Functionalized graphene-based epoxy zinc-containing coating additive, preparation method and application

Abstract

The invention discloses a functionalized graphene-based epoxy zinc-containing coating additive as well as a preparation method and application thereof. The preparation method comprises the following steps: carrying out in-situ polymerization on graphene oxide and an aniline monomer, carrying out alkali reduction, carrying out secondary doping with sulfuric acid, modifying and reducing a graphene oxide / polyaniline composite nano material by using a silane coupling agent, and finally, doping and anchoring an active factor 1-hydroxyethylidene-1, 1-diphosphonic acid or 1-hydroxyethylidene-1, 1-diphosphonate to obtain the graphene / polyaniline composite material. The active factor doped reduced graphene oxide / polyaniline functionalized nano composite material is obtained; the composite material is used as an additive to prepare an epoxy zinc-containing coating, the mass percent of the additive in the epoxy zinc-containing coating is 0.5%-10%, the cathode protection time of the zinc-containing coating can be obviously prolonged even if the additive amount is 0.5%, and meanwhile, the self-repairing effect is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of preparation of anti-corrosion zinc-containing coating additives, and in particular to a functionalized graphene-based epoxy zinc-containing coating additive, a preparation method and application thereof. Background Art

[0002] Organic zinc-containing epoxy coating is one of the most efficient and economical methods to protect metals from corrosion damage. Epoxy zinc-containing coating is a coating system with cathodic protection properties. However, over time, due to the rapid oxidation of zinc particles, zinc oxide corrosion products are produced, which hinder the connection between the remaining zinc powder and the steel substrate, and the electrical contact is rapidly reduced, resulting in a decrease in the anodic sacrificial performance of the coating. The utilization rate of the zinc powder content, which is usually added at 80wt% of the dry film, is only about 30%. Effectively extending the cathodic protection time of the coating is of great significance for the maintenance of the metal surface of marine machinery and equipment.

[0003] In order to improve the utilization rate of zinc powder in epoxy zinc-containing coatings and solve the shortcomings of coating performance at low zinc content, researchers have added different conductive nanofillers, such as graphene, polyaniline, polypyrrole, etc. to maintain the connectivity of the conductive pathways inside the coating and replace the role of zinc powder. At the same time, the filling of nanomaterials can extend the diffusion path of corrosive media and enhance the barrier properties of coatings, and has been widely studied in the field of metal corrosion protection. However, certain characteristics of nanomaterials can also accelerate the corrosion of the substrate. Therefore, the development of new zinc-rich coating additives that improve the utilization rate of zinc powder and have excellent corrosion resistance is a hot topic for researchers at home and abroad. Summary of the invention

[0004] In view of the above problems, the present invention provides a functionalized graphene-based epoxy zinc-containing coating additive, a preparation method and an application thereof. The cathodic protection time of the zinc-containing coating can be significantly improved by utilizing the synergistic effect between the components and the activation effect of the active factor on zinc. The physical shielding effect and self-healing effect of the composite material further improve the anti-corrosion performance of the coating.

[0005] The first aspect of the present invention provides a method for preparing a functionalized graphene-based epoxy zinc-containing coating additive, comprising the following steps:

[0006] (1) adding the aniline monomer solution to the graphene oxide dispersion and stirring for 1-2 hours to mix them evenly;

[0007] (2) slowly adding the hydrochloric acid solution of ammonium persulfate to the mixed system of step (1), and placing in an ice-water bath for 12-24 hours;

[0008] (3) After the reaction is complete, add a certain concentration of sodium hydroxide solution, keep the temperature at 75°C-105°C for 4.5-6 hours, cool, add sulfuric acid solution to make the pH value of the reaction system 2-4, react for 10-15 hours, then filter and wash until neutral;

[0009] (4) re-dispersing the solid separation obtained in step (3) in an aqueous solution, adding a silane coupling agent, reacting in a water bath at 50-95° C. for 2-5 hours, and cooling to room temperature;

[0010] (5) Weigh a certain amount of active factor hydroxyethylidene diphosphonic acid or hydroxyethylidene diphosphonate, disperse it into the mixed system of step (4), stir for 30-60 minutes, dry it, and grind the powder to obtain the additive.

