Abstract: Associative thickeners of the present invention are water soluble polymer compositions that have a backbone of poly(acetal- or ketal-polyether) with ends that are capped with hydrophobic groups. They are prepared by copolymerizing an alpha, omega-diol, -di,thiol or-diamino polyether with a gem-dihalide compound in the presence of a base to form an alpha, omega-diol, -dithiol or -diamino poly(acetal- or ketal-polyether) which in turn is reacted with hydrophobic reagents to form the final product. These associative thickeners are used in film forming coating compositions, such as latex paints.