Active Ligand for Low PPM Miniemulsion Atom Transfer Radical Polymerization

By Elsen, Andrea M.; Burdyš„ska, Joanna; Park, Sangwoo & Matyjaszewski, Krzysztof
Published in Macromolecules NULL 2012

Abstract

Modification of bis(2-pyridylmethyl)octadecylamine (BPMODA), a ligand commonly used in ATRP in aqueous dispersed media, was accomplished through the incorporation of electron-donating substituents, resulting in a new, more powerful ligand, bis[2-(4-methoxy-3,5-dimethyl)pyridylmethyl]octadecylamine (BPMODA*). Cyclic voltammetry (CV) indicated the newly synthesized ligand formed much more reducing, i.e., by an order of magnitude more active ATRP catalyst, as compared to BPMODA. Homogeneous polymerizations under normal ATRP conditions confirmed BPMODA* to accelerate polymerization vs BPMODA, with a retained control over the polymerization. Partition experiments of the ligands demonstrate the hydrophobicity of CuBr2/BPMODA has not been compromised by the EDGs as the majority of CuBr2/BPMODA* remains in the organic phase. Heterogeneous polymerizations conducted over a range of catalyst concentrations (2000 -250 ppm) with BPMODA* consistently resulted in polymerizations with increased control throughout the polymerizations.

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