Graphene nanometer heavy anti-corrosion coating and preparation method thereof

Abstract

The invention discloses a graphene nanometer heavy anti-corrosion coating and a preparation method thereof, and belongs to the technical field of anti-corrosion coatings. The coating is prepared from the following components in parts by mass: 50 to 70 parts of diallyl bisphenol A type epoxy resin, 8 to 15 parts of histidine modifier, 12 to 20 parts of graphene nano composite modified filler, 5 to 10 parts of curing agent, 0.5 to 2 parts of flatting agent and 0.3 to 1 part of defoaming agent. The preparation method of the histidine modifier comprises the following steps: carrying out a Schiff base reaction on 1-palmitoyl-2-oleoyl ethanolamine and N-formyl-L-histidine to generate an intermediate A; reacting with a spiro quaternization reagent to form a quaternary ammonium salt intermediate B; and then compounding with aminopropyltriethoxysilane and silicotungstic heteropoly acid salt to obtain the product. The graphene nano-composite modified filler is prepared by modifying the surface of a graphene oxide / bentonite mutual intercalation layer structure through allyl trimethoxy silane. The graphene nano heavy anti-corrosion coating prepared by the invention forms a high-density cross-linked network, and has excellent barrier property, strong adhesive force, impact resistance and long-acting anti-corrosion performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of anti-corrosion coatings, and in particular relates to a graphene nano heavy-duty anti-corrosion coating and a preparation method thereof. Background Art

[0002] Corrosion is the spontaneous destructive phenomenon of metal materials in their service environments (such as the atmosphere, soil, seawater, and chemical media), causing significant economic losses to global industry each year. To effectively protect metal structures and extend their service life, anti-corrosion coatings are widely used. Among them, heavy-duty anti-corrosion coatings are high-performance coatings that provide long-term, effective protection in harsh corrosive environments such as marine environments, chemical atmospheres, acid, alkali, and salt spray, and high temperatures and humidity. They typically exhibit excellent resistance to chemical media, salt spray, weathering, wear, strong adhesion, and excellent physical and mechanical properties.

[0003] Epoxy resin coatings, due to their excellent adhesion, chemical resistance, good mechanical properties, and ease of application and curing, have become one of the most widely used resin matrices in heavy-duty corrosion protection. However, traditional epoxy heavy-duty corrosion protection coatings face several pressing bottlenecks when subjected to long-term service in extreme environments. The epoxy resin inevitably shrinks during the curing process, leading to defects such as micropores and microcracks within the coating. These defects provide permeation pathways for corrosive media, and once the media reaches the metal substrate surface, corrosion ensues. Increasing crosslink density can improve this, but often at the expense of flexibility. While epoxy resin inherently possesses some barrier properties, the microscopic pathways formed by its polymer chains are insufficient to completely block the slow penetration of small-molecule corrosive media. Adding traditional flake fillers can extend the permeation pathways, but these fillers suffer from poor dispersibility, easy sedimentation, insufficient aspect ratios, and weak interfacial bonding with the resin, limiting further improvements in their barrier efficiency. Conventional fillers or modifiers often lack interfacial compatibility and chemical bonding strength with the epoxy resin matrix, leading to the formation of a weak interfacial layer or phase separation. This not only reduces the overall density of the coating, creating a weak point for media penetration, but can also lead to failure due to peeling from the substrate or filler interface under physical stress. For sacrificial anodic coatings such as zinc-rich epoxies, zinc powder consumption is rapid, limiting long-term protection. Barrier coatings, on the other hand, are generally less capable of actively passivating the metal substrate.

[0004] In recent years, the rise of nanotechnology has brought new opportunities for the development of heavy-duty anti-corrosion coatings. Graphene, in particular, is considered an ideal nanomaterial for enhancing the corrosion resistance of coatings due to its unique single-atomic-layer two-dimensional structure, extremely high specific surface area, exceptional mechanical strength, outstanding chemical inertness, and near-perfect barrier properties. Its lamellar structure effectively extends the penetration path of corrosive media, providing excellent physical shielding. However, strong van der Waals and π-π interactions between graphene sheets make them prone to agglomeration, making it difficult to achieve a uniform and stable single-layer or small-layer dispersion in the resin. Agglomerates not only lose their nanoscale effects but can also become stress concentration points and permeation pathways. The graphene surface is inert and lacks reactive groups. Its interfacial interaction with epoxy resin is primarily physical adsorption, with weak chemical bonding. This results in insufficient interfacial bonding strength, low stress transfer efficiency, and prone to delamination at the interface. Therefore, the development of a graphene-based heavy-duty anti-corrosion coating that can effectively solve the problems of micro-defects, limited barrier efficiency, weak interface bonding, etc. in traditional epoxy resin coatings and existing graphene composite coatings, and at the same time has high density, strong adhesion, excellent barrier properties and long-term protection capabilities, has important theoretical significance and broad application prospects. Summary of the Invention

[0005] In response to the above situation, in order to overcome the defects of the prior art, the present invention fills the gaps and cracks generated during the curing of epoxy resin through a histidine modifier and a graphene nanocomposite modified filler, forming an effective isolation protective layer, thereby improving the corrosion resistance and impact resistance of the epoxy resin coating. The prepared coating also has good density and adhesion, thereby further improving the anti-corrosion performance and protection ability.

