Tandem catalysis of Atom Transfer Radical Polymerization of acrylonitrile based on simultaneous use of two copper complexes

The novel approach for conducting ARGET ATRP based on simultaneous use of two copper complexes based on tris[2-(dimethylamino)ethyl]amine (Me₆TREN), 2,2’-bipyridine (bipy) and tris(2-pyridylmethyl)amine (TPMA) in one pot is proposed. This approach allows to increase the rate of polymerization of acrylonitrile and to achieve polymers with high molecular weights. The performed electrochemical studies allowed establishing the possible mechanism of tandem catalysis where the more reducing complex mostly acts as activator determining the high polymerization rate while the second one reversible deactivates polymer chain preserving the control over the process. The influence of initiator nature and the ratio between copper catalysts on the polymerization rate and the molecular weight parameters of the samples was studied. It was shown that the proposed system may be applied for obtaining well-defined copolymers of acrylonitrile with methyl acrylate and dimethyl itaconate via ARGET ATRP mechanism using low copper concentrations.