Graphene nanometer heavy-duty anticorrosive coating and preparation method thereof

Abstract

The application discloses a kind of graphene nanometer heavy anticorrosive coating and preparation method thereof, belong to anticorrosive coating technical field.The coating includes the following mass parts of components: diallyl bisphenol A type epoxy resin 50-70 parts, histidine modifier 8-15 parts, graphene nanometer composite modified filler 12-20 parts, curing agent 5-10 parts, leveling agent 0.5-2 parts, defoaming agent 0.3-1 part.Histidine modifier is generated by 1-palmitoyl-2-oleoyl ethanolamine and N-formyl-L-histidine through Schiff base reaction intermediate A;Again with spiro ring quaternary ammonium reagent reaction forms quaternary ammonium salt intermediate B;Again with aminopropyl triethoxysilane and silicotungstate composite is obtained.Graphene nanometer composite modified filler is formed by graphene oxide / bentonite intercalation structure, by allyl trimethoxysilane surface modification.The graphene nanometer heavy anticorrosive coating prepared by the application forms high dense crosslinking network, has excellent barrier property, strong adhesion, impact resistance and long-acting anticorrosion performance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of anticorrosive coatings, and particularly relates to a graphene nanometer heavy-duty anticorrosive coating and a preparation method thereof. BACKGROUND

[0002] Corrosion is a spontaneous destruction phenomenon of metal materials in their service environment (such as atmosphere, soil, seawater, chemical medium, etc.), which causes a large amount of economic loss to the global industry every year. In order to effectively protect metal structures and prolong their service life, anticorrosive coatings are widely used. Among them, heavy-duty anticorrosive coatings refer to high-performance coatings that can provide long-term effective protection in harsh corrosive environments such as marine environment, chemical atmosphere, acid, alkali and salt fog, high temperature and high humidity, etc. They usually have excellent chemical resistance, salt fog resistance, weather resistance, wear resistance, high adhesion and excellent physical and mechanical properties.

[0003] Epoxy resin coatings have become one of the most widely used resin matrices in the heavy-duty anticorrosive field due to their excellent adhesion, chemical resistance, good mechanical properties and easy construction and curing characteristics. However, there are still some bottleneck problems to be solved when traditional epoxy heavy-duty anticorrosive coatings are used in extreme environments for a long time: epoxy resin inevitably shrinks in the curing process, resulting in the formation of defects such as micropores and microcracks inside the coating. These defects provide a penetration channel for corrosive media, and once the media reaches the surface of the metal substrate, corrosion occurs. Although the crosslinking density can be improved, it is often at the expense of flexibility. Although epoxy resin itself has a certain barrier property, the micro-path formed by its polymer chain segment is still insufficient to completely block the slow penetration of small molecule corrosive media. Adding traditional sheet-shaped fillers can prolong the penetration path, but these fillers have problems such as poor dispersibility, easy sedimentation, insufficient aspect ratio, weak interface combination with resin, etc., which limit the further improvement of their barrier efficiency. The interface compatibility and chemical bonding strength of conventional fillers or modifiers with the epoxy resin matrix are often insufficient, which can easily form a weak interface layer or phase separation. This not only reduces the overall density of the coating and becomes a weak point for medium penetration, but also can cause the coating to peel off from the substrate or filler interface under physical stress. For zinc-rich epoxy and other sacrificial anode type coatings, zinc powder is consumed quickly, and long-term protection is limited; and for shielding type coatings, their ability to actively passivate metal substrates is usually weak.

