Star polymers by ATRP of styrene and acrylates employing multifunctional initiators

Katja Atanassova Jankova, Melania Bednarek, Søren Hvilsted

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Multifunctional initiators for atom transfer radical polymerization (ATRP) are prepared by converting ditrimethylolpropane with four hydroxyl groups, dipentaerythritol with six hydroxyl groups, and poly(3-ethyl-3-hydroxymethyl-oxetane) with similar to 11 hydroxyl groups to the corresponding 2-bromoisobutyrates or 2-bromopropionates as obtained by reaction with acid bromides. Star polystyrene (PS) is produced by using these macroinitiators and neat styrene in a controlled manner by ATRP at 110 degrees C, employing the catalytic system CuBr and bipyridine. M. up to 51,000 associated with narrow molecular weight distributions (PDI <1.1) are obtained with conversions up to 32%. Hydrolysis of the star-PS leads to linear chains having the expected M-n values. The star-PS polymers based on dipentaerythritol degrade thermally in nitrogen in a two-step process in which the first low-temperature step involves scission of the ester linkages and the second step corresponds to the normal PS degradation. Star poly(methyl acrylates) with various cores are likewise prepared in a controlled manner by ATRP of methyl acrylate in bulk and in solution at 6080 degrees C with the 1,1,4,7,7-pentamethyldiethylene triamine ligand. Under these conditions, higher conversions were possible still maintaining low PDI signaling controlled star growth. Multiarm stars of poly(n-butyl acrylate) and poly(n-hexyl acrylate) with controlled characteristics have also been prepared.
Original languageEnglish
JournalJournal of Polymer Science. Part A, Polymer Chemistry
Volume43
Issue number17
Pages (from-to)3748-3759
ISSN0887-624X
Publication statusPublished - 2005

Cite this

@article{8ac2321968ba4866b61a7f19669f3015,
title = "Star polymers by ATRP of styrene and acrylates employing multifunctional initiators",
abstract = "Multifunctional initiators for atom transfer radical polymerization (ATRP) are prepared by converting ditrimethylolpropane with four hydroxyl groups, dipentaerythritol with six hydroxyl groups, and poly(3-ethyl-3-hydroxymethyl-oxetane) with similar to 11 hydroxyl groups to the corresponding 2-bromoisobutyrates or 2-bromopropionates as obtained by reaction with acid bromides. Star polystyrene (PS) is produced by using these macroinitiators and neat styrene in a controlled manner by ATRP at 110 degrees C, employing the catalytic system CuBr and bipyridine. M. up to 51,000 associated with narrow molecular weight distributions (PDI <1.1) are obtained with conversions up to 32{\%}. Hydrolysis of the star-PS leads to linear chains having the expected M-n values. The star-PS polymers based on dipentaerythritol degrade thermally in nitrogen in a two-step process in which the first low-temperature step involves scission of the ester linkages and the second step corresponds to the normal PS degradation. Star poly(methyl acrylates) with various cores are likewise prepared in a controlled manner by ATRP of methyl acrylate in bulk and in solution at 6080 degrees C with the 1,1,4,7,7-pentamethyldiethylene triamine ligand. Under these conditions, higher conversions were possible still maintaining low PDI signaling controlled star growth. Multiarm stars of poly(n-butyl acrylate) and poly(n-hexyl acrylate) with controlled characteristics have also been prepared.",
author = "Jankova, {Katja Atanassova} and Melania Bednarek and S{\o}ren Hvilsted",
year = "2005",
language = "English",
volume = "43",
pages = "3748--3759",
journal = "Journal of Polymer Science. Part A, Polymer Chemistry",
issn = "0887-624X",
publisher = "JohnWiley & Sons, Inc.",
number = "17",

}

Star polymers by ATRP of styrene and acrylates employing multifunctional initiators. / Jankova, Katja Atanassova; Bednarek, Melania; Hvilsted, Søren.

In: Journal of Polymer Science. Part A, Polymer Chemistry, Vol. 43, No. 17, 2005, p. 3748-3759.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Star polymers by ATRP of styrene and acrylates employing multifunctional initiators

AU - Jankova, Katja Atanassova

AU - Bednarek, Melania

AU - Hvilsted, Søren

PY - 2005

Y1 - 2005

N2 - Multifunctional initiators for atom transfer radical polymerization (ATRP) are prepared by converting ditrimethylolpropane with four hydroxyl groups, dipentaerythritol with six hydroxyl groups, and poly(3-ethyl-3-hydroxymethyl-oxetane) with similar to 11 hydroxyl groups to the corresponding 2-bromoisobutyrates or 2-bromopropionates as obtained by reaction with acid bromides. Star polystyrene (PS) is produced by using these macroinitiators and neat styrene in a controlled manner by ATRP at 110 degrees C, employing the catalytic system CuBr and bipyridine. M. up to 51,000 associated with narrow molecular weight distributions (PDI <1.1) are obtained with conversions up to 32%. Hydrolysis of the star-PS leads to linear chains having the expected M-n values. The star-PS polymers based on dipentaerythritol degrade thermally in nitrogen in a two-step process in which the first low-temperature step involves scission of the ester linkages and the second step corresponds to the normal PS degradation. Star poly(methyl acrylates) with various cores are likewise prepared in a controlled manner by ATRP of methyl acrylate in bulk and in solution at 6080 degrees C with the 1,1,4,7,7-pentamethyldiethylene triamine ligand. Under these conditions, higher conversions were possible still maintaining low PDI signaling controlled star growth. Multiarm stars of poly(n-butyl acrylate) and poly(n-hexyl acrylate) with controlled characteristics have also been prepared.

AB - Multifunctional initiators for atom transfer radical polymerization (ATRP) are prepared by converting ditrimethylolpropane with four hydroxyl groups, dipentaerythritol with six hydroxyl groups, and poly(3-ethyl-3-hydroxymethyl-oxetane) with similar to 11 hydroxyl groups to the corresponding 2-bromoisobutyrates or 2-bromopropionates as obtained by reaction with acid bromides. Star polystyrene (PS) is produced by using these macroinitiators and neat styrene in a controlled manner by ATRP at 110 degrees C, employing the catalytic system CuBr and bipyridine. M. up to 51,000 associated with narrow molecular weight distributions (PDI <1.1) are obtained with conversions up to 32%. Hydrolysis of the star-PS leads to linear chains having the expected M-n values. The star-PS polymers based on dipentaerythritol degrade thermally in nitrogen in a two-step process in which the first low-temperature step involves scission of the ester linkages and the second step corresponds to the normal PS degradation. Star poly(methyl acrylates) with various cores are likewise prepared in a controlled manner by ATRP of methyl acrylate in bulk and in solution at 6080 degrees C with the 1,1,4,7,7-pentamethyldiethylene triamine ligand. Under these conditions, higher conversions were possible still maintaining low PDI signaling controlled star growth. Multiarm stars of poly(n-butyl acrylate) and poly(n-hexyl acrylate) with controlled characteristics have also been prepared.

M3 - Journal article

VL - 43

SP - 3748

EP - 3759

JO - Journal of Polymer Science. Part A, Polymer Chemistry

JF - Journal of Polymer Science. Part A, Polymer Chemistry

SN - 0887-624X

IS - 17

ER -