A corrosion-resistant stainless steel pipe and its preparation method, and its application in marine engineering

Abstract

The invention discloses a corrosion-resistant stainless steel pipe and a preparation method thereof, and application of the pipe in marine engineering, and belongs to the technical field of stainless steel materials, and is used to solve the technical problem that the corrosion resistance and antifouling performance of stainless steel in the prior art need to be improved; wherein the preparation method of the corrosion-resistant stainless steel pipe comprises: adding epoxy-modified titanium dioxide and 2-aminoethyl methacrylate to anhydrous ethanol, stirring, adding hydrochloric acid aqueous solution, heating, reacting, and obtaining modified titanium dioxide; adding epoxy-modified carbon quantum dots and modified titanium dioxide to the hydrochloric acid aqueous solution, heating, reacting, and ending the reaction, filtering, washing, and drying to obtain epoxy-modified carbon quantum dot grafted modified titanium dioxide; the corrosion-resistant stainless steel pipe prepared by the invention not only has good corrosion resistance and antifouling performance, meets the application of the pipe in marine engineering, but also has good weather resistance and durability, is conducive to prolonging the service life, and reduces the cost of later maintenance.

Description

Technical Field

[0001] The invention relates to the technical field of stainless steel materials, and in particular to a corrosion-resistant stainless steel pipe and a preparation method thereof, and applications thereof in marine engineering. Background Art

[0002] Stainless steel is one of the metal materials and plays an important role in marine engineering. It is widely used in ships, offshore platforms, port facilities and marine renewable energy devices. With people's exploration of the ocean, the working environment of stainless steel is becoming more and more harsh. Biofouling and corrosion can damage marine facilities. Among them, biofouling can promote corrosion, mainly because the formation of biofouling will form a protective film on the surface of the material. This film may cause local hypoxia or other changes in the chemical environment, thereby accelerating the corrosion process. People generally use coatings on the surface of stainless steel to increase corrosion resistance, reduce the frequency of regular maintenance and repair, and reduce costs. In the marine environment, chloride ions can easily cause stress corrosion cracking of stainless steel, especially when stainless steel is under high stress. As the cracks develop, it will cause brittle fracture of the structure, seriously affecting safety. Marine organisms (such as algae, shellfish, etc.) are easily attached to the surface of stainless steel in the marine environment, which may affect its durability and structural performance, and biofouling may also lead to increased water resistance and reduced energy efficiency.

[0003] Chinese patent CN112501668B discloses a method for treating the surface of stainless steel with high adhesion to a coating, comprising removing a passivation film on the surface of the stainless steel by pickling; sandblasting the stainless steel surface with a non-metallic abrasive to achieve a Sa2-Sa2.5 grade; inhibiting the passivation of the stainless steel surface with a cathode microcurrent; coating; forming a passivation layer on the uncoated side of the stainless steel with a microcurrent; and improving the adhesion of the coating on the surface of the stainless steel after the surface treatment by this method. This method has high technical requirements for operators, especially in the process of microcurrent adjustment and sandblasting, the accuracy and consistency of the equipment must be ensured. Chinese patent CN104277664B discloses a marine anticorrosive coating, wherein the marine anticorrosive coating is composed of waterborne epoxy resin emulsion, waterborne polyurethane, modified asphalt, waterborne epoxy curing agent, modified nano titanium dioxide, modified carbon nanotubes, red iron oxide, zinc powder, fiber fluff, chitosan, film-forming aid, defoamer, wetting agent, dispersant, leveling agent, thickener and water in a mass ratio of 100:(5-16):(1-2.5):(5-10):(10-30):(5-16):(5-15):(3-5):(2-15):

[0004] (0.9-2.5):(3-8):(0.5-1.3):(0.3-1.5):(0.6-1.5):(0.5-1.6):(0.2-0.8):(5-15) are mixed and prepared. The anti-corrosion performance of the marine anti-corrosion coating prepared by this invention needs to be further improved, and it does not have good anti-fouling performance, which slows down the failure time of stainless steel pipes in marine engineering. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a corrosion-resistant stainless steel pipe and a preparation method thereof, and application in marine engineering, which solves the problem that the corrosion resistance and anti-fouling performance of the stainless steel pipe need to be further improved; the preparation method of the corrosion-resistant stainless steel pipe proposed in the present invention has the characteristics of simple operation and reduced cost. The prepared stainless steel pipe meets the application requirements in marine engineering, delays the damage time of stainless steel, and is beneficial to the service life.

[0006] In order to achieve the above object, the present invention provides a method for preparing a corrosion-resistant stainless steel pipe, comprising the following steps:

[0007] The surface of the stainless steel pipe material is polished with sandpaper, immersed in a passivation solution, heated and passivated, and after the passivation is completed, taken out and dried to obtain a preliminarily treated stainless steel pipe; epoxy resin is used as a primer, applied to the surface of the preliminarily treated stainless steel pipe, and cured to obtain a stainless steel pipe with a primer; modified polyurethane is applied to the surface of the stainless steel pipe with a primer, and cured to obtain a corrosion-resistant stainless steel pipe;

[0008] Wherein, the preparation method of modified polyurethane comprises the following steps:

[0009] In a nitrogen atmosphere, polyether polyol and isophorone diisocyanate are mixed, heated and kept warm, 2,2-dihydroxymethyl propionic acid, propylene glycol, TMP and dibutyl dilauryl tin are added and kept warm to obtain a polyurethane prepolymer; the temperature is lowered, epoxy-modified carbon quantum dots are added to graft-modified titanium dioxide, react and keep warm; the temperature is lowered, ethylenediamine is added, reacted, and the reaction is terminated; water is added, stirred at a high speed, and distilled under reduced pressure to obtain a polyurethane aqueous dispersion containing unsaturated double bonds;

[0010] The polyurethane aqueous dispersion containing unsaturated double bonds is mixed with methyl methacrylate, trifluoroethyl methacrylate and diacetone acrylamide, heated, an initiator is added, reacted, the pH is adjusted, adipic acid dihydrazide is added, mixed evenly, and distilled under reduced pressure to obtain a modified polyurethane;

[0011] The preparation method of epoxy-modified carbon quantum dots grafted modified titanium dioxide comprises the following steps:

[0012] Step (1) adding epoxy-modified titanium dioxide and 2-aminoethyl methacrylate to anhydrous ethanol, stirring, adding hydrochloric acid aqueous solution, heating, reacting, filtering, washing, and drying after the reaction is completed to obtain modified titanium dioxide;

[0013] Step (2) mixing carbon quantum dots, anhydrous ethanol and γ-(2,3-epoxypropoxy)propyltrimethoxysilane uniformly, heating, reacting, centrifuging, washing and drying after the reaction is completed to obtain epoxy-modified carbon quantum dots;

[0014] Step (3) adding epoxy-modified carbon quantum dots and modified titanium dioxide into a hydrochloric acid aqueous solution, heating, reacting, filtering, washing, and drying after the reaction is completed to obtain epoxy-modified carbon quantum dots grafted modified titanium dioxide.

