Redispersible graphene powder, preparation method and application of redispersible graphene powder in anticorrosive paint

Abstract

The invention discloses redispersible graphene powder, a preparation method and application of the redispersible graphene powder in anticorrosive paint, and belongs to the technical field of nano material dispersion and anticorrosive paint modification. The modified graphene powder comprises the following raw materials: 40%-90% of a solvent, 8%-50% of a modifier and 0.5%-10% of graphene powder; the modifier is one of fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, polysorbate and isomeric alcohol polyoxyethylene ether. According to the preparation method, specific nonionic surfactant modification and drying processes are carried out on graphene, so that the functionalized powder which can be directly added into a coating matrix is obtained. The graphene powder greatly reduces the packaging and transportation cost, keeps the excellent redispersibility of graphene after long-term storage (6 months), and can be used for preparing water-based and oil-based anticorrosive coatings. The invention provides a ready-to-use and high-durability anti-corrosion solution for harsh corrosion environments such as ocean engineering equipment, oil and gas field equipment pipelines, chemical equipment and the like.

Description

Technical Field

[0001] This invention belongs to the field of nanomaterial dispersion and anti-corrosion coating modification technology, specifically relating to a redispersible graphene powder, its preparation method, and its application in anti-corrosion coatings. Background Technology

[0002] Graphene, with its unique two-dimensional sheet structure, excellent chemical inertness, and superior barrier properties, theoretically holds broad application prospects in the field of anti-corrosion coatings. Studies have shown that, under ideal conditions, graphene sheets can form a dense physical barrier, effectively blocking the penetration of water, oxygen, and corrosive ions, while simultaneously inhibiting the electrochemical corrosion of the metal matrix by constructing a conductive network. However, in practical applications, the high specific surface area of ​​graphene leads to strong van der Waals forces between its sheets, making it prone to irreversible aggregation. This aggregation phenomenon is particularly prominent in coating systems, not only weakening the physical barrier effect of graphene and hindering its theoretical barrier performance, but also creating defect channels in the coating, potentially exacerbating localized corrosion. These practical problems severely restrict the industrial application of graphene in anti-corrosion coatings.

[0003] To address the dispersibility issue of graphene in coatings, current technologies commonly employ a graphene pre-dispersion slurry method. This involves first preparing a highly stable graphene dispersion slurry in a specific dispersion medium (such as water or an organic solvent) through ultrasonication, high-speed shearing, or chemical modification. This slurry is then mixed with a resin matrix to form coating component I. After being transported to the construction site, component I is mixed with a curing agent (component II) before application. Alternatively, the graphene dispersion slurry can be transported to the construction site and then mixed with resin and curing agent before use.

[0004] Although this method can improve the dispersibility of graphene in coatings and enhance corrosion resistance to some extent (e.g., increasing the salt spray test life of water-based coatings to 1200-2000 hours), it still has significant limitations from the perspective of industrial application:

[0005] (1) High storage and transportation costs: The liquid medium (water or organic solvent) significantly increases the quality of graphene dispersion slurry and requires special packaging protection (such as antifreeze, anti-settling, and anti-mildew), increasing transportation and storage costs by more than 40% compared to powder.

[0006] (2) Short shelf life: The shelf life of graphene dispersion slurry is usually less than 30 days. After the expiration period, irreversible sedimentation, flocculation or dispersant failure are likely to occur. Moreover, after graphene agglomerates, secondary dispersion is difficult, which seriously affects the consistency of coating performance.

[0007] (3) Poor construction convenience: It requires precise on-site mixing of slurry and resin, which increases the complexity and time cost of construction;

[0008] (4) Low system universality: Water-based slurries are difficult to use in oil-based systems, and oil-based slurries are also poorly compatible with water-based systems, which restricts the flexibility of formulation design and the universality of graphene in different types of coatings.

[0009] (5) Risk of solvent residue: Organic solvents in graphene dispersion slurry may not only damage the crosslinking density of the coating (such as reducing the curing degree of epoxy), but also release volatile organic compounds (VOCs) to pollute the environment, which is not in line with the development trend of green coatings.

[0010] In summary, while existing graphene pre-dispersion slurry methods have made initial progress in dispersion technology, they still have significant shortcomings in terms of economy, storage stability, ease of application, system compatibility, and environmental friendliness. The industry urgently needs to develop a new generation of efficient, stable, and scalable dry dispersion processes to overcome current technological limitations and truly propel graphene coatings towards mature industrialization. Summary of the Invention

[0011] To address the shortcomings of existing technologies, this invention proposes a redispersible modified graphene powder, its preparation method, and its application in oil-based and water-based anti-corrosion coatings.

[0012] In a first aspect, this application provides a modified graphene powder, which comprises the following raw materials in mass fractions: 40% to 90% solvent, 8% to 50% modifier, and 0.5% to 10% graphene powder;

[0013] The solvent is an organic solvent, including one of ethanol, acetone, ethylene glycol, and isopropanol;

[0014] The modifier is one of the following: fatty alcohol polyoxyethylene ether (AEO series), nonylphenol polyoxyethylene ether (NP series), octylphenol polyoxyethylene ether (OP series), polysorbate (Tween series), and isomeric alcohol polyoxyethylene ether (DNS series).

[0015] The method for preparing the modified graphene powder includes: dissolving a modifier in a solvent to obtain a modifier solution; mixing and stirring the modifier solution with graphene powder; allowing it to stand for 20-26 hours; and then separating the solid and liquid phases and drying to obtain the modified graphene powder. The mixing and stirring speed is 100 rpm to 1000 rpm. The drying is performed under vacuum at 100-120℃.

[0016] In some embodiments, the concentration of ethanol is ≥99.7 wt%, and the concentration of acetone is ≥99.7 wt%.

[0017] In some embodiments, the fatty alcohol polyoxyethylene ethers (AEO series) are one of fatty alcohol polyoxyethylene (3) ether, fatty alcohol polyoxyethylene (5) ether, fatty alcohol polyoxyethylene (7) ether, fatty alcohol polyoxyethylene (9) ether, and fatty alcohol polyoxyethylene (15) ether. They are abbreviated as AEO-3, AEO-5, AEO-7, AEO-9, and AEO-15. Their corresponding ethylene oxide addition (EO) numbers are 3, 5, 7, 9, and 15, respectively. AEO-3 and AEO-5 are oil-soluble, and the modified graphene powder is used in oil-based resin matrices; AEO-7, AEO-9, and AEO-15 are water-soluble, and the modified graphene powder is used in water-based resin matrices.

[0018] In some embodiments, the nonylphenol polyoxyethylene ether (NP series) is one of nonylphenol polyoxyethylene (3) ether, nonylphenol polyoxyethylene (4) ether, nonylphenol polyoxyethylene (6) ether, nonylphenol polyoxyethylene (7) ether, nonylphenol polyoxyethylene (10) ether, nonylphenol polyoxyethylene (15) ether, or nonylphenol polyoxyethylene (40) ether. It is abbreviated as NP-3, NP-4, NP-6, NP-7, NP-10, NP-15, and NP-40. Among them, NP-3 and NP-4 have EO numbers of 3 and 4 respectively, and are oil-soluble. The modified graphene powder is used in oil-based resin matrices. NP-15 and NP-40 have EO numbers of 15 and 40 respectively, and are water-soluble. The modified graphene powder is used in water-based resin matrices. NP-6, NP-7, and NP-10 have intermediate EO numbers and are facultative. The modified graphene powder can be used in both oil-based and water-based resin matrices.

[0019] In some embodiments, the octylphenol polyoxyethylene ether (OP series) is one of octylphenol polyoxyethylene (4) ether, octylphenol polyoxyethylene (7) ether, octylphenol polyoxyethylene (9) ether, octylphenol polyoxyethylene (10) ether, octylphenol polyoxyethylene (15) ether, octylphenol polyoxyethylene (30) ether, octylphenol polyoxyethylene (40) ether, and octylphenol polyoxyethylene (50) ether. It is abbreviated as OP-4, OP-7, OP-9, OP-10, OP-15, OP-30, OP-40, and OP-50. Among them, OP-4 and OP-7 have low EO numbers and are oil-soluble, and the modified graphene powder is used in oil-based resin matrices; OP-9, OP-10, and OP-15 have medium EO numbers and are facultative, and the modified graphene powder can be used in both oil-based and water-based resin matrices; OP-30, OP-40, and OP-50 have high EO numbers and are water-soluble, and the modified graphene powder is used in water-based resin matrices.

