Synthesis and characterization of a new acrylic emulsion with dual efficacy: UV-shielding and antibacterial function

To improve the weatherability and antibacterial property of acrylic emulsion, a new kind of acrylic emulsion with UV-shielding and antibacterial properties was prepared by soap-free emulsion polymerization with (3-acrylamidopropyl)trimethyl ammonium chloride (ATAC) and 2- [3-(2H-Benzotriazol-2-yl)-4-hydroxyphenyl] ethyl methacrylate (BHEM) as functional monomers. A series of testing methods, including transmission electron microscopy (TEM), zeta potential, dynamic light scattering (DLS), gel permeation chromatography (GPC), Fourier transform infrared spectrum (FT-IR), ultraviolet absorption spectrum (UV), X-ray photoelectron spectroscopy (XPS), artificial accelerated aging test and antibacterial test, were adopted to characterize the emulsion and its coating. Results based on the characterization indicated that the particle size and zeta potential of the emulsion were 82.68 nm and 26.5 mv respectively, and its polydispersity index (PDI) was 1.4076. The emulsion was modified by the functional monomers and endowed it with good antibacterial property and strong UV-shielding performance at 295 nm and 340 nm. After 240 h aging test, the color difference (ΔE) and rate of loss of gloss (ΔG) of the coating made by the new emulsion were only 2.81 and 5.12% respectively, which were much lower than 16.85 and 52.43% of the unmodified coating. The antibacterial test showed that only a few colonies appeared on the surface of the medium coated with the new emulsion after 24 h incubation, while dozens of colonies were appeared in the control groups.