[0015] Preferably, in the passivation solution, the mass ratio of sodium molybdate, phosphoric acid, ethanol and deionized water is (18-26):(5-8):(30-50):(24-32); the passivation temperature is 50-60°C, and the time is 2-4 min.

[0016] Preferably, the coating amount of epoxy resin is 200g / m 2 .

[0017] Preferably, the preparation method of epoxy-modified titanium dioxide comprises the following steps:

[0018] Titanium dioxide, anhydrous ethanol and γ-(2,3-epoxypropoxy)propyltrimethoxysilane are uniformly mixed, heated, reacted, centrifuged, washed and dried to obtain epoxy-modified titanium dioxide;

[0019] Wherein, the mass ratio of titanium dioxide, anhydrous ethanol and γ-(2,3-epoxypropoxy)propyltrimethoxysilane is 40:(2000-4000):(8-12);

[0020] The reaction temperature is 65-85°C and the reaction time is 3-5h.

[0021] Preferably, the epoxy resin primer curing conditions are: curing at 90-95° C. for 50-70 min.

[0022] Preferably, the mass ratio of polyether polyol, isophorone diisocyanate, 2,2-dimethylolpropionic acid, propylene glycol, TMP, dibutyl dilauryl tin, epoxy-modified carbon quantum dot grafted modified titanium dioxide, ethylenediamine and water is 1000:(240-440):(10-30):(10-30):(4-8):(0.5-1):(12-20):(6-10):(1500-2500).

[0023] Preferably, the mass ratio of the polyurethane aqueous dispersion containing unsaturated double bonds, methyl methacrylate, trifluoroethyl methacrylate, diacetone acrylamide, initiator and adipic acid dihydrazide is (40-60):(30-50):(8-20):(1-5):(0.1-1.3):(5-9); the reaction conditions are: react at a temperature of 75-85°C for 10-18h.

[0024] Preferably, the pH is adjusted to a range of 7-8.

[0025] Preferably, in the preparation process of the polyurethane aqueous dispersion containing unsaturated double bonds, the first heating temperature is 75-85°C, and the reaction time is 1.8-2.2h; the first cooling temperature is 65-75°C, and the reaction time is 2.8-3.2h; the second cooling temperature is 25-35°C, and the reaction time is 20-40min.

[0026] Preferably, the initiator is AIBN.

[0027] Preferably, the mass ratio of epoxy-modified titanium dioxide, 2-aminoethyl methacrylate, anhydrous ethanol and hydrochloric acid aqueous solution is (30-50):(180-300):(2000-4000):(10-18); the reaction temperature is 55-75°C, and the reaction time is 5-9h.

[0028] Preferably, the mass ratio of carbon quantum dots, anhydrous ethanol and γ-(2,3-epoxypropoxy)propyltrimethoxysilane is (30-40):(2000-4000):(7-9); the reaction temperature is: 65-85°C, and the reaction time is 4-6h.

[0029] Preferably, the mass ratio of epoxy-modified carbon quantum dots, modified titanium dioxide and hydrochloric acid aqueous solution is 60:(400-800):(1500-3500); the reaction temperature is: 70-90°C, the reaction time is 2-4h; and the concentration of the hydrochloric acid aqueous solution is 0.01mol / L.

[0030] Preferably, the corrosion-resistant stainless steel pipe is prepared by the method for preparing the corrosion-resistant stainless steel pipe.

[0031] Preferably, the corrosion-resistant stainless steel pipe is used in marine engineering.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The titanium dioxide in the present invention is a heat-resistant inorganic material with certain UV resistance. Its UV resistance principle is mainly to achieve UV resistance by absorbing ultraviolet rays and converting them into heat energy, or by scattering ultraviolet rays; titanium dioxide also has antibacterial properties, especially under ultraviolet irradiation, the surface of titanium dioxide can produce redox reactions and generate free radicals, which have a bactericidal effect; in the marine environment, it can effectively reduce the attachment of plankton and reduce the fouling of the later coating. The modified titanium dioxide has improved dispersibility and compatibility; added to the matrix, the mechanical properties can be appropriately increased. The introduced carbon quantum dots are a fluorescent material with good antibacterial properties, optical properties, biocompatibility and other advantages. It has highly stable dispersibility and good film-forming properties in water, and can be used as a corrosion inhibitor to play a good corrosion resistance. It can form a dense adsorption film on the surface of metal materials through physical adsorption and chemical adsorption to inhibit corrosion. The epoxy group in the epoxy-modified titanium dioxide undergoes a ring-opening reaction with the amino group in 2-aminoethyl methacrylate to obtain a modified titanium dioxide containing an imine group (-NH-), a hydroxyl group and an olefin group; the imine group (-NH-) in the modified titanium dioxide reacts with the epoxy group in the epoxy-modified carbon quantum dots to obtain epoxy-modified carbon quantum dot-grafted modified titanium dioxide; the two together promote corrosion resistance and antifouling properties.

[0034] In the present invention, the epoxy-modified carbon quantum dot grafted modified titanium dioxide reacts with the isocyanate group in the polyurethane prepolymer through the hydroxyl group it contains, and is embedded in the chain in the polyurethane aqueous dispersion containing unsaturated double bonds to increase its compatibility; the polyurethane aqueous dispersion containing unsaturated double bonds and trifluoroethyl methacrylate generate a modified polyurethane containing fluorine under the action of an initiator, so that the fluorine-containing chain segment migrates to the surface of the film and is enriched on the surface of the film. The electronegativity of the fluorine atom is relatively large, which increases water resistance, thereby improving corrosion resistance, and is not conducive to biological adhesion in the ocean, which helps to improve antifouling performance; at the same time, the CF bond in the modified polyurethane has high strength and large bond energy. When used in marine engineering, the energy of ultraviolet light is not enough to destroy the CF bond, which increases weather resistance, helps to extend the service life, and protects the safety of marine steel pipes. A strong hydrogen bond network structure is formed inside the modified polyurethane, which can prevent water penetration, thereby improving its effectiveness as an anti-corrosion coating.