[0020] In some embodiments, the polysorbate (Tween series) is one of polyoxyethylene (20) sorbitan monolaurate, polyoxyethylene (20) sorbitan monopalmitate, polyoxyethylene (20) sorbitan monostearate, and polyoxyethylene (20) sorbitan monooleate. It is abbreviated as Tween20, Tween40, Tween60, and Tween80. The EO number of Tween20, Tween40, Tween60, and Tween80 is 20. The numbers in the naming represent differences in fatty acid types; the smaller the number, the shorter the carbon chain, and vice versa. Graphene powder modified with Tween80 is used in oil-based resin matrices; graphene powder modified with Tween20 is used in water-based resin matrices; and graphene powder modified with Tween40 and Tween60 can be used in both oil-based and water-based resin matrices.

[0021] In some embodiments, the isomeric alcohol polyoxyethylene ether (DNS series) is one of isomeric tridecyl alcohol polyoxyethylene (5) ether, namely DNS-500, isomeric tridecyl alcohol polyoxyethylene (7) ether, namely DNS-700, and isomeric tridecyl alcohol polyoxyethylene (1340) ether, namely DNS-1340. DNS-500 has an EO number of 5, exhibiting oil solubility, and the modified graphene powder is used in oil-based resin matrices; DNS-700 has an EO number of 7, exhibiting amphoteric properties, and the modified graphene powder can be used in both oil-based and water-based resin matrices; DNS-1340 has an EO number of 40, exhibiting water solubility, and the modified graphene powder is used in water-based resin matrices.

[0022] In some embodiments, the modified graphene powder comprises the following raw materials in mass fractions: 40%–85% solvent, 8%–50% modifier, and 0.5%–10% graphene powder.

[0023] In some embodiments, the preparation method of the modified graphene powder includes the following steps:

[0024] S1: Add the modifier to the solvent and stir at 25-50℃ until the modifier is completely dissolved to obtain solution A;

[0025] S2: Add graphene powder to solution A, stir at 100 rpm to 1000 rpm for 25-40 min at 25-50℃, and let stand for 20-26 h to obtain slurry B;

[0026] S3: Filter slurry B, and vacuum dry the filtered solids at 100-120℃ to obtain modified graphene powder.

[0027] The preparation method uses a low or medium stirring speed, requiring only a common stirrer combined with drying equipment to prepare modified graphene powder. This modified graphene powder can significantly reduce packaging and transportation costs, and maintains excellent redispersibility even after long-term storage (6 months).

[0028] Secondly, this application provides applications of the modified graphene powder, the applications including:

[0029] (a1) Its application in the preparation of anti-corrosion coatings;

[0030] (a2) Application in the preparation of thermally conductive materials;

[0031] (a3) Application as a conductive additive or negative electrode material in the preparation of lithium-ion batteries;

[0032] (a4) Application of catalyst support in the preparation of fuel cells;

[0033] (a5) Application as a reinforcing or toughening component, or a conductive or thermally conductive component in the preparation of composite materials.

[0034] Thirdly, this application provides a graphene anti-corrosion coating comprising the following raw materials in the indicated mass fractions: 35%–80% resin matrix, 5%–50% curing agent, and 0.1%–2% modified graphene powder;

[0035] The modified graphene powder is as described in any of the above descriptions, and the resin matrix is ​​one of bisphenol A type epoxy resin, waterborne epoxy resin emulsion, and waterborne polyurethane. Based on the properties of the resin matrix, the prepared graphene anti-corrosion coatings include oil-based graphene anti-corrosion coatings and waterborne graphene anti-corrosion coatings.

[0036] In some embodiments, a graphene anti-corrosion coating comprises the following raw materials in weight fractions: 40% to 80% resin matrix, 10% to 50% curing agent, and 0.1% to 2% modified graphene powder.

[0037] More preferably, the graphene anti-corrosion coating comprises the following raw materials in the indicated mass fractions: 50%–70% resin matrix, 20%–40% curing agent, and 0.1%–2% modified graphene powder.

[0038] In some embodiments, the bisphenol A type epoxy resin is a bisphenol A type epoxy resin with an epoxy equivalent of 450-650 g / eq; for example, bisphenol A type epoxy resins of type E-51, E-44, and E-35.

[0039] And / or; the aqueous epoxy resin emulsion is an aqueous epoxy resin emulsion with an epoxy equivalent in the range of 450-650 g / eq; wherein, the aqueous epoxy resin emulsion is an environmentally friendly product made from bisphenol A type epoxy resin or other types of epoxy resin as raw materials through water-based technology.

[0040] And / or; the waterborne polyurethane includes one of anionic waterborne polyurethane, cationic waterborne polyurethane, and nonionic waterborne polyurethane.

[0041] And / or; the curing agent is diethylenetriamine for bisphenol A type epoxy resin and waterborne epoxy resin emulsion, and hexamethylene diisocyanate isocyanurate (HDI) trimer for waterborne polyurethane matrix (hereinafter referred to as HDI trimer).

[0042] The three common types of resin matrices are: bisphenol A type epoxy resin (oil-based matrix), waterborne epoxy resin (waterborne matrix), and waterborne polyurethane (waterborne matrix). All three types of resin matrices are suitable for the modified graphene powder prepared in this application, meaning that the modified graphene powder prepared in this application can be redispersed in all three types of matrices.

[0043] This graphene anti-corrosion coating contains three components: resin matrix, curing agent, and modified graphene powder. These components can be stored and transported separately and mixed on-site for immediate use.

[0044] Fourthly, this application provides a method for preparing the graphene anti-corrosion coating, comprising the following steps:

[0045] S4: Add modified graphene powder to the resin matrix and stir at 100 rpm to 1000 rpm for 30-120 min to obtain slurry C;

[0046] S5: Add curing agent to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0047] In some embodiments, in step S4, after stirring at a speed of 500 rpm to 900 rpm for 30-120 minutes, slurry C is obtained. The stirring speed is low or medium, and only a common mixer is needed on-site to achieve immediate mixing and use of the graphene anti-corrosion coating.

[0048] Fifthly, this application provides a graphene anti-corrosion coating, which is formed by coating the graphene anti-corrosion coating or the graphene anti-corrosion coating prepared by the above-mentioned graphene anti-corrosion coating or preparation method onto the surface of a substrate and then drying and curing it; the substrate includes a metal substrate and a non-metal substrate.

[0049] In some embodiments, the oil-based graphene anti-corrosion coating with a thickness of 60±5 μm has a salt spray resistance life ≥3800h (according to GB / T 10125-2021 Artificial Atmosphere Corrosion Test Salt Spray Test Neutral Salt Spray Test, 5% NaCl, 35±2℃); the coating charge transfer resistance (R) ct >1.0×10 8 Ω·cm 2 (Based on EIS electrochemical impedance spectroscopy, frequency range 100kHz-10mHz, amplitude 10mV).

[0050] In some embodiments, the waterborne graphene anti-corrosion coating with a thickness of 60±5μm has a salt spray resistance life ≥2600h (according to GB / T 10125-2021 Artificial Atmosphere Corrosion Test Salt Spray Test Neutral Salt Spray Test, 5% NaCl, 35±2℃); the coating charge transfer resistance (R) ct >7.5×10 7 Ω·cm 2 (Based on EIS electrochemical impedance spectroscopy, frequency range 100kHz-10mHz, amplitude 10mV).

[0051] Traditional coatings (without graphene) typically have a salt spray resistance life of 600-800 hours, and the coating charge transfer resistance (R) is... ct ) in 10 3 Order of magnitude.

[0052] The salt spray resistance of oil-based coatings formed by adding traditional graphene slurry to resin is generally 3000 hours, while that of water-based coatings is generally 1200 hours. Moreover, this graphene is non-redispersible.

[0053] Sixthly, this application provides the application of the graphene anti-corrosion coating, which is used to prepare any of the following protective coatings:

[0054] (b1) Protective coatings for marine engineering facilities, including but not limited to oil drilling platforms, offshore wind turbine towers and steel piles for cross-sea bridges;

[0055] (b2) Protective coatings for oil and gas transportation and chemical equipment, including but not limited to oil and gas pipelines, storage tanks and chemical equipment surfaces;

[0056] (b3) Protective coatings for ship components, including but not limited to the hull, deck and cabin.