[0011] Furthermore, the mass ratio of aniline monomer to graphene oxide is 4:1.

[0012] Furthermore, the mass ratio of ammonium persulfate to graphene oxide is 20:1.

[0013] Furthermore, the sodium hydroxide solution of a certain concentration refers to 8 mol / L sodium hydroxide solution.

[0014] Furthermore, the molar ratio of the sodium hydroxide in the sodium hydroxide solution to the hydrochloric acid in the ammonium persulfate hydrochloric acid solution is 5 to 6:1.

[0015] Furthermore, the silane coupling agent may be an amino silane coupling agent or an epoxy silane coupling agent. Preferably, the silane coupling agent is γ-aminopropyltriethoxysilane.

[0016] Furthermore, the mass ratio of the silane coupling agent to graphene oxide is 2 to 4:1.

[0017] Furthermore, grinding generally uses a planetary ball mill, which can be wet ball milling or dry ball milling, with a rotation speed of 400-550r / min and a time of 1-2h.

[0018] Furthermore, the mass ratio of hydroxyethylidene diphosphonic acid or hydroxyethylidene diphosphonate to graphene oxide is 1:1.

[0019] The second aspect of the present invention provides a functionalized graphene-based epoxy zinc-containing coating additive prepared by the method described in the first aspect.

[0020] The third aspect of the present invention provides an anti-corrosion coating, which includes the functionalized graphene-based epoxy zinc-containing coating additive described in the first aspect.

[0021] Preferably, the solid content of the functionalized graphene-based epoxy zinc-rich coating additive in the anti-corrosion coating is 0.5-10wt%.

[0022] Preferably, the anti-corrosion coating further comprises zinc powder, and the solid content of the zinc powder in the anti-corrosion coating is 40-80wt%.

[0023] Specifically, the zinc powder can be spherical zinc powder or flaky zinc powder, and the zinc powder is 500 mesh.

[0024] The fourth aspect of the present invention provides an anti-corrosion coating, which is obtained by coating the anti-corrosion coating described in the third aspect on a substrate.

[0025] Compared with the prior art, the advantages of the present invention are: the organic combination of the additive components of the functionalized graphene-based epoxy zinc-containing coating prepared by alkali in the preparation method provided by the present invention produces a synergistic effect, which gives the coating an excellent physical shielding effect and effectively prevents the penetration of corrosive media. At the same time, the functionalized graphene-based epoxy zinc-containing coating has active and passive anti-corrosion effects, especially the activation of the anchored active factors, self-repair and other multifunctional properties, which can significantly extend the cathodic protection time in the zinc-rich coating. The functionalized graphene-based epoxy zinc-containing coating maintains cathodic protection for nearly 50 days in a 3.5wt% NaCl solution, which is better than the pure zinc coating without the addition of the functionalized graphene-based epoxy zinc-containing coating and the zinc-containing coating of the graphene composite material without the active factor. The low-frequency impedance of the 0.5wt% functionalized graphene-based epoxy zinc-containing coating after immersion in a 3.5wt% NaCl solution for 70 days is still within 10 6 Ωcm 2 above. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a comparison chart of infrared spectra of the functionalized graphene-based epoxy zinc-containing coating additive powder prepared in Example 1 and GO.

[0027] Figure 2 This is a comparison chart of infrared spectra of the functionalized graphene-based epoxy zinc-containing coating additive powder and the active factor prepared in Example 1.

[0028] Figure 3 The open circuit potential diagrams are obtained when the anti-corrosion coatings prepared according to Embodiment Examples 1-5 and Comparative Examples 1-5 were immersed in a 3.5% NaCl solution for different days.

