| Because of its excellent performance,coil steel is widely used in the field of household appliances and outdoor buildings.The coatings used on the surface are mainly traditional polyester and epoxy coatings,which contain a large number of toxic organic volatile solvents,causing great harm to the environment and people’s health.With the development of waterborne chemical technology,waterborne coating has become the mainstream of the market,non-toxic,environmental protection,non-flammable and other advantages so that it has a great prospect for development.However,water-based coatings still have some difficulties to overcome with water as dispersant,such as anti-adhesion phenomenon of hydrophilic coating,lack of anti-corrosion performance and longer drying time.(1)In view of the weak anti-corrosion performance of water-based coating for steel coils,functional graphene and zinc phosphate composite materials were prepared by one-step precipitation method with anticorrosive filler as the starting point.Graphene oxide,sulfonated graphene and zinc phosphate crystal composites were respectively used to prepare the composite materials.By infrared spectroscopy,X-ray photoelectron spectroscopy and X-ray diffraction analysis to determine the success of the zinc phosphate crystals in composite materials synthesis,by scanning electron microscope(sem)and transmission electron microscopy(tem)analysis found that graphene oxide/zinc phosphate composite sandwich"sandwich"structure,sulfonated graphene/zinc phosphate composite material is uniform spherical structure.(2)The subject is to prepare coil waterborne coatings for the corrosion caused by defects in the process of coil steel,and the paint film falling off.The inorganic silicon-titanium nanoparticles modified acrylic hyperbranched resin is the main film-forming material,supplemented by The adipic acid dihydrazide crosslinker was added and the functional graphene/zinc phosphate composite was added.Electrochemical impedance spectroscopy(EIS)test results show that the corrosion resistance of composites is higher than that of single fillers.The corrosion resistance of sulfonated graphene/zinc phosphate materials is better than that of graphene oxide/phosphoric acid.Zinc composites.When the sulfonated graphene/zinc phosphate composite with 5wt%content is added,the corrosion resistance of the coating is obviously improved,and the corrosion current density of the coating is reduced from 10.37μA/cm~2(without adding anti-corrosion filler)to 0.4252μA/cm~2(sulfonation).Graphene/zinc phosphate composite coating),the charge transfer resistance(Rct)of the coating increased from 820.2Ωcm~2(without added anti-corrosion filler)to 15610Ωcm~2(sulfonated graphene/zinc phosphate composite coating)The corrosion resistance of the coating is significantly improved.(3)In order to solve the problem of long drying time of waterborne coatings in baking and drying mode,a silicone waterborne coating containing inorganic aluminum sol nanoparticles was prepared as a coiled steel topcoat with methyltrimethoxysilane andγ-shrinkage.Glyceroloxypropyltrimethoxysilane is the main film-forming material and explores the feasibility of the coating to achieve rapid drying.After the paint is dried,it has excellent hardness,water resistance and T-bend performance.The subject adopts a mixed drying method,preheating by baking high temperature,and then using electromagnetic waves to pass through the metal substrate to generate powerful Joule heat at the bottom,so that the coating can be applied.Fast drying is achieved. |
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