Xanthate-Mediated Living Radical Polymerization of Vinyl Acetate in Miniemulsion

The MADIX/RAFT mechanism, employing a xanthate as the reversible chain‐transfer agent, has been shown to facilitate the living radical polymerization of vinyl acetate in miniemulsion. Methyl (ethoxycarbonothioyl)sulfanyl acetate (MESA) successfully mediated the polymerization which was initiated with either of the water‐soluble initiators 2,2′‐azobis{2‐[1‐(2‐hydroxyethyl)‐2‐imidazolin‐2‐yl]propane} dihydrochloride (VA‐060) or 2,2′‐azobis[2‐(2‐dimidazolin‐2‐yl)propane] dihydrochloride (VA‐044). The polymerizations exhibit living characteristics, demonstrated by the evolution of molecular weight distributions. The formulation of the miniemulsion produced stable latexes with no coagulum. The number‐average molecular weight and PDI as a function of monomer conversion for the RAFT miniemulsion polymerization of vinyl acetate.