[0057] In summary, compared with the prior art, this application achieves the following technical effects:

[0058] This application provides a solution for redispersible graphene powder. By modifying graphene with a specific nonionic surfactant and employing a drying process, functionalized graphene powder that can be directly added to coating matrices is obtained. This powder possesses the following breakthrough advantages:

[0059] (1) Mix and use immediately: The powder can be directly added to oily / watery resins and graphene can be quickly redispersed by simple stirring (100rpm to 1000rpm with a regular stirrer). No pre-dispersion process is required, and the problem of solvent residue is avoided.

[0060] (2) Storage and transportation economy: The graphene powder form greatly reduces packaging and transportation costs, and still maintains excellent redispersibility after long-term storage (6 months);

[0061] (3) Broad spectrum compatibility: Through the design of surfactant molecular structure, stable dispersion of powder in oily and watery systems such as epoxy resin, waterborne epoxy resin emulsion, and polyurethane is achieved;

[0062] (4) Improved corrosion resistance: A dense graphene network is formed in all types of base coatings, which improves the coating’s resistance to salt spray corrosion and is significantly better than similar coatings prepared by traditional methods.

[0063] This application breaks through the reliance on on-site dispersion equipment in traditional slurry methods, providing a ready-to-use and highly durable anti-corrosion solution for harsh corrosive environments such as marine engineering equipment, oil and gas field equipment pipelines, and chemical equipment. Attached Figure Description

[0064] Figure 1 This is a SEM image of the modified graphene powder prepared in step (3) of Example 2 of this application.

[0065] Figure 2 This is a SEM image of graphene separated from slurry C in Example 2 of this application using standard methods.

[0066] Figure 3 This is a SEM image of graphene separated from slurry C in Example 3 of this application using standard methods.

[0067] Figure 4 The modified graphene prepared in step (3) of Example 2 of this application was placed for 6 months, and then slurry C was prepared according to step (4) of Example 2. The SEM image of the graphene separated by the standard method is shown. Detailed Implementation

[0068] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0069] Addressing the key technical bottlenecks in existing graphene-modified coatings, such as high storage and transportation costs, short shelf life, and poor application convenience, as well as poor powder redispersibility, low solvent system compatibility, and environmental pollutant residues, this application provides a redispersible graphene powder and its preparation method. Through a molecular interface anchoring-steric hindrance synergistic mechanism and drying process, long-term stable dispersion of graphene powder in oil-based / water-based coatings is achieved, improving the coating's density and corrosive media barrier properties. This technology overcomes the dependence on on-site dispersion equipment in traditional slurry methods, providing a ready-to-use, highly durable anti-corrosion solution for harsh corrosive environments such as marine engineering equipment, oil and gas field equipment pipelines, and chemical equipment.

[0070] The term "redispersibility" in this application refers to the process of preparing graphene into microscopically porous and fluffy "pseudo-aggregates" through a combination of molecular interface anchoring-steric hindrance synergistic mechanism and drying technology. These special powder particles, when subjected to low-intensity mechanical forces (such as conventional stirring ≤1000 rpm) in a dispersant, can rapidly disintegrate and release the originally dispersed, independent graphene sheets, rather than forming hard, difficult-to-open agglomerates.

[0071] Unless otherwise specified, the experimental methods used in the following specific embodiments are conventional methods. Unless otherwise specified, the materials and reagents used in the following specific embodiments can be obtained from conventional commercial sources or prepared according to conventional methods in the art.

[0072] The solvents used in the examples were ethanol and acetone with a concentration ≥99.7wt%; the aqueous epoxy resin emulsion was a commercially available aqueous epoxy resin emulsion with an epoxy equivalent in the range of 450-650 g / eq. The graphene used as raw material in step (2) of the examples was in powder form with a sheet particle size of approximately 2-20 μm.

[0073] Hexamethylene diisocyanate isocyanurate (HDI) trimer, CAS number 3779-63-3, is abbreviated as HDI trimer in the examples.

[0074] Example 1:

[0075] (1) Add 22.4g of the modifier fatty alcohol polyoxyethylene ether AEO-3 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0076] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0077] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0078] (4) Add 1g of modified graphene powder (1.3% by mass) to 46g of bisphenol A type epoxy resin E-44 resin matrix (mass fraction of 59.7%), stir at 800rpm for 60min to obtain slurry C.

[0079] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.0%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0080] Example 2:

[0081] (1) Add 22.4g of the modifier fatty alcohol polyoxyethylene ether AEO-5 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0082] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0083] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0084] (4) Add 1g of modified graphene powder (1.3% by mass) to 46g of bisphenol A type epoxy resin E-44 resin matrix (mass fraction of 59.7%), stir at 800rpm for 60min to obtain slurry C.

[0085] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.0%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0086] Example 3:

[0087] (1) Add 22.4g of the modifier fatty alcohol polyoxyethylene ether AEO-7 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0088] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0089] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0090] (4) Add 0.62g of modified graphene powder (mass fraction of 0.8%) to 46g of waterborne polyurethane resin matrix (mass fraction of 60.0%), stir at 800rpm for 60min to obtain slurry C;

[0091] (5) Add 30g of curing agent HDI trimer (mass fraction of 39.2%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0092] Example 4:

[0093] (1) Add 22.4g of the modifier fatty alcohol polyoxyethylene ether AEO-9 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0094] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0095] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0096] (4) Add 0.62g of modified graphene powder (mass fraction of 0.8%) to 46g of waterborne polyurethane resin matrix (mass fraction of 60.0%), stir at 800rpm for 60min to obtain slurry C;

[0097] (5) Add 30g of curing agent HDI trimer (mass fraction of 39.2%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0098] Example 5:

[0099] (1) Add 22.4g of the modifier fatty alcohol polyoxyethylene ether AEO-15 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0100] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0101] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0102] (4) Add 0.62g of modified graphene powder (mass fraction of 0.8%) to 46g of waterborne polyurethane resin matrix (mass fraction of 60.0%), stir at 800rpm for 60min to obtain slurry C;

[0103] (5) Add 30g of curing agent HDI trimer (mass fraction of 39.2%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0104] Example 6:

[0105] (1) Add 22.4g of modifier nonylphenol polyoxyethylene ether NP-3 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0106] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0107] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0108] (4) Add 1g of modified graphene powder (1.3% by mass) to 46g of bisphenol A type epoxy resin E-44 resin matrix (mass fraction of 59.7%), stir at 800rpm for 60min to obtain slurry C.

[0109] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.0%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0110] Example 7:

[0111] (1) Add 22.4g of modifier nonylphenol polyoxyethylene ether NP-4 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0112] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0113] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0114] (4) Add 1g of modified graphene powder (1.3% by mass) to 46g of bisphenol A type epoxy resin E-44 resin matrix (mass fraction of 59.7%), stir at 800rpm for 60min to obtain slurry C.

[0115] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.0%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0116] Example 8:

[0117] (1) Add 22.4g of modifier nonylphenol polyoxyethylene ether NP-6 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0118] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0119] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0120] (4) Add 0.77g of modified graphene powder (1.0% by mass) to 46g of waterborne epoxy resin emulsion (mass fraction of 59.9%), stir at 800rpm for 60min to obtain slurry C;

[0121] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.1%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0122] Example 9:

[0123] (1) Add 22.4g of modifier nonylphenol polyoxyethylene ether NP-7 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0124] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0125] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0126] (4) Add 0.77g of modified graphene powder (1.0% by mass) to 46g of waterborne epoxy resin emulsion (mass fraction of 59.9%), stir at 800rpm for 60min to obtain slurry C;

[0127] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.1%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0128] Example 10:

[0129] (1) Add 22.4g of modifier nonylphenol polyoxyethylene ether NP-10 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0130] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0131] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0132] (4) Add 0.77g of modified graphene powder (1.0% by mass) to 46g of waterborne epoxy resin emulsion (mass fraction of 59.9%), stir at 800rpm for 60min to obtain slurry C;

[0133] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.1%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0134] Example 11:

[0135] (1) Add 22.4g of modifier nonylphenol polyoxyethylene ether NP-10 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0136] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0137] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0138] (4) Add 1g of modified graphene powder (1.3% by mass) to 46g of bisphenol A type epoxy resin E-44 resin matrix (mass fraction of 59.7%), stir at 800rpm for 60min to obtain slurry C.

