Characterization and performance of organic-inorganic composite zinc phosphate with nano-sheet structure synthesized by a composite reaction of sol-gel with silane modification

Organic-inorganic composite zinc phosphate pigment with nano sheet structure (KH560-SZP, sheet zinc phosphate with γ-(2,3-epoxypropoxy) propytrimethoxysilane) was prepared by a simple composite reaction of silane modification method and solation-gelation method. Then the characteristics of KH560-SZP pigment, interfacial compatibility of KH560-SZP pigment/resin and corrosion inhibition of KH560-SZP coating with defect were studied through Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive Spectroscopy (EDS), Thermal Gravimetric Analysis (TG), sedimentation experiment, Inductively Coupled Plasma (ICP-OES), electrochemical test, and salt spray test. Result showed that the prepared KH560-SZP pigment had a nanosheet structure with thickness of 25-40nm, and there were 2.11% of organic resin functional groups in the pigment, which made the pigment well dispersed in the resin. The dissolution rate of PO43− in the KH560-SZP extracting was faster, and its concentration reached saturation just 2 h (the SZP needed 4 h). Hence, the KH560-SZP coating showed effectively prolong the diffusion path of electrolyte in the scratch-free coating and inhibit the corrosion reaction at the scratch areas.