Corrosion inhibitor for rusted bronze protection, method for preparing the same and film forming method of the corrosion inhibitor

Abstract

The present application relates to a kind of preparation methods of rusted bronze protection inhibitor, including the preparation of ammonium molybdate, 2-mercaptobenzothiazole and solution and the preparation steps of compound inhibitor, also provide the rusted bronze protection inhibitor prepared by preparation method and the film forming method of inhibitor on the surface of rusted bronze.The method of the present application utilizes the coordination properties of ethylenediaminetetraacetic acid disodium, makes it separate from the unstable rust structure in the rusted bronze inhibitor film system, enhances the stability and corrosion inhibition performance of organic-inorganic hybrid corrosion inhibitor film, the appearance of the corrosion inhibitor film obtained by the method is small for bronze sample, corrosion resistance is improved, and compared with original organic-inorganic corrosion inhibitor film, it is increased by 80%, suitable for the corrosion protection treatment of rusted bronze under the environment of collection.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of preparation of composite corrosion inhibitor. BACKGROUND

[0002] Bronze ware is an important part of ancient Chinese culture, representing the brilliant achievements of ancient Chinese civilization. After being excavated, bronze ware is separated from the original relatively stable storage conditions and comes into contact with oxygen and moisture in the air, which further accelerates its corrosion. Therefore, reasonable corrosion inhibition treatment of unearthed bronze ware will play a crucial role in cultural heritage protection research.

[0003] Currently, common corrosion inhibitors are mainly divided into inorganic corrosion inhibitors and organic corrosion inhibitors. The general corrosion inhibition mechanism of organic corrosion inhibitors is to generate an adsorption film by chemical or physical adsorption of polar groups, thereby hindering the diffusion of corrosion reaction products and reducing the corrosion rate to achieve the corresponding corrosion inhibition effect. Inorganic corrosion inhibitors mainly form an oxide or hydroxide protective film by reacting with the anode metal to inhibit anode polarization and achieve corrosion inhibition effect. The combination of organic and inorganic corrosion inhibitors can greatly improve the corrosion inhibition performance of the system. Binary combination has been studied more, and its corrosion inhibition performance has been improved accordingly.

[0004] However, whether it is an organic corrosion inhibitor, an inorganic corrosion inhibitor, or an organic-inorganic hybrid corrosion inhibitor, it only considers the chemical conversion of the corrosion film. However, due to the presence of numerous unstable rust structures in the bronze itself, the integrity and density of the corrosion film are affected, which is not conducive to the protection of bronze ware. Therefore, there is currently no corrosion inhibitor suitable for protecting bronze with rust. SUMMARY

[0005] The present application aims to avoid the shortcomings of the prior art and provide a corrosion inhibitor for bronze protection with rust, a preparation method thereof, and a film forming method of the corrosion inhibitor, which can induce the unstable rust structure to separate synchronously during the formation of the corrosion film, thereby improving the overall density of the corrosion film and the corrosion resistance.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present application is as follows: a preparation method of a corrosion inhibitor for bronze protection with rust, comprising the following steps:

[0007] Step 1: Preparation of ammonium molybdate, 2-mercaptobenzothiazole, and solution:

[0008] Ammonium molybdate, 2-mercaptobenzothiazole, and ethylenediaminetetraacetic acid disodium salt are dissolved in distilled water, respectively, and stirred for 10-120 min to obtain ammonium molybdate solution with a concentration of 0.3-0.6 mol / L, 2-mercaptobenzothiazole solution with a concentration of 0.3-0.6 mol / L, and ethylenediaminetetraacetic acid disodium salt solution with a concentration of 0.3-0.6 mol / L;

[0009] Step 2: Preparation of a compounded corrosion inhibitor:

[0010] The ammonium molybdate solution, the 2-mercaptobenzothiazole solution and the disodium ethylenediaminetetraacetate solution are mixed according to a volume ratio of 1:2:0.5 to obtain the ammonium molybdate / 2-mercaptobenzothiazole / disodium ethylenediaminetetraacetate composite corrosion inhibitor solution, that is, the composite corrosion inhibitor.

