New insights for multifunctional matte WPU coatings
With the change of people’s aesthetic concepts, low-gloss coatings are becoming a new hotspot of interest. As low-gloss waterborne polyurethane (WPU) coatings usually are all single-functional coatings, which are difficult to meet the requirements of complex application environments, researchers have now reported on a series of low-gloss WPU nanocoatings with versatility via mono-layered organic montmorillonite (OMt) nanosheets. These WPU coatings have then been applied to polyester fabric.
Rougher surface topography is the reason for the decrease in gloss
Ultraviolet-visible (UV–vis) examination indicated that the OMt nanosheets made the as-prepared nanocoatings have unique UV-shielding performance. Thermogravimetric analysis (TGA) curves showed that the OMt nanosheets increased the thermal stability of the nanocoatings. Moreover, Fourier transforms infrared (FTIR) spectroscopy confirmed the existence of hydrogen bonds between OMt nanosheets and WPU molecular chains, which is the essential reason why the nanocoating had a matte level of gloss on the fabric. Rougher surface topography of the nanocoating compared with pristine WPU coating and fabric observed by scanning electron microscopy (SEM) is the direct reason for the decrease in gloss.
The study has been published in Progress in Organic Coatings, Volume 159, October 2021.