[0139] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.0%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0140] Example 12:

[0141] (1) Add 22.4g of modifier nonylphenol polyoxyethylene ether NP-15 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0142] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0143] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0144] (4) Add 0.62g of modified graphene powder (mass fraction of 0.8%) to 46g of waterborne polyurethane resin matrix (mass fraction of 60.0%), stir at 800rpm for 60min to obtain slurry C;

[0145] (5) Add 30g of curing agent HDI trimer (mass fraction of 39.2%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0146] Example 13:

[0147] (1) Add 22.4g of modifier nonylphenol polyoxyethylene ether NP-40 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0148] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0149] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0150] (4) Add 0.62g of modified graphene powder (mass fraction of 0.8%) to 46g of waterborne polyurethane resin matrix (mass fraction of 60.0%), stir at 800rpm for 60min to obtain slurry C;

[0151] (5) Add 30g of curing agent HDI trimer (mass fraction of 39.2%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0152] Example 14:

[0153] (1) Add 22.4g of modifier octylphenol polyoxyethylene ether OP-4 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0154] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0155] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0156] (4) Add 1g of modified graphene powder (1.3% by mass) to 46g of bisphenol A type epoxy resin E-44 resin matrix (mass fraction of 59.7%), stir at 800rpm for 60min to obtain slurry C.

[0157] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.0%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0158] Example 15:

[0159] (1) Add 22.4g of modifier octylphenol polyoxyethylene ether OP-7 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0160] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0161] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0162] (4) Add 1g of modified graphene powder (1.3% by mass) to 46g of bisphenol A type epoxy resin E-44 resin matrix (mass fraction of 59.7%), stir at 800rpm for 60min to obtain slurry C.

[0163] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.0%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0164] Example 16:

[0165] (1) Add 22.4g of modifier octylphenol polyoxyethylene ether OP-9 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0166] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0167] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0168] (4) Add 0.77g of modified graphene powder (1.0% by mass) to 46g of waterborne epoxy resin emulsion (mass fraction of 59.9%), stir at 800rpm for 60min to obtain slurry C;

[0169] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.1%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0170] Example 17:

[0171] (1) Add 22.4g of modifier octylphenol polyoxyethylene ether OP-10 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0172] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0173] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0174] (4) Add 0.77g of modified graphene powder (1.0% by mass) to 46g of waterborne epoxy resin emulsion (mass fraction of 59.9%), stir at 800rpm for 60min to obtain slurry C;

[0175] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.1%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0176] Example 18:

[0177] (1) Add 22.4g of modifier octylphenol polyoxyethylene ether OP-15 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0178] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0179] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0180] (4) Add 0.77g of modified graphene powder (1.0% by mass) to 46g of waterborne epoxy resin emulsion (mass fraction of 59.9%), stir at 800rpm for 60min to obtain slurry C;

[0181] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.1%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0182] Example 19:

[0183] (1) Add 22.4g of modifier octylphenol polyoxyethylene ether OP-15 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0184] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0185] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0186] (4) Add 1g of modified graphene powder (1.3% by mass) to 46g of bisphenol A type epoxy resin E-44 resin matrix (mass fraction of 59.7%), stir at 800rpm for 60min to obtain slurry C.

[0187] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.0%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0188] Example 20:

[0189] (1) Add 22.4g of modifier octylphenol polyoxyethylene ether OP-30 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0190] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0191] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0192] (4) Add 0.62g of modified graphene powder (mass fraction of 0.8%) to 46g of waterborne polyurethane resin matrix (mass fraction of 60.0%), stir at 800rpm for 60min to obtain slurry C;

[0193] (5) Add 30g of curing agent HDI trimer (mass fraction of 39.2%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0194] Example 21:

[0195] (1) Add 22.4g of modifier octylphenol polyoxyethylene ether OP-40 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0196] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0197] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0198] (4) Add 0.62g of modified graphene powder (mass fraction of 0.8%) to 46g of waterborne polyurethane resin matrix (mass fraction of 60.0%), stir at 800rpm for 60min to obtain slurry C;

[0199] (5) Add 30g of curing agent HDI trimer (mass fraction of 39.2%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0200] Example 22:

[0201] (1) Add 22.4g of modifier octylphenol polyoxyethylene ether OP-50 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0202] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0203] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0204] (4) Add 0.62g of modified graphene powder (mass fraction of 0.8%) to 46g of waterborne polyurethane resin matrix (mass fraction of 60.0%), stir at 800rpm for 60min to obtain slurry C;

[0205] (5) Add 30g of curing agent HDI trimer (mass fraction of 39.2%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0206] Example 23:

[0207] (1) Add 22.4g of the modifier polysorbate Tween20 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0208] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0209] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0210] (4) Add 1g of modified graphene powder (1.3% by mass) to 46g of bisphenol A type epoxy resin E-44 resin matrix (mass fraction of 59.7%), stir at 800rpm for 60min to obtain slurry C.

[0211] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.0%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0212] Example 24:

[0213] (1) Add 22.4g of the modifier polysorbate Tween40 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0214] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0215] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0216] (4) Add 0.77g of modified graphene powder (1.0% by mass) to 46g of waterborne epoxy resin emulsion (mass fraction of 59.9%), stir at 800rpm for 60min to obtain slurry C;

[0217] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.1%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0218] Example 25:

[0219] (1) Add 22.4g of the modifier polysorbate Tween60 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0220] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0221] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0222] (4) Add 0.77g of modified graphene powder (1.0% by mass) to 46g of waterborne epoxy resin emulsion (mass fraction of 59.9%), stir at 800rpm for 60min to obtain slurry C;

[0223] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.1%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0224] Example 26:

[0225] (1) Add 22.4g of the modifier polysorbate Tween80 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0226] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0227] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0228] (4) Add 0.62g of modified graphene powder (mass fraction of 0.8%) to 46g of waterborne polyurethane resin matrix (mass fraction of 60.0%), stir at 800rpm for 60min to obtain slurry C;

[0229] (5) Add 30g of curing agent HDI trimer (mass fraction of 39.2%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0230] Example 27:

[0231] (1) Add 22.4g of modifier isomeric alcohol polyoxyethylene ether DNS-500 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0232] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0233] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0234] (4) Add 1g of modified graphene powder (1.3% by mass) to 46g of bisphenol A type epoxy resin E-44 resin matrix (mass fraction of 59.7%), stir at 800rpm for 60min to obtain slurry C.

[0235] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.0%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0236] Example 28:

[0237] (1) Add 22.4g of modifier isomeric alcohol polyoxyethylene ether DNS-700 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0238] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0239] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0240] (4) Add 0.77g of modified graphene powder (1.0% by mass) to 46g of waterborne epoxy resin emulsion (mass fraction of 59.9%), stir at 800rpm for 60min to obtain slurry C;

[0241] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.1%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0242] Example 29:

[0243] (1) Add 22.4g of modifier isomeric alcohol polyoxyethylene ether DNS-1340 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0244] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0245] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0246] (4) Add 0.62g of modified graphene powder (mass fraction of 0.8%) to 46g of waterborne polyurethane resin matrix (mass fraction of 60.0%), stir at 800rpm for 60min to obtain slurry C;

[0247] (5) Add 30g of curing agent HDI trimer (mass fraction of 39.2%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0248] Example 30:

[0249] (1) Add 7.15g of the modifier fatty alcohol polyoxyethylene ether AEO-5 (mass fraction of 8.0%) to 75g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0250] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0251] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0252] (4) Add 1g of modified graphene powder (1.3% by mass) to 46g of bisphenol A type epoxy resin E-44 resin matrix (mass fraction of 59.7%), stir at 800rpm for 60min to obtain slurry C.

[0253] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.0%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0254] Example 31:

[0255] (1) Add 45g of the modifier fatty alcohol polyoxyethylene ether AEO-5 (mass fraction of 50.0%) to 37.8g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0256] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0257] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0258] (4) Add 1g of modified graphene powder (1.3% by mass) to 46g of bisphenol A type epoxy resin E-44 resin matrix (mass fraction of 59.7%), stir at 800rpm for 60min to obtain slurry C.

[0259] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.0%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0260] Example 32:

[0261] (1) Add 7.15g of modifier nonylphenol polyoxyethylene ether NP-4 (mass fraction of 8.0%) to 75g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0262] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0263] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0264] (4) Add 1g of modified graphene powder (1.3% by mass) to 46g of bisphenol A type epoxy resin E-44 resin matrix (mass fraction of 59.7%), stir at 800rpm for 60min to obtain slurry C.