[0006] In order to achieve the above-mentioned purpose, the following technical scheme is adopted: On the one hand, the present invention provides a graphene nano heavy-duty anti-corrosion coating, comprising the following components in parts by mass: 50-70 parts of diallyl bisphenol A type epoxy resin, 8-15 parts of histidine modifier, 12-20 parts of graphene nano composite modified filler, 5-10 parts of curing agent, 0.5-2 parts of leveling agent, and 0.3-1 parts of defoaming agent.

[0007] Furthermore, the histidine modifier is prepared by the following steps: (1) 1-palmitoyl-2-oleoylethanolamine and N-formyl-L-histidine were added to anhydrous ethanol at a mass volume ratio of 1:8-1:10 g / mL, stirred and dissolved, and then 0.5-1.0% acetic acid was added to the total mass of the reaction system. The reaction was stirred at 50-60°C for 4-5 hours. After the reaction was completed, the product was cooled to room temperature and filtered to obtain a solid product. The solid product was washed with anhydrous ethanol three times and vacuum dried at 60-70°C for 4-6 hours to obtain a histidine modified intermediate A. (2) Histidine modified intermediate A and (6CI,7CI,8CI,9CI)-3,9-bis(2-chloroethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane were added to acetonitrile at a mass volume ratio of 1:10-1:12 g / mL. The temperature was raised to 80-90°C under nitrogen protection and refluxed for 7-8 hours. After the reaction, 80% of the acetonitrile was removed by vacuum distillation. After cooling to room temperature, anhydrous ether was added at a volume ratio of 1:1 to the remaining reaction solution to precipitate the product. After filtration, the precipitate was washed with anhydrous ether three times and vacuum dried at 50-60°C for 5-6 hours to obtain histidine modified intermediate B. (3) Histidine modified intermediate B and aminopropyltriethoxysilane are added to toluene in a mass volume ratio of 1:12-1:15 g / mL, and dibutyltin dilaurate is added in an amount of 0.3-0.5% of the total mass of the reaction system. The mixture is stirred at 70-80°C for 3-4 hours under nitrogen protection, and then silicon tungsten heteropolyacid salt is added, and the reaction is continued at 60-70°C for 2-3 hours. After the reaction is completed, the mixture is cooled to room temperature, filtered to obtain a solid product, washed with toluene 3 times, and vacuum dried at 70-80°C for 6-8 hours to obtain the histidine modifier.

[0008] Furthermore, the graphene nanocomposite modified filler is prepared by the following steps: S1. Sodium bentonite is dispersed in deionized water at a mass volume ratio of 1:20-1:25 g / mL, and ultrasonically dispersed at a power of 300-400 W for 30-40 min to obtain a sodium bentonite dispersion. Graphene oxide is dispersed in deionized water at a mass volume ratio of 1:50-1:60 g / mL, and ultrasonically dispersed at a power of 400-500 W for 40-50 min to obtain a graphene oxide dispersion. The sodium bentonite dispersion and the graphene oxide dispersion are mixed at a volume ratio of 1:1, 0.2-0.3% sodium lauryl sulfate based on the total mass of the mixture is added, and the mixture is magnetically stirred at 300-400 r / min for 2-3 h at 30-35 ° C, and then vacuum dried at 60-70 ° C for 12-15 h, and ground through a 200 mesh sieve to obtain a graphene oxide / bentonite intercalated material; S2. Add graphene oxide / bentonite intercalated material into anhydrous toluene at a mass volume ratio of 1:15-1:20 g / mL, ultrasonically disperse at 300 W power for 20-30 min, then add allyltrimethoxysilane, and then add triethylamine accounting for 0.5-0.8% of the total mass of the reaction system, and reflux at 80-90 ° C for 5-6 h under nitrogen protection; after the reaction is completed, cool to room temperature, filter to obtain a solid product, wash with toluene and anhydrous ethanol twice each, vacuum dry at 80-90 ° C for 8-10 h, grind and pass through a 300 mesh sieve to obtain the graphene nanocomposite modified filler.

[0009] Furthermore, in step (1), the mass ratio of 1-palmitoyl-2-oleoylethanolamine to N-formyl-L-histidine is 1.0:1.1-1.3.

[0010] Furthermore, in step (2), the mass ratio of the modified intermediate A to (6CI,7CI,8CI,9CI)-3,9-bis(2-chloroethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane is 1.0:1.2-1.5.

[0011] Furthermore, in step (3), the mass ratio of the modified intermediate B to aminopropyltriethoxysilane is 1.0:0.8-1.0; the mass ratio of the modified intermediate B to silicotungstic heteropolyacid salt is 1.0:0.3-0.5.

[0012] Furthermore, in step S1, the mass ratio of sodium bentonite to graphene oxide is 1.0:0.3-0.5.

[0013] Furthermore, in step S2, the mass ratio of the graphene oxide / bentonite intercalation material to allyltrimethoxysilane is 1.0:0.4-0.6.

[0014] Furthermore, the curing agent is selected from one or more of diethylenetriamine, triethylenetetramine, Jeffamine D-230, Jeffamine T-403, and Aradur-42; the leveling agent is selected from one or more of BYK333, BYK381, TEGO-410, TEGO-440, and TEGO-450; and the defoaming agent is selected from one or more of tributyl phosphate, methyl silicone oil, BYK-021, BYK-024, and BYK-028.