[0029] Figure 4 The impedance modulus graphs of the anti-corrosion coatings prepared based on Embodiment Examples 1-5 and Comparative Examples 1-5 after being immersed in 3.5% NaCl solution for different days. DETAILED DESCRIPTION

[0030] The following is a detailed description of the present invention with specific implementation examples, but the implementation examples do not limit the present invention in any way.

[0031] The present invention organically compounds a functionalized reduced graphene oxide / polyaniline composite material with an active factor hydroxyethylidene diphosphonic acid or hydroxyethylidene diphosphonate. In the preparation process, hydrochloric acid is neutralized by sodium hydroxide to prevent corrosive ions and chloride ions from being brought into the coating; at the same time, graphene oxide can be reduced by a high concentration of sodium hydroxide, further giving graphene oxide weak conductivity, and the low conductivity of reduced graphene oxide reduces the corrosion-promoting properties of graphene, and zinc powder can be activated by adding the active factor hydroxyethylidene diphosphonic acid / salt, hindering the generation of non-conductive corrosion products on the zinc surface, so that the zinc powder always remains active. At the same time, the combination product of the active factor and the metal ion can also play a role in filling coating defects and has a self-repairing function. The synergy of the three components in the novel functionalized graphene-based zinc-containing coating additive also gives the coating an excellent physical shielding effect, effectively preventing the infiltration of corrosive media, and playing an active and passive anti-corrosion role, a novel functionalized graphene-based zinc-rich coating additive material.

[0032] Implementation Example 1

[0033] 1. Preparation of functionalized graphene-based epoxy zinc-containing coating additive powder

[0034] (1) First, take 50 mL of graphene oxide aqueous solution (commercially available, 10 mg / mL), add 200 mL of deionized water to dilute and disperse evenly by ultrasonic. Take 2 mL of aniline monomer and add 150 mL of deionized water to dilute and stir. Add the aniline monomer solution to the evenly dispersed graphene oxide solution and stir for 1 hour. Mix well and then place it in an ice water bath and stir.

[0035] (2) Prepare a certain concentration of ammonium persulfate hydrochloric acid solution: Dissolve 0.044 mol of ammonium persulfate in 40 mL of 1 M hydrochloric acid solution. Slowly add the prepared ammonium persulfate hydrochloric acid solution to the solution in (1) above and place in an ice-water bath for 24 hours.

[0036] (3) After the reaction is complete, add 28.8 mL of 8 M sodium hydroxide solution and keep the temperature at 90° C. for 5 h. After cooling, add 0.2 M sulfuric acid solution to make the pH value of the reaction system about 2, react for 12 h, and then filter and wash until neutral.

[0037] (4) The obtained product was placed in a flask, dispersed in an aqueous solution, and 1 g of silane coupling agent γ-aminopropyltriethoxysilane was added to react in a water bath at 80° C. for 4 h. The mixture was cooled to room temperature.

[0038] (5) Weigh 0.5 g of hydroxyethylidene diphosphonic acid, dissolve it in the solution of (4), stir mechanically for 40 min, freeze-dry and grind for 1 h to obtain functionalized graphene-based epoxy zinc-containing coating additive powder.

[0039] 2. Coating preparation and evaluation of electrochemical performance

[0040] (a) Weigh 0.017 g of the obtained functionalized graphene-based epoxy zinc-containing coating additive powder, add 2 mL of xylene to ultrasonically disperse it evenly, then add 1 g of bisphenol A epoxy resin E51 and ball mill it evenly, then add 1.3 g of zinc powder and stir it evenly, finally add 1 g of polyamide B component curing agent diluted with xylene and stir it evenly to obtain a zinc-containing anti-corrosion coating with an additive solid content of 0.5% and a zinc powder solid content of 40%.