[0035] The present invention provides a method for preparing a corrosion-resistant stainless steel pipe, wherein the stainless steel surface is polished, the surface is roughened, and better adhesion is provided; the passivation film formed by passivation can effectively block the corrosion of the metal surface by external harmful substances (such as oxygen, chloride, etc.), and improve the stability of stainless steel in acidic or corrosive environments; the primer (epoxy resin) provides additional anti-corrosion protection to prevent moisture, oxygen and other corrosive substances from penetrating into the stainless steel surface, and its high adhesion ensures the strong bonding between the coating and the substrate, which helps to improve the corrosion resistance of the entire coating; the modified polyurethane is applied on the primer to form a multi-level coating system, which gradually enhances the anti-corrosion, weathering, anti-fouling and mechanical properties of the stainless steel pipe; the corrosion-resistant stainless steel pipe obtained by the present invention is suitable for special environments, especially applications in marine engineering. At the same time, the carbon quantum dots added by the present invention can emit fluorescence under the excitation of ultraviolet light or visible light, and when the coating is damaged (such as cracks or peeling), the fluorescence characteristics may change, which makes it possible to visually detect the integrity of the coating, repair the coating in time, and reduce maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a process flow chart for preparing the corrosion-resistant stainless steel pipe of the present invention;

[0037] Figure 2 The present invention is a process flow chart for preparing the modified polyurethane;

[0038] Figure 3 The figure is a process flow chart of the preparation of epoxy-modified carbon quantum dots grafted modified titanium dioxide in the present invention;

[0039] Figure 4 The schematic diagram of the reaction for preparing modified titanium dioxide in the present invention. DETAILED DESCRIPTION

[0040] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Example 1

[0042] This embodiment provides a method for preparing a corrosion-resistant stainless steel pipe, comprising the following steps:

[0043] The surface of the stainless steel pipe material was polished with sandpaper, immersed in the passivation solution, passivated at 50°C for 4 minutes, taken out, and dried to obtain a preliminarily treated stainless steel pipe; the epoxy resin was coated at a coating amount of 200g / m 2Apply the modified polyurethane to the surface of the stainless steel pipe with primer, and cure it at 90°C for 70 minutes to obtain a stainless steel pipe with primer; apply the modified polyurethane to the surface of the stainless steel pipe with primer, and cure it at 80°C for 180 minutes to obtain a corrosion-resistant stainless steel pipe with a coating thickness of 70 μm;

[0044] The mass ratio of sodium molybdate, phosphoric acid, ethanol and deionized water in the passivation solution is 18:5:30:24;

[0045] Wherein, the preparation method of modified polyurethane comprises the following steps:

[0046] In a nitrogen atmosphere, polytetramethylene glycol and isophorone diisocyanate were mixed, reacted at 75°C for 2.2 hours, 2,2-dihydroxymethyl propionic acid, propylene glycol, TMP and dibutyl dilauryl tin were added and kept warm for 2 hours to obtain a polyurethane prepolymer; epoxy-modified carbon quantum dots were added to graft-modified titanium dioxide, and reacted at 65°C for 3.2 hours; ethylenediamine was added, and reacted at 25°C for 40 minutes, and the reaction was completed; water was added, stirred at a speed of 4000r / min for 20 minutes, and vacuum distilled at 0.08MPa and 60°C for 4 hours to obtain a polyurethane aqueous dispersion containing unsaturated double bonds;

[0047] The mass ratio of polytetramethylene glycol, isophorone diisocyanate, 2,2-dimethylol propionic acid, propylene glycol, TMP, dibutyl dilauryl tin, epoxy-modified carbon quantum dots grafted modified titanium dioxide, ethylenediamine and water is 1000:240:10:10:4:0.5:12:6:1500;

[0048] The polyurethane aqueous dispersion containing unsaturated double bonds was mixed with methyl methacrylate, trifluoroethyl methacrylate and diacetone acrylamide, and AIBN was added, and the mixture was reacted at 75°C for 18 hours. After the reaction was completed, the pH was adjusted to 7, adipic acid dihydrazide was added, the mixture was mixed evenly, and the mixture was subjected to reduced pressure distillation at 0.08 MPa and 80°C for 12 hours to obtain a modified polyurethane.

[0049] The mass ratio of the polyurethane aqueous dispersion containing unsaturated double bonds, methyl methacrylate, trifluoroethyl methacrylate, diacetone acrylamide, AIBN and adipic acid dihydrazide is 40:30:8:1:0.1:5;

[0050] The preparation method of epoxy-modified carbon quantum dots grafted modified titanium dioxide comprises the following steps:

[0051] Step (1) epoxy-modified titanium dioxide, 2-aminoethyl methacrylate, anhydrous ethanol and 0.1 mol / L hydrochloric acid aqueous solution are mixed in a mass ratio of 30:180:2000:10, reacted at 55° C. for 9 h, filtered, washed, and dried at 80° C. for 6 h to obtain modified titanium dioxide;

[0052] Step (2) mixing carbon quantum dots, anhydrous ethanol and γ-(2,3-epoxypropoxy)propyltrimethoxysilane in a mass ratio of 30:2000:7, reacting at 65°C for 6 hours, centrifuging, washing, and drying at 60°C for 10 hours to obtain epoxy-modified carbon quantum dots;

[0053] Step (3) The epoxy-modified carbon quantum dots, modified titanium dioxide and 0.01 mol / L hydrochloric acid aqueous solution are mixed in a mass ratio of 60:400:1500, reacted at 70°C for 4 hours, filtered, washed with deionized water, and dried at 70°C for 5 hours to obtain epoxy-modified carbon quantum dots grafted with modified titanium dioxide.