[0015] On the other hand, the present invention also provides a method for preparing the graphene nano heavy-duty anti-corrosion coating, comprising the following steps: weighing each component by mass, adding diallyl bisphenol A type epoxy resin into a reactor, heating to 60-70°C, stirring at 300-500 r / min for 10-15 min, adding a histidine modifier and a graphene nano composite modified filler, raising the temperature to 80-90°C, high-speed dispersing at 800-1000 r / min for 30-40 min, cooling to 50-60°C, adding a leveling agent and a defoaming agent, stirring at 400-600 r / min for 20-30 min, continuing to cool to 25-30°C, adding a curing agent, stirring at 200-300 r / min for 10-15 min, filtering the material, and obtaining the graphene nano heavy-duty anti-corrosion coating.

[0016] The beneficial effects of the present invention are: The present invention fills the gaps and cracks generated during the curing of epoxy resin by using a histidine modifier and a graphene nanocomposite modified filler, forming an effective insulating protective layer, thereby improving the corrosion resistance and impact resistance of the epoxy resin coating. The prepared coating also has good density and adhesion, thereby further improving the anti-corrosion performance and protective ability.

[0017] The present invention forms a connection by Schiff base reaction between 1-palmitoyl-2-oleoylethanolamine and N-formyl-L-histidine, and then reacts with (6CI, 7CI, 8CI, 9CI)-3,9-bis(2-chloroethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane to form a quaternary ammonium salt structure on the imidazole ring of histidine, and then couples with aminopropyltriethoxysilane, and finally compounds with tungstosilicic acid heteropolyacid. The amino group on the histidine can undergo ring-opening with the epoxy group of the epoxy resin. The long-chain alkanes introduced by 1-palmitoyl-2-oleoylethanolamine can strengthen the interaction with the epoxy resin matrix through physical entanglement, while the unsaturated double bonds at the ends can participate in free radical reactions during the curing process, cross-linking with the epoxy resin matrix, especially with the graphene nanocomposite modified filler, further improving the cross-linking density and network density of the entire system.

[0018] Graphene nanocomposite modified fillers are formed by constructing an intercalated structure of sodium bentonite and graphene oxide, followed by surface modification with allyltrimethoxysilane. The bentonite flakes effectively prevent graphene stacking, increasing its effective barrier area. Silanization introduces reactive allylic double bonds, allowing the modified filler to form a highly dispersed, randomly oriented flake barrier within the coating. These flakes significantly extend and tortuously reduce the penetration path of corrosive media such as water, oxygen, and corrosive ions to the metal substrate, resulting in a significant physical barrier effect.

[0019] The quaternary ammonium salt structure in the histidine modifier has a rigid tetraoxaspiro ring structure, which works together with the long-chain hydrophobic alkyl of 1-palmitoyl-2-oleoylethanolamine to form a hydrophobic region within the coating and at the interface between the metal substrate, effectively hindering the adsorption and infiltration of water molecules. The cationic center of the quaternary ammonium salt carries a strong positive charge and can form a stable ionic bond with the strongly negatively charged heteropolyacid through electrostatic attraction. This composite structure enhances the mechanical properties and stability of the coating. The cationic center can strongly adsorb on the negatively charged metal substrate surface, significantly improving the adhesion of the coating and helping to passivate the metal surface, slowing the initiation of electrochemical corrosion. The introduction of the heteropolyacid not only stabilizes the quaternary ammonium salt structure through electrostatic action, but also has good catalytic activity and passivation ability, which can further enhance the protective effect of the coating on the metal substrate. This highly dense cross-linked network, combined with the physical filling effect of the modifier and filler, effectively fills the microgaps and microcracks generated during the curing and shrinkage of the epoxy resin, significantly reducing the penetration channels within the coating.

[0020] The long-chain alkanes and specific spiro / heterocyclic structures introduced into the modifier, as well as the reinforcing effect of the graphene / bentonite nanosheets, jointly contribute to the improvement of the toughness of the coating, giving it better impact resistance and resistance to physical damage, thereby preventing the coating from losing its protective function due to mechanical damage. The high density, strong adhesion, excellent barrier properties and hydrophobicity of the modifier and graphene / bentonite nanosheets together give the coating excellent corrosion resistance and long-term protection capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A bar graph showing adhesion test results of heavy-duty anti-corrosion coatings prepared in various embodiments and comparative examples of the present invention; Figure 2 This is a bar chart of the impact resistance test results of the heavy-duty anti-corrosion coatings prepared in various embodiments and comparative examples of the present invention.

[0022] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those familiar to those skilled in the art. Furthermore, any methods and materials similar or equivalent to those described herein can be applied to the present invention. The preferred embodiments and materials described herein are for illustrative purposes only and are not intended to limit the scope of this application.

[0025] The experimental methods in the following examples, unless otherwise specified, are all conventional methods, and the experimental materials used in the following examples, unless otherwise specified, are all purchased from commercial channels.

