Study On Wind And Sand Erosion Resistance Of Modified Graphene Oxide/Polyurethane Coating

As one of the main structural forms,steel structure is used more and more widely.Deserts in Inner Mongolia are widely distributed,with strong UV radiation intensity and long time.Steel structure buildings and facilities built in the desert and surrounding areas have been exposed to wind and sand erosion and UV radiation for a long time,resulting in corrosion and aging damage to the protective coating on the surface of steel structures.Finally,the steel substrate is exposed and corroded,which causes a safety hazard to the steel structure and seriously reduces its service life.This article is aimed at steel structure polyurethane(PU)coatings.The excellent mechanical properties of graphene oxide(GO)are used to modify steel structure polyurethane coatings.Modified graphite oxide is used to improve the protective performance of steel structure coatings through modification.Olefin / polyurethane(FGO / PU)composite coatings,and its anti-sand erosion resistance and anti-erosion resistance after aging under ultraviolet radiation were studied.The subject is subject to the National Natural Science Foundation project "Research on Mechanical Behavior and Damage Evaluation of Steel Structure Coatings in Windy Sand Environment"(Grant No.11162011);"(Grant No.11862022);Inner Mongolia Autonomous Region Natural Science Fund Project(2018MS05047);Inner Mongolia Autonomous Region Grassland Talents Funding Project;Inner Mongolia University Young Technology Talent Support Program(NJYT-17-A09)The research content of the subject is as follows:1.Modified graphene oxide / polyurethane composite coatings with uniform dispersion and different contents(0 wt.%,0.5 wt.%,1.0 wt.% And 2.0 wt.%)Were prepared through chemical modification and physical dispersion Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD),Raman spectroscopy,and scanning electron microscopy(SEM)were used to analyze the functional groups and crystal structures of graphene oxide before and after modification,and the content of different fillers.The cross-section morphology of the coating was analyzed.The results show that the modification treatment can make graphene oxide be well dispersed in the polyurethane coating,and when the filler content is 2.0 wt.%,A large number of modified graphene oxide aggregates appear in the coating.2.The hardness,flexibility and other mechanical properties of modified graphene oxide / polyurethane composite coatings with different filler contents were measured.The test results showed that the hardness of polyurethane composite coatings with modified graphene oxide with good dispersibility increased.When the modified graphene oxide content is 0.5 wt.%,The hardness and flexibility of the composite coating are the best.When the modified graphene oxide content is 2.0 wt.%,The hardness and flexibility of the coating are lower than those of ordinary polyurethane coatings.When the content is further increased,the modified graphene oxide in the coating tends to saturate,and agglomeration begins to occur,resulting in the coating's mechanical properties gradually decreasing.3.Simulated aeolian sand erosion tests were performed on ordinary polyurethane coatings and modified graphene oxide / polyurethane composite coatings,and the damage morphology of modified graphene oxide / polyurethane composite coatings after aeolian sand erosion was analyzed by SEM.And damage mechanisms.The results show that graphene oxide has better dispersibility in the coating and better compatibility with the substrate,which enhances the mechanical properties and wear resistance of the coating,and significantly enhances the erosion resistance of the coating.The average erosion rate decreased by 43.52%;the coatings with different angle erosion will have more obvious damage morphology and different damage mechanisms.4.Simulated UV aging experiments were performed on ordinary polyurethane coatings and modified graphene oxide / polyurethane composite coatings to analyze the effects of UV aging on the chemical structure and constituent elements of polyurethane,and the effects of UV aging on the mechanical properties of coatings.And simulated sand erosion tests were performed on coatings with different UV aging durations.The results show that after simulated three years of UV aging,the erosion rate of the modified graphene oxide / polyurethane composite coating is 58.05% lower than that of ordinary polyurethane coatings.The erosion resistance of the modified graphene oxide coating after UV aging was also significantly enhanced.