The use of cycloaliphatic epoxides in latex and ultraviolet-curable coatings

The use of more environmentally friendly coating technology continues to grow as more stringent EPA regulations demand their usage. Two types of coatings commonly employed for addressing these issues are latex and UV-curable systems. In this dissertation, the use of cycloaliphatic epoxides was investigated in both crosslinkable core-shell latex formulations as well as the major component in cationic UV-curable coatings. In order to reduce the heat required for latex synthesis, redox initiators were studied as an alternative to the thermal initiator commonly used. It was found that using such initiators gave similar properties to the latexes prepared with the thermal initiator, as well as some enhanced properties. In addition, the base used for neutralizing the carboxyl-functional latexes was studied. It was found that the base used can have an effect on particle size as well as mechanical properties. The UV-curable formulations were studied in terms of the effect of composition variables on the mechanical properties as well as on the UV-curing kinetics. The introduction of more mobile species into cycloaliphatic epoxide formulations resulted in an increase in the cure rate during UV irradiation and an enhancement in coating properties. The effect of introducing different components into the formulations was also studied in terms of cure kinetics and coatings properties. By using model alcohols and a model epoxide monomer, the UV cure rate was enhanced as the concentration of these materials was increased. The effect of post-cure treatment on the films was also investigated to determine both physical and chemical changes in the films as a function of treatment. The treatments studied included annealing, solvent treatment, and acid treatment. These treatments were found to have both physical and chemical effects on the films. In addition, the effect of post-cure humidity was evaluated for the effect on the dark cure reactions in the films. High humidity had a greater effect on the films, essentially quenching the dark cure reaction by reaction of the films with the water present in the environment.