[0026] Example 1: A graphene nano heavy-duty anti-corrosion coating comprises the following components in parts by mass: 50 parts of diallyl bisphenol A epoxy resin, 8 parts of histidine modifier, 12 parts of graphene nanocomposite modified filler, 5 parts of curing agent diethylenetriamine, 0.5 parts of leveling agent BYK333, and 0.3 parts of defoaming agent tributyl phosphate. The histidine modifier is prepared by the following steps: (1) 1-Palmitoyl-2-oleoylethanolamine and N-formyl-L-histidine were added to anhydrous ethanol at a mass-to-volume ratio of 1:10 g / mL. After stirring and dissolving, 1.0% acetic acid accounting for the total mass of the reaction system was added and stirred at 60°C for 5 h. After the reaction was completed, the product was cooled to room temperature and filtered to obtain a solid product. The solid product was washed with anhydrous ethanol three times and dried in vacuo at 70°C for 6 h to obtain histidine-modified intermediate A. (2) Histidine modified intermediate A and (6CI,7CI,8CI,9CI)-3,9-bis(2-chloroethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane were added to acetonitrile at a mass volume ratio of 1:12 g / mL. The temperature was raised to 90°C under nitrogen protection and refluxed for 8 h. After the reaction, 80% of the acetonitrile was removed by vacuum distillation. After cooling to room temperature, anhydrous ether was added at a volume ratio of 1:1 to the remaining reaction solution to precipitate the product. After filtration, the precipitate was washed with anhydrous ether three times and dried in vacuo at 60°C for 6 h to obtain histidine modified intermediate B. (3) Histidine modified intermediate B and aminopropyltriethoxysilane were added to toluene at a mass volume ratio of 1:15 g / mL, and dibutyltin dilaurate accounting for 0.5% of the total mass of the reaction system was added. The mixture was stirred at 80°C for 4 h under nitrogen protection, and then silicon tungsten heteropolyacid salt was added and the reaction was continued at 70°C for 3 h. After the reaction was completed, the mixture was cooled to room temperature and filtered to obtain a solid product, which was washed with toluene 3 times and vacuum dried at 80°C for 8 h to obtain the histidine modifier. The graphene nanocomposite modified filler is prepared by the following steps: S1. Sodium bentonite was dispersed in deionized water at a mass volume ratio of 1:25 g / mL, and ultrasonically dispersed at a power of 400 W for 40 minutes to obtain a sodium bentonite dispersion. Graphene oxide was dispersed in deionized water at a mass volume ratio of 1:60 g / mL, and ultrasonically dispersed at a power of 500 W for 50 minutes to obtain a graphene oxide dispersion. The sodium bentonite dispersion and the graphene oxide dispersion were mixed at a volume ratio of 1:1, 0.3% sodium lauryl sulfate accounting for the total mass of the mixture was added, and the mixture was magnetically stirred at 400 r / min at 35°C for 3 hours, and then vacuum dried at 70°C for 15 hours, and ground through a 200 mesh sieve to obtain a graphene oxide / bentonite intercalated material; S2. Add graphene oxide / bentonite intercalated material into anhydrous toluene at a mass-to-volume ratio of 1:20 g / mL, ultrasonically disperse at 300 W power for 30 min, then add allyltrimethoxysilane, and then add triethylamine accounting for 0.8% of the total mass of the reaction system, and reflux at 90 ° C for 6 h under nitrogen protection; after the reaction is completed, cool to room temperature, filter to obtain a solid product, wash with toluene and anhydrous ethanol twice each, vacuum dry at 90 ° C for 10 h, grind and pass through a 300 mesh sieve to obtain the graphene nanocomposite modified filler. In the step (1), the mass ratio of 1-palmitoyl-2-oleoylethanolamine to N-formyl-L-histidine is 1.0:1.3; in the step (2), the mass ratio of the modified intermediate A to (6CI,7CI,8CI,9CI)-3,9-bis(2-chloroethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane is 1.0:1.5; in the step (3), the mass ratio of the modified intermediate B to aminopropyltriethoxysilane is 1.0:1.0; the mass ratio of the modified intermediate B to silicotungsten heteropolyacid is 1.0:0.5; in the step S1, the mass ratio of sodium bentonite to graphene oxide is 1.0:0.5; and in the step S2, the mass ratio of the graphene oxide / bentonite intercalated material to allyltrimethoxysilane is 1.0:0.6. A method for preparing the graphene nano heavy-duty anti-corrosion coating comprises the following steps: weighing each component by mass, adding diallyl bisphenol A epoxy resin into a reaction kettle, heating to 70°C, stirring at 500 r / min for 15 minutes, adding a histidine modifier and a graphene nano composite modified filler, heating to 90°C, high-speed dispersing at 1000 r / min for 40 minutes, cooling to 60°C, adding a leveling agent and a defoaming agent, stirring at 600 r / min for 30 minutes, continuing to cool to 30°C, adding a curing agent, stirring at 300 r / min for 15 minutes, filtering the material, and obtaining the graphene nano heavy-duty anti-corrosion coating. Example 2: A graphene nano heavy-duty anti-corrosion coating comprises the following components in parts by mass: 70 parts of diallyl bisphenol A epoxy resin, 15 parts of histidine modifier, 20 parts of graphene nanocomposite modified filler, 5 parts of triethylenetetramine, 5 parts of Jeffamine D-230, 1 part of BYK 381, 1 part of TEGO-410, 0.5 parts of methyl silicone oil, and 0.5 parts of BYK-021.

