Facile Synthesis of Macromonomers via ATRP-Nitroxide Radical Coupling and Well-Controlled Brush Block Copolymers

We report facile and efficient synthesis of macromonomers (MMs) via nitroxide radical coupling (NRC) of a norbornene moiety to the chain end of various polymers prepared using atom transfer radical polymerization (ATRP). The synthesis can be simplified to a one-pot procedure for MMs of polyacrylate homopolymers and block copolymers. The MMs synthesized by this method underwent well-controlled ring-opening metathesis polymerization (ROMP) to almost complete conversions (>90%) to yield brush polymers and block copolymers with low dispersities (<1.2) and high molecular weights (300-3000 kDa). This facile method of MM synthesis provided a range of high-quality MMs, which enabled easy access to diverse well-defined brush multiblock copolymers with different blocks in the backbone and/or side chains.