A Very Useful Redox Initiator for Aqueous RAFT Polymerization of N‐Isopropylacrylamide and Acrylamide at Room Temperature

Reversible addition fragmentation chain transfer (RAFT) polymerizations of N ‐isopropylacrylamide (NIPAM), and acrylamide (AM) were successfully performed in aqueous media at ambient temperature using a redox initiator, potassium persulfate (K 2 S 2 O 8 ), and sodium thiosulfate (Na 2 S 2 O 3 ). The molecular weight of the polymers obtained increases linearly with monomer conversion, molecular weight distribution is narrow even at high conversion (>90%), and a linear relationship exists between ln([M] 0 /[M]) and polymerization time. Moreover, self‐chain extension reaction also proceeded successfully. All the results demonstrate that K 2 S 2 O 8 –Na 2 S 2 O 3 is a very efficient initiating system for the RAFT polymerizations of NIPAM and AM in aqueous media at room temperature. magnified image