[0027] The histidine modifier is prepared by the following steps: (1) 1-Palmitoyl-2-oleoylethanolamine and N-formyl-L-histidine were added to anhydrous ethanol at a mass-to-volume ratio of 1:8 g / mL, stirred and dissolved, and then 0.5% acetic acid was added to the total mass of the reaction system. The mixture was stirred and reacted at 50°C for 4 h. After the reaction was completed, the mixture was cooled to room temperature and filtered to obtain a solid product. The solid product was washed with anhydrous ethanol three times and dried in vacuum at 60°C for 4 h to obtain histidine-modified intermediate A. (2) Histidine modified intermediate A and (6CI,7CI,8CI,9CI)-3,9-bis(2-chloroethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane were added to acetonitrile at a mass volume ratio of 1:10 g / mL. The temperature was raised to 80°C under nitrogen protection and refluxed for 7 h. After the reaction, 80% of the acetonitrile was removed by vacuum distillation. After cooling to room temperature, anhydrous ether was added at a volume ratio of 1:1 to the remaining reaction solution to precipitate the product. After filtration, the precipitate was washed with anhydrous ether three times and dried in vacuo at 50°C for 5 h to obtain histidine modified intermediate B. (3) Histidine modified intermediate B and aminopropyltriethoxysilane were added to toluene at a mass volume ratio of 1:12 g / mL, and dibutyltin dilaurate accounting for 0.3% of the total mass of the reaction system was added. The mixture was stirred at 70°C for 3 h under nitrogen protection, and then silicon tungsten heteropolyacid was added and the reaction was continued at 60°C for 2 h. After the reaction was completed, the mixture was cooled to room temperature and filtered to obtain a solid product, which was washed with toluene 3 times and vacuum dried at 70°C for 6 h to obtain the histidine modifier. The graphene nanocomposite modified filler is prepared by the following steps: S1. Sodium bentonite was dispersed in deionized water at a mass volume ratio of 1:20 g / mL, and ultrasonically dispersed at a power of 300 W for 30 minutes to obtain a sodium bentonite dispersion. Graphene oxide was dispersed in deionized water at a mass volume ratio of 1:50 g / mL, and ultrasonically dispersed at a power of 400 W for 40 minutes to obtain a graphene oxide dispersion. The sodium bentonite dispersion and the graphene oxide dispersion were mixed at a volume ratio of 1:1, 0.2% sodium lauryl sulfate accounting for the total mass of the mixture was added, and the mixture was magnetically stirred at 300 r / min at 30°C for 2 hours, and then vacuum dried at 60°C for 12 hours, and ground through a 200-mesh sieve to obtain a graphene oxide / bentonite intercalated material; S2. Add graphene oxide / bentonite intercalated material into anhydrous toluene at a mass volume ratio of 1:15 g / mL, ultrasonically disperse at a power of 300 W for 20 minutes, then add allyltrimethoxysilane, and then add triethylamine accounting for 0.5% of the total mass of the reaction system, and reflux at 80°C for 5 hours under nitrogen protection; after the reaction is completed, cool to room temperature, filter to obtain a solid product, wash it with toluene and anhydrous ethanol twice each, vacuum dry it at 80°C for 8 hours, grind it through a 300-mesh sieve to obtain the graphene nanocomposite modified filler. In the step (1), the mass ratio of 1-palmitoyl-2-oleoylethanolamine to N-formyl-L-histidine is 1.0:1.1; in the step (2), the mass ratio of the modified intermediate A to (6CI,7CI,8CI,9CI)-3,9-bis(2-chloroethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane is 1.0:1.2; in the step (3), the mass ratio of the modified intermediate B to aminopropyltriethoxysilane is 1.0:0.8; the mass ratio of the modified intermediate B to silicotungsten heteropolyacid is 1.0:0.3; in the step S1, the mass ratio of sodium bentonite to graphene oxide is 1.0:0.3; and in the step S2, the mass ratio of the graphene oxide / bentonite intercalated material to allyltrimethoxysilane is 1.0:0.4. A method for preparing the graphene nano heavy-duty anti-corrosion coating comprises the following steps: weighing each component by mass, adding diallyl bisphenol A epoxy resin into a reaction kettle, heating to 60° C., stirring at 300 r / min for 10 min, adding a histidine modifier and a graphene nano composite modified filler, heating to 80° C., high-speed dispersing at 800 r / min for 30 min, cooling to 50° C., adding a leveling agent and a defoaming agent, stirring at 400 r / min for 20 min, continuously cooling to 25° C., adding a curing agent, stirring at 200 r / min for 10 min, filtering the material, and obtaining the graphene nano heavy-duty anti-corrosion coating. Example 3: A graphene nano heavy-duty anti-corrosion coating, comprising the following components in parts by mass: 60 parts of diallyl bisphenol A epoxy resin, 12 parts of histidine modifier, 15 parts of graphene nanocomposite modified filler, 3 parts of Jeffamine D-230, 3 parts of Jeffamine T-403, 2 parts of Aradur-42, 0.5 parts of TEGO-410, 0.3 parts of TEGO-440, 0.2 parts of TEGO-450, 0.2 parts of BYK-021, 0.2 parts of BYK-024, and 0.2 parts of BYK-028. The histidine modifier is prepared by the following steps: (1) 1-Palmitoyl-2-oleoylethanolamine and N-formyl-L-histidine were added to anhydrous ethanol at a mass-to-volume ratio of 1:9 g / mL. After stirring and dissolving, 0.75% of acetic acid, which accounted for the total mass of the reaction system, was added and stirred at 55°C for 4.5 h. After the reaction was completed, the product was cooled to room temperature and filtered to obtain a solid product. The solid product was washed with anhydrous ethanol three times and dried in vacuo at 65°C for 5 h to obtain histidine-modified intermediate A. (2) Histidine modified intermediate A and (6CI,7CI,8CI,9CI)-3,9-bis(2-chloroethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane were added to acetonitrile at a mass volume ratio of 1:11 g / mL. The temperature was raised to 85°C under nitrogen protection and refluxed for 7.5 h. After the reaction, 80% of the acetonitrile was removed by vacuum distillation. After cooling to room temperature, anhydrous ether was added at a volume ratio of 1:1 to the remaining reaction solution to precipitate the product. After filtration, the precipitate was washed with anhydrous ether three times and dried in vacuo at 55°C for 5.5 h to obtain histidine modified intermediate B. (3) Histidine modified intermediate B and aminopropyltriethoxysilane were added to toluene at a mass volume ratio of 1:13.5 g / mL, and dibutyltin dilaurate accounting for 0.4% of the total mass of the reaction system was added. The mixture was stirred at 75°C for 3.5 hours under nitrogen protection, and then silicon tungsten heteropolyacid was added and the reaction was continued at 65°C for 2.5 hours. After the reaction was completed, the mixture was cooled to room temperature and filtered to obtain a solid product, which was washed with toluene three times and dried in vacuum at 75°C for 7 hours to obtain the histidine modifier. The graphene nanocomposite modified filler is prepared by the following steps: S1. Sodium bentonite was dispersed in deionized water at a mass volume ratio of 1:22.5 g / mL, and ultrasonically dispersed at a power of 350 W for 35 minutes to obtain a sodium bentonite dispersion. Graphene oxide was dispersed in deionized water at a mass volume ratio of 1:55 g / mL, and ultrasonically dispersed at a power of 450 W for 45 minutes to obtain a graphene oxide dispersion. The sodium bentonite dispersion and the graphene oxide dispersion were mixed at a volume ratio of 1:1, and 0.25% sodium lauryl sulfate accounting for the total mass of the mixture was added. The mixture was magnetically stirred at 350 r / min at 32.5°C for 2.5 hours, and then vacuum dried at 65°C for 13.5 hours. The mixture was ground through a 200-mesh sieve to obtain a graphene oxide / bentonite intercalated material. S2. Add graphene oxide / bentonite intercalated material into anhydrous toluene at a mass-to-volume ratio of 1:17.5 g / mL, ultrasonically disperse at a power of 300 W for 25 min, then add allyltrimethoxysilane, and then add triethylamine accounting for 0.65% of the total mass of the reaction system, and reflux at 85°C for 5.5 h under nitrogen protection; after the reaction is completed, cool to room temperature, filter to obtain a solid product, wash with toluene and anhydrous ethanol twice each, vacuum dry at 85°C for 9 h, grind through a 300-mesh sieve to obtain the graphene nanocomposite modified filler. In the step (1), the mass ratio of 1-palmitoyl-2-oleoylethanolamine to N-formyl-L-histidine is 1.0:1.2; in the step (2), the mass ratio of the modified intermediate A to (6CI,7CI,8CI,9CI)-3,9-bis(2-chloroethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane is 1.0:1.35; in the step (3), the mass ratio of the modified intermediate B to aminopropyltriethoxysilane is 1.0:0.9; the mass ratio of the modified intermediate B to silicotungsten heteropolyacid is 1.0:0.4; in the step S1, the mass ratio of sodium bentonite to graphene oxide is 1.0:0.4; and in the step S2, the mass ratio of the graphene oxide / bentonite intercalated material to allyltrimethoxysilane is 1.0:0.5. A method for preparing the graphene nano heavy-duty anti-corrosion coating comprises the following steps: weighing each component by mass, adding diallyl bisphenol A epoxy resin into a reaction kettle, heating to 65° C., stirring at 400 r / min for 12.5 min, adding a histidine modifier and a graphene nano composite modified filler, heating to 85° C., high-speed dispersing at 900 r / min for 35 min, cooling to 55° C., adding a leveling agent and a defoaming agent, stirring at 500 r / min for 25 min, continuing to cool to 27.5° C., adding a curing agent, stirring at 250 r / min for 12.5 min, filtering the material, and obtaining the graphene nano heavy-duty anti-corrosion coating.