[0041] (b) The zinc-containing anticorrosive coating was applied to 1cm*2cm tinplate with a thickness of about 100μm. The coating was cured at 80℃ for 4h. The resulting coating was named coating 1. The coating was aged at room temperature for 3-5 days. The bottom, both sides and back of the coating were sealed, leaving a 1cm 2 The coating in the area was immersed in 3.5% NaCl salt solution for electrochemical testing. The results are as follows Figure 3 and Figure 4 shown.

[0042] The electrochemical workstation of Jiangsu Donghua was used, and the electrochemical test conditions were: open circuit potential 1000s; impedance test frequency 10 - 2 Hz-10 5 Hz.

[0043] Comparative Example 1

[0044] 1. Preparation of functionalized graphene-based epoxy zinc-containing coating additive powder

[0045] For comparison, the steps of Example 1 were repeated, but step (3) was not performed. Other conditions remained the same, and the resulting additive powder was named comparative powder 1.

[0046] 2. Coating preparation and evaluation of electrochemical performance

[0047] The preparation steps of the zinc-rich anti-corrosion coating are the same as those of Example 1, except that in step (a), the functionalized graphene-based epoxy zinc-containing coating additive powder is replaced with the comparative sample powder 1.

[0048] The coating preparation process and test process are the same as those in Example 1. The obtained coating is named comparative coating 1. The test results are shown in Figure 3 and Figure 4 shown.

[0049] Comparative Example 2

[0050] 1. Preparation of functionalized graphene-based epoxy zinc-containing coating additive powder

[0051] For comparison, the steps of Example 1 were repeated, but step (4) was not performed. Other conditions remained the same, and the resulting additive powder was named comparative sample powder 2.

[0052] 2. Coating preparation and evaluation of electrochemical performance

[0053] The preparation steps of the zinc-rich anti-corrosion coating are the same as those of Example 1, except that in step (a), the functionalized graphene-based epoxy zinc-containing coating additive powder is replaced with the comparison sample powder 2.

[0054] The coating preparation process and test process are the same as those in Example 1. The obtained coating is named comparative coating 2. The test results are as follows: Figure 3 and Figure 4 shown.

[0055] Comparative Example 3

[0056] 1. Preparation of functionalized graphene-based epoxy zinc-containing coating additive powder

[0057] For comparison, the steps of Example 1 were repeated, but step (5) was not performed. Other conditions remained the same, and the obtained additive powder was named comparative sample powder 3.

[0058] 2. Coating preparation and evaluation of electrochemical performance

[0059] The steps for preparing the zinc-rich anti-corrosion coating are the same as those of Example 1, except that in step (a), the functionalized graphene-based epoxy zinc-containing coating additive powder is replaced with the comparison sample powder 3.

[0060] The coating preparation process and test process are the same as those in Example 1. The obtained coating is named comparative coating 3. The test results are as follows: Figure 3 and Figure 4 shown.

[0061] Comparative Example 4

[0062] For comparison, a coating with the active factor hydroxyethylidene diphosphonate as an additive was prepared. The process for preparing the coating was the same as step (a) of implementation case 1, except that the functionalized graphene-based epoxy zinc-containing coating additive powder was replaced with hydroxyethylidene diphosphonate to obtain a zinc-containing anti-corrosion coating with a hydroxyethylidene diphosphonate solid content of 0.5% and a zinc powder solid content of 40%.

[0063] The coating preparation process and test process are the same as those in Example 1. The obtained coating is named comparative coating 4. The test results are shown in Figure 3 and Figure 4 shown.

[0064] Comparative Example 5

[0065] As a comparison, a coating without functionalized graphene-based epoxy zinc-containing coating additive powder was prepared. The process of preparing the coating was the same as step (a) of Implementation Case 1, except that the functionalized graphene-based epoxy zinc-containing coating additive powder was changed to 0g to obtain a zinc-rich anti-corrosion coating with a zinc powder solid content of 80%.

