Amino alcohol additives for the fast living radical polymerization of methyl methacrylate with RuCl2(PPh3)3

A series of amino alcohols [e.g., R2N-CH2)(n)-OH (R = Me, Et, etc.; n = 2, 3, or 4)] were examined as additives for rate enhancement and finer reaction control in the living radical polymerization of methyl methacrylate with RuCl2(PPh3)(3). In general, these additives were more effective in acceleration than the corresponding amines as well as mixtures of an amine and a nonsubstituted alcohol, diamines, or diols. For example, 2-(diethylamino)ethanol significantly accelerated the polymerization (23 h, 91% at 60 degreesC) and gave polymers with narrower molecular weight distributions [weight-average molecular weight/number-average molecular weight (M-w/M-n) = 1.23], with respect to the system without the additive (550 h, 95%, M-W/M-n similar to 2.0 at 80 degreesC; no polymerization at 60 degreesC). H-1 NMR analysis showed the interaction between the amino alcohols and RuCl2(PPh3)(3), which apparently formed a more active catalyst. Amino alcohols were also effective in Ru(Ind)Cl)PPh3)(2)-catalyzed systems (96% in 8 h at 80 T). High-molecular-weight poly(methyl methacrylate) (M-n similar to 1.1 x 10(5)) was synthesized with the RuCl2(PPh3)(3)/2-(diethylamino)ethanol system, in which the polymerization reached 97% conversion in 4 h. (C) 2003 Wiley Periodicals, Inc.