[0028] Example 4: A graphene nano heavy-duty anti-corrosion coating, comprising the following components in parts by mass: 60 parts of diallyl bisphenol A epoxy resin, 12 parts of histidine modifier, 15 parts of graphene nanocomposite modified filler, 3 parts of triethylenetetramine, 3 parts of Jeffamine T-403, 2 parts of Aradur-42, 0.5 parts of BYK333, 0.3 parts of BYK381, 0.2 parts of TEGO-450, 0.2 parts of tributyl phosphate, 0.2 parts of BYK-024, and 0.2 parts of BYK-028.

[0029] Example 5: A graphene nano heavy-duty anti-corrosion coating, comprising the following components in parts by mass: 60 parts of diallyl bisphenol A epoxy resin, 12 parts of histidine modifier, 15 parts of graphene nanocomposite modified filler, 3 parts of diethylenetriamine, 3 parts of Jeffamine T-403, 2 parts of Jeffamine D-230, 0.5 parts of BYK333, 0.3 parts of BYK381, 0.2 parts of TEGO-450, 0.2 parts of tributyl phosphate, 0.2 parts of BYK-021, 0.1 parts of BYK-024, and 0.1 parts of BYK-028.

[0030] Comparative Example 1: In this comparative example, an equal amount of aminopropyltriethoxysilane was used instead of the histidine modifier, and the rest was the same as in Example 3.

[0031] Comparative Example 2: In this comparative example, an equal amount of graphene oxide is used to replace the graphene nanocomposite modified filler, and the rest is the same as Example 3.

[0032] Test Example 1: Anti-corrosion Performance Test of Heavy-Duty Anti-corrosion Coatings The neutral salt spray resistance time of the heavy-duty anti-corrosion coatings prepared in each embodiment of the present invention and the comparative example was tested with reference to "GB / T1771-2007 Determination of neutral salt spray resistance of paints and varnishes". The heavy-duty anti-corrosion coatings were applied to 0.8 mm cold-rolled steel plates and immersed in 20% sulfuric acid and 20% sodium hydroxide at 25°C for 60 days, respectively. The coatings were observed for cracks, blistering, peeling, rust, etc. to evaluate their anti-corrosion performance. The results are shown in the table below.

