Steel bar rust inhibitor for complex chloride environment and preparation method and use method thereof

Abstract

The present invention discloses a steel bar rust inhibitor for use in complex chloride environments, as well as its preparation and use methods. The steel bar rust inhibitor comprises a solvent and a solute dissolved therein, wherein the solvent is hydrolase-free double-distilled water with a pH greater than 6.0; the solute comprises, by mass percentage, 80%-90% DAP dry powder and 10%-20% PVA powder; wherein the DAP is prepared by grafting adenosine monophosphate, adenosine diphosphate, and adenosine triphosphate onto a nucleoside phosphorous acid activated intermediate. Compared with existing rust inhibitors, the present invention utilizes a more simplified synthesis method, which, while ensuring significant rust inhibition, avoids the limitations of the use environment and the agglomeration phenomenon caused by excessive molecular weight.

Description

Technical Field

[0001] The invention relates to a steel bar rust inhibitor and a preparation method and a use method thereof, and in particular to a steel bar rust inhibitor for use in a complex chloride environment and a preparation method and a use method thereof, belonging to the field of anti-corrosion of building materials. Background Art

[0002] Reinforced concrete, a high-strength, ductile, and inexpensive building material, has been widely used in various civil engineering projects. However, due to the interaction between internal and external environments, reinforced concrete structures are extremely susceptible to cracks and corrosion during service, often suffering significant damage before reaching their expected lifespan. The primary factor is the corrosion of steel within reinforced concrete structures by chloride salts. Chloride ions, as a powerful depassivating agent, directly interact with the passive film, entering the concrete structure and causing corrosion of the steel.

[0003] Premature structural failure caused by steel corrosion has caused enormous economic losses and waste of resources to human society. Common protective measures generally include the use of stainless steel, protective coatings, cathodic protection, electrochemical dechlorination, corrosion inhibitors, etc. Corrosion inhibitors are effective in preventing steel corrosion due to their long-lasting effects, simple operation, cost-effectiveness, and the fact that they do not fundamentally change the properties of concrete. They are being used more and more widely around the world. Nitrite was the first corrosion inhibitor to be used on a large scale. However, nitrite is a toxic substance. When nitrite is insufficient, there is a risk of deep pitting corrosion of steel. With the urgent need for environmental protection, the development of efficient and environmentally friendly corrosion inhibitors for concrete construction has important practical significance and economic value.

[0004] Furthermore, current studies of reinforced concrete corrosion in chloride environments mostly use a single sodium chloride solution to simulate the corrosive environment. However, the chloride ion corrosion process in actual construction environments is affected by other coexisting ions in the external and internal chemical environments. Sodium chloride, potassium chloride, calcium chloride, and magnesium chloride solutions are the most common chlorinated ice salts in service environments. Therefore, the development of a steel bar rust inhibitor specifically tailored to complex chloride environments holds great significance and holds broad research prospects. Summary of the Invention

[0005] Purpose of the invention: The purpose of the present invention is to provide a steel bar rust inhibitor for use in a complex chloride salt environment; another purpose of the present invention is to provide a preparation method of the steel bar rust inhibitor for use in a complex chloride salt environment; another purpose of the present invention is to provide a method for using the steel bar rust inhibitor for use in a complex chloride salt environment.

[0006] Technical solution: The present invention provides a steel bar rust inhibitor for use in a complex chloride environment, comprising a solvent and a solute dissolved therein, wherein the solvent is hydrolase-free double-distilled water with a pH greater than 6.0; the solute comprises, by mass percentage, 80%-90% DAP dry powder and 10%-20% PVA powder; wherein the DAP is prepared by grafting adenosine monophosphate, adenosine diphosphate, and adenosine triphosphate onto a nucleoside phosphorous acid activated intermediate.

[0007] As a further preferred embodiment of the present invention, the raw materials for preparing DAP dry powder include the following components: by mass percentage, 30%-50% nucleotides, 5%-15% adenosine monophosphate, 15%-25% adenosine diphosphate, and 25%-35% adenosine triphosphate.

[0008] As a further preferred embodiment of the present invention, the DAP dry powder is prepared by the following steps:

[0009] (1) Using hydrogen gas to catalyze hydrogenolysis at room temperature and pressure to remove the protecting group of the 5'-hydroxyl group in the nucleotide to obtain a free 5'-hydroxyl group;

[0010] (2) using phosphoramidite-protected nucleotide monomers and mixing them with a tetrazolium activator to obtain a nucleoside phosphorous acid activated intermediate;

[0011] (3) The above-mentioned nucleoside phosphite activated intermediate undergoes a condensation reaction with the free 5'-hydroxyl group, and then adenosine monophosphate, adenosine diphosphate and adenosine triphosphate are added in proportion to graft them onto the surface of the nucleoside phosphite activated intermediate, and then the condensation reaction is terminated; the obtained product is DAP;

[0012] (4) After purification and drying, DAP dry powder is obtained.

