Well-defined poly(N,N-dimethylacrylamide) from a fast Cu(0)-mediated reversible-deactivation radical polymerization in water

Copper-catalyzed reversible deactivation radical polymerization (RDRP) of N,N-dimethylacrylamide (DMA) has been a significant challenge, particularly in aqueous environments, such as low yields, broad molecular weight distribution (MWD), and ill-controlled molecular weights (MWs). In this work, we report the synthesis of well-defined poly(N,N-dimethylacrylamide) (PDMA) via a facile Cu(0)-mediated RDRP in water. The results show that, unlike other acrylamide monomers, for DMA with abundant tertiary amide groups, the sufficient deactivation-the key to realizing control in copper-catalyzed RDRP-cannot be simply fulfilled by just increasing the amount of deactivator (i.e., Cu-II species). The enhanced deactivation must be appropriately determined by also considering and selecting other reaction parameters. It is demonstrated that the use of methyl 2-chloropropionate (MCP) as initiator and copper(II) chloride (CuCl2) as the additional catalyst is an effective combination to simultaneously enhance the deactivation control and facilitate the chain growth in aqueous Cu(0)-mediated RDRP of DMA. This strategy successfully achieved the fast and well-controlled synthesis of PDMAs with high monomer conversion, narrow MWDs, and a range of predefined MWs, and the well-controlled in situ chain extensions.