Ruthenium-catalyzed fast living radical polymerization of methyl methacrylate: The RCl/Ru(Ind)Cl(PPh3)2/n-Bu2NH initiating system

A fast living radical polymerization of methyl methacrylate (MMA) proceeded with the (MMA)2Cl/Ru(Ind)Cl(PPh3)2 initiating system in the presence of n‐Bu2NH as an additive [where (MMA)2Cl is dimethyl 2‐chloro‐2,4,4‐trimethyl glutarate]. The polymerization reached 94% conversion in 5 h to give polymers with controlled number‐average molecular weights (Mn's) in direct proportion to the monomer conversion and narrow molecular weight distributions [MWDs; weight‐average molecular weight/number‐average molecular weight (Mw/Mn) ≤ 1.2]. A poly(methyl methacrylate) with a high molecular weight (Mn ∼ 105) and narrow MWD (Mw/Mn ≤ 1.2) was obtained with the system within 10 h. A similarly fast but slightly slower living radical polymerization was possible with n‐Bu3N, whereas n‐BuNH2 resulted in a very fast (93% conversion in 2.5 h) and uncontrolled polymerization. These added amines increased the catalytic activity through some interaction such as coordination to the ruthenium center. © 2002 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 617–623, 2002; DOI 10.1002/pola.10148 A fast living radical polymerization of methyl methacrylate proceeded with the RCl/Ru(Ind)Cl(PPh3)2 initiating system in the presence of n‐Bu2NH as an additive and reached quantitative conversion within 10 h. The number‐average molecular weight (Mn) increased in direct proportion to the monomer conversion (up to 105), and the molecular weight distributions were very narrow [weight‐average molecular weight/number‐average molecular weight (Mw/Mn) ≤ 1.2].