[0004] In recent years, the rise of nanotechnology has brought new opportunities for the development of heavy-duty coatings. In particular, graphene, with its unique single-atom layer two-dimensional structure, extremely high specific surface area, excellent mechanical strength, outstanding chemical inertness, and nearly perfect barrier properties, is considered an ideal nanomaterial for improving the corrosion protection performance of coatings. Its sheet structure can effectively prolong the penetration path of corrosion media and provide excellent physical shielding. However, there is strong van der Waals force and π-π interaction between graphene sheets, which easily leads to agglomeration and makes it difficult to achieve uniform and stable monolayer or few-layer dispersion in resins. Agglomerates not only lose their nano-effect, but also may become stress concentration points and penetration channels. The surface of graphene is inert and lacks active groups, and the interfacial interaction between graphene and epoxy resin is mainly physical adsorption, with weak chemical bonding, resulting in insufficient interfacial bonding strength and low stress transfer efficiency, which easily leads to interfacial peeling. Therefore, it is of great theoretical significance and broad application prospects to develop a graphene-based heavy-duty coating that can effectively solve the problems of micro-defects, limited barrier efficiency, and weak interfacial bonding in traditional epoxy resin coatings and existing graphene composite coatings, while having high density, strong adhesion, excellent barrier properties, and long-term protection capability. SUMMARY

[0005] In view of the above, in order to overcome the defects of the prior art, the present application fills the voids and cracks generated during the curing of the epoxy resin by using histidine modifier and graphene nanocomposite modified filler, forms an effective protective layer, improves the corrosion resistance and impact resistance of the epoxy resin coating, and the prepared coating also has good density and adhesion, thereby further improving the corrosion protection performance and protection capability.

[0006] In order to achieve the above-mentioned purpose, the following technical scheme is adopted: on the one hand, the present application provides a graphene nanometer heavy-duty coating, which comprises the following components by mass: diallyl bisphenol A type epoxy resin 50-70 parts, histidine modifier 8-15 parts, graphene nanocomposite modified filler 12-20 parts, curing agent 5-10 parts, leveling agent 0.5-2 parts, and defoaming agent 0.3-1 part.

[0007] Further, the histidine modifier is prepared by the following steps:

[0008] (1) 1-palmitoyl-2-oleoyl ethanolamine and N-formyl-L-histidine are added to anhydrous ethanol in a mass-volume ratio of 1:8-1:10 g / mL, stirred and dissolved, then 0.5-1.0% of acetic acid based on the total mass of the reaction system is added, and stirred at 50-60°C for 4-5h; after the reaction is completed, cool to room temperature, and filter to obtain a solid product, wash with anhydrous ethanol 3 times, and vacuum dry at 60-70°C for 4-6h to obtain histidine modification intermediate A;

[0009] (2) histidine-modified intermediate A and (6CI, 7CI, 8CI, 9CI)-3, 9-bis (2-chloroethyl)-2, 4, 8, 10-tetraoxaspiro [5.5] undecane are added to acetonitrile in a mass-volume ratio of 1:10-1:12 g / mL, and heated to 80-90°C under nitrogen protection to reflux for 7-8h. After the reaction is completed, 80% acetonitrile is removed by distillation under reduced pressure. After cooling to room temperature, the product is precipitated by adding anhydrous ether in a volume ratio of 1:1 with the remaining reaction solution. After suction filtration, the precipitate is washed with anhydrous ether for 3 times, and dried at 50-60°C under vacuum for 5-6h to obtain histidine-modified intermediate B;

[0010] (3) histidine-modified intermediate B and aminopropyltriethoxysilane are added to toluene in a mass-volume ratio of 1:12-1:15 g / mL, and 0.3-0.5% of dibutyltin dilaurate based on the total mass of the reaction system is added. Stirring is carried out at 70-80°C under nitrogen protection for 3-4h. Then silicotungstate is added, and the reaction is continued at 60-70°C for 2-3h. After the reaction is completed, the temperature is cooled to room temperature, and the solid product is obtained by suction filtration. The product is washed with toluene for 3 times, and dried at 70-80°C under vacuum for 6-8h to obtain the histidine-modified agent.

