Aqueous SET-LRP catalyzed with "in situ" generated Cu(0) demonstrates surface mediated activation and bimolecular termination

Samanta, Shampa R., Nikolaou, Vasiliki, Keller, Shauni, Monteiro, Michael J., Wilson, Daniela A., Haddleton, David M. and Percec, Virgil (2015) Aqueous SET-LRP catalyzed with "in situ" generated Cu(0) demonstrates surface mediated activation and bimolecular termination. Polymer Chemistry, 6 11: 2084-2097. doi:10.1039/c4py01748j


Author Samanta, Shampa R.
Nikolaou, Vasiliki
Keller, Shauni
Monteiro, Michael J.
Wilson, Daniela A.
Haddleton, David M.
Percec, Virgil
Title Aqueous SET-LRP catalyzed with "in situ" generated Cu(0) demonstrates surface mediated activation and bimolecular termination
Formatted title
Aqueous SET-LRP catalyzed with "in situ" generated Cu(0) demonstrates surface mediated activation and bimolecular termination
Journal name Polymer Chemistry   Check publisher's open access policy
ISSN 1759-9962
1759-9954
Publication date 2015-03-21
Year available 2015
Sub-type Article (original research)
DOI 10.1039/c4py01748j
Open Access Status Not Open Access
Volume 6
Issue 11
Start page 2084
End page 2097
Total pages 14
Place of publication Cambridge, United Kingdom
Publisher RSC Publications
Collection year 2016
Language eng
Formatted abstract
The aqueous SET-LRP catalyzed with “in situ” generated Cu(0) of the two amphiphilic monomers 2-hydroxyethyl acrylate (HEA) and oligo(ethylene oxide) methyl ether acrylate (OEOMEA) was investigated at temperatures from −22 to +25 °C. The kappp values of both monomers are higher at 0 °C (4.61 min−1 for OEOMEA and 2.60 min−1 for HEA) than at 25 °C (1.60 min−1 for OEOMEA and 1.12 min−1 for HEA). These unexpected and unprecedented results are explained by the lower Cu(0) particle size obtained by the disproportionation of CuBr at 0 °C in H2O. Poly(OEOMEA) obtained by aqueous SET-LRP at 0 °C with the unexpectedly high kappp = 4.61 min−1 exhibits 88% chain-end functionality at 100% monomer conversion, while the theoretical value would have to be [similar]0%. This high experimental chain-end functionality was explained by the slow desorption of the hydrophobic backbone containing the propagating radicals of these amphiphilic polymers from the surface of the catalyst due to their strong hydrophobic effect. Polymer radicals adsorbed on the surface of Cu(0) undergo monomer addition and reversible deactivation but do not undergo the bimolecular termination that requires desorption. This amplified adsorption–desorption process that mediates both the activation and the bimolecular termination explains the unexpectedly high chain-end functionality of the polymers synthesized by SET-LRP.
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2016 Collection
Australian Institute for Bioengineering and Nanotechnology Publications
 
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