Copper-catalyzed controlled polymerization of acrylamide
(AM) has
always been a challenge, which typically exhibits low monomer conversion
and broad molecular weight distribution (MWD) or requires complex/multistep
reaction procedures, due to the highly active nature of the AM radical
and its side reactions. To overcome the above challenges, herein,
we report the successful synthesis of well-defined polyacrylamide
(PAM) via a facile one-pot and one-step aqueous Cu(0)-mediated reversible-deactivation
radical polymerization (RDRP). The results of this strategy show that
strong deactivation control is the key for the controllability of
AM RDRPs, which depends on the equilibria of polymerization and mutual
conversion of different copper species. With the fast-propagating
monomer AM, extra addition of CuIIinto the reaction system
is an effective way to enhance deactivation. Based on this kinetically
controlled strategy, well-defined PAMs with narrow molecular weight
distributions (MWDs) and varied molecular weights (Mws) were successfully achieved.