[0265] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.0%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0266] Example 33:

[0267] (1) Add 45g of modifier nonylphenol polyoxyethylene ether NP-4 (mass fraction of 50.0%) to 37.8g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0268] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0269] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0270] (4) Add 1g of modified graphene powder (1.3% by mass) to 46g of bisphenol A type epoxy resin E-44 resin matrix (mass fraction of 59.7%), stir at 800rpm for 60min to obtain slurry C.

[0271] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.0%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0272] Example 34:

[0273] (1) Add 7.15g of modifier octylphenol polyoxyethylene ether OP-7 (mass fraction of 8.0%) to 75g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0274] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0275] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0276] (4) Add 1g of modified graphene powder (1.3% by mass) to 46g of bisphenol A type epoxy resin E-44 resin matrix (mass fraction of 59.7%), stir at 800rpm for 60min to obtain slurry C.

[0277] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.0%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0278] Example 35:

[0279] (1) Add 45g of modifier octylphenol polyoxyethylene ether OP-7 (mass fraction of 50.0%) to 37.8g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0280] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0281] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0282] (4) Add 1g of modified graphene powder (1.3% by mass) to 46g of bisphenol A type epoxy resin E-44 resin matrix (mass fraction of 59.7%), stir at 800rpm for 60min to obtain slurry C.

[0283] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.0%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0284] Example 36:

[0285] (1) Add 7.15g of the modifier polysorbate Tween20 (mass fraction of 8.0%) to 75g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0286] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0287] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0288] (4) Add 1g of modified graphene powder (1.3% by mass) to 46g of bisphenol A type epoxy resin E-44 resin matrix (mass fraction of 59.7%), stir at 800rpm for 60min to obtain slurry C.

[0289] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.0%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0290] Example 37:

[0291] (1) Add 45g of the modifier polysorbate Tween20 (mass fraction of 50.0%) to 37.8g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0292] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0293] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0294] (4) Add 1g of modified graphene powder (1.3% by mass) to 46g of bisphenol A type epoxy resin E-44 resin matrix (mass fraction of 59.7%), stir at 800rpm for 60min to obtain slurry C.

[0295] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.0%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0296] Example 38:

[0297] (1) Add 7.15g of modifier isomeric alcohol polyoxyethylene ether DNS-500 (mass fraction of 8.0%) to 75g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0298] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0299] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0300] (4) Add 1g of modified graphene powder (1.3% by mass) to 46g of bisphenol A type epoxy resin E-44 resin matrix (mass fraction of 59.7%), stir at 800rpm for 60min to obtain slurry C.

[0301] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.0%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0302] Example 39:

[0303] (1) Add 45g of modifier isomeric alcohol polyoxyethylene ether DNS-500 (mass fraction of 50.0%) to 37.8g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0304] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0305] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0306] (4) Add 1g of modified graphene powder (1.3% by mass) to 46g of bisphenol A type epoxy resin E-44 resin matrix (mass fraction of 59.7%), stir at 800rpm for 60min to obtain slurry C.

[0307] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.0%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0308] Example 40:

[0309] (1) Add 22.4g of the modifier fatty alcohol polyoxyethylene ether AEO-5 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0310] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0311] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0312] (4) Add 0.076g of modified graphene powder (0.1% by mass) to 46g of bisphenol A type epoxy resin E-44 resin matrix (mass fraction of 60.5%), and stir at 800rpm for 60min to obtain slurry C.

[0313] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.4%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0314] Example 41:

[0315] (1) Add 22.4g of the modifier fatty alcohol polyoxyethylene ether AEO-5 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0316] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0317] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0318] (4) Add 1.56g of modified graphene powder (2.0% by mass) to 46g of bisphenol A type epoxy resin E-44 resin matrix (mass fraction of 59.3%), and stir at 800rpm for 60min to obtain slurry C.

[0319] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 38.7%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0320] Example 42:

[0321] (1) Add 22.4g of modifier nonylphenol polyoxyethylene ether NP-7 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0322] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0323] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0324] (4) Add 0.076g of modified graphene powder (0.1% by mass) to 46g of waterborne epoxy resin emulsion (mass fraction of 60.5%), and stir at 800rpm for 60min to obtain slurry C.

[0325] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.4%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0326] Example 43:

[0327] (1) Add 22.4g of modifier nonylphenol polyoxyethylene ether NP-7 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0328] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0329] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0330] (4) Add 1.56g of modified graphene powder (2.0% by mass) to 46g of waterborne epoxy resin emulsion (mass fraction of 59.3%), stir at 800rpm for 60min to obtain slurry C;

[0331] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 38.7%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0332] Example 44:

[0333] (1) Add 22.4g of modifier octylphenol polyoxyethylene ether OP-40 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0334] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0335] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0336] (4) Add 0.076g of modified graphene powder (0.1% by mass) to 46g of waterborne polyurethane resin matrix (mass fraction of 60.5%), stir at 800rpm for 60min to obtain slurry C;

[0337] (5) Add 30g of curing agent HDI trimer (mass fraction of 39.4%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0338] Example 45:

[0339] (1) Add 22.4g of modifier octylphenol polyoxyethylene ether OP-40 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0340] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0341] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0342] (4) Add 1.56g of modified graphene powder (2.0% by mass) to 46g of waterborne polyurethane resin matrix (mass fraction of 59.3%), stir at 800rpm for 60min to obtain slurry C;

[0343] (5) Add 30g of curing agent HDI trimer (mass fraction of 38.7%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0344] Example 46:

[0345] (1) Add 22.4g of the modifier fatty alcohol polyoxyethylene ether AEO-5 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0346] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0347] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0348] (4) Add 1g of modified graphene powder (1.3% by mass) to 46g of bisphenol A type epoxy resin E-51 resin matrix (mass fraction of 59.7%), stir at 800rpm for 60min to obtain slurry C.

[0349] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.0%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0350] Example 47:

[0351] (1) Add 22.4g of the modifier fatty alcohol polyoxyethylene ether AEO-5 (mass fraction of 25.0%) to 60g of ethanol, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0352] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0353] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0354] (4) Add 1g of modified graphene powder (1.3% by mass) to 46g of bisphenol A type epoxy resin E-35 resin matrix (mass fraction of 59.7%), stir at 800rpm for 60min to obtain slurry C.

[0355] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.0%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0356] Example 48:

[0357] (1) Add 22.4g of the modifier fatty alcohol polyoxyethylene ether AEO-5 (mass fraction of 25.0%) to 60g of acetone, and stir at 30℃ until the modifier is completely dissolved to obtain solution A;

[0358] (2) Add 7.17g of graphene powder (mass fraction of 8.0%) to solution A, stir at 500rpm for 30min at 30℃, and let stand for 24h to obtain slurry B;

[0359] (3) Filter slurry B, place the filtered solid material in a vacuum drying oven at 110℃ and dry it completely to obtain modified graphene powder.

[0360] (4) Add 1g of modified graphene powder (1.3% by mass) to 46g of bisphenol A type epoxy resin E-44 resin matrix (mass fraction of 59.7%), stir at 800rpm for 60min to obtain slurry C.

[0361] (5) Add 30g of curing agent diethylenetriamine (mass fraction of 39.0%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0362] Compared with existing methods, the graphene powder provided in this application exhibits excellent redispersibility in both oil-soluble and water-soluble resin matrices, and the resulting graphene anti-corrosion coating demonstrates superior anti-corrosion performance compared to similar coatings. To more intuitively demonstrate the performance advantages of the technical solution in practical applications, the following tests were conducted:

[0363] Test case

[0364] 1. Morphological characterization of graphene in graphene powder / coating

[0365] This application utilizes scanning electron microscopy (SEM) to directly characterize the morphology of the modified graphene powder prepared in step (3) of the examples.

[0366] In addition, the microstructure of graphene in the coating (without curing agent) obtained in step (4) was characterized according to the T / CSTM 00229-2020 standard ("Determination of Graphene Materials in Coatings by Scanning Electron Microscopy-Energy Dispersive Spectroscopy"). The specific steps are as follows: Take an appropriate amount of slurry C and put it into a centrifuge tube. Add a 1:1 (volume ratio) xylene / acetone mixed solvent and stir evenly. Put the centrifuge tube into a centrifuge and centrifuge at a high speed of 11000 r / min for 20 min to separate the supernatant. Add ethanol to the supernatant and stir evenly. Centrifuge at a low speed of 2000 r / min for 20 min. Take an appropriate amount of the supernatant and evenly drop it onto a copper tape. After the solvent has evaporated, put it into the sample chamber of a scanning electron microscope (SEM) to observe the microstructure of the sample.

