Living polymerization of acrylamides catalysed by N-heterocyclic olefin-based Lewis pairs

Abstract

A Lewis pair composed of a strong nucleophilic N-heterocyclic olefin (NHO) as a Lewis base (LB) and triphenylaluminum (AlPh₃) as a Lewis acid (LA) was employed to achieve the rapid and living polymerization of acrylamides including N,N-dimethylacrylamide (DMAA) and N,N-diethylacrylamide (DEAA) at room temperature in toluene. The livingness of this Lewis pair polymerization (LPP) was unequivocally verified by the observed linear increase of polymer M_nvs. monomer conversion and monomer-to-initiator ratio, successful chain extensions and high end-group fidelity. Moreover, well-defined diblock and triblock copolymers with narrow Đ values were also successfully synthesized through the sequential addition method, regardless of the comonomer addition order.