[0011] The application further provides the corrosion inhibitor prepared by the preparation method, which can dissolve and separate unstable parts in a rust layer of the rusted bronze, and the remaining rust layer and the corrosion inhibitor system form a polarization resistance of 13400-13500 Ω·cm 2 , and the rusted bronze has a compact corrosion layer with a surface roughness of 20-30.

[0012] The application further provides a film forming method of the corrosion inhibitor on a rusted bronze surface, which comprises the following steps:

[0013] The rusted bronze is immersed in the composite corrosion inhibitor at a temperature of 25-40 DEG C for at least 24 hours, and then taken out and cleaned with distilled water and dried for standby, so that the rusted bronze with a compact corrosion layer is obtained.

[0014] Further, the rusted bronze is immersed in the composite corrosion inhibitor at a temperature of 30 DEG C for 24 hours, and then taken out and cleaned with distilled water and dried for standby.

[0015] The method mainly utilizes the coordination performance of disodium ethylenediaminetetraacetate (EDTA-2Na) to separate unstable rust structures in the rusted bronze from the corrosion film system, so as to enhance the stability and corrosion inhibition performance of the organic-inorganic hybrid corrosion film. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a Tafel polarization curve diagram of different bronze samples in the application;

[0017] Figure 2 is a scanning electron microscope photo of a rusted bronze sample surface;

[0018] Figure 3 is a bronze surface scanning electron microscope photo of the rusted bronze+composite corrosion inhibitor 1 in the application;

[0019] Figure 4 is a bronze surface scanning electron microscope photo of the rusted bronze+composite corrosion inhibitor 2 in the application. DETAILED DESCRIPTION

[0020] The principles and features of the present application are described below in conjunction with the accompanying drawings, which are provided only for explanation of the present application and are not intended to limit the scope of the present application.

[0021] To achieve the above-mentioned purpose, the present application provides the following specific embodiments:

[0022] Embodiment 1: A preparation method of an inhibitor for rusted bronze, comprising the following steps:

[0023] Step 1: Preparation of ammonium molybdate, 2-mercaptobenzothiazole and disodium ethylenediaminetetraacetate solutions:

[0024] Ammonium molybdate, 2-mercaptobenzothiazole and disodium ethylenediaminetetraacetate are respectively dissolved in distilled water, and stirred for 10-120 min to obtain ammonium molybdate solution with a concentration of 0.3-0.6 mol / L, 2-mercaptobenzothiazole solution with a concentration of 0.3-0.6 mol / L, and disodium ethylenediaminetetraacetate solution with a concentration of 0.3-0.6 mol / L.

[0025] Step 2: Preparation of a compounded inhibitor:

[0026] The ammonium molybdate solution, 2-mercaptobenzothiazole solution and disodium ethylenediaminetetraacetate solution are mixed according to a volume ratio of 1:2:0.5 to obtain a compounded ammonium molybdate / 2-mercaptobenzothiazole / disodium ethylenediaminetetraacetate corrosion inhibitor solution, which is the compounded inhibitor.

[0027] Embodiment 2: The present application also provides the inhibitor for rusted bronze prepared by the preparation method, which can dissolve and separate unstable parts in the rust layer of the rusted bronze, and the remaining rust layer can form a polarization resistance of 13400-13500 Ω·cm with the inhibitor system. 2 , and the rusted bronze surface has a compact corrosion layer with a roughness of 20-30.

[0028] Embodiment 3: The present application also provides a film forming method of the inhibitor prepared by the preparation method on the surface of the rusted bronze, comprising the following steps:

[0029] The rusted bronze is immersed in the compounded inhibitor at a temperature of 25-40℃ for at least 24 hours, and then taken out, washed with distilled water and air-dried for standby use.

[0030] Embodiment 4: The same as Embodiment 3, except that the rusted bronze is immersed in the compounded inhibitor at a temperature of 30℃ for 24 hours, and then taken out, washed with distilled water and air-dried for standby use.

[0031] As Figures 1-4 shown, in order to better illustrate the technical effects of the present application, the present application provides specific experimental examples:

[0032] 1. Configuration of corrosion inhibitor:

[0033] (1) Ammonium molybdate, 2-mercaptobenzothiazole (MBT) and disodium ethylenediaminetetraacetate (EDTA-2Na) were dissolved in distilled water respectively, and stirred for 60 min, to obtain ammonium molybdate solution with a concentration of 0.5 mol / L, MBT solution with a concentration of 0.5 mol / L and EDTA-2Na solution with a concentration of 0.5 mol / L.

