Living radical polymerization of alkyl methacrylates with ruthenium complex and synthesis of their block copolymers

Living radical polymerizations of ethyl and n-butyl methacrylates (EMA and BMA, respectively) have been achieved with ternary initiating systems that consist of carbon tetrachloride, tris(triphenylphosphine)ruthenium dichloride [RuCl2(PPh(3))(3)], and aluminum compounds such as MeAl-(ODBP)2 (ODBP, 2,6-di-tert-butylphenoxy) and Al(OiPr)(3) in toluene at 60-80 degrees C. The produced polymers had narrow molecular weight distributions (MWDs) ((M) over bar(w)/(M) over bar(n) = 1.2-1.5) and controlled molecular weights that are nearly proportional to monomer conversion. Sequential living polymerizations of these methacrylates from methyl methacrylate (MMA) afforded AB-type block copolymers with narrow MWDs ((M) over bar(w)/(M) over bar(n) similar to 1.2). Further addition of MMA into the living AB block copolymers gave ABA-type triblock copolymers poly(MMA-b-BMA-b-MMA).