초록 |
Polymer/clay nanocomposites have received much attention from many researchers since late 1980's. Interest in these nanocomposites is due to the considerable enhancement of polymer properties by the inclusion of nanoclay. These nanocomposites have been shown to posses superior mechanical properties, barrier properties, thermal stability, and chemical resistance at low loadings of clay. Polymer nanocomposite formation can be accomplished by ultraviole(UV) curing and an improvement in properties of the polymer nanocomposite is expected. In this study, UV curing behavior of a urethane acrylate/clay nanocomposite was investigated by FTIR spectroscopy and compared with that of a urethane acrylate resin system without clay. Clay used was a natural montmorillonite modified organically with a quaternary ammonium salt. The content of the clay in the urethane acrylate/clay nanocomposites was varied from 0 to 3 phr. The content of a reactive diluent, hexanediol diacrylate (HDDA), was 30 phr. The content of a photoinitiator, 1-hydroxy-cyclohexyl-phenyl-ketone, was 2 phr. The mechanical and thermal properties of UV cured urethane acrylate/clay nanocomposite films were investigated using UTM, DSC, TMA and TGA. The dispersion and nanostructures of clay in the nanocomposites were characterized by X-ray diffractometer and transmission electron microscope. |