Green fabrication of ultraviolet curable epoxy acrylate-silica hybrid coatings

Ultraviolet (UV) curable organic-inorganic hybrid materials have attracted increasing researchers' attention due to the environmental advantages and extensive application potential. In this work, a novel green fabrication of UV curable epoxy acrylate (EA)-silica hybrid coating via a sol-gel process induced by photochemical reaction was presented. The inorganic phase, silica was formed at present of an iodonium salt and tetraethyl orthosilicate, avoiding the application of acid or base in traditional synthesis method. The hybrid coatings were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and thermogravimetric analysis(TGA). Three kinds of silane coupling agents including KFI-550, KH-560 and KH-570 were investigated to modify the silica sol. The distribution of SiO2 in the hybrid coating with KH-570 modification is most homogeneous. TGA results indicate that the hybrid coating with 10% of silica exhibits the most excellent thermal stability. The effects of adding content of silica on the hybrid film's tack free time and hardness were also investigated for the preliminary study.