[0367] 2. Corrosion resistance test of the coating

[0368] This application conducted corrosion resistance tests on the coatings according to GB / T 10125-2021 standard. Oil-based / water-based graphene anti-corrosion coatings prepared in the embodiments of this application were sprayed onto carbon steel surfaces. After the coatings were completely dried and cured, an organic coating (approximately 60 μm thick) was formed on the metal surface. After exposure to a neutral salt spray environment at 35±2℃ for a certain period of time in a 5% NaCl aqueous solution (pH 6.5-7.2), the salt spray life of the coating was obtained based on whether changes occurred on the coating surface, such as the appearance of the first corrosion point (blistering, peeling, or rust).

[0369] Electrochemical impedance spectroscopy (EIS) was performed using a standard three-electrode system. The test conditions were: open-circuit voltage, frequency range of 100 kHz–10 mHz, and amplitude of 10 mV. The charge transfer resistance value R was obtained by fitting the EIS results using ZView2 software. ct .

[0370] The specific experimental data are summarized in the following tables and figures. The percentage (%) of modifier mentioned in the tables and instructions refers to the proportion of modifier in the modified graphene powder raw material, and the percentage of modified graphene refers to the proportion of modified graphene powder in the anti-corrosion coating.

[0371] Figure 1 This is a SEM image of the modified graphene powder prepared in step (3) of Example 2 of this application.

[0372] Figure 2This is a SEM image of the graphene separated from slurry C in Example 2 of this application according to the above standard method.

[0373] Figure 3 This is a SEM image of the graphene separated from slurry C in Example 3 of this application according to the above standard method.

[0374] Figure 4 The modified graphene prepared in step (3) of Example 2 of this application was placed for 6 months, and slurry C was prepared according to step (4) of Example 2. The graphene was then separated according to the above standard method.

[0375] Depend on Figure 1 It can be seen that the graphene powder has uniform particles and a distinct layered structure with a layer thickness of approximately 20 nm. Figure 2 and Figure 3 It can be seen that the graphene isolated from both epoxy resin matrix and waterborne polyurethane matrix exhibits the following characteristics: uniform particle size, sheet size similar to that of modified graphene powder, and no agglomeration or uniform dispersion during slurry preparation; the graphene layer thickness is approximately 25 nm, comparable to that of modified graphene powder. Therefore, the modified graphene powder prepared in this application demonstrates excellent redispersibility in both oil-soluble and water-soluble resin matrices, allowing for direct and uniform dispersion within the resin matrix without significant agglomeration or clumping. Figure 4 As can be seen, the graphene particles are uniform and have not agglomerated, indicating that the graphene can still maintain excellent dispersibility after 6 months. The above results fully demonstrate that the graphene powder prepared in this application has good stability and a long shelf life.

[0376] Table 1. Salt spray resistance and charge transfer resistance R of coatings in Examples 1-5 ct

[0377] Example Example 1 Example 2 Example 3 Example 4 Example 5 resin matrix E-44 E-44 Waterborne polyurethane Waterborne polyurethane Waterborne polyurethane Types of modifiers AEO-3 AEO-5 AEO-7 AEO-9 AEO-15 Percentage of modifier (%) 25 25 25 25 25 Percentage of graphene powder used in raw materials (%) 8 8 8 8 8 Percentage of modified graphene in the coating (%) 1.3 1.3 0.8 0.8 0.8 Salt spray resistance life (h) 3900 4300 2700 2800 2900 <![CDATA[R ct (Ω·cm 2 )]]> <![CDATA[1.1×10 8 ]]> <![CDATA[2.0×10 8 ]]> <![CDATA[7.6×10 7 ]]> <![CDATA[7.8×10 7 ]]> <![CDATA[7.9×10 7 ]]>

[0378] Under otherwise unchanged conditions, Examples 1-5 utilize AEO series modifiers to modify graphene powder, thereby enhancing the corrosion resistance of oil-soluble or water-soluble coatings. Table 1 shows that the oil-soluble system (E-44) exhibits improved salt spray resistance and R... ct Both are superior to water-soluble systems (waterborne polyurethane), but the graphene-modified coatings of this application have better corrosion resistance than traditional coatings of the same type.

[0379] Table 2 Salt spray resistance life and charge transfer resistance value R of coatings in Examples 6-13 ct

[0380]

[0381] Table 2 shows the corrosion resistance of coatings (Examples 6-13) prepared by adding graphene modified with NP series modifiers to oil-soluble and water-soluble resin matrices, respectively. The results in Table 2 show that the oil-soluble system has a salt spray resistance life >7000h, and R... ct 10 9 The order of magnitude indicates that the coating in the example exhibits excellent corrosion resistance; the salt spray life of the water-soluble system is >5500h, R ct 10 8 -10 9 The magnitude indicates that the corrosion resistance of the coating in this example is superior to that of conventional coatings of the same type.

[0382] Table 3. Salt spray resistance and charge transfer resistance R of the coatings in Examples 14-22 ct

[0383]

[0384] Table 3 shows the corrosion resistance of coatings (Examples 14-22) obtained by spraying coatings prepared by adding graphene modified with OP series modifiers to oil-soluble and water-soluble resin matrices, respectively. The results in Table 3 show that the salt spray resistance life of the oil-soluble system is >6000h, and R... ct All are 10 9 The order of magnitude indicates that the coating in the example exhibits excellent corrosion resistance; the salt spray life of the water-soluble system is >4500h, R ct 10 8 -10 9 The magnitude indicates that the corrosion resistance of the coating in this example is superior to that of conventional coatings of the same type.

[0385] Table 4. Salt spray resistance and charge transfer resistance R of coatings in Examples 23-26 ct

[0386]

[0387] Table 4 shows the corrosion resistance of coatings (Examples 23-26) obtained by spraying coatings prepared by modifying graphene with Tween series modifiers and then adding them to oil-soluble and water-soluble resin matrices. The results in Table 4 show that the oil-soluble system has a salt spray resistance life >5300h, R... ct 10 8 The order of magnitude indicates that the coating in the example exhibits excellent corrosion resistance; the salt spray life of the water-soluble system is >4300h, R ct 10 8 The magnitude indicates that the corrosion resistance of the coating in this example is superior to that of conventional coatings of the same type.

[0388] Table 5 Salt spray resistance life and charge transfer resistance R of coatings in Examples 27-29ct

[0389]

[0390] Table 5 shows the corrosion resistance of coatings (Examples 27-29) obtained by spraying coatings prepared by adding graphene modified with DNS series modifiers to oil-soluble and water-soluble resin matrices. The results in Table 5 show that the oil-soluble system has a salt spray resistance life as high as 9000 hours. ct 7.5×10 9 Ω·cm 2 The coating in this embodiment exhibits excellent corrosion resistance; the salt spray resistance life of the water-soluble system is >6500h, R ct 10 9 The magnitude indicates that the corrosion resistance of the coating in this example is far superior to that of conventional coatings of the same type.

[0391] Table 1-5 compares the effects of different types of modifiers on the anti-corrosion performance of graphene powder modified with oil-soluble and water-soluble resin matrices. The results in Table 1-5 show that, for the same resin matrix, the improvement in anti-corrosion performance of the coating by adding different types of graphene powder is as follows: DNS series > NP series > OP series > Tween series > AEO series. For the same type of modifier, the anti-corrosion performance of oil-soluble resin matrix is ​​better than that of water-based epoxy resin and water-based polyurethane matrix.

[0392] Table 6. Salt spray resistance life and charge transfer resistance value R of the coatings in Examples 30-31 and Example 2. ct

[0393]

[0394] Using E-44 as the resin matrix and AEO-5, the AEO series modifier with the best modification effect, as the modifier, the effect of modifier concentration on the graphene modification effect was studied. Table 6 shows that as the concentration of AEO-5 modifier increased from 8% to 50%, the salt spray resistance life and Ro of the graphene anticorrosive coating increased. ct All showed a trend of first increasing and then decreasing. Among this group of coatings, Example 2 had the best anti-corrosion performance, with a modifier concentration of 25% and a salt spray resistance life of 4300 hours. ct 2.0×10 8 Ω·cm 2 .

