Abstract

Waterborne polyurethane/laponite composites used for leather finishing have been prepared via the solution mixing method. The dispersion stability of laponite and composite emulsions were determined by atomic force microscopy (AFM) and dynamic light scattering (DLS). Thermogravimetric analysis (TGA), tensile testing and UV-Vis spectra were used to test the performance of the resulting films. The results indicate that the nano-particles with negative charges can form highly stable aqueous dispersion under alkaline condition and exhibit good compatibility with anionic waterborne polyurethanes. The emulsions possess good storage stability with an average particle diameter of 80~94nm. The uniformly dispersed clay platelets can markedly improve the thermal stability and mechanical properties of the composites. In addition, the incorporation of small-sized clay is capable of maintaining the transparent appearance of the film and giving an UV-resistant property.