Preparation And Ptoperties Of Graphene/organic Silicon Modified Polyurethane Anti-corrosion Coating

Polyurethane coating, with its excellent physics mechanical properties and corrosion resistance, is often used as the finish coat of heavy anti-corrosion system.But its poor heat and water resistance limited its application. While silicon resin has excellent hydrophobic, high and low temperature resistance, weather ability and physiological inertness characteristic, and it can be used to modify polyurethane to prepare the resin with excellent performance. Graphene is a new two-dimensional carbon nanomaterials, and its lamellar structure can effectively block the penetration of water and corrosive ions. Its conductive performance is also superior. When corrosion occurs, anodic reaction Fe lost electrons and these electrons can rapidly transfer to the coating surface through it, so that Fe3+ and HO- can be isolated,hindering the corrosion. So adding graphene to the composite coatings can effectively enhance the corrosion resistance.In this research, 2, 4-toluene diisocyanate and polyether glycol are used as the raw material to prepare polyurethane prepolymer. Then it explores the ratio of the n(-NCO)/n(-OH) impacts on the contact angle, hardness, impact resistance, surface morphology and adhesion of the coating. The results show that n(-NCO)/n(-OH) is2:1, and the hydrophobic, impact strength is at the maximum, coating with relatively smooth surface and good adhesion.Dimethyl silicone oil is used to modify polyurethane prepolymer, exploring different amount of silicone oil impacts on the composite coating in contact angle,hardness, impact resistance, surface morphology and adhesion. The results show that dimethicone greatly enhance the hydrophobic properties of the coating, as 6%dimethyl silicone oil was added, the hydrophobic properties, hardness, impact strength of the coating are best. At the same time, dimethyl silicone oil can make up for the defects on the surface of the composite coating.Natural graphite is used as raw material to prepare grahene by thermal reduction, XRD, Raman, SEM. The analysis shows that RGO has layer structure,and some oxygen groups and folds are on the edge of it. RGO is used as pigments to the composite coating, testing basic physical and electrochemical performance of the composite coating that containing different amount of graphene. The results show that as 0.1% RGO was added, the corrosion potential and corrosion current density was-0.9 V and 0.067 μA/cm2, indicating the composite coating has good anticorrosion properties.