Model alkali-soluble rheology modifiers were synthesized through the reversible addition-fragmentation chain transfer polymerization of methyl methacrylate, methacrylic acid, and three different associative macromonomers containing 20, 50, and 100 ethylene oxide spacer units, respectively. The synthesized polymers showed well-controlled molar masses and narrow molar mass distributions. The rheological properties of the model alkali-soluble rheology modifiers were measured in alkali solutions and in the presence of a well-characterized core-shell emulsion. The steady-shear viscosity data for the emulsion solutions, thickened with the associative rheology modifiers, were described by the Carreau model. The rheology modifiers containing the macromonomers with the longest ethylene oxide spacer units produced the highest viscosity in the latex systems but the lowest viscosity in alkali solutions. The highest viscosities in alkali solutions were obtained for the rheology modifiers containing macromonomers with 50 ethylene oxide spacer units. (C) 2004 Wiley Periodicals, Inc.