[0013] As a further preferred embodiment of the present invention, in step (3), the graft copolymerization is carried out using acetate kinase as a catalyst; and the condensation reaction is terminated using acetic anhydride and 1-methylimidazole reagents.

[0014] As a further preferred embodiment of the present invention, step (3) further includes an oxidation step, in which after the condensation reaction is terminated, oxidation is performed using an oxidizing agent, iodine, to make the phosphate skeleton more stable.

[0015] As a further preferred embodiment of the present invention, in step (4), the purification and drying process is as follows: the product is immersed in a 50%-70% alcohol solution, stirred at low temperature until fully dissolved, and then vacuum dried until the weight no longer changes.

[0016] As a further preferred embodiment of the present invention, the degree of polymerization of the PVA powder is 500-600, and the degree of alcoholysis is 88±2%; the molecular weight of the DAP dry powder is 19750-19870 g / mol.

[0017] As a further preferred embodiment of the present invention, the purity of the adenosine monophosphate is above 98%.

[0018] As a further preferred embodiment of the present invention, the purity of the adenosine diphosphate is above 98%.

[0019] As a further preferred embodiment of the present invention, the purity of the adenosine triphosphate is above 98%.

[0020] On the other hand, the present invention provides a method for preparing the above-mentioned steel bar rust inhibitor, which comprises mixing 80%-90% DAP dry powder and 10%-20% PVA powder evenly, then adding double-distilled water without hydrolase, shaking and mixing, and dispersing evenly at low temperature to obtain the steel bar rust inhibitor.

[0021] On the other hand, the present invention provides a method for using the above-mentioned steel bar rust inhibitor for complex chloride salt environment. During use, the steel bar rust inhibitor is directly coated on the steel bar surface, or is added into the concrete in the form of an admixture during the concrete mixing process, and the addition amount is 2%-6% of the mixing water mass.

[0022] As a further preference of the present invention, the service environment of the steel bar rust inhibitor is a complex chloride salt environment, and the complex chloride salt environment includes sodium chloride, potassium chloride, calcium chloride and magnesium chloride.

[0023] The steel bar rust inhibitor of the present invention uses a dense, highly crystalline film formed by dissolving PVA in water as a matrix, and DAP molecules are evenly dispersed on its surface to form a more complete, insoluble, and dense film layer, which avoids the agglomeration of DAP molecules and reduces the contact between oxygen and steel bars, thereby reducing the redox reaction. In addition, the high content of phosphate in the DAP molecules can combine with the d-vacant orbitals of iron on the surface of the steel bars to form a stable chemical structure, thereby inhibiting chloride ions from acting as a depassivating agent to accelerate the redox reaction on the surface of the steel bars, thereby controlling the corrosion of the steel bar surface. In a complex chloride corrosion environment, relative to sodium chloride and potassium chloride solutions, the hydration of calcium chloride and magnesium chloride will generate calcium hydroxide and magnesium hydroxide, lowering the pH value of the system, reducing the concentration of hydroxide, and at the same time reducing the content of DAP molecules on the surface of the steel bars. Compared with calcium chloride solution, the chemical combination of DAP molecules and calcium ions can form a layer of slightly soluble DAP-calcium phosphate precipitate, which can inhibit the degradation of the steel bar surface rust inhibitor and protect the steel bar surface from corrosion caused by chloride ions.

[0024] Based on the above mechanism, the steel bar rust inhibitor of the present invention exhibits significant corrosion inhibition despite varying performance in different chloride environments. This can be summarized into two basic principles: (1) the hydration of chlorides affects the pH value of the environment; and (2) calcium chloride reacts with the steel bar rust inhibitor to form a slightly soluble DAP-calcium phosphate precipitate, thereby affecting the inhibitor's corrosion resistance.