[0066] The coating preparation process and test process are the same as those in Example 1. The obtained coating is named comparative coating 5. The test results are shown in Figure 3 and Figure 4 shown.

[0067] Implementation Example 2

[0068] 1. Preparation of functionalized graphene-based epoxy zinc-containing coating additive powder

[0069] The preparation process of the additive powder of this embodiment is the same as that of Embodiment 1, except that in step (5), hydroxyethylidene diphosphonic acid is replaced with hydroxyethylidene diphosphonate to obtain functionalized graphene-based epoxy zinc-containing coating additive nanopowder.

[0070] 2. Coating preparation and evaluation of electrochemical performance

[0071] The preparation steps of the zinc-rich anti-corrosion coating of this embodiment are the same as those of Example 1, except that: in step (a), 0.034 g of the additive powder of Example 2 is used to obtain a zinc-containing anti-corrosion coating with an additive powder solid content of 1% and a zinc powder solid content of 40%.

[0072] The coating preparation process and test process are the same as those in Example 1. The obtained coating is named as Coating 2. The test results are shown in Figure 3 and Figure 4 shown.

[0073] Implementation Example 3

[0074] 1. Preparation of functionalized graphene-based epoxy zinc-containing coating additive powder

[0075] The preparation process of the additive powder in this embodiment is the same as that in Embodiment 2.

[0076] 2. Coating preparation and evaluation of electrochemical performance

[0077] The preparation steps of the zinc-rich anti-corrosion coating of this embodiment are the same as those of Example 2, except that: in step (a), 0.33 g of the additive powder of Example 2 is used to obtain a zinc-containing anti-corrosion coating with an additive powder solid content of 10% and a zinc powder solid content of 40%.

[0078] The coating preparation process and testing process are the same as those in Example 2. The obtained coating is named coating 3. The test results are shown in Figure 3 and Figure 4 shown.

[0079] Implementation Example 4

[0080] 1. Preparation of functionalized graphene-based epoxy zinc-containing coating additive powder

[0081] The preparation process of the additive powder in this embodiment is the same as that in Embodiment 2.

[0082] 2. Coating preparation and evaluation of electrochemical performance

[0083] The preparation steps of the zinc-rich anti-corrosion coating of this embodiment are the same as those of Example 2, except that: in step (a), 0.055 g of additive powder and 3.5 g of zinc powder are used to obtain a zinc-rich anti-corrosion coating with an additive powder solid content of 1% and a zinc powder solid content of 60%.

[0084] The coating preparation process and test process are the same as those of Example 2. The obtained coating is coating 4, and its test results are as follows: Figure 3 and Figure 4 shown.

[0085] Implementation Example 5

[0086] 1. Preparation of functionalized graphene-based epoxy zinc-containing coating additive powder

[0087] The preparation process of the additive powder in this embodiment is the same as that in Embodiment 2.

[0088] 2. Coating preparation and evaluation of electrochemical performance

[0089] The preparation steps of the zinc-rich anti-corrosion coating of this embodiment are the same as those of Example 2, except that: in step (a), 0.16 g of additive powder and 8.6 g of zinc powder are used to obtain a zinc-rich anti-corrosion coating with an additive powder solid content of 1.5% and a zinc powder solid content of 80%.

[0090] The coating preparation process and testing process are the same as those in Example 2. The obtained coating is named coating 5. The test results are shown in Figure 3 and Figure 4 shown.

[0091] Figure 1 Infrared images of graphene oxide and functionalized graphene-based epoxy zinc-containing coating additive (Implementation Example 1) are compared, 3300, 1380 cm -1 The left and right sides correspond to the stretching vibration and deformation vibration of -OH of -COOH of GO, 1719, 1619cm -1 The corresponding stretching vibrations are the C=O and C=C in -COOH in GO; 1237, 1048 cm -1 This corresponds to the vibration absorption peak of CO in COC in GO. -1The new characteristic peaks that appeared were also related to the CC vibration in r-GO. The successful polymerization of aniline on graphene oxide flakes was confirmed. The absorption peak of C=O in the functionalized graphene-based epoxy zinc-containing coating additive was red-shifted to 1700 cm -1 The absorption peak of the CO group also undergoes a certain degree of red shift, and the COOH group enters the vicinity of the N atom on the PANI molecular chain as a doping acid.

