the concentration of active propagating species via reversible sulfonium ion formation.

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Cationic Polymerization of Isobutyl Vinyl Ether: Livingness Enhancement by Dialkyl Sulfides

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