Epoxy systems (resins) offer good adhesion, high mechanical and thermal properties, and good chemical resistance as industrial maintenance coatings.^1,2 These properties protect different surfaces, such as concrete, from decomposing in challenging environments. Amines, phenols, thiols and carboxylic acids are well suited co-reactants for hardening epoxy resins. Therefore, there is a wide portfolio of resins with different applications. In flooring applications,³ cycloaliphatic diamine hardeners often are the reactant of choice because they harden at low temperatures and bond readily to wet concrete.⁴ Additional advantages are simple handling, low viscosity and toxicity, good adhesion, outstanding color stability and a fast cure.

Amine adducts are often used in flooring applications. Blushing occurs when primary amines react with atmospheric carbon dioxide and water to form carbamate salts. In adduct form, the relative primary amine content has been reduced in the molecule, resulting in reduced hygroscopicity in the adduct and therefore reduced blushing.^2-4 Amine adducts are also less corrosive and less volatile. On the downside, adduction leads to a significant increase in viscosity. The formulation with solvents or plasticizers such as benzyl alcohol (BnOH) lowers the viscosity of amine adducts and also accelerates the epoxy-amine reaction at ambient or sub-ambient temperatures.^3,4