Synthesis and Antibacterial Activity of Metal-Containing Ultraviolet-Cured Wood Floor Coatings

In our previous report, the antibacterial agents with different metals, mono(hydroxyethoxyethyl)phthalate [M(HEEP)(2), M = Zn, Mn, and Ca], were synthesized. For increasing their yields, modified synthesis and purified processes were further investigated. The result of energy-dispersive X-ray spectroscopy showed the M(HEEP)(2) could be stable and successfully synthesized, and their yields were raised to 73–85% from our previous report of 43–55%. For ultraviolet-cured wood floor coating application, the Zn(HEEP)(2) was selected as an antibacterial agent and mixed with commercial UV wood floor coating. The effects on the antibacterial activity of UV films with different Zn(HEEP)(2) additions of 0, 4, 8, and 12 phr as well as the commercial nano-Ag of 12 phr against Escherichia coli were evaluated. In the static antibacterial test, the UV films with Zn(HEEP)(2) additions had similar antibacterial activity of 57–59%. In another dynamic shaking antibacterial test, the film containing 12 phr Zn(HEEP)(2) had the best antibacterial activity among all the UV films. On the film properties, the Zn(HEEP)(2)-containing UV films had lower gloss and abrasion resistance, and slightly increased the hardness than those of UV film without Zn(HEEP)(2) addition. However, there were no noticeable differences in mass retention, lightfastness, and thermal stability between UV films with and without the Zn(HEEP)(2) addition. In this study, the 12 phr Zn(HEEP)(2)-containing UV film provided the best antibacterial activity against E. coli and had the balanced film properties for application on the UV wood floor coating.