[0025] Beneficial Effects: Compared with existing technologies, this invention offers the following significant advantages: Compared with existing rust inhibitors, this invention utilizes a more simplified synthesis method, ensuring significant rust inhibition while avoiding environmental limitations and the agglomeration problems associated with excessive molecular weight. This environmentally friendly, simple synthesis process, and excellent rust inhibition performance are advantages that make it effective in complex chloride environments, providing theoretical basis and technical guidance for actual service conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The figure shows the corrosion current density of steel bars in a saturated calcium hydroxide solution of 0.15 mol / L sodium chloride without adding steel bar rust inhibitor, and in a saturated calcium hydroxide solution of sodium chloride, potassium chloride, calcium chloride and magnesium chloride with a chloride ion concentration of 0.15 mol / L with adding 90% DAP as steel bar rust inhibitor.

[0027] Figure 2 It is the Nyquist plot of steel bars without adding steel bar rust inhibitor in saturated calcium hydroxide solution of 0.15 mol / L sodium chloride and steel bar rust inhibitor added in saturated calcium hydroxide solution of 0.15 mol / L chloride ion concentration of sodium chloride, potassium chloride, calcium chloride and magnesium chloride.

[0028] Figure 3 The figure shows the corrosion current density of steel bars in a saturated calcium hydroxide solution of 0.15 mol / L sodium chloride without adding steel bar rust inhibitor, and in a saturated calcium hydroxide solution of 0.15 mol / L chloride ion concentration of sodium chloride, potassium chloride, calcium chloride and magnesium chloride with adding 85% DAP rust inhibitor.

[0029] Figure 4 It is the Nyquist plot of steel bars without adding steel bar rust inhibitor in saturated calcium hydroxide solution of 0.15 mol / L sodium chloride and steel bar rust inhibitor added in saturated calcium hydroxide solution of 0.15 mol / L chloride ion concentration of sodium chloride, potassium chloride, calcium chloride and magnesium chloride.

[0030] Figure 5 The figure shows the corrosion current density of steel bars in a saturated calcium hydroxide solution of 0.15 mol / L sodium chloride without adding steel bar rust inhibitor, and in a saturated calcium hydroxide solution of 0.15 mol / L chloride ion concentration of sodium chloride, potassium chloride, calcium chloride and magnesium chloride with adding 80% DAP rust inhibitor.

[0031] Figure 6It is the Nyquist plot of steel bars without adding steel bar rust inhibitor in saturated calcium hydroxide solution of 0.15 mol / L sodium chloride and steel bar rust inhibitor added in saturated calcium hydroxide solution of 0.15 mol / L chloride ion concentration of sodium chloride, potassium chloride, calcium chloride and magnesium chloride. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0033] Example 1

[0034] The steel bar rust inhibitor for complex chloride environments of this embodiment comprises a solvent and a solute dissolved therein. The solvent is hydrolase-free double-distilled water with a pH of 7.0. The solute in the steel bar rust inhibitor is composed of 90% DAP dry powder and 10% PVA powder. During the experiment, the dry powder was centrifuged at 3000-4000 rpm for 5 minutes, then hydrolase-free double-distilled water was added at a mass ratio of 1:5000, and the mixture was shaken and mixed. The mixture was then sonicated in ice water for 1 hour until uniformly dispersed. The PVA powder has a degree of polymerization of 500-600 and a degree of alcoholysis of 88±2%. The molecular weight of the DAP dry powder is 19750-19870 g / mol.

[0035] DAP is produced by grafting adenosine monophosphate, adenosine diphosphate, and adenosine triphosphate onto activated nucleoside phosphite intermediates. Specifically, the raw materials for DAP dry powder include the following components, by mass: 40% nucleotides, 10% adenosine monophosphate, 20% adenosine diphosphate, and 30% adenosine triphosphate.

[0036] The monomer structure of the above nucleotide is shown below:

[0037]

[0038] The preparation process of DAP dry powder includes the following steps:

[0039] (1) Using hydrogen gas to catalyze hydrogenolysis at room temperature and pressure to remove the protecting group of the 5'-hydroxyl group in the nucleotide to obtain a free 5'-hydroxyl group;

[0040] (2) using phosphoramidite-protected nucleotide monomers and mixing them with a tetrazolium activator to obtain a nucleoside phosphorous acid activated intermediate;

[0041] (3) The above-mentioned nucleoside phosphite activated intermediate undergoes a condensation reaction with the free 5'-hydroxyl group, and then adenosine monophosphate, adenosine diphosphate and adenosine triphosphate are added in proportion, and acetate kinase is used as a catalyst to graft them onto the surface of the nucleoside phosphite activated intermediate. Then, acetic anhydride and 1-methylimidazole reagents are used to terminate the condensation reaction; iodine is used as an oxidant to oxidize the phosphate skeleton to make it more stable; the obtained product is DAP;

