Photopolymerization of epoxy coatings containing silica nanoparticles

Silica nanoparticles were employed to obtain organic-inorganic hybrid coatings via UV curing of an epoxy based system. The influence of the presence of SiO₂ on the rate of polymerization was investigated by real time FT-IR. The silica nanofiller induced both a bulk and a surface modification of UV cured coatings with an increase on T_g, modulus and surface hardness by increasing the amount of silica into the photocurable resin. TEM investigations confirmed that silica filler has a size distribution range between 5 and 50 nm without formation of aggregates. The strong decrease on water uptake in the presence of SiO2 makes these nanocomposites materials particularly interesting for gas-barrier coatings applications.