ma6b02037_si_001.pdf (266.14 kB)
Electrochemical Atom Transfer Radical Polymerization in Miniemulsion with a Dual Catalytic System
journal contribution
posted on 2016-11-14, 19:05 authored by Marco Fantin, Sangwoo Park, Yi Wang, Krzysztof MatyjaszewskiAn
electrochemical approach was used to control atom transfer radical
polymerization (ATRP) of n-butyl acrylate (BA) in
miniemulsion. Electropolymerization required a dual catalytic system,
composed of an aqueous phase catalyst and an organic phase catalyst.
This allowed shuttling the electrochemical stimulus from the working
electrode (WE) to the continuous aqueous phase and to the dispersed
monomer droplets. As aqueous phase catalysts, the hydrophilic Cu complexes
with the ligands N,N-bis(2-pyridylmethyl)-2-hydroxyethylamine
(BPMEA), 2,2′-bipyridine (bpy), and tris(2-pyridylmethyl)amine
(TPMA) were tested. As organic phase catalysts, the hydrophobic complexes
with the ligands bis(2-pyridylmethyl)octadecylamine (BPMODA)
and bis[2-(4-methoxy-3,5-dimethyl)pyridylmethyl]octadecylamine
(BPMODA*) were evaluated. Highest rates and best control of BA electropolymerization
were obtained with the water-soluble Cu/BPMEA used in combination
with the oil-soluble Cu/BPMODA*. The polymerization rate could be
further enhanced by changing the potential applied at the WE. Differently
from traditional ATRP systems, reactivity of the dual catalytic system
did not depend on the redox potential of the catalysts but instead
depended on the hydrophobicity and partition coefficient of the aqueous
phase catalyst.