[0033] Table 1 Comparison of anti-corrosion performance test results of heavy-duty anti-corrosion coatings serial number Neutral salt spray resistance time Acid corrosion resistance Alkali corrosion resistance Example 1 ＞3000h No cracks, blistering, peeling or rust No cracks, blistering, peeling or rust Example 2 ＞3000h No cracks, blistering, peeling or rust No cracks, blistering, peeling or rust Example 3 ＞3000h No cracks, blistering, peeling or rust No cracks, blistering, peeling or rust Example 4 ＞3000h No cracks, blistering, peeling or rust No cracks, blistering, peeling or rust Example 5 ＞3000h No cracks, blistering, peeling or rust No cracks, blistering, peeling or rust Comparative Example 1 ＜2000h There are cracks and bubbles, but no peeling or rust There are cracks, bubbles, peeling, but no rust Comparative Example 2 ＜2000h There are cracks and bubbles, but no peeling or rust There are cracks and bubbles, but no peeling or rust As can be seen from Table 1, the neutral salt spray resistance time of the heavy-duty anti-corrosion coatings prepared in each embodiment is greater than 3000h, and no cracks, blistering, peeling or rusting occurs in the acid corrosion resistance and alkali corrosion resistance tests, indicating that the heavy-duty anti-corrosion coatings prepared in the present invention have excellent anti-corrosion properties and are resistant to salt spray, acid and alkali.

[0034] Test Example 2: Comparison of aging resistance test results of heavy-duty anti-corrosion coatings The heavy-duty anti-corrosion coatings prepared in the embodiments and comparative examples of the present invention were tested for aging resistance in accordance with GB / T 23987-2009 "Paint and varnish coatings - Artificial weathering - Exposure to fluorescent ultraviolet light and water." UVA-340 lamps were used for a 3000-h test cycle under the following cycle conditions: 60°C UV irradiation for 4 h + 50°C condensation for 4 h. The coatings were observed for cracking, blistering, and flaking. The chalking grade was assessed in accordance with GBT 1766-2008 "Paint and varnish coatings - Rating method for aging." The results are shown in the table below.

[0035] Table 2 Aging resistance test of heavy-duty anti-corrosion coatings It can be seen from Table 2 that the heavy-duty anti-corrosion coatings prepared in various embodiments also have excellent aging resistance.

[0036] Test Example 3: Heavy-duty anti-corrosion coating adhesion test Adhesion tests were conducted on the heavy-duty anti-corrosion coatings prepared in the embodiments and comparative examples of the present invention according to GB / T 5210-2006: Adhesion test for paints and varnishes by pull-off method. A tensile testing machine was used to pull the test column vertically at a rate of 1.0 MPa / s. The force (MPa) required to pull the coating apart was recorded as the adhesion. The results are shown in Table 1. Figure 1 .

[0037] from Figure 1 It can be seen that the adhesion of the heavy-duty anti-corrosion coatings prepared in each embodiment is significantly higher than that of the comparative example, and has good adhesion.

[0038] Test Example 4: Impact resistance test of heavy-duty anti-corrosion coatings The impact resistance of the heavy-duty anti-corrosion coatings prepared in each embodiment of the present invention and the comparative example was tested according to GB / T1732-2020 Determination of impact resistance of paint films. The results are shown in Table 1. Figure 2 .

[0039] from Figure 2 It can be seen that the impact strength of the heavy-duty anti-corrosion coatings prepared in each embodiment is greater than 65 cm, while the impact strength of the heavy-duty anti-corrosion coatings prepared in the comparative example is between 50-60 cm, indicating that the heavy-duty anti-corrosion coatings prepared in the present invention have good impact resistance.

[0040] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

[0041] The present invention and its embodiments are described above. Such description is not restrictive. The embodiment shown in the embodiment is only one embodiment of the present invention, and actual application is not limited thereto. In short, if a person skilled in the art is inspired by the above, and does not deviate from the purpose of the invention, without creatively designing methods and embodiments similar to the technical solution, they shall fall within the scope of protection of the present invention.

Claims

1. A graphene nano heavy-duty anti-corrosion coating, characterized by: The invention comprises the following components in parts by mass: 50-70 parts of diallyl bisphenol A epoxy resin, 8-15 parts of histidine modifier, 12-20 parts of graphene nanocomposite modified filler, 5-10 parts of curing agent, 0.5-2 parts of leveling agent and 0.3-1 parts of defoaming agent.

