초록
UV-Curable polyurethane acrylates were prepared from urethane-acrylate prepolymer, three type of reactive diluents, and 1-hydroxycyclohexyl phenyl ketone (Irgacure 184) as a photoinitiator. The urethane-acrylate prepolymer, which influenced toughness, abrasion resistance, and flexibility of the resulting polymer, was synthesized from 4,4'-diphenylmethane diisocyanate (MDI), poly(tetramethylne oxide) glycol (PTMG, $M_{w}$ 1,000), 1,6-hexanediol (HD), and 2-hydroxyethyl acrylate (HEA) using dibutyltin dilaurate as a catalyst. The three types of reactive diluents having mono-, di-, and trifunctionality are acrylate monomers with double bond functionalities such as phenoxyethyl acrylate (PEA), hexanediol diacrylate (HDDA), and trimethylopropane triacrylate (TMPTA), respctively, UV-Cured films of polyurethane acrylates were obtained by curing with a medium-pressure mercury lamp (80 W/cm; ${\lambda}_{max}$=365 nm). In this work, the effects of the chemical structure and the reactive diluent composition on mechanical and dynamic thermal mechanical properties of UV-cured polyurethane acrylates were studied. The structure and properties of the films obtained from the UV photopolymerization of urethane-acrylate prepolymer were investigated by FT-IR spectroscopy, dynamic mechanical measurement, and tensile testing.