Off-Diagonal Effects of Alkanolamines in Waterborne Coatings
Alkanolamines are ideal pH-neutralizing agents in a number of ways, including compatibility with latex emulsions, solubility in latex emulsions, a sufficiently high pKa value to allow for efficient neutralization to pH values between 8 and 10, and intermediate vapor pressures that allow for evaporation at a controlled rate. The optimum alkanolamine for a given coating formulation will be the one with the best balance of physical properties, allowing for the maximum number of benefits and the minimum number of negative side effects (e.g., odor).
One of the easiest ways to evaluate and compare different alkanolamines as additives in waterborne coatings is through the concept of off-diagonal effects, and this paper will, for clarity, start with a generic description of the off-diagonal analysis of additive effects. The generic discussion will be followed by some physical data summaries useful in illustrating how off-diagonal effects can be predicted ab initio. Ultimately, we hope to convince the reader that Arkema's Advantex™ additive is a useful neutralizing alkanolamine alternative for waterborne coatings.