Copper-mediated initiators for continuous activator regeneration atom transfer radical polymerization of acrylonitrile

Abstract

Initiators for continuous activator regeneration atom transfer radical polymerization technique was first accessed to acrylonitrile by using CuBr2/2,2′-bipyridine as the catalyst, ethyl 2-bromoisobutyrate as the halogen initiator, and azobis(isobutyronitrile) as the free radical initiator. The key to success is ascribed to the facile achievement of the rapid equilibrium between active species and dormant species. Effects of ligand, catalyst concentration, free radical initiator concentration, and reaction temperature on the polymerization reaction and molecular weight (MW) as well as polydispersity index (PDI) were investigated in detail. The polymerization proceeded in a controlled/living fashion even though the concentration of copper catalyst decreased to 50 ppm, which is evident in pseudo first-order kinetics of polymerization, linear increase of molecular weight, low PDI, and high chain-end functionality of the generated polymer. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012