[0054] Example 2

[0055] This embodiment provides a method for preparing a corrosion-resistant stainless steel pipe, comprising the following steps:

[0056] The surface of the stainless steel pipe material was polished with sandpaper, immersed in the passivation solution, passivated at 50°C for 4 minutes, taken out, and dried to obtain a preliminarily treated stainless steel pipe; the epoxy resin was coated at a coating amount of 200g / m 2 Apply the modified polyurethane to the surface of the stainless steel pipe with primer, and cure it at 90°C for 70 minutes to obtain a stainless steel pipe with primer; apply the modified polyurethane to the surface of the stainless steel pipe with primer, and cure it at 80°C for 180 minutes to obtain a corrosion-resistant stainless steel pipe with a coating thickness of 70 μm;

[0057] The mass ratio of sodium molybdate, phosphoric acid, ethanol and deionized water in the passivation solution is 20:5.7:35:26;

[0058] Wherein, the preparation method of modified polyurethane comprises the following steps:

[0059] In a nitrogen atmosphere, polytetramethylene glycol and isophorone diisocyanate were mixed, reacted at 77°C for 2.1h, 2,2-dihydroxymethylpropionic acid, propylene glycol, TMP and dibutyl dilauryl tin were added and kept warm for 1.8h to obtain a polyurethane prepolymer; epoxy-modified carbon quantum dots were added to graft-modified titanium dioxide, and reacted at 67°C for 3.1h; ethylenediamine was added, and reacted at 27°C for 35min, and the reaction was completed; water was added, stirred at a speed of 5000r / min for 18min, and vacuum distilled at 0.08MPa and 60°C for 3.5h to obtain a polyurethane aqueous dispersion containing unsaturated double bonds;

[0060] Among them, the mass ratio of polytetramethylene glycol, isophorone diisocyanate, 2,2-dimethylol propionic acid, propylene glycol, TMP, dibutyl dilauryl tin, epoxy-modified carbon quantum dots grafted modified titanium dioxide, ethylenediamine and water is 1000:290:15:15:5:0.6:14:7:1750;

[0061] The polyurethane aqueous dispersion containing unsaturated double bonds was mixed with methyl methacrylate, trifluoroethyl methacrylate and diacetone acrylamide, and AIBN was added, and the mixture was reacted at 77°C for 16 hours. After the reaction was completed, the pH was adjusted to 7, and adipic acid dihydrazide was added, and the mixture was mixed evenly. The mixture was subjected to reduced pressure distillation at 0.08 MPa and 80°C for 11.5 hours to obtain a modified polyurethane.

[0062] The mass ratio of the polyurethane aqueous dispersion containing unsaturated double bonds, methyl methacrylate, trifluoroethyl methacrylate, diacetone acrylamide, AIBN and adipic acid dihydrazide is 45:35:11:2:0.4:6;

[0063] The preparation method of epoxy-modified carbon quantum dots grafted modified titanium dioxide comprises the following steps:

[0064] Step (1) epoxy-modified titanium dioxide, 2-aminoethyl methacrylate, anhydrous ethanol and 0.1 mol / L hydrochloric acid aqueous solution are mixed in a mass ratio of 35:210:2500:12, reacted at 60° C. for 8 h, filtered, washed, and dried at 85° C. for 5.5 h to obtain modified titanium dioxide;

[0065] Step (2) mixing carbon quantum dots, anhydrous ethanol and γ-(2,3-epoxypropoxy)propyltrimethoxysilane in a mass ratio of 32:2500:7.5, reacting at 70°C for 5.5h, centrifuging, washing, and drying at 65°C for 9.5h to obtain epoxy-modified carbon quantum dots;

[0066] Step (3) The epoxy-modified carbon quantum dots, modified titanium dioxide and 0.01 mol / L hydrochloric acid aqueous solution are mixed in a mass ratio of 60:500:2000, reacted at 75°C for 3.5 hours, filtered, washed with deionized water, and dried at 75°C for 4.5 hours to obtain epoxy-modified carbon quantum dots grafted with modified titanium dioxide.

[0067] Example 3

[0068] This embodiment provides a method for preparing a corrosion-resistant stainless steel pipe, comprising the following steps:

[0069] The surface of the stainless steel pipe material was polished with sandpaper, immersed in the passivation solution, passivated at 50°C for 4 minutes, taken out, and dried to obtain a preliminarily treated stainless steel pipe; the epoxy resin was coated at a coating amount of 200g / m 2 Apply the modified polyurethane to the surface of the stainless steel pipe with primer, and cure it at 90°C for 70 minutes to obtain a stainless steel pipe with primer; apply the modified polyurethane to the surface of the stainless steel pipe with primer, and cure it at 80°C for 180 minutes to obtain a corrosion-resistant stainless steel pipe with a coating thickness of 70 μm;

[0070] The mass ratio of sodium molybdate, phosphoric acid, ethanol and deionized water in the passivation solution is 22:6.5:40:28;

[0071] Wherein, the preparation method of modified polyurethane comprises the following steps:

[0072] In a nitrogen atmosphere, polytetramethylene glycol and isophorone diisocyanate were mixed, reacted at 80°C for 2h, 2,2-dihydroxymethyl propionic acid, propylene glycol, TMP and dibutyl dilauryl tin were added and kept warm for 1.5h to obtain a polyurethane prepolymer; epoxy-modified carbon quantum dots were added to graft-modified titanium dioxide, and reacted at 70°C for 3h; ethylenediamine was added, and reacted at 30°C for 30min, and the reaction was completed; water was added, stirred at a speed of 6000r / min for 15min, and vacuum distilled at 0.08MPa and 60°C for 3h to obtain a polyurethane aqueous dispersion containing unsaturated double bonds;

[0073] Among them, the mass ratio of polytetramethylene glycol, isophorone diisocyanate, 2,2-dimethylol propionic acid, propylene glycol, TMP, dibutyl dilauryl tin, epoxy-modified carbon quantum dots grafted modified titanium dioxide, ethylenediamine and water is 1000:340:20:20:6:0.8:16:8:2000;

[0074] The polyurethane aqueous dispersion containing unsaturated double bonds was mixed with methyl methacrylate, trifluoroethyl methacrylate and diacetone acrylamide, and AIBN was added, and the mixture was reacted at 80°C for 14 hours. After the reaction was completed, the pH was adjusted to 8, adipic acid dihydrazide was added, the mixture was mixed evenly, and the mixture was subjected to reduced pressure distillation at 0.08 MPa and 80°C for 11 hours to obtain a modified polyurethane.

[0075] The mass ratio of the polyurethane aqueous dispersion containing unsaturated double bonds, methyl methacrylate, trifluoroethyl methacrylate, diacetone acrylamide, AIBN and adipic acid dihydrazide is 50:40:14:3:0.7:7;

[0076] The preparation method of epoxy-modified carbon quantum dots grafted modified titanium dioxide comprises the following steps:

[0077] Step (1) epoxy-modified titanium dioxide, 2-aminoethyl methacrylate, anhydrous ethanol and 0.1 mol / L hydrochloric acid aqueous solution are mixed in a mass ratio of 40:240:3000:14, reacted at 65° C. for 7 h, filtered, washed, and dried at 90° C. for 5 h to obtain modified titanium dioxide;

[0078] Step (2) mixing carbon quantum dots, anhydrous ethanol and γ-(2,3-epoxypropoxy)propyltrimethoxysilane in a mass ratio of 35:3000:8, reacting at 75°C for 5 hours, centrifuging, washing, and drying at 70°C for 9 hours to obtain epoxy-modified carbon quantum dots;

[0079] Step (3) The epoxy-modified carbon quantum dots, modified titanium dioxide and 0.01 mol / L hydrochloric acid aqueous solution are mixed in a mass ratio of 60:600:2500, reacted at 80°C for 3 hours, filtered, washed with deionized water, and dried at 80°C for 4 hours to obtain epoxy-modified carbon quantum dots grafted with modified titanium dioxide.

