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 Tg, 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.