[0042] (4) Finally, immerse in a 50%-70% alcohol solution, stir at low temperature for 0.5-1h with a magnetic stirrer until fully dissolved, and then vacuum dry in an electric blast drying oven until the weight no longer changes. According to the above technical solution, a Φ10mm, 10mm long plain round steel bar segment is selected. Before the test, it is polished to smoothness in order with 360 mesh, 800 mesh, 1200 mesh and 2000 mesh metallographic sandpaper. A plain round steel bar segment is selected as the working surface, and the other end is connected to a copper wire. Then, epoxy resin is coated on the area except the working surface, and the working surface is polished to smoothness again with sandpaper. After degreasing with acetone, it is cleaned with anhydrous ethanol to obtain the required working electrode.

[0043] The corrosion current density diagram and Nyquist diagram of the working electrode were respectively tested in a saturated calcium hydroxide solution of 0.15 mol / L sodium chloride without adding the steel bar rust inhibitor, and in a saturated calcium hydroxide solution of sodium chloride, potassium chloride, calcium chloride and magnesium chloride with a chloride ion concentration of 0.15 mol / L with the addition of the steel bar rust inhibitor.

[0044] from Figure 1 and Figure 2 It can be seen that after the steel bar rust inhibitor is added to the steel bar in different chloride salt corrosion solutions, the current density of the steel bar decreases and the fitting radius of the Nyquist plot increases significantly, indicating that the steel bar rust inhibitor has a good rust inhibition effect in different chloride salt corrosion solutions. The current density of the steel bar in the sodium chloride and potassium chloride environments is significantly lower than that in the calcium chloride and magnesium chloride environments, and the fitting radius of the Nyquist plot increases significantly, indicating that the adsorption film on the steel bar surface is significantly larger, the thickness of the protective layer is increased, and the rust inhibition effect is better; the calcium chloride environment is second, and the magnesium chloride environment is slightly weaker, but still has a fairly good rust inhibition effect compared to the steel bar without the steel bar rust inhibitor.

[0045] Example 2

[0046] The steel bar rust inhibitor in this example consisted of 85% DAP dry powder and 15% PVA powder. During the experiment, the dry powder was centrifuged at 3000-4000 rpm for 5 minutes. Hydrolase-free double-distilled water was then added at a mass ratio of 1:5000 and mixed by vortexing. The mixture was then sonicated in ice water for 1 hour until uniformly dispersed. The DAP dry powder was prepared using the same method as in Example 1.

[0047] According to the above technical scheme, a Φ10mm, 10mm long smooth round steel bar segment was selected. Before the test, it was polished to smoothness using 360-mesh, 800-mesh, 1200-mesh, and 2000-mesh metallographic sandpaper in sequence. A section of the smooth round steel bar was selected as the working surface, and the other end was connected to a copper wire. Then, the area except the working surface was coated with epoxy resin, and the working surface was polished to smoothness again using sandpaper. After degreasing with acetone, it was cleaned with anhydrous ethanol to obtain the required working electrode.

[0048] The corrosion current density diagram and Nyquist diagram of the working electrode were respectively tested in a saturated calcium hydroxide solution of 0.15 mol / L sodium chloride without adding the steel bar rust inhibitor, and in a saturated calcium hydroxide solution of sodium chloride, potassium chloride, calcium chloride and magnesium chloride with a chloride ion concentration of 0.15 mol / L with the addition of the steel bar rust inhibitor.

[0049] from Figure 3 and Figure 4 It can be seen that the steel bar is in different chloride salt corrosion solutions. After the steel bar rust inhibitor is added, the current density of the steel bar decreases, and the fitting radius of the Nyquist diagram increases significantly, indicating that the steel bar rust inhibitor has a good rust-proof effect on different chloride salt corrosion solutions. The current density of the steel bar in sodium chloride and potassium chloride solutions is small, and the impedance arc is large; the current density under magnesium chloride environment is the largest, and the impedance arc is the smallest, indicating that the rust-proof effect of the steel bar rust inhibitor in sodium chloride and potassium chloride environments is the best, calcium chloride is second, and magnesium chloride solution is slightly weaker, but compared to the steel bar to which the steel bar rust inhibitor is not added, the rust-proof effect is still significantly improved. Compared to Example 1, its current density in each chloride salt environment is smaller, and the impedance arc is larger, i.e., the chloride ion corrosion resistance of Example 2 is also better, and this is because the PVA molecular content is low in Example 1, so that the DAP molecules cannot be evenly dispersed on its surface, so that part of them are entangled, resulting in performance being slightly lower than Example 2.