[0080] Example 4

[0081] This embodiment provides a method for preparing a corrosion-resistant stainless steel pipe, comprising the following steps:

[0082] The surface of the stainless steel pipe material was polished with sandpaper, immersed in the passivation solution, passivated at 50°C for 4 minutes, taken out, and dried to obtain a preliminarily treated stainless steel pipe; the epoxy resin was coated at a coating amount of 200g / m 2 Apply the modified polyurethane to the surface of the stainless steel pipe with primer, and cure it at 90°C for 70 minutes to obtain a stainless steel pipe with primer; apply the modified polyurethane to the surface of the stainless steel pipe with primer, and cure it at 80°C for 180 minutes to obtain a corrosion-resistant stainless steel pipe with a coating thickness of 70 μm;

[0083] The mass ratio of sodium molybdate, phosphoric acid, ethanol and deionized water in the passivation solution is 24:7.3:45:30;

[0084] Wherein, the preparation method of modified polyurethane comprises the following steps:

[0085] In a nitrogen atmosphere, polytetramethylene glycol and isophorone diisocyanate were mixed, reacted at 82°C for 1.9h, 2,2-dihydroxymethylpropionic acid, propylene glycol, TMP and dibutyl dilauryl tin were added and kept warm for 1.3h to obtain a polyurethane prepolymer; epoxy-modified carbon quantum dots were added to graft-modified titanium dioxide, and reacted at 73°C for 2.9h; ethylenediamine was added, and reacted at 33°C for 25min, and the reaction was completed; water was added, stirred at a speed of 7000r / min for 13min, and vacuum distilled at 0.08MPa and 60°C for 2.5h to obtain a polyurethane aqueous dispersion containing unsaturated double bonds;

[0086] Among them, the mass ratio of polytetramethylene glycol, isophorone diisocyanate, 2,2-dimethylol propionic acid, propylene glycol, TMP, dibutyl dilauryl tin, epoxy-modified carbon quantum dots grafted modified titanium dioxide, ethylenediamine and water is 1000:390:25:25:7:0.9:18:9:2250;

[0087] The polyurethane aqueous dispersion containing unsaturated double bonds was mixed with methyl methacrylate, trifluoroethyl methacrylate and diacetone acrylamide, and AIBN was added, and the mixture was reacted at 83°C for 12 hours. After the reaction was completed, the pH was adjusted to 8, adipic acid dihydrazide was added, the mixture was mixed evenly, and the mixture was subjected to reduced pressure distillation at 0.08 MPa and 80°C for 10.5 hours to obtain a modified polyurethane.

[0088] The mass ratio of the polyurethane aqueous dispersion containing unsaturated double bonds, methyl methacrylate, trifluoroethyl methacrylate, diacetone acrylamide, AIBN and adipic acid dihydrazide is 55:45:17:4:1:8;

[0089] The preparation method of epoxy-modified carbon quantum dots grafted modified titanium dioxide comprises the following steps:

[0090] Step (1) epoxy-modified titanium dioxide, 2-aminoethyl methacrylate, anhydrous ethanol and 0.1 mol / L hydrochloric acid aqueous solution are mixed in a mass ratio of 45:270:3500:16, reacted at 70° C. for 6 h, filtered, washed, and dried at 95° C. for 4.5 h to obtain modified titanium dioxide;

[0091] Step (2) mixing carbon quantum dots, anhydrous ethanol and γ-(2,3-epoxypropoxy)propyltrimethoxysilane in a mass ratio of 37:3500:8.5, reacting at 80°C for 4.5h, centrifuging, washing, and drying at 75°C for 8.5h to obtain epoxy-modified carbon quantum dots;

[0092] Step (3) The epoxy-modified carbon quantum dots, modified titanium dioxide and 0.01 mol / L hydrochloric acid aqueous solution are mixed in a mass ratio of 60:700:3000, reacted at 85°C for 2.5 hours, filtered, washed with deionized water, and dried at 85°C for 3.5 hours to obtain epoxy-modified carbon quantum dots grafted with modified titanium dioxide.

[0093] Example 5

[0094] This embodiment provides a method for preparing a corrosion-resistant stainless steel pipe, comprising the following steps:

[0095] The surface of the stainless steel pipe material was polished with sandpaper, immersed in the passivation solution, passivated at 50°C for 4 minutes, taken out, and dried to obtain a preliminarily treated stainless steel pipe; the epoxy resin was coated at a coating amount of 200g / m 2 Apply the modified polyurethane to the surface of the stainless steel pipe with primer, and cure it at 90°C for 70 minutes to obtain a stainless steel pipe with primer; apply the modified polyurethane to the surface of the stainless steel pipe with primer, and cure it at 80°C for 180 minutes to obtain a corrosion-resistant stainless steel pipe with a coating thickness of 70 μm;

[0096] The mass ratio of sodium molybdate, phosphoric acid, ethanol and deionized water in the passivation solution is 26:8:50:32;

[0097] Wherein, the preparation method of modified polyurethane comprises the following steps:

[0098] In a nitrogen atmosphere, polytetramethylene glycol and isophorone diisocyanate were mixed, reacted at 85°C for 1.8 hours, 2,2-dihydroxymethyl propionic acid, propylene glycol, TMP and dibutyl dilauryl tin were added and kept warm for 1 hour to obtain a polyurethane prepolymer; epoxy-modified carbon quantum dots were added to graft-modified titanium dioxide, and reacted at 75°C for 2.8 hours; ethylenediamine was added, and reacted at 35°C for 20 minutes, and the reaction was completed; water was added, stirred at a speed of 8000r / min for 10 minutes, and vacuum distilled at 0.08MPa and 60°C for 2 hours to obtain a polyurethane aqueous dispersion containing unsaturated double bonds;

[0099] The mass ratio of polytetramethylene glycol, isophorone diisocyanate, 2,2-dimethylol propionic acid, propylene glycol, TMP, dibutyl dilauryl tin, epoxy-modified carbon quantum dots grafted modified titanium dioxide, ethylenediamine and water is 1000:440:30:30:8:1:20:10:2500;

[0100] The polyurethane aqueous dispersion containing unsaturated double bonds is mixed with methyl methacrylate, trifluoroethyl methacrylate and diacetone acrylamide, and AIBN is added, and the mixture is reacted at 85°C for 10 hours. After the reaction is completed, the pH is adjusted to 8, adipic acid dihydrazide is added, the mixture is mixed evenly, and the mixture is subjected to reduced pressure distillation at 0.08 MPa and 80°C for 10 hours to obtain a modified polyurethane.