[0034] (2) The ammonium molybdate solution and the MBT solution were mixed in a ratio of 1:2 and stirred for 10 min to obtain an ammonium molybdate / MBT corrosion inhibiting solution, which was denoted as corrosion inhibitor 1.

[0035] Then, the ammonium molybdate solution, the MBT solution and the EDTA-2Na solution were mixed in a ratio of 1:2:0.5 to obtain an ammonium molybdate / MBT / EDTA-2Na composite solution, which was a corrosion inhibitor provided by the present application and was denoted as corrosion inhibitor 2.

[0036] 2. Preparation of rusted bronze samples for simulating real bronze cultural relics:

[0037] Two pure bronze samples were immersed in a 0.5 mol / L NaCl solution for 24 hours, and then taken out and dried. Subsequently, water was sprayed every 8 hours for 5 days to obtain bronze samples with basic copper chloride rust, which were used to simulate real rusted bronze. As shown in FIG. 1, the surface of the bronze sample was rough, porous and had obvious cracks. Figure 2

[0038] 3. Corrosion treatment of rusted bronze:

[0039] One bronze sample was placed in corrosion inhibitor 1 for 24 hours at a controlled temperature of 30°C, and then taken out, washed with distilled water and air-dried for standby, which was denoted as "rusted bronze+corrosion inhibitor 1".

[0040] Meanwhile, another bronze sample was placed in corrosion inhibitor 2 for 24 hours at a controlled temperature of 30°C, and then taken out, washed with distilled water and air-dried for standby, which was denoted as "rusted bronze+corrosion inhibitor 2".

[0041] 4. Comprehensive performance test of rusted bronze:

[0042] (1) A colorimeter was used to study the appearance change of the bronze sample before and after corrosion treatment;

[0043] (2) A contact angle measuring instrument was used to study the wettability of the bronze sample to pure water;

[0044] (3) A roughness meter was used to characterize the surface roughness of the bronze sample;

[0045] ​(4) Electrochemical three-electrode system was used to evaluate the corrosion resistance of bronze samples.

[0046] Data test results of specific experimental examples:

[0047] Table 1 is the color value results of each bronze sample. As can be seen from Table 1, after immersion treatment with the compounded corrosion inhibitor 1 and the compounded corrosion inhibitor 2, the color change of the rusted bronze is 3.2 and 3.7 respectively, indicating that the overall color is small, which meets the principle of not changing the appearance in cultural relic restoration.

[0048] Table 1 is the color value results of each bronze sample. As can be seen from Table 1, after immersion treatment with the compounded corrosion inhibitor 1 and the compounded corrosion inhibitor 2, the color change of the rusted bronze is 3.2 and 3.7 respectively, indicating that the overall color is small, which meets the principle of not changing the appearance in cultural relic restoration.

[0049]

[0050] Table 2 is the contact angle and roughness test results of each bronze sample. As can be seen from Table 2, after immersion treatment with the compounded corrosion inhibitor 1 and the compounded corrosion inhibitor 2, the contact angle of the sample increases, which means that the corrosion inhibitor reduces the hydrophilicity of the original bronze rust layer and weakens the diffusion behavior of the water-based corrosion medium to the inside of the rust layer. In addition, the roughness of the sample treated with the compounded corrosion inhibitor 1 changes little, while the roughness of the sample treated with the compounded corrosion inhibitor 2 decreases by about 10 μm, because EDTA-2Na promotes the dissolution and separation of unstable parts in the rust layer, so that the remaining rust layer and the organic-inorganic corrosion inhibitor system form a more dense corrosion layer structure.

[0051] Table 2 is the contact angle and roughness test results of each bronze sample. As can be seen from Table 2, after immersion treatment with the compounded corrosion inhibitor 1 and the compounded corrosion inhibitor 2, the contact angle of the sample increases, which means that the corrosion inhibitor reduces the hydrophilicity of the original bronze rust layer and weakens the diffusion behavior of the water-based corrosion medium to the inside of the rust layer. In addition, the roughness of the sample treated with the compounded corrosion inhibitor 1 changes little, while the roughness of the sample treated with the compounded corrosion inhibitor 2 decreases by about 10 μm, because EDTA-2Na promotes the dissolution and separation of unstable parts in the rust layer, so that the remaining rust layer and the organic-inorganic corrosion inhibitor system form a more dense corrosion layer structure.