[0092] Figure 2 The infrared images of the active factor and the functionalized graphene-based epoxy zinc-containing coating additive (Implementation Example 1) are compared. Compared with the active factor, the functionalized graphene-based epoxy zinc-containing coating additive has the following infrared images at 2731-2500, 1307, 1243, and 638 cm -1 The appearance of vibration peaks related to phosphonate groups can prove the synthesis of functionalized graphene-based epoxy zinc-containing coating additives.

[0093] Figure 3 It is the open circuit potential of coating 1-5 of implementation examples 1-5 and comparative sample coating 1-5 of comparative example 1-5 immersed in 3.5% NaCl solution for different days. Comparative sample coating 5 of comparative example 5 has a cathodic protection effect of nearly 40 days when immersed in 3.5% NaCl solution, and the coating fails at 50 days, which is due to the increase in the porosity of the coating caused by the large amount of zinc powder added. Compared with the comparative sample coating 5, coating 1-5 of implementation examples 1-5 has a better cathodic protection effect. The test results of coating 1 of implementation example 1 show that even when the solid content of the functionalized graphene-based epoxy zinc-containing coating additive is 0.5% and the solid content of zinc powder is 40%, coating 1 still has a cathodic protection time of nearly 50 days. Coating 2-5 of implementation examples 2-5 illustrates that with the increase of the solid content of the functionalized graphene-based epoxy zinc-containing coating additive and the increase of the solid content of zinc powder, the cathodic protection time of the coating can be extended. This shows that the addition of functionalized graphene-based epoxy zinc-containing coating additive can activate zinc powder. The comparative coating 1 of comparative example 1 failed in 30 days, because the additive that has not been neutralized and reduced with sodium hydroxide contains corrosive chloride ions. The comparative coating 2 in comparative example 2 has a cathodic protection time of 30 days, because the additive that has not been modified with a silane coupling agent is unevenly dispersed in the coating. The comparative coating 3 in comparative example 3 has cathodic protection only within 5-20 days, because no active factor is added to the graphene-based composite material, and the effect of activating zinc powder cannot be achieved. The comparative coating 4 of comparative example 4 has no cathodic protection, because no conductive graphene-based material is added. It can be seen that the addition of the functionalized graphene-based epoxy zinc-containing coating additive of the present invention significantly prolongs the cathodic protection time of the coating and significantly improves the corrosion resistance life of the coating.

[0094] Figure 4The impedance modulus of coatings 1-5 of implementation examples 1-5 and comparative sample coatings 1-5 of comparative examples 1-5 after being immersed in 3.5% NaCl solution for different days. The impedance modulus of coatings 1-5 after being immersed in 3.5% NaCl solution for 70 days is still higher than that of comparative sample coatings 1-5, which indicates that the addition of functionalized graphene-based epoxy zinc-containing coating additives significantly improves the physical shielding effect of coatings 1-5. The impedance modulus of comparative sample coating 1 of comparative example 1 is the lowest, because corrosive ions chloride ions are introduced into comparative sample coating 1, and chloride ions accelerate the corrosion of the comparative sample coating. The comparative sample coating 2 of comparative example 2 still did not fail after being immersed in 3.5% NaCl solution for 70 days, but the impedance modulus was smaller than that of coating 1, which shows that the addition of silane coupling agent can enhance the dispersion of materials in the resin and enhance the compactness of the coating; the comparative sample coating 3 of comparative example 3 had an impedance modulus greater than that of coating 1 in the first 10 days of immersion in 3.5% NaCl solution, and then dropped sharply. At 70 days, the impedance modulus value of coating 1 was about 1 order of magnitude higher than that of comparative sample coating 3, which shows that the addition of active factors can enhance the anti-corrosion performance of the coating; the comparative sample coating 4 of comparative example 4 failed after being immersed in 3.5% NaCl solution for 50 days, and compared with coating 1, it shows that the addition of graphene-based materials can enhance the physical shielding effect of the coating. The impedance modulus of comparative sample coating 5 of comparative example 5 was also relatively low during the time from immersion in 3.5% NaCl solution until complete failure, indicating that excessive zinc powder content will increase the porosity of the coating and seriously reduce the physical shielding effect of the coating. Therefore, by comparison, it can be seen that the functionalized graphene-based epoxy zinc-containing coating additive obtained by neutralization and reduction with sodium hydroxide and modification with a silane coupling agent has an obvious physical shielding effect, which greatly extends the life of the coating. Coatings 1-5 are still not invalid after being immersed in a 3.5% NaCl solution for 70 days.