[0101] The mass ratio of the polyurethane aqueous dispersion containing unsaturated double bonds, methyl methacrylate, trifluoroethyl methacrylate, diacetone acrylamide, AIBN and adipic acid dihydrazide is 60:50:20:5:1.3:9;

[0102] The preparation method of epoxy-modified carbon quantum dots grafted modified titanium dioxide comprises the following steps:

[0103] Step (1) epoxy-modified titanium dioxide, 2-aminoethyl methacrylate, anhydrous ethanol and 0.1 mol / L hydrochloric acid aqueous solution are mixed in a mass ratio of 50:300:4000:18, reacted at 75° C. for 5 h, filtered, washed, and dried at 100° C. for 4 h to obtain modified titanium dioxide;

[0104] Step (2) mixing carbon quantum dots, anhydrous ethanol and γ-(2,3-epoxypropoxy)propyltrimethoxysilane in a mass ratio of 40:4000:9, reacting at 85°C for 4 hours, centrifuging, washing, and drying at 80°C for 8 hours to obtain epoxy-modified carbon quantum dots;

[0105] Step (3) The epoxy-modified carbon quantum dots, modified titanium dioxide and 0.01 mol / L hydrochloric acid aqueous solution are mixed in a mass ratio of 60:800:3500, reacted at 90°C for 2 hours, filtered, washed with deionized water, and dried at 90°C for 3 hours to obtain epoxy-modified carbon quantum dots grafted with modified titanium dioxide.

[0106] Example 6

[0107] This embodiment provides a method for preparing epoxy-modified titanium dioxide, comprising the following steps:

[0108] Titanium dioxide, anhydrous ethanol and γ-(2,3-epoxypropoxy)propyltrimethoxysilane were mixed evenly in a mass ratio of 40:4000:12, reacted at 75°C for 4 hours, and after the reaction was completed, centrifuged, washed with deionized water, and dried at 90°C for 5 hours to obtain epoxy-modified titanium dioxide.

[0109] Comparative Example 1

[0110] This comparative example provides a method for preparing a corrosion-resistant stainless steel pipe, comprising the following steps:

[0111] The surface of the stainless steel pipe material was polished with sandpaper to obtain a preliminarily treated stainless steel pipe; the epoxy resin was coated at a coating amount of 200g / m 2 Apply the modified polyurethane to the surface of the stainless steel pipe with primer, and cure it at 90°C for 70 minutes to obtain a stainless steel pipe with primer; apply the modified polyurethane to the surface of the stainless steel pipe with primer, and cure it at 80°C for 180 minutes to obtain a corrosion-resistant stainless steel pipe with a coating thickness of 70 μm;

[0112] Wherein, the preparation method of modified polyurethane comprises the following steps:

[0113] In a nitrogen atmosphere, polytetramethylene glycol and isophorone diisocyanate were mixed, reacted at 75°C for 2.2 hours, 2,2-dihydroxymethyl propionic acid, propylene glycol, TMP and dibutyl dilauryl tin were added and kept warm for 2 hours to obtain a polyurethane prepolymer; epoxy-modified carbon quantum dots were added to graft-modified titanium dioxide, and reacted at 65°C for 3.2 hours; ethylenediamine was added, and reacted at 25°C for 40 minutes, and the reaction was completed; water was added, stirred at a speed of 4000r / min for 20 minutes, and vacuum distilled at 0.08MPa and 60°C for 4 hours to obtain a polyurethane aqueous dispersion containing unsaturated double bonds;

[0114] The mass ratio of polytetramethylene glycol, isophorone diisocyanate, 2,2-dimethylol propionic acid, propylene glycol, TMP, dibutyl dilauryl tin, epoxy-modified carbon quantum dots grafted modified titanium dioxide, ethylenediamine and water is 1000:240:10:10:4:0.5:12:6:1500;

[0115] The polyurethane aqueous dispersion containing unsaturated double bonds was mixed with methyl methacrylate, trifluoroethyl methacrylate and diacetone acrylamide, and AIBN was added, and the mixture was reacted at 75°C for 18 hours. After the reaction was completed, the pH was adjusted to 7, adipic acid dihydrazide was added, the mixture was mixed evenly, and the mixture was subjected to reduced pressure distillation at 0.08 MPa and 80°C for 12 hours to obtain a modified polyurethane.

[0116] The mass ratio of the polyurethane aqueous dispersion containing unsaturated double bonds, methyl methacrylate, trifluoroethyl methacrylate, diacetone acrylamide, AIBN and adipic acid dihydrazide is 40:30:8:1:0.1:5;

[0117] The preparation method of epoxy-modified carbon quantum dots grafted modified titanium dioxide comprises the following steps:

[0118] Step (1) epoxy-modified titanium dioxide, 2-aminoethyl methacrylate, anhydrous ethanol and 0.1 mol / L hydrochloric acid aqueous solution are mixed in a mass ratio of 30:180:2000:10, reacted at 55° C. for 9 h, filtered, washed, and dried at 80° C. for 6 h to obtain modified titanium dioxide;

[0119] Step (2) mixing carbon quantum dots, anhydrous ethanol and γ-(2,3-epoxypropoxy)propyltrimethoxysilane in a mass ratio of 30:2000:7, reacting at 65°C for 6 hours, centrifuging, washing, and drying at 60°C for 10 hours to obtain epoxy-modified carbon quantum dots;

[0120] Step (3) The epoxy-modified carbon quantum dots, modified titanium dioxide and 0.01 mol / L hydrochloric acid aqueous solution are mixed in a mass ratio of 60:400:1500, reacted at 70°C for 4 hours, filtered, washed with deionized water, and dried at 70°C for 5 hours to obtain epoxy-modified carbon quantum dots grafted with modified titanium dioxide.

