Effect of rutile titania dioxide nanoparticles on the mechanical property, thermal stability, weathering resistance and antibacterial property of styrene acrylic polyurethane coating

Abstract

This study aims to enhance the mechanical properties, thermal stability, weathering resistance and antibacterial property of a styrene acrylic polyurethane coating by adding rutile titania dioxide (R-TiO2) nanoparticles in coating formulation. The styrene acrylic polyurethane/R-TiO2 nanocomposite had been prepared by using ultrasonication. The effects of nanoparticles on the mechanical properties, thermal stability and weathering resistance of as-prepared coatings were investigated by using the adhesion strength and ball impact tests, the Fourier transform infrared and UV–vis analyses, thermogravimetric analysis (TGA), and UV/condensation weathering chamber equipped with UVA-340 fluorescent lamps, respectively. The disperse quality of nanoparticles in the coating was examined by using the field emission scanning electron microscope (FESEM). The mechanical test results showed that suitable content of R-TiO2 nanoparticles in the nanocomposite coating was 2 wt%. The FESEM images indicated that the nanoparticles were dispersed homogeneously into the entire volume of the coating. For the nanocomposite prepared by 3 h of ultrasonication, the average size of nanoparticles was in range of 40–50 nm. The ball impact and adhesion tests showed that the incorporation of nanoparticles into the coating significantly enhanced the impact strength from 120 to 145 kg cm and increased the adhesion from level 1 to level 0. The TGA test illustrated that in presence of nanoparticles, the decomposition temperature of coating increased from 146.9 °C to 154.21 °C. For the temperature at 50% loss in mass (T50%), it was found that the T50% of the neat coating is 351.86 °C. Adding the 2 wt% R-TiO2 nanoparticles into coating increased the T50% value to 360.06 °C. After UV/condensation accelerated weathering test (30 cycles), the significant improvement in weight loss, impact strength and adhesion of the neat coating was observed with the presence of nanoparticles. The antibacterial test showed that in the nanocomposite coating, R-TiO2 nanoparticles exhibited their photocatalytic effect in the inhibition against E. coli bacterial growth. Incorporating 2 wt% of R-TiO2 nanoparticles into the coating reduced the bacterial concentration by 6.1% after 60 min of culture.

The Synergistic Effects of Sio2 Nanoparticles and Organic Photostabilizers for Enhanced Weathering Resistance of Acrylic Polyurethane Coating

“…Adding these additives at appropriate content could increase the weathering durability of the polymer coatings by 2-3 times [3]. Besides, as reported in literature, some metal oxides (TiO 2 , ZnO, ZrO 2 ) can absorb ultraviolet (UV) rays, therefore having an ability to protect the polymer substrates from harmful UV light [4][5][6][7][8][9].…”

“…In order to improve the weathering resistance of the outdoor coatings, in addition to selecting the main components such as resins and pigments with high weathering durability, organic and inorganic light stabilizing additives are usually added to the paint formulation [3][4][5][6][7]. Previous published works showed that organic light stabilizers (such as Tinuvin 384, Tinuvin 1130, Tinuvin 292) exhibited an excellent light stabilizing efficiency.…”

The Effects of Curcuma Longa on the Functionality of Pigmentation for Thin Film Coating

“…3. This is due to the formation of covalent bonds between the solvent and hardener molecules into Curcuma Longa pigment of the thin film coating and substrate of metal surfaces to enhance the adhesion resistance [6]. Figure 3 The results of classification of adhesion test (B) at different percentages of Curcuma Longa of 20%, 40%, 60% and 80% for 3, 6 and 9 layers.…”

Recent advance in antibacterial activity of nanoparticles contained polyurethane

“…reported that the dispersion of TiO 2 NPs dominated the acrylic PU surface morphological changes during UV radiation and greatly affected the filled coatings degradation process. In another study, however, Nguyen et al . indicated that the rutile TiO 2 NPs mitigated the chemical change, weight loss, and mechanical degradation of the styrene acrylic PU coating, but exhibited a photocatalytic effect in the inhibition of E. coli bacterial growth.…”

“…Nowadays, TiO 2 NPs is showing a new approach for notable applications as an attractive multifunctional material, especially in photocatalysis, catalysis self‐cleaning, UV‐protecting agents, and environmental purification . TiO 2 NPs exhibited a broad spectrum of activity against microorganisms, including positive‐bacteria, Gram‐negative, and fungi and also inhibit the growth of pathogens including bacteria, viruses, and cancer cells under mild UV‐light irradiation . Its antibacterial activity is attributed to the hydroxyl radicals and reactive oxygen species (ROS) generated on the surface of illuminated TiO 2 and inactivate the microorganism by oxidizing the polyunsaturated phospholipid components of the microbes' cell membrane …”