Ab Initio Emulsion Atom-Transfer Radical Polymerization

Stable latexes of poly(meth)acrylates with predetermined molecular weights, narrow molecular-weight distributions, and controlled architecture were prepared by true ab initio emulsion atom-transfer radical polymerization. Water-soluble (macro)initiators in combination with a hydrophilic catalyst, Cu/tris(2-pyridylmethyl)amine, initiated the polymerization in the aqueous phase. The catalyst strongly interacted with the surfactant sodium dodecyl sulfate (SDS), thereby tuning the polymerization within nucleated hydrophobic polymer particles. Long-term stable latexes were obtained, even with SDS loading below 3 wt % relative to monomer. Block and gradient copolymers were prepared in situ. The reaction volume and solid content were successfully increased to 100 mL and 40 vol %, respectively, thus suggesting facile scale-up of this technique. The proposed setup could be integrated in existing industrial plants used for emulsion polymerization.