[0121] Comparative Example 2

[0122] This comparative example provides a method for preparing a corrosion-resistant stainless steel pipe, comprising the following steps:

[0123] The surface of the stainless steel pipe material is polished with sandpaper to obtain a preliminarily treated stainless steel pipe; the epoxy resin is coated at a coating amount of 200g / m 2 Apply the modified polyurethane to the surface of the stainless steel pipe with primer, and cure it at 90°C for 70 minutes to obtain a stainless steel pipe with primer; apply the modified polyurethane to the surface of the stainless steel pipe with primer, and cure it at 80°C for 180 minutes to obtain a corrosion-resistant stainless steel pipe with a coating thickness of 70 μm;

[0124] Wherein, the preparation method of modified polyurethane comprises the following steps:

[0125] In a nitrogen atmosphere, polytetramethylene glycol and isophorone diisocyanate were mixed, reacted at 75°C for 2.2 hours, 2,2-dihydroxymethyl propionic acid, propylene glycol, TMP and dibutyl dilauryl tin were added and kept warm for 2 hours to obtain a polyurethane prepolymer; epoxy-modified carbon quantum dots were added to graft-modified titanium dioxide, and reacted at 65°C for 3.2 hours; ethylenediamine was added, and reacted at 25°C for 40 minutes, and the reaction was completed; water was added, stirred at a speed of 4000r / min for 20 minutes, and vacuum distilled at 0.08MPa and 60°C for 4 hours to obtain a modified polyurethane;

[0126] The mass ratio of polytetramethylene glycol, isophorone diisocyanate, 2,2-dimethylol propionic acid, propylene glycol, TMP, dibutyl dilauryl tin, epoxy-modified carbon quantum dots grafted modified titanium dioxide, ethylenediamine and water is 1000:240:10:10:4:0.5:12:6:1500;

[0127] The preparation method of epoxy-modified carbon quantum dots grafted modified titanium dioxide comprises the following steps:

[0128] Step (1) epoxy-modified titanium dioxide, 2-aminoethyl methacrylate, anhydrous ethanol and 0.1 mol / L hydrochloric acid aqueous solution are mixed in a mass ratio of 30:180:2000:10, reacted at 55° C. for 9 h, filtered, washed, and dried at 80° C. for 6 h to obtain modified titanium dioxide;

[0129] Step (2) mixing carbon quantum dots, anhydrous ethanol and γ-(2,3-epoxypropoxy)propyltrimethoxysilane in a mass ratio of 30:2000:7, reacting at 65°C for 6 hours, centrifuging, washing, and drying at 60°C for 10 hours to obtain epoxy-modified carbon quantum dots;

[0130] Step (3) The epoxy-modified carbon quantum dots, modified titanium dioxide and 0.01 mol / L hydrochloric acid aqueous solution are mixed in a mass ratio of 60:400:1500, reacted at 70°C for 4 hours, filtered, washed with deionized water, and dried at 70°C for 5 hours to obtain epoxy-modified carbon quantum dots grafted with modified titanium dioxide.

[0131] Comparative Example 3

[0132] This comparative example provides a method for preparing a corrosion-resistant stainless steel pipe, comprising the following steps:

[0133] The surface of the stainless steel pipe material was polished with sandpaper to obtain a preliminarily treated stainless steel pipe; the epoxy resin was coated at a coating amount of 200g / m 2Apply the modified polyurethane to the surface of the stainless steel pipe with primer, and cure it at 90°C for 70 minutes to obtain a stainless steel pipe with primer; apply the modified polyurethane to the surface of the stainless steel pipe with primer, and cure it at 80°C for 180 minutes to obtain a corrosion-resistant stainless steel pipe with a coating thickness of 70 μm;

[0134] Wherein, the preparation method of modified polyurethane comprises the following steps:

[0135] In a nitrogen atmosphere, polytetramethylene glycol and isophorone diisocyanate were mixed, reacted at 75°C for 2.2 hours, 2,2-dihydroxymethyl propionic acid, propylene glycol, TMP and dibutyl dilauryl tin were added and kept warm for 2 hours to obtain a polyurethane prepolymer; modified titanium dioxide was added and reacted at 65°C for 3.2 hours; ethylenediamine was added and reacted at 25°C for 40 minutes, and the reaction was completed; water was added and stirred at a speed of 4000r / min for 20 minutes, and vacuum distilled at 0.08MPa and 60°C for 4 hours to obtain a modified polyurethane;

[0136] The mass ratio of polytetramethylene ether glycol, isophorone diisocyanate, 2,2-dimethylol propionic acid, propylene glycol, TMP, dibutyl dilauryl tin, modified titanium dioxide, ethylenediamine and water is 1000:240:10:10:4:0.5:12:6:1500;

[0137] The preparation method of modified titanium dioxide comprises the following steps:

[0138] Epoxy-modified titanium dioxide, 2-aminoethyl methacrylate, anhydrous ethanol and 0.1 mol / L hydrochloric acid aqueous solution were mixed in a mass ratio of 30:180:2000:10, reacted at 55°C for 9 hours, filtered, washed, and dried at 80°C for 6 hours to obtain modified titanium dioxide.

[0139] The epoxy-modified titanium dioxide in Examples 1-5 and Comparative Examples 1-3 all adopts the epoxy-modified titanium dioxide prepared in Example 6.

[0140] In each embodiment and comparative example of the present invention, the epoxy resin comes from Wuxi Qianguang Chemical Raw Materials Co., Ltd., model: bisphenol A epoxy resin E51; polytetramethylene ether glycol comes from Shanghai McLean Biochemical Technology Co., Ltd., PTMG2000; sodium molybdate comes from Suzhou Shangrun Chemical Co., Ltd., content: 99%; carbon quantum dots come from Guangdong Fangxin Biotechnology Co., Ltd.; titanium dioxide is purchased from Xuancheng Jingrui New Materials Co., Ltd., model JR05, with an average particle size of 5 nm; trifluoroethyl methacrylate comes from Weihai Xinyuan Chemical Co., Ltd.

[0141] The preparation methods of the corrosion-resistant stainless steel pipes prepared in Examples 1-5 and Comparative Examples 1-3 were tested accordingly.

[0142] (1) Anticorrosion test: The salt spray resistance for 480 h and the salt spray resistance for 1000 h were tested according to the standard GB / T1771-2007, as shown in Table 1;

[0143] (2) Antifouling test: The test was conducted in accordance with GB / T 5370-2007, with a test period of 12 months. The biofouling on the hanging board was observed and the biofouling area was recorded, as shown in Table 1.

