Physical Properties of UV-cured Epoxy Nanocomposite Films
Cationic UV-curing of a cycloaliphatic epoxy proceeds efficiently at room temperature, resulting in a highly crosslinked polymer network exhibiting the same excellent physical properties as obtained by thermal curing. However, the highly crosslinked rigid polymer network generally shows undesirable brittleness. Therefore, in this study, three kinds of reactive diluents, one epoxy and two polyols, were tested to prepare a cycloaliphatic epoxy film with reasonable physical properties by cationic UV-curing. Also, effects of nanosilica on the physical properties of the epoxy film were investigated. FTIR spectroscopy was used to investigate the UV-curing behaviour of the epoxy resin systems. Amongst the diluents enhanced UV-curing rate and final conversion levels, the epoxy diluent was the most effective. The tensile properties of the epoxy films were investigated by UTM. At a fixed diluent content of 30 phr, the film with the epoxy diluent showed best tensile strength. The film with the epoxy diluent 40 phr showed optimum tensile properties. The film with the epoxy diluent 40 phr showed further enhanced tensile properties at the nanosilica content 0.05 phr.