Abstract
Organo-cobalt complexes have demonstrated unique properties in the mediation of radical polymerizations such as catalytic chain transfer polymerization (CCTP) of methacrylates and reversible deactivation radical polymerization (RDRP) of unconjugated monomers particularly vinyl acetate (VAc). Two pathways of reversible termination (RT) and degenerative transfer (DT) have been rationalized as the major control mechanisms in cobalt mediated RDRP. In this chapter, cobalt(II) phenoxy-imine complexes mediated radical polymerization of vinyl acetate is reported. The increasing of electron donating property of phenoxy-imine ligand could switch the polymerization mechanism from RDRP to CCTP, demonstrating the potential of this system to combine CCTP and RDRP techniques.