When superior film properties are needed, a two-component (2K) system will have superior properties compared to a one-component (1K) system. These properties include water resistance, corrosion resistance, chemical resistance, abrasion resistance, and many others.
Two of the more common 2K coatings systems are polyurethane and epoxy. In this and next month’s columns, we will concentrate on urethanes. While I will use polyurethane and urethane in this article, the reference will be to polyurethane polymers. Polyurethanes are formed by the reaction of an alcohol and an isocyanate. The polyol’s hydroxyl group reacts with the following order of speed of reaction: primary > secondary > tertiary.