[0050] Example 3

[0051] The steel bar rust inhibitor in this example consisted of 80% DAP dry powder and 20% PVA powder. During the experiment, the dry powder was centrifuged at 3000-4000 rpm for 5 minutes. Hydrolase-free double-distilled water was then added at a mass ratio of 1:5000 and mixed by vortexing. The mixture was then sonicated in ice water for 1 hour until uniformly dispersed. The DAP dry powder was prepared using the same method as in Example 1.

[0052] According to the above technical scheme, a Φ10mm, 10mm long smooth round steel bar segment was selected. Before the test, it was polished to smoothness using 360-mesh, 800-mesh, 1200-mesh, and 2000-mesh metallographic sandpaper in sequence. A section of the smooth round steel bar was selected as the working surface, and the other end was connected to a copper wire. Then, the area except the working surface was coated with epoxy resin, and the working surface was polished to smoothness again using sandpaper. After degreasing with acetone, it was cleaned with anhydrous ethanol to obtain the required working electrode.

[0053] The corrosion current density diagram and Nyquist diagram of the working electrode were respectively tested in a saturated calcium hydroxide solution of 0.15 mol / L sodium chloride without adding the steel bar rust inhibitor, and in a saturated calcium hydroxide solution of sodium chloride, potassium chloride, calcium chloride and magnesium chloride with a chloride ion concentration of 0.15 mol / L with the addition of the steel bar rust inhibitor.

[0054] from Figure 5 and Figure 6 It can be seen that after the steel bar is added with the steel bar rust inhibitor in different chloride salt corrosion solutions, the current density of the steel bar decreases, and the fitting radius of the Nyquist diagram increases significantly, indicating that the steel bar rust inhibitor has a good rust-proof effect on different chloride salt corrosion solutions. The current density of the steel bar in sodium chloride and potassium chloride solutions is small, and the impedance arc is large; the current density under the magnesium chloride environment is the largest, and the impedance arc is the smallest, indicating that the steel bar rust inhibitor has the best rust-proof effect in sodium chloride and potassium chloride environments, followed by calcium chloride, and magnesium chloride is slightly worse, but compared to the steel bar without the addition of the steel bar rust inhibitor, the rust-proof effect is still significantly improved. Compared to Example 2, due to the low content of DAP molecules, the content of molecular groups that inhibit the redox reaction of the steel bar is reduced, so the performance is slightly lower than that of Example 2.

[0055] Example 4

[0056] This example differs from Example 2 in the raw materials used to prepare the DAP dry powder; otherwise, the DAP is identical to Example 2. The DAP in this example is prepared by grafting adenosine monophosphate, adenosine diphosphate, and adenosine triphosphate onto an activated nucleoside phosphite intermediate. Specifically, the raw materials for the DAP dry powder include the following components, by mass: 30% nucleotides, 10% adenosine monophosphate, 25% adenosine diphosphate, and 35% adenosine triphosphate. The resulting steel bar rust inhibitor exhibits similar rust-inhibiting effects to those of Example 2.

[0057] Example 5

[0058] This example differs from Example 2 in the raw materials used to prepare the DAP dry powder; otherwise, the DAP is identical to Example 2. The DAP in this example is prepared by grafting adenosine monophosphate, adenosine diphosphate, and adenosine triphosphate onto an activated nucleoside phosphite intermediate. Specifically, the raw materials for the DAP dry powder include the following components, by mass: 50% nucleotides, 10% adenosine monophosphate, 15% adenosine diphosphate, and 25% adenosine triphosphate. The resulting steel bar rust inhibitor exhibits similar rust-inhibiting effects to those of Example 2.

[0059] Example 6

[0060] This example differs from Example 2 in the raw materials used to prepare the DAP dry powder; otherwise, the DAP is identical to Example 2. The DAP in this example is prepared by grafting adenosine monophosphate, adenosine diphosphate, and adenosine triphosphate onto a nucleoside phosphorous acid activated intermediate. Specifically, the raw materials for the DAP dry powder include the following components, by mass: 50% nucleotides, 5% adenosine monophosphate, 20% adenosine diphosphate, and 25% adenosine triphosphate. The resulting steel bar rust inhibitor exhibits similar rust-inhibiting properties to that of Example 2.

