||January 1, 2006
Associative thickeners have had a profound effect on the rheology and performance properties of latex polymer formulations. The colloidal interactions of associative polymers and latexes in the presence of surfactants are complex, but can be characterized in terms of dispersion and flocculation behavior. In addition to good particle dispersion, both bridging and depletion flocculation can occur. Dispersion/flocculation phase diagrams have been developed to help visualize the phase behavior and explain rheological and physical properties of the systems. Interaction between latex particles and both HEUR and HASE associative thickeners will be described and compared to nonassociative thickeners. The effects of latex particle size, latex surface hydrophobicity, associative polymer concentration, electrolyte, and surfactant concentration will be explored.