Concurrent atom transfer radical polymerization and nitroxide radical coupling relay polymerization

Abstract

Simultaneous atom transfer radical polymerization (ATRP) and nitroxide radical coupling (NRC) seems impossible because the presence of nitroxide radicals would quench the radical polymerization immediately. However, by combining a nitroxide radical and an ATRP active halogen, a halogen group that can initiate one polymer chain by ATRP, into one functional reagent and adding this functional reagent to an ATRP system, concurrent ATRP-NRC relay polymerization was carried out successfully under proper reaction conditions. The key to success was the conjugate radical trapping and re-initiation took place repeatedly, resulting in polymers with inserted alkoxyamine linkages. This novel relay polymerization method provides numerous possibilities for macromolecular architecture/functionality tailoring by using of different functional reagents.