The kinetics of the polymerization of n-butyl acrylate initiated by lithiated ester enolates in the presence of aluminum alkyls was investigated in toluene and in toluene/Lewis base mixed solvents at -78 degrees C. In pure toluene, curved time-conversion plots, incomplete monomer conversion, and broad molecular weight distributions (M-w/M-n approximate to 2) are observed-in the absence of aluminum alkyls the molecular weight distributions are significantly broader (M-w/M-n > 14). High monomer conversions and narrower molecular weight distributions (M-w/M-n approximate to 1.5) are obtained when using Lewis bases (e.g., methyl pivalate) as cosolvents. The polymerization of tert-butyl acrylate rapidly reaches full monomer conversion with rather broad molecular weight distributions (M-w/M-n approximate to 2); the addition of a Lewis base, however, does not have a pronounced effect on these values.