[0395] Table 7 Salt spray resistance life and charge transfer resistance value R of the coatings in Examples 32-33 and Example 7 ct

[0396]

[0397] Using E-44 as the resin matrix and NP-4, the NP series modifier with the best modification effect, as the modifier, the effect of modifier concentration on the graphene modification effect was studied. Table 7 shows that as the concentration of NP-4 modifier increased from 8% to 50%, the salt spray resistance and R0 of the graphene anticorrosive coating increased. ct All showed a trend of first increasing and then decreasing. Among this group of coatings, Example 7 had the best anti-corrosion performance, with a modifier concentration of 25% and a salt spray resistance life of 7450 hours. ct 2.9×10 9 Ω·cm 2 .

[0398] Table 8. Salt spray resistance and charge transfer resistance R of the coatings in Examples 34-35 and Example 15. ct

[0399]

[0400] Using E-44 as the resin matrix and OP-7, the best modifier in the OP series, as the modifier, the effect of modifier concentration on the graphene modification effect was studied. Table 8 shows that as the concentration of OP-7 modifier increased from 8% to 50%, the salt spray resistance and Ro of the graphene anticorrosive coating increased. ct All showed a trend of first increasing and then decreasing. Among this group of coatings, Example 15 had the best anti-corrosion performance, with a modifier concentration of 25% and a salt spray resistance life of 6500 hours. ct 1.5×10 9 Ω·cm 2 .

[0401] Table 9. Salt spray resistance and charge transfer resistance R of coatings in Examples 36-37 and Example 23. ct

[0402]

[0403] Using E-44 as the resin matrix and Tween20, the best modifier in the Tween series, as the modifier, the effect of modifier concentration on the graphene modification effect was studied. Table 9 shows that as the concentration of Tween20 modifier increased from 8% to 50%, the salt spray resistance and R0 of the graphene anticorrosive coating increased. ct All showed a trend of first increasing and then decreasing. Among this group of coatings, Example 23 had the best anti-corrosion performance, with a modifier concentration of 25% and a salt spray resistance life of 5400 hours. ct It is 9.6×10 8 Ω·cm 2 .

[0404] Table 10 Salt spray resistance life and charge transfer resistance value R of coatings in Examples 38-39 and Example 27 ct

[0405]

[0406] Using E-44 as the resin matrix and DNS-500, the best modifier in the DNS series, as the modifier, the effect of modifier concentration on the graphene modification effect was studied. Table 10 shows that as the concentration of DNS-500 modifier increased from 8% to 50%, the salt spray resistance and Ro of the graphene anticorrosive coating increased. ct All showed a trend of first increasing and then decreasing. Among this group of coatings, Example 27 had the best anti-corrosion performance, with a modifier concentration of 25% and a salt spray resistance life of up to 9000 hours. ct 7.5×10 9 Ω·cm 2 .

[0407] Table 11 Salt spray resistance life and charge transfer resistance value R of the coatings in Examples 40-41 and Example 2 ct

[0408]

[0409] Table 12 Salt spray resistance life and charge transfer resistance value R of the coatings in Examples 42-43 and Example 9 ct

[0410]

[0411] Table 13 Salt spray resistance lifetime and charge transfer resistance value R of coatings in Examples 44-45 and Example 21 ct

[0412]

[0413] Oil-soluble and water-soluble resins were used as the matrix, and corresponding typical modifiers were selected. The graphene was modified with the optimal addition amount of the modifier. Finally, modified graphene powder with different percentage concentrations was added to the resin matrix to study the effect of the amount of modified graphene powder added to the resin matrix on the anti-corrosion performance of the coating. The results are shown in Table 11-13.

[0414] Table 11 shows the anti-corrosion performance of coatings obtained by adding 25% AEO-5 modified graphene powder to the E-44 resin matrix. As the percentage concentration of modified graphene powder increases from 0.1% to 2.0%, the salt spray life and R... ctAll showed a trend of first increasing and then decreasing. Among this group of coatings, Example 2 had the best anti-corrosion performance, with a modified graphene percentage of 1.3% and a salt spray resistance life of 4300 hours. ct 2.0×10 8 Ω·cm 2 .

[0415] Table 12 shows the anti-corrosion performance of coatings obtained by adding 25% NP-7 modified graphene powder to an aqueous epoxy resin emulsion matrix. As the percentage concentration of modified graphene powder increases from 0.1% to 2.0%, the salt spray life and R0 of the graphene anti-corrosion coating also increase. ct All showed a trend of first increasing and then decreasing. Among this group of coatings, Example 9 had the best anti-corrosion performance, with a modified graphene percentage of 1.0% and a salt spray resistance life of 7000 hours. ct 1.7×10 9 Ω·cm 2 .

[0416] Table 13 shows the anti-corrosion performance results of coatings obtained by adding 25% OP-40 modified graphene powder to a waterborne polyurethane matrix. As the percentage concentration of modified graphene powder increases from 0.1% to 2.0%, the salt spray life and R0 of the graphene anti-corrosion coating also increase. ct All showed a trend of first increasing and then decreasing. Among this group of coatings, Example 21 had the best anti-corrosion performance, with a modified graphene percentage of 0.8% and a salt spray resistance life of 5200 hours. ct 9.4×10 8 Ω·cm 2 .

[0417] Table 14 Salt spray resistance life and charge transfer resistance value R of the coatings in Examples 46-47 and Example 2 ct

[0418]

[0419] To verify the influence of the same type of resin matrix on the corrosion resistance of coatings, bisphenol A type epoxy resins with different epoxy equivalents were used as the matrix, and 25% AEO-5 modified graphene was added, while maintaining the modified graphene addition at 1.3%. The corrosion resistance of the coatings in Examples 46-47 and Example 2 was compared, and the results are shown in Table 14. The corrosion resistance of the graphene coatings with three different epoxy resin matrices with different epoxy equivalents is very similar, indicating that the difference in the resin matrix has little impact on the overall corrosion resistance of the coating. Other types of resin matrices can also be selected.

[0420] Table 15 Salt spray resistance life and charge transfer resistance value R of the coatings in Examples 48 and 2 ct

[0421]

[0422] To verify the influence of the type of dispersion solvent during the modification process on the corrosion resistance of the coating, ethanol and acetone were used as solvents respectively, and other conditions were kept the same. The corrosion resistance of the coatings in Example 48 and Example 2 were compared, and the results are shown in Table 15. As can be seen from the table, when the solvents are acetone and ethanol respectively, the salt spray life and R of the coatings in Example 48 and Example 2 are significantly different. ct The values ​​were all relatively similar, indicating that the solvent had little impact on the corrosion resistance of the coating. Furthermore, this study found that organic solvents such as ethylene glycol and isopropanol are also suitable.

[0423] Storage period test:

[0424] Repeat the operations of Examples 2 and 3 above. After storing the modified graphene powder obtained in step (3) in a sealed container at room temperature for 6 months, proceed with the corresponding steps (4) and (5) to obtain the graphene anti-corrosion coating. The coating's corrosion resistance is then tested.

[0425] The results showed that the performance results were consistent with those of Examples 2 and 3 of this application, indicating that the modified graphene prepared in this application has excellent stability and a long shelf life.

[0426] Figure 4 The modified graphene powder prepared in step (3) of Example 2 of this application was sealed and stored at room temperature for 6 months. Slurry C was then prepared according to step (4) of Example 2. The SEM image of graphene separated by the standard method, namely T / CSTM 00229-2020 standard ("Determination of Graphene Materials in Coatings: Scanning Electron Microscopy-Energy Dispersive Spectroscopy"), is shown. Figure 4 The graphene particles are uniform and have not agglomerated, indicating that the graphene still maintains excellent dispersibility after 6 months. This result fully demonstrates that the graphene powder prepared in this application has good stability and a long shelf life, which can meet the long-term storage requirements for industrial applications.

[0427] To illustrate the effect of adding modified graphene powder on improving the overall corrosion resistance of coatings, a performance evaluation of Comparative Examples 1-6 was conducted to compare the corrosion resistance of coatings without graphene and those with unmodified ordinary graphene powder.