2. The graphene nano heavy-duty anti-corrosion coating according to claim 1, characterized in that: The histidine modifier is prepared by the following steps: (1) 1-palmitoyl-2-oleoylethanolamine and N-formyl-L-histidine were added to anhydrous ethanol at a mass volume ratio of 1:8-1:10 g / mL, stirred and dissolved, and then 0.5-1.0% acetic acid was added to the total mass of the reaction system. The reaction was stirred at 50-60°C for 4-5 hours. After the reaction was completed, the product was cooled to room temperature and filtered to obtain a solid product. The solid product was washed with anhydrous ethanol three times and vacuum dried at 60-70°C for 4-6 hours to obtain a histidine modified intermediate A. (2) Histidine modified intermediate A and (6CI,7CI,8CI,9CI)-3,9-bis(2-chloroethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane were added to acetonitrile at a mass volume ratio of 1:10-1:12, g / mL, and the temperature was raised to 80-90°C under nitrogen protection and refluxed for 7-8 hours. After the reaction, 80% of the acetonitrile was removed by vacuum distillation. After cooling to room temperature, anhydrous ether was added at a volume ratio of 1:1 to the remaining reaction solution to precipitate the product. After filtration, the precipitate was washed with anhydrous ether three times and dried in vacuo at 50-60°C for 5-6 hours to obtain histidine modified intermediate B. (3) Histidine modified intermediate B and aminopropyltriethoxysilane are added to toluene in a mass volume ratio of 1:12-1:15 g / mL, and dibutyltin dilaurate is added in an amount of 0.3-0.5% of the total mass of the reaction system. The mixture is stirred at 70-80°C for 3-4 hours under nitrogen protection, and then silicon tungsten heteropolyacid salt is added, and the reaction is continued at 60-70°C for 2-3 hours. After the reaction is completed, the mixture is cooled to room temperature, filtered to obtain a solid product, washed with toluene 3 times, and vacuum dried at 70-80°C for 6-8 hours to obtain the histidine modifier.

3. The graphene nano heavy-duty anti-corrosion coating according to claim 2, characterized in that: The graphene nanocomposite modified filler is prepared by the following steps: S1. Sodium bentonite is dispersed in deionized water at a mass volume ratio of 1:20-1:25 g / mL, and ultrasonically dispersed at a power of 300-400 W for 30-40 min to obtain a sodium bentonite dispersion. Graphene oxide is dispersed in deionized water at a mass volume ratio of 1:50-1:60 g / mL, and ultrasonically dispersed at a power of 400-500 W for 40-50 min to obtain a graphene oxide dispersion. The sodium bentonite dispersion and the graphene oxide dispersion are mixed at a volume ratio of 1:1, 0.2-0.3% sodium lauryl sulfate based on the total mass of the mixture is added, and the mixture is magnetically stirred at 300-400 r / min for 2-3 h at 30-35 ° C, and then vacuum dried at 60-70 ° C for 12-15 h, and ground through a 200 mesh sieve to obtain a graphene oxide / bentonite intercalated material; S2. Add graphene oxide / bentonite intercalated material into anhydrous toluene at a mass volume ratio of 1:15-1:20 g / mL, ultrasonically disperse at 300 W power for 20-30 min, then add allyltrimethoxysilane, and then add triethylamine accounting for 0.5-0.8% of the total mass of the reaction system, and reflux at 80-90 ° C for 5-6 h under nitrogen protection; after the reaction is completed, cool to room temperature, filter to obtain a solid product, wash with toluene and anhydrous ethanol twice each, vacuum dry at 80-90 ° C for 8-10 h, grind and pass through a 300 mesh sieve to obtain the graphene nanocomposite modified filler.

4. The graphene nano heavy-duty anti-corrosion coating according to claim 3, characterized in that: In the step (1), the mass ratio of 1-palmitoyl-2-oleoylethanolamine to N-formyl-L-histidine is 1.0:1.1-1.

3.

5. The graphene nano heavy-duty anti-corrosion coating according to claim 4, characterized in that: In the step (2), the mass ratio of the modified intermediate A to (6CI,7CI,8CI,9CI)-3,9-bis(2-chloroethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane is 1.0:1.2-1.

5.

6. The graphene nano heavy-duty anti-corrosion coating according to claim 5, characterized in that: In the step (3), the mass ratio of the modified intermediate B to aminopropyltriethoxysilane is 1.0:0.8-1.0; the mass ratio of the modified intermediate B to silicotungstic heteropolyacid salt is 1.0:0.3-0.

5.

7. The graphene nano heavy-duty anti-corrosion coating according to claim 6, characterized in that: In step S1, the mass ratio of sodium bentonite to graphene oxide is 1.0:0.3-0.

5.

8. The graphene nano heavy-duty anti-corrosion coating according to claim 7, characterized in that: In step S2, the mass ratio of the graphene oxide / bentonite intercalation material to allyltrimethoxysilane is 1.0:0.4-0.

6.

9. The graphene nano heavy-duty anti-corrosion coating according to claim 8, characterized in that: The curing agent is selected from one or more of diethylenetriamine, triethylenetetramine, Jeffamine D-230, Jeffamine T-403, and Aradur-42; the leveling agent is selected from one or more of BYK333, BYK381, TEGO-410, TEGO-440, and TEGO-450; and the defoaming agent is selected from one or more of tributyl phosphate, methyl silicone oil, BYK-021, BYK-024, and BYK-028.

10. A method for preparing the graphene nano heavy-duty anti-corrosion coating according to any one of claims 1 to 9, characterized in that: The following steps are involved: The components are weighed in parts by mass, diallyl bisphenol A epoxy resin is added into a reaction kettle, the temperature is raised to 60-70°C, and the mixture is stirred at 300-500 r / min for 10-15 min. Then, a histidine modifier and a graphene nanocomposite modified filler are added, the temperature is raised to 80-90°C, and high-speed dispersion is carried out at 800-1000 r / min for 30-40 min. The mixture is cooled to 50-60°C, a leveling agent and a defoaming agent are added, and the mixture is stirred at 400-600 r / min for 20-30 min. The mixture is further cooled to 25-30°C, a curing agent is added, and the mixture is stirred at 200-300 r / min for 10-15 min. The material is filtered to obtain the graphene nano heavy-duty anti-corrosion coating.

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