Preparation of Surface-Modified Nano Zinc Sulfide/Polyurethane Inorganic-Organic Transparent Coating and Its Application in Resin Lens

Abstract

The surface modified hydrophilic zinc sulfide nano powder was prepared by hydrothermal method, and the corresponding zinc sulfide/polyurethane organic-inorganic composite transparent coating via in-situ polymerization. The structure of ZnS Nanoparticles and organic-inorganic composite coating were characterized by Infrared Spectroscopy, X-Ray Diffraction, Laser Particle Size Analyzer and Scanning Electron Microscopy. The optical properties were measured by Ultraviolet-Visible spectrophotometer and ellipsometry. The results show that the monodisperse hydrophilic nano zinc sulfide powder with a particle size of about 70 nm can be obtained by thioglycolic acid (TGA) modification, which has good compatibility with waterborne polyurethane. Nano zinc sulfide increased the refractive index of the coating significantly and the refractive index of the coatings could be controlled in the region of 1.46–1.71 organic-inorganic composite coating by adding ZnS. When the amount of nano ZnS added was 30%, the refractive index of the hybrid coating can reach 1.71, and the transmittance was more than 90%. The cured coatings were smooth and no agglomeration between nano ZnS particles could be found. After application on the surfaces of resin lens, the coatings presented better impact resistance, which indicated that the coating has application prospects in the field of fine processing of lens’ surfaces.