Versatile cobalt(Salen‐NEt₂) for aqueous cobalt‐mediated radical polymerization

Abstract Cobalt‐mediated radical polymerization (CMRP) has enabled the polymerization of a wide range of monomers with predictable molecular parameters and well‐defined compositions and architectures. However, the synthesis of hydrophilic polymers by CMRP directly in the aqueous phase is still challenging. Herein, a handy cobalt complex was developed to perform CMRP of N ‐vinylpyrrolidone (NVP), 2‐hydroxyethyl acrylate (HEA), and N,N ‐dimethylacrylamide (DMA) with linearly increased molecular weight, low polydispersity values, and smoothly shifted gel permeation chromatography (GPC) traces. The chain extensions of NVP, HEA, and DMA revealed the well chain‐end fidelity for the synthesis of block copolymers. Moreover, the poly( N ‐vinylpyrrolidone)‐ block ‐poly(vinyl acetate) (PVP‐ b ‐PVAc) amphiphilic block copolymer colloidal solution was achieved directly in aqueous phase by cobalt‐mediated radical polymerization‐induced self‐assembly (CMR‐PISA), forming the nanoparticles consisting of a hydrophilic PVP corona and a hydrophobic PVAc core. This new mediator opens the opportunity for the synthesis of various hydrophilic (co)polymers in an environmentally friendly manner.