[0144] Table 1

[0145]

[0146]

[0147] According to the test results in Table 1, it can be seen that the corrosion-resistant stainless steel pipes prepared in Examples 1-5 have good corrosion resistance and antifouling properties, which are beneficial to their application in marine engineering. Epoxy-modified titanium dioxide has good antibacterial properties, and its dispersibility is better than titanium dioxide, which increases the compatibility with the matrix material and is beneficial to antifouling properties. The introduced fluorine atoms have large electronegativity, and as the fluorine content enriched on the surface of the film increases, the surface energy is lower, the water contact angle is higher, it has certain water resistance, and is not conducive to biological adhesion in the ocean, which helps to improve the antifouling performance. Compared with Example 1, the surface of the stainless steel pipe in Comparative Example 1 lacks a passivation layer, and its corrosion resistance is reduced; Comparative Example 2 lacks trifluoroethyl methacrylate and fluorine atoms compared to Comparative Example 1, so the corrosion resistance and antifouling properties of Comparative Example 2 are lower than those of Comparative Example 1; Comparative Example 3 lacks carbon quantum dots as corrosion inhibitors compared to Comparative Example 2, and its corrosion resistance is reduced, and there is no carbon quantum dots to cooperate with titanium dioxide for antibacterial, so its antifouling performance is naturally reduced.

[0148] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that all equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A method for preparing a corrosion-resistant stainless steel pipe, characterized in that: The following steps are involved: Use sandpaper to polish the surface of the stainless steel pipe material, immerse it in the passivation solution, heat and passivate it, take it out after the passivation is completed, dry it, and obtain the preliminarily treated stainless steel pipe; Applying epoxy resin as a primer to the surface of the preliminarily treated stainless steel pipe and curing it to obtain a stainless steel pipe with a primer; applying modified polyurethane to the surface of the stainless steel pipe with a primer and curing it to obtain a corrosion-resistant stainless steel pipe; Wherein, the preparation method of modified polyurethane comprises the following steps: In a nitrogen atmosphere, polyether polyol and isophorone diisocyanate are mixed, heated and kept warm, 2,2-dihydroxymethyl propionic acid, propylene glycol, TMP and dibutyl dilauryl tin are added and kept warm to obtain a polyurethane prepolymer; the temperature is lowered, epoxy-modified carbon quantum dots are added to graft-modified titanium dioxide, react and keep warm; the temperature is lowered, ethylenediamine is added, reacted, and the reaction is terminated; water is added, stirred at a high speed, and distilled under reduced pressure to obtain a polyurethane aqueous dispersion containing unsaturated double bonds; The polyurethane aqueous dispersion containing unsaturated double bonds is mixed with methyl methacrylate, trifluoroethyl methacrylate and diacetone acrylamide, heated, an initiator is added, reacted, the pH is adjusted, adipic acid dihydrazide is added, mixed evenly, and distilled under reduced pressure to obtain a modified polyurethane; The preparation method of epoxy-modified carbon quantum dots grafted modified titanium dioxide comprises the following steps: Step (1) adding epoxy-modified titanium dioxide and 2-aminoethyl methacrylate to anhydrous ethanol, stirring, adding hydrochloric acid aqueous solution, heating, reacting, filtering, washing, and drying after the reaction is completed to obtain modified titanium dioxide; Step (2) uniformly mixing carbon quantum dots, anhydrous ethanol and γ-(2,3-epoxypropoxy)propyltrimethoxysilane, heating, reacting, centrifuging, washing and drying to obtain epoxy-modified carbon quantum dots; Step (3) adding epoxy-modified carbon quantum dots and modified titanium dioxide into a hydrochloric acid aqueous solution, heating, reacting, filtering, washing, and drying to obtain epoxy-modified carbon quantum dots grafted modified titanium dioxide.

2. The method for preparing a corrosion-resistant stainless steel pipe according to claim 1, characterized in that: In the passivation solution, the mass ratio of sodium molybdate, phosphoric acid, ethanol and deionized water is (18-26):(5-8):(30-50):(24-32); the passivation temperature is 50-60°C and the time is 2-4 minutes.

3. The method for preparing a corrosion-resistant stainless steel pipe according to claim 1, characterized in that: The mass ratio of polyether polyol, isophorone diisocyanate, 2,2-dihydroxymethylpropionic acid, propylene glycol, TMP, dibutyl dilauryl tin, epoxy-modified carbon quantum dot grafted modified titanium dioxide, ethylenediamine and water is 1000:(240-440):(10-30):(10-30):(4-8):(0.5-1):(12-20):(6-10):(1500-2500).

4. The method for preparing a corrosion-resistant stainless steel pipe according to claim 1, characterized in that: The mass ratio of the polyurethane aqueous dispersion containing unsaturated double bonds, methyl methacrylate, trifluoroethyl methacrylate, diacetone acrylamide, initiator and adipic acid dihydrazide is (40-60):(30-50):(8-20):(1-5):(0.1-1.3):(5-9).

5. The method for preparing a corrosion-resistant stainless steel pipe according to claim 1, characterized in that: The initiator was AIBN.

6. The method for preparing a corrosion-resistant stainless steel pipe according to claim 1, characterized in that: In step (1), the mass ratio of epoxy-modified titanium dioxide, 2-aminoethyl methacrylate, anhydrous ethanol and hydrochloric acid aqueous solution is (30-50):(180-300):(2000-4000):(10-18); the reaction temperature is 55-75°C, and the reaction time is 5-9h.

7. The method for preparing a corrosion-resistant stainless steel pipe according to claim 1, characterized in that: In step (2), the mass ratio of carbon quantum dots, anhydrous ethanol and γ-(2,3-epoxypropoxy)propyltrimethoxysilane is (30-40):(2000-4000):(7-9); the reaction temperature is 65-85°C, and the reaction time is 4-6h.

8. The method for preparing a corrosion-resistant stainless steel pipe according to claim 1, characterized in that: In step (3), the mass ratio of epoxy-modified carbon quantum dots, modified titanium dioxide and hydrochloric acid aqueous solution is 60:(400-800):(1500-3500); the reaction temperature is: 70-90°C, the reaction time is 2-4h; and the concentration of the hydrochloric acid aqueous solution is 0.01mol / L.

9. A corrosion-resistant stainless steel pipe prepared by the method for preparing a corrosion-resistant stainless steel pipe according to any one of claims 1 to 8.

10. Use of the corrosion-resistant stainless steel pipe according to claim 9 in marine engineering.

Images