[0052]

[0053] Figure 1 Table 3 is the Tafel polarization curve and corresponding fitting results of each bronze sample. By comparing the corrosion current density and polarization resistance, it can be seen that various rust layer structures can reduce the corrosion current density of bronze matrix, i.e. in the short term, the corrosion resistance of bronze matrix is improved.

[0054] Table 3 is the Tafel polarization curve and corresponding fitting results of each bronze sample. By comparing the corrosion current density and polarization resistance, it can be seen that various rust layer structures can reduce the corrosion current density of bronze matrix, i.e. in the short term, the corrosion resistance of bronze matrix is improved.

[0055]

[0056] After treatment with the compounded corrosion inhibitor 1, the polarization resistance of the bronze sample is 9624 Ω·cm 2 , which is 2 times that of the original rusted bronze and 8 times that of the bronze matrix. Figure 3 It can be seen that the surface of the bronze sample is relatively smooth, but there are obvious cracks;

[0057] After treatment with the compounded corrosion inhibitor 2, the polarization resistance of the bronze sample is 13474 Ω·cm 2 , which is 3 times that of the original rusted bronze and 11 times that of the bronze matrix.Figure 4 It can be seen that the surface of the bronze sample is smooth and has no obvious cracks;

[0058] That is, the sample after the compound corrosion inhibitor 2 treatment has the optimal corrosion resistance.

[0059] From the above, the unstable part in the rust layer is removed by induction, the roughness is further reduced, the diffusion of the corrosive medium to the inside of the rust layer is weakened, and the corrosion resistance of the sample is improved.

[0060] The above data proves that the concept of the present application provides beneficial reference for innovating the existing bronze corrosion inhibition strategy, and has important significance for the protection of the same type of metal cultural relics.

[0061] The above only describes the preferred embodiments of the present application and is not intended to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a corrosion inhibitor for protecting rusty bronze, characterized in that: The following steps are involved: Step 1: Preparation of ammonium molybdate, 2-mercaptobenzothiazole and disodium ethylenediaminetetraacetic acid solution: Dissolve ammonium molybdate, 2-mercaptobenzothiazole, and disodium ethylenediaminetetraacetate in distilled water, respectively, and stir for 10 to 120 minutes to obtain a 0.3 to 0.6 mol / L ammonium molybdate solution, a 0.3 to 0.6 mol / L 2-mercaptobenzothiazole solution, and a 0.3 to 0.6 mol / L disodium ethylenediaminetetraacetate solution; Step 2: Preparation of compound corrosion inhibitor: The ammonium molybdate solution, 2-mercaptobenzothiazole solution and disodium ethylenediaminetetraacetic acid solution are mixed in a volume ratio of 1:2:0.5 to obtain an ammonium molybdate / 2-mercaptobenzothiazole / disodium ethylenediaminetetraacetic acid composite corrosion inhibition solution, which is a composite corrosion inhibitor.

2. The corrosion inhibitor for protecting rusty bronze prepared by the preparation method according to claim 1, characterized in that: The corrosion inhibitor dissolves and separates the unstable part of the rust layer of the rusty bronze, and the remaining rust layer and the corrosion inhibitor system form a polarization resistance of 13400 to 13500 Ω·cm 2 , a dense corrosion inhibition layer with a surface roughness of 20 to 30 on the rusty bronze.

3. The method for forming a film of a corrosion inhibitor on a rusty bronze surface as claimed in claim 2, characterized in that: The following steps are involved: The rusty bronze is immersed in a compound corrosion inhibitor at a temperature of 25-40° C. for at least 24 hours. After being taken out, the rusty bronze is cleaned with distilled water and air-dried for standby use, thereby obtaining the rusty bronze with a dense corrosion inhibition layer.

4. The method for forming a film of a corrosion inhibitor on a rust bronze surface as claimed in claim 3, characterized in that: The rusty bronze is immersed in a compound corrosion inhibitor at a temperature of 30° C. for 24 hours, taken out, cleaned with distilled water, and air-dried for later use.

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