[0428] Comparative Example 1:

[0429] (1) Add 30g of curing agent diethylenetriamine (39.5% by mass) to 46g of bisphenol A type epoxy resin E-44 resin matrix (mass fraction of 60.5%), stir evenly, and obtain anti-corrosion coating.

[0430] Comparative Example 2:

[0431] (1) Add 30g of curing agent diethylenetriamine (39.5% by mass) to 46g of waterborne epoxy resin emulsion (mass fraction of 60.5%), stir evenly, and the anti-corrosion coating is obtained.

[0432] Comparative Example 3:

[0433] (1) Add 30g of curing agent HDI trimer (39.5% by mass) to 46g of waterborne polyurethane resin matrix (mass fraction of 60.5%), stir evenly, and the anti-corrosion coating is obtained.

[0434] Comparative Example 4:

[0435] (1) Add 1g of unmodified graphene powder (1.3% by mass) to 46g of bisphenol A type epoxy resin E-44 resin matrix (mass fraction of 59.7%), and stir at 800rpm for 60min to obtain slurry C.

[0436] (2) Add 30g of curing agent diethylenetriamine (mass fraction of 39.0%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0437] Comparative Example 5:

[0438] (1) Add 0.76g of unmodified graphene powder (1.0% by mass) to 46g of waterborne epoxy resin emulsion (mass fraction of 59.9%), and stir at 800rpm for 60min to obtain slurry C;

[0439] (2) Add 30g of curing agent diethylenetriamine (mass fraction of 39.1%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0440] Comparative Example 6:

[0441] (1) Add 0.62g of unmodified graphene powder (0.8% by mass) to 46g of waterborne polyurethane resin matrix (mass fraction of 60.0%), and stir at 800rpm for 60min to obtain slurry C;

[0442] (2) Add 30g of curing agent HDI trimer (mass fraction of 39.2%) to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

[0443] The performance test results of Comparative Examples 1-6 and Examples 27-29 are shown in Table 16. Comparative Examples 1-3, without graphene, showed blistering in their coatings after 320 hours in a neutral salt spray environment, with charge transfer resistance values ​​below 10. 3The corrosion resistance of the coatings was poor, orders of magnitude greater than that of the original coatings; comparative examples 4-6, with the addition of unmodified graphene powder, showed improved salt spray resistance and R0. ct Compared to comparative examples 1-3 without graphene, the coating showed a slight improvement, but its overall corrosion resistance was very poor, indicating that the graphene powder was not uniformly dispersed in the resin matrix, thus failing to fully realize its intended function. Examples 27-29 incorporated graphene powder modified with DNS series modifiers, resulting in improved salt spray resistance and R... ct The significant improvement indicates that the corresponding coating has excellent corrosion resistance. Therefore, the graphene powder modification technology provided in this application can effectively solve the problem of uniform dispersion of graphene in the resin matrix, and significantly improve the corrosion resistance of the coating through the action of graphene.

[0444] Table 16 Performance test results for Comparative Examples 1-6 and Examples 27-29

[0445]

[0446] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A modified graphene powder, characterized in that, The modified graphene powder comprises the following raw materials in the following mass fractions: solvent 40%–90%, modifier 8%–50%, and graphene powder 0.5%–10%. The solvent is an organic solvent, including one of ethanol, acetone, ethylene glycol, and isopropanol; The modifier is one of fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, polysorbate, and isomeric alcohol polyoxyethylene ether.

2. The modified graphene powder according to claim 1, characterized in that, The method for preparing the modified graphene powder includes: dissolving the modifier in a solvent to obtain a modifier solution, mixing and stirring the modifier solution with graphene powder, letting it stand for 20-26 hours, and obtaining the modified graphene powder after solid-liquid separation and drying.

3. The modified graphene powder according to claim 1, characterized in that, The fatty alcohol polyoxyethylene ether is one of fatty alcohol polyoxyethylene (3) ether, fatty alcohol polyoxyethylene (5) ether, fatty alcohol polyoxyethylene (7) ether, fatty alcohol polyoxyethylene (9) ether, and fatty alcohol polyoxyethylene (15) ether; And / or; the nonylphenol polyoxyethylene ether is one of nonylphenol polyoxyethylene (3) ether, nonylphenol polyoxyethylene (4) ether, nonylphenol polyoxyethylene (6) ether, nonylphenol polyoxyethylene (7) ether, nonylphenol polyoxyethylene (10) ether, nonylphenol polyoxyethylene (15) ether, and nonylphenol polyoxyethylene (40) ether; And / or; the octylphenol polyoxyethylene ether is one of octylphenol polyoxyethylene (4) ether, octylphenol polyoxyethylene (7) ether, octylphenol polyoxyethylene (9) ether, octylphenol polyoxyethylene (10) ether, octylphenol polyoxyethylene (15) ether, octylphenol polyoxyethylene (30) ether, octylphenol polyoxyethylene (40) ether, and octylphenol polyoxyethylene (50) ether; And / or; the polysorbate is one of polyoxyethylene (20) sorbitan monolaurate, polyoxyethylene (20) sorbitan monopalmitate, polyoxyethylene (20) sorbitan monostearate, and polyoxyethylene (20) sorbitan monooleate; And / or; the isomeric alcohol polyoxyethylene ether is one of isomeric tridecyl alcohol polyoxyethylene (5) ether, isomeric tridecyl alcohol polyoxyethylene (7) ether, and isomeric tridecyl alcohol polyoxyethylene (1340) ether.

4. The method for preparing the modified graphene powder according to any one of claims 1-3, characterized in that, The preparation method includes the following steps: S1: Add the modifier to the solvent and stir at 25-50℃ until the modifier is completely dissolved to obtain solution A; S2: Add graphene powder to solution A, stir at 100 rpm to 1000 rpm for 25-40 min at 25-50℃, and let stand for 20-26 h to obtain slurry B; S3: Filter slurry B, and vacuum dry the filtered solids at 100-120℃ to obtain modified graphene powder.

5. The application of the modified graphene powder according to any one of claims 1-3, characterized in that: The applications include: (a1) Its application in the preparation of anti-corrosion coatings; (a2) Application in the preparation of thermally conductive materials; (a3) Applications in the preparation of lithium-ion batteries; (a4) Applications in the preparation of fuel cells; (a5) Application in the preparation of composite materials.

6. A graphene anti-corrosion coating, characterized in that, The raw materials include the following mass fractions: resin matrix 35%–80%, curing agent 5%–50%, and modified graphene powder 0.1%–2%; The modified graphene powder is as described in any one of claims 1-3; the resin matrix is ​​one of bisphenol A type epoxy resin, waterborne epoxy resin emulsion, and waterborne polyurethane.

7. The graphene anti-corrosion coating according to claim 6, characterized in that, The bisphenol A type epoxy resin is a bisphenol A type epoxy resin with an epoxy equivalent of 450-650 g / eq; And / or; the aqueous epoxy resin emulsion is an aqueous epoxy resin emulsion with an epoxy equivalent of 450-650 g / eq. And / or; the waterborne polyurethane includes one of anionic waterborne polyurethane, cationic waterborne polyurethane, and nonionic waterborne polyurethane; And / or; the curing agent is one of diethylenetriamine, hexamethylene diisocyanate isocyanurate trimer.

8. The method for preparing the graphene anti-corrosion coating according to any one of claims 6-7, characterized in that, Includes the following steps: S4: Add modified graphene powder to the resin matrix and stir at 100 rpm to 1000 rpm for 30-120 min to obtain slurry C; S5: Add curing agent to slurry C, stir evenly, and obtain graphene anti-corrosion coating.

9. A graphene anti-corrosion coating, characterized in that, The graphene anti-corrosion coating is formed by coating the graphene anti-corrosion coating of any one of claims 6-7 or the graphene anti-corrosion coating prepared by the preparation method of claim 8 onto the surface of a substrate, and then drying and curing it; the substrate includes a metal substrate and a non-metal substrate.

10. The application of the graphene anti-corrosion coating according to any one of claims 6-7, characterized in that, The coating is used to prepare any of the following protective coatings: (b1) Protective coatings for marine engineering facilities, including but not limited to oil drilling platforms, offshore wind turbine towers and steel piles for cross-sea bridges; (b2) Protective coatings for oil and gas transportation and chemical equipment, including but not limited to oil and gas pipelines, storage tanks and chemical equipment surfaces; (b3) Protective coatings for ship components, including but not limited to the hull, deck and cabin.

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