Amine Blush Testing Elusive Mystery or Good Old-Fashioned Organic Chemistry?

摘要

Two recurring issues in the coatings industry that owners, applicators and inspectors struggle with is how to accurately determine whether amine blush is present on epoxy coatings, and the ability to differentiate an amine blush from an amine bloom. There are test methods currently available that can identify amine blush, but they are generally available specifically to the trained analytical chemist and involve costly equipment and technical expertise. Several years ago, a purported test method to determine amine blush based on pH was introduced, but it was quickly rejected as it only gave an indication that the environment was optimal for developing blush and did not actually determine if blush occurred. A simple understanding that an amine blush is actually a salt leads one to the conclusion that this resulting salt itself is not alkaline, and therefore determining the pH of the surface in order to identify an amine blush is ineffective. Subsequently, that test was quickly removed from the marketplace.