Reducing the degree of branching in polyacrylates via midchain radical patching: A quantitative melt-state NMR study

Marianne Gaborieau; Sandy P.S. Koo; Patrice Castignolles; Thomas Junkers; Christopher Barner-Kowollik

doi:10.1021/ma100991c

Reducing the degree of branching in polyacrylates via midchain radical patching: A quantitative melt-state NMR study

Marianne Gaborieau, Sandy P.S. Koo, Patrice Castignolles, Thomas Junkers, Christopher Barner-Kowollik

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

40 Citations (Scopus)

Abstract

Degrees of branching were measured with ¹³C melt-state NMR in poly(n-butyl acrylates) synthesized in both the presence and absence of 1-octanethiol at various temperatures, and their precision calculated based on the signal-to-noise ratio of the quaternary carbon at the branching point. Nitrogen gas was used for all pneumatics. Samples synthesized with thiol were measured in 7 mm rotors at MAS rotational frequencies of 1.8 to 4.5 kHz, while samples synthesized without thiol were measured in 4 mm rotors at 9 kHz MAS. The relative standard deviation SD of DB was calculated from the signal-to-noise ratio of the quaternary carbon SNR. The accuracy of measured degrees of branching was ensured by full relaxation of the relevant signals between pulses. A significant decrease of branching was observed in the presence of a thiol during the polymerization process, experimentally confirming the patching effect of midchain tertiary radicals by the thiol.

Original language	English
Pages (from-to)	5492-5495
Number of pages	4
Journal	Macromolecules
Volume	43
Issue number	13
DOIs	https://doi.org/10.1021/ma100991c
Publication status	Published - 13 Jul 2010
Externally published	Yes

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title = "Reducing the degree of branching in polyacrylates via midchain radical patching: A quantitative melt-state NMR study",

abstract = "Degrees of branching were measured with 13C melt-state NMR in poly(n-butyl acrylates) synthesized in both the presence and absence of 1-octanethiol at various temperatures, and their precision calculated based on the signal-to-noise ratio of the quaternary carbon at the branching point. Nitrogen gas was used for all pneumatics. Samples synthesized with thiol were measured in 7 mm rotors at MAS rotational frequencies of 1.8 to 4.5 kHz, while samples synthesized without thiol were measured in 4 mm rotors at 9 kHz MAS. The relative standard deviation SD of DB was calculated from the signal-to-noise ratio of the quaternary carbon SNR. The accuracy of measured degrees of branching was ensured by full relaxation of the relevant signals between pulses. A significant decrease of branching was observed in the presence of a thiol during the polymerization process, experimentally confirming the patching effect of midchain tertiary radicals by the thiol.",

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doi = "10.1021/ma100991c",

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T1 - Reducing the degree of branching in polyacrylates via midchain radical patching

T2 - A quantitative melt-state NMR study

AU - Gaborieau, Marianne

AU - Koo, Sandy P.S.

AU - Castignolles, Patrice

AU - Junkers, Thomas

AU - Barner-Kowollik, Christopher

PY - 2010/7/13

Y1 - 2010/7/13

N2 - Degrees of branching were measured with 13C melt-state NMR in poly(n-butyl acrylates) synthesized in both the presence and absence of 1-octanethiol at various temperatures, and their precision calculated based on the signal-to-noise ratio of the quaternary carbon at the branching point. Nitrogen gas was used for all pneumatics. Samples synthesized with thiol were measured in 7 mm rotors at MAS rotational frequencies of 1.8 to 4.5 kHz, while samples synthesized without thiol were measured in 4 mm rotors at 9 kHz MAS. The relative standard deviation SD of DB was calculated from the signal-to-noise ratio of the quaternary carbon SNR. The accuracy of measured degrees of branching was ensured by full relaxation of the relevant signals between pulses. A significant decrease of branching was observed in the presence of a thiol during the polymerization process, experimentally confirming the patching effect of midchain tertiary radicals by the thiol.

AB - Degrees of branching were measured with 13C melt-state NMR in poly(n-butyl acrylates) synthesized in both the presence and absence of 1-octanethiol at various temperatures, and their precision calculated based on the signal-to-noise ratio of the quaternary carbon at the branching point. Nitrogen gas was used for all pneumatics. Samples synthesized with thiol were measured in 7 mm rotors at MAS rotational frequencies of 1.8 to 4.5 kHz, while samples synthesized without thiol were measured in 4 mm rotors at 9 kHz MAS. The relative standard deviation SD of DB was calculated from the signal-to-noise ratio of the quaternary carbon SNR. The accuracy of measured degrees of branching was ensured by full relaxation of the relevant signals between pulses. A significant decrease of branching was observed in the presence of a thiol during the polymerization process, experimentally confirming the patching effect of midchain tertiary radicals by the thiol.

UR - https://www.scopus.com/pages/publications/77955825484

U2 - 10.1021/ma100991c

DO - 10.1021/ma100991c

M3 - Article

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SN - 0024-9297

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JO - Macromolecules

JF - Macromolecules

IS - 13

ER -

Reducing the degree of branching in polyacrylates via midchain radical patching: A quantitative melt-state NMR study

Abstract

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