[0061] Example 7

[0062] This example differs from Example 2 in the raw materials used to prepare the DAP dry powder; otherwise, the DAP is identical to Example 2. The DAP in this example is prepared by grafting adenosine monophosphate, adenosine diphosphate, and adenosine triphosphate onto an activated nucleoside phosphite intermediate. Specifically, the raw materials for the DAP dry powder include the following components, by mass: 40% nucleotides, 15% adenosine monophosphate, 10% adenosine diphosphate, and 35% adenosine triphosphate. The resulting steel bar rust inhibitor exhibits similar rust-inhibiting effects to those of Example 2.

[0063] The present invention is beneficial in that, compared to existing rust inhibitors, it utilizes a more simplified synthesis method. This ensures the desired rust-inhibiting effect while avoiding environmental limitations and the agglomeration problems associated with excessive molecular weight. This product offers advantages such as environmental friendliness, a simple synthesis process, and excellent rust-inhibiting properties. It can be effectively applied in complex chloride environments, providing theoretical support and technical guidance for practical construction conditions, and improving the quality of major engineering structures in my country.

[0064] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be considered as the scope of protection of the present invention.

Claims

1. A steel bar rust inhibitor for use in complex chloride salt environments, characterized in that: The steel bar rust inhibitor comprises a solvent and a solute dissolved therein, wherein the solvent is double distilled water without hydrolase and has a pH greater than 6.0; the solute comprises, by mass percentage, 80%-90% DAP dry powder and 10%-20% PVA powder; wherein the DAP is prepared by grafting adenosine monophosphate, adenosine diphosphate, and adenosine triphosphate onto a nucleoside phosphorous acid activated intermediate; the PVA powder has a degree of polymerization of 500-600 and a degree of alcoholysis of 88±2%; the molecular weight of the DAP dry powder is 19750-19870 g / mol; and the DAP dry powder is prepared by the following steps: (1) Using hydrogen gas to catalyze hydrogenolysis at room temperature and pressure to remove the 5'-hydroxyl protecting group in the nucleotide to obtain a free 5'-hydroxyl group; (2) Phosphoramidite-protected nucleotide monomers are mixed with tetrazolium activators to obtain nucleoside phosphite-activated intermediates; (3) The above-mentioned nucleoside phosphite activated intermediate undergoes a condensation reaction with the free 5'-hydroxyl group, and then adenosine monophosphate, adenosine diphosphate and adenosine triphosphate are added in proportion to graft them onto the surface of the nucleoside phosphite activated intermediate, and then the condensation reaction is terminated; the obtained product is DAP; (4) After purification and drying, DAP dry powder is obtained.

2. The steel bar rust inhibitor for complex chloride salt environment according to claim 1, characterized in that: The raw materials for preparing DAP dry powder include the following components: by mass percentage, 30%-50% nucleotides, 5%-15% adenosine monophosphate, 15%-25% adenosine diphosphate, and 25%-35% adenosine triphosphate.

3. The steel bar rust inhibitor for complex chloride salt environment according to claim 1, characterized in that: In step (3), the graft copolymerization is carried out using acetate kinase as a catalyst; and the condensation reaction is terminated using acetic anhydride and 1-methylimidazole reagents.

4. The steel bar rust inhibitor for complex chloride salt environment according to claim 1, characterized in that: Step (3) also includes an oxidation step, in which iodine is used as an oxidant to oxidize the phosphate skeleton after the condensation reaction is terminated to make the phosphate skeleton more stable.

5. The steel bar rust inhibitor for complex chloride salt environment according to claim 1, characterized in that: In step (4), the purification and drying process is as follows: the product is immersed in a 50%-70% alcohol solution, stirred at low temperature until fully dissolved, and then vacuum dried until the weight no longer changes.

6. A method for preparing a steel bar rust inhibitor according to any one of claims 1 to 5, characterized in that: Mix 80%-90% DAP dry powder and 10%-20% PVA powder evenly, then add double-distilled water without hydrolase, shake and mix, and disperse evenly at low temperature to obtain the product.

7. A method for using the steel bar rust inhibitor for use in a complex chloride environment according to any one of claims 1 to 5, characterized in that: The steel bar rust inhibitor is directly applied to the steel bar surface during use, or added into the concrete in the form of an admixture during the concrete mixing process, with the dosage being 2%-6% of the mixing water mass.

8. The steel bar rust inhibitor for complex chloride salt environment according to claim 1, characterized in that: The service environment of steel bar rust inhibitor is a complex chloride salt environment, which includes sodium chloride, potassium chloride, calcium chloride and magnesium chloride.

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