Efficient RAFT polymerization of methacrylamides with non-polar pendant groups

Although controlled radical polymerization (CRP) has enabled the preparation of a wide range of well-defined polymeric materials, the controlled polymerization of methacrylamide monomers, especially those with non-polar pendant groups, remains largely underexplored with moderate conversions and low livingness often cited as the main challenges. Herein, an optimized thermal RAFT polymerization approach is introduced, by judiciously investigating the reaction temperature, solvent, initiator concentration and RAFT agent choice. High monomer conversion (>80%) with enhanced polymerization rates is obtained within four hours, yielding polymethacrylamides with narrow molar mass distributions ( Ð < 1.15) and high livingness, exemplified by efficient chain-extensions and block copolymers formation. The versatility of the strategy is demonstrated by polymerization of phenyl methacrylamide with a range of chain lengths (DP = 30–650, highest M n = 136,000), and of several methacrylamide-based monomers including benzyl, butyl, and isopropyl methacrylamide. A variety of RAFT agents also proved compatible with our reaction conditions, thus establishing this approach as a highly efficient methodology for the preparation of well-defined polymethacrylamides