Unifying Model for Understanding HEUR Associative Thickener Influences on Waterborne Coatings: I. HEUR Interactions with a Small Particle Latex

By Mao Chen, Wylie H. Wetzel, Zeying Ma, J. Edward Glass, Robert J. Buchacek, John G. Dickinson

The structural features of associative thickeners influence their viscosifying properties in neat and surfactant containing aqueous solutions and in architectural coating formulations. Our understanding of the phenomena based on model associative thickener of the Hydrophobically modified Ethoxylate URethane (HEUR) type are presented.

These studies provide general concepts in aqueous solutions, but they do not provide a quantitative model for understanding the influence of associative thickeners in coating formulations. To provide a more quantitative description, the interactions of associative thickeners with the film forming latex are considered in this study. T

his requires a knowledge of the free surfactant concentration in the formulation that depends on the residual amount present in the latex and the amounts added with the pigment grind, colorant, etc. The competitive interaction of the surfactants and associative thickener types for the surface of both disperse phases is a key variable.

These interactions with the latex will be discussed in this article in an effort to define an encompassing model for understanding how HEUR associative thickeners influence waterborne coatings.