Synthesis and Characterization of UV-Curable Polyurethane Acrylates Derived from Trimethylolpropane and Hydroxyethyl Methacrylate: Effect of HEMA Content on Thermal Stability, Gloss Properties, and Microstructure

This study presents the synthesis of a series of UV-curable polyurethane acrylates (PUAs) derived from trimethylolpropane (TMP) and hydroxyethyl methacrylate (HEMA) through a one-step polymerization method. The phase analysis using FTIR reveals distinct vibration bands corresponding to different functional groups within the polyurethane structure. Thermogravimetric analysis demonstrates two degradation steps in UV-cured PUA _3/0 films, revealing the influence of HEMA content on thermal stability. Gloss properties exhibit a complex relationship with HEMA content, with initial improvement followed by a decline, emphasizing the impact on film glossiness. Hydrophilic/hydrophobic properties, measured by contact angle values, indicate increased crosslinking and less polar surfaces with higher HEMA content. Microstructure analysis using SEM demonstrates that UV-cured PUA _3/0 films achieve effective chemical crosslinking and a dense microstructure, contributing to enhanced film properties.