Optimization of a UV-curable acrylate-based protective coating by experimental design

The influence of composition and processing parameters controlling the properties of UV-cured films was studied by the screening and quantification tools of experimental design methodology. Various formulations including acrylated prepolymers based on a polyurethane or a bis-phenol A core were blended with mono- and difunctional reactive diluents, isobornyl acrylate and hexanediol diacrylate, respectively. The influence of photo-initiator content and UV-dose were examined in experiments combining the different factors. The approach allowed formulating on rational bases a reactive blend yielding a coating exhibiting sufficient elasticity without exhibiting tackiness by blending the two types of prepolymers. An optimal domain of composition was defined by implementing a Scheffé's mixture design.