Synthesis and properties of UV-curable polyurethane acrylates containing fluorinated acrylic monomer/vinyltrimethoxysilane

A series of UV-curable polyurethane acrylates containing fluorinated acrylic monomer (heptadecafluorodecyl methacrylate, PFA, 6 wt%)/vinyltrimethoxysilane (VTMS, 0–9 wt%) [FPUA6/0, FPUA6/3, FPUA6/6 and FPUA6/9, where the numbers indicate the wt% of PFA/VTMS] were synthesized from a reactive urethane oligomer (40 wt%) and diluents (60 wt%). This study examined the effect of bulky VTMS (0–9 wt%)/bulky IBOA (34–25 wt%) weight ratio on the properties of the UV-curable polyurethane acrylates for transparent anti-fouling coating materials. In the wavelength range of 400–800 nm, the transmittance % of the FPUA film samples increased markedly up to nearly 100 % with increase in the VTMS content up to 9 wt%. As the VTMS content increased, the storage modulus/tensile modulus/hardness of the UV-cured film samples increased significantly and the tensile strength/glass transition temperature increased a little; however, the elongation at break decreased significantly. XPS showed that the film–air surface of the UV-cured polyurethane acrylate film had a higher fluorine content than the film–dish interface indicating the gradient concentration of fluorine in the structure of the film from the film–air surface to the film–glass interface. As the VTMS content increased from 0 to 9 wt%, the surface tension of the UV-cured urethane acrylate films decreased from 17.2 to 15.9 mN/m, whereas the water/methylene iodide contact angles of the film–air surface increased significantly from 107.9/80.9° to 114.2.9/84.2°. These results suggest that the UV-curable polyurethane acrylate containing 9 wt% of VTMS has strong potential as a coating material for transparent antifouling applications.