New Initiators for Controlled Radical Polymerization of Acrylic Monomers

Polymerization of acrylic monomers was redox initiated by mixtures 11 of transition metal derivatives acetates, metallocenes with arenediazonium salts. In most cases, molecular weights increase with the conversion and polydispersities are lower than in a typical radical or anionic polymerization at these temperatures. Trapping experiments and relative monomer reactivities based on copolymerization studies indicate that these polymerizations proceed via a radical mechanism. The improved polymerization control can be ascribed to an equilibrium between growing radicals and dormant persistent radicals.