Preparation and Performances of Nano-SiO2 Modified Graphene Oxide/Waterborne Polyurethane Composites
Nano-SiO2 modified graphene oxide(GO-S)was prepared by in-situ hydrolysis of tetraethoxysilane(TEOS).Comparative studies were conducted on GO and GO-S using infrared spectroscopy,Raman spectroscopy,X-ray photoelectron spectroscopy,transmission electron microscopy,and scanning electron microscope,demonstrating the successful preparation of GO-S.The waterborne polyurethane(WPU),WPU/GO and WPU/GO-S composites were further prepared,and their properties were comparatively studied.The mechanical performance results show that,compared with pure WPU,the tensile strength of WPU/GO is improved,but the elongation at break is significantly reduced.The tensile strength of WPU/GO-S is significantly increased to 256%of WPU,while the elongation at break is slightly decreased.The water contact angle test results show that the water contact angle of WPU/GO-S is as high as 75°,which is significantly higher than that of WPU(61°),indicating that the addition of GO-S significantly improves the hydrophobicity of WPU coatings.The corrosion resistance test results show that the impedance modulus of WPU/GO-S is the highest.Compared with the substrate,the impedance modulus of WPU/GO-S is increased by about one order of magnitude and also significantly better than that of WPU/GO coating.The WPU/GO-S has the best corrosion resistance.