Claims

1. A method for preparing a functionalized graphene-based epoxy zinc-containing coating additive, characterized in that: The steps include: (1) Add the aniline monomer solution to the graphene oxide dispersion and stir for 1-2 h to mix them evenly; (2) Slowly add the hydrochloric acid solution of ammonium persulfate to the mixed system of step (1) and place in an ice water bath for 12-24 hours; (3) After the reaction is complete, add a certain concentration of sodium hydroxide solution and keep it at a constant temperature of 75℃-105℃ for 4.5-6 hours. After cooling, add sulfuric acid solution to make the pH value of the reaction system 2-4, react for 10-15 hours, and then filter and wash until neutral; (4) Re-dispersing the solid separation obtained in step (3) in an aqueous solution, adding a silane coupling agent, reacting in a water bath at 50-95°C for 2-5 hours, and cooling to room temperature; (5) Weigh a certain amount of active factor hydroxyethylidene diphosphonic acid or hydroxyethylidene diphosphonate, disperse it into the mixed system of step (4), stir for 30-60 minutes, dry it, and grind the powder to obtain the additive.

2. The method according to claim 1, characterized in that The mass ratio of aniline monomer to graphene oxide is 4:1; the mass ratio of ammonium persulfate to graphene oxide is 20:

1.

3. The method according to claim 1, characterized in that A sodium hydroxide solution of a certain concentration refers to a sodium hydroxide solution of 8 mol / L.

4. The method according to claim 1, characterized in that The molar ratio of the sodium hydroxide in the sodium hydroxide solution to the hydrochloric acid in the ammonium persulfate hydrochloric acid solution is 5-6:

1.

5. The method according to claim 1, characterized in that The silane coupling agent is an amino silane coupling agent or an epoxy silane coupling agent. Preferably, the silane coupling agent is γ-aminopropyltriethoxysilane.

6. The method according to claim 1, characterized in that The mass ratio of silane coupling agent to graphene oxide is 2~4:

1.

7. The method according to claim 1, characterized in that The mass ratio of hydroxyethylidene diphosphonic acid or hydroxyethylidene diphosphonate to graphene oxide is 1:

1.

8. A functionalized graphene-based epoxy zinc-containing coating additive prepared by the method according to any one of claims 1 to 7.

9. An anticorrosive coating, characterized in that: It comprises a functionalized graphene-based epoxy zinc-containing coating additive prepared by the method according to any one of claims 1 to 7; Preferably, the solid content of the functionalized graphene-based epoxy zinc-rich coating additive in the anti-corrosion coating is 0.5-10 wt %; Preferably, the anti-corrosion coating further comprises zinc powder, and the solid content of the zinc powder in the anti-corrosion coating is 40-80 wt%.

10. An anti-corrosion coating, characterized in that: The anti-corrosion coating is obtained by coating the anti-corrosion coating as claimed in claim 9 on a substrate.

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