Effect of composition on performance properties in cationic UV-curable coating systems

Cycloaliphatic epoxides have been widely studied in the coatings industry because of the excellent mechanical properties of films prepared using these monomers and various diluents. In this study, polyol was studied as a diluent for formulations containing cycloaliphatic epoxide and oxetane in order to evaluate the effect on coatings properties and curing kinetics. The addition of polyol was shown to have an effect on both mobility of the cation as a chain transfer agent, along with the more general effect of flexibility, as evidenced by the hardness data, which increased when a small amount of polyol was added, but decreased as more polyol was included in the formulation. In terms of crosslinking kinetics, it was found that the inclusion of polyol resulted in an increase in conversion during UV irradiation. The level of polyol also had an effect on other properties, such as T-8 and crosslink density.