Polyaspartic acid esters (polyaspartics) have been in use since the 1990s. Originally, they were used as reactive diluents that helped to reduce the volatile organic compounds (VOC) in conventional 2-component polyurethane coatings (2C-PU). Polyaspartics are formed during the reaction of sterically hindered secondary diamines - polyaspartic acid esters - with aliphatic polyisocyanates (Figure 1). The reaction rate depends largely on the hydrocarbon groups on the aspartics and the aliphatic group selected for the polyisocyanate. That choice also influences hardness, chemical resistance and other essential coating properties of the resulting products. With the development of ...