Study On Multi-functional Pu Nanocomposite Coating On Aluminum Alloy Surface

For the western development of rail transit construction,not only to consider the southwest area of acid rain cause aluminum alloy corrosion failure,also consider laying in the northwest railway,the land not only high altitude,low ultraviolet altitude on the plateau to affect the rail transit body and rail structure,so develop a corrosion resistance,self-repair,anti bacterial and ultraviolet function together,to solve the western development of aluminum alloy components in the use due to environmental failure is particularly important.Therefore,this paper intends to use polyurethane as a corrosion protective coating base,through the introduction of polyglutamate compound polyurethane obtained self-repair unit,using CVD method on the aluminum alloy surface CNTs adsorption corrosion inhibitor,MOFs antibacterial resistance unit and low surface energy unit on the surface of aluminum alloy,the specific results are as follows.1.Three different MOFs materials,MIL-53(Al),ZIF-8(Zn)and MIL-125(Ti),were successfully prepared by solvent heating method,After optimizing the process,The size of the specific surface area of the three MOFs materials prepared are: ZIF-8(Zn)> MIL-53(Al)> MIL-125(Ti),The specific surface area of ZIF-8(Zn)is 1241 m~2/g;All three MOFs have horseradase-like activity and antibacterial,The static properties are highly correlated with horseradase viability,Its size: ZIF-8(Zn)>MIL-53(Al)> MIL-125(Ti),The enzyme vitality of ZIF-8(Zn)was up to 1.56 U / mg after 60 min of the reaction,The antibacterial rate is up to 95%;All three MOFs can serve as nanocontainers for corrosion inhibitors,Among them,MIL-53(Al)and ZIF-8(Zn)are significantly better effective than MIL-125(Ti),Its corrosion inhibitor encapsulation rate is IP6> BTA> GA,ZIF-8(Zn)sealing rate of IP6 is as high as 91%,And medium MIL-53(Al)and ZIF-8(Zn)showed an enhanced significant absorption of UV light significance after loading with IP6.2.CNTs protective coating was successfully grown in situ by CVD method,By optimizing its preparation process,Even CNTs protective coating was grown at 600℃for 60 min(average pipe diameter: 30.22±1.1 nm);Using BTA and GA as corrosion inhibitors,Loaded with a CNTs coating on the aluminum alloy surface,The results showed a loading rate of up to 90%;In the simulation solution,Test the corrosive coating,The corrosion properties of the coating was studied by electrochemical AC impedance and SEM,The results indicate that BTA@CNT> GA@CNT,BTA with the corrosion medium increases the impedance radius of the aluminum alloy surface by three orders of magnitude.3.Polyurethane is used as the substrate of corrosion protection coating,and polyglutamate,BTA@CNTs,IP6@MOFs are introduced into the polyurethane network system to prepare the nanocomposite coating with self-repair,anti-UV,antibacterial and anti-corrosion.The results showed that MFPU coating showed moderate sensitivity to Gram-positive bacteria,with self-repair in 4 hours under natural conditions and more than 98% of the original sample after more than 7 cycles.MFPU coating showed 20 times more protection than pure PU after 240 hours in simulated acid rain solution,increasing the failure time to more than 30 days;and its nanocoating surface can reach super hydrophobic after grafting low surface energy material.