[0011] Further, the graphene nanocomposite modified filler is prepared by the following steps:

[0012] S1, sodium-based bentonite is dispersed in deionized water in a mass-volume ratio of 1:20-1:25 g / mL, and ultrasonic dispersion is carried out at a power of 300-400W for 30-40min to obtain a sodium-based bentonite dispersion. Graphene oxide is dispersed in deionized water in a mass-volume ratio of 1:50-1:60 g / mL, and ultrasonic dispersion is carried out at a power of 400-500W for 40-50min to obtain a graphene oxide dispersion. The sodium-based bentonite dispersion and the graphene oxide dispersion are mixed in a volume ratio of 1:1, and 0.2-0.3% of sodium dodecyl sulfate based on the total mass of the mixed solution is added. Magnetic stirring is carried out at 300-400r / min at 30-35°C for 2-3h, and then vacuum drying is carried out at 60-70°C for 12-15h. The product is ground through a 200 mesh sieve to obtain an intercalated graphene oxide / bentonite material.

[0013] S2, the intercalated graphene oxide / bentonite material is added to anhydrous toluene in a mass-volume ratio of 1:15-1:20 g / mL, and ultrasonic dispersion is carried out at a power of 300W for 20-30min. Then allyltrimethoxysilane is added, and 0.5-0.8% of triethylamine based on the total mass of the reaction system is added. Refluxing is carried out at 80-90°C under nitrogen protection for 5-6h. After the reaction is completed, the temperature is cooled to room temperature, and the solid product is obtained by suction filtration. The product is washed with toluene and anhydrous ethanol for 2 times respectively, and dried at 80-90°C under vacuum for 8-10h. The product is ground through a 300 mesh sieve to obtain the graphene nanocomposite modified filler.

[0014] Further, the mass ratio of 1-palmitoyl-2-oleoyl ethanolamine to N-formyl-L-histidine in step (1) is 1.0:1.1-1.3.

[0015] Further, the mass ratio of modified intermediate A to (6CI,7CI,8CI,9CI)-3,9-bis(2-chloroethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane in step (2) is 1.0:1.2-1.5.

[0016] Further, the mass ratio of modified intermediate B to aminopropyl triethoxysilane in step (3) is 1.0:0.8-1.0; the mass ratio of modified intermediate B to silicotungstate is 1.0:0.3-0.5.

[0017] Further, the mass ratio of sodium-based bentonite to graphene oxide in step S1 is 1.0:0.3-0.5.

[0018] Further, the mass ratio of graphene oxide / bentonite intercalation material to allyl trimethoxysilane in step S2 is 1.0:0.4-0.6.

[0019] Further, the curing agent is selected from one or more of diethylene triamine, triethylene tetramine, Jeffamine D-230, Jeffamine T-403, Aradur-42; the leveling agent is selected from one or more of BYK333, BYK381, TEGO-410, TEGO-440, TEGO-450; the defoaming agent is selected from one or more of tributyl phosphate, methyl silicone oil, BYK-021, BYK-024, BYK-028.

[0020] In another aspect, the present application also provides a method for preparing the graphene nanometer heavy-duty anticorrosive coating, comprising the following steps: weighing each component according to the mass fraction, adding diallyl bisphenol A type epoxy resin into a reaction kettle, heating to 60-70 DEG C, stirring at 300-500 r / min for 10-15 min, then adding histidine modifier and graphene nanometer composite modified filler, increasing the temperature to 80-90 DEG C, high-speed dispersing at 800-1000 r / min for 30-40 min, cooling to 50-60 DEG C, adding leveling agent and defoaming agent, stirring at 400-600 r / min for 20-30 min, continuing to cool to 25-30 DEG C, adding curing agent, stirring at 200-300 r / min for 10-15 min, filtering the product, and obtaining the graphene nanometer heavy-duty anticorrosive coating.

[0021] The beneficial effects of the present application are:

[0022] The application fills the gap and crack generated during the curing of the epoxy resin by the histidine modifier and the graphene nanocomposite modified filler, forms an effective protective layer, improves the corrosion resistance and impact resistance of the epoxy resin coating, and the prepared coating also has good compactness and adhesion, thereby further improving the corrosion resistance and protection ability.

[0023] The application forms a Schiff base reaction by 1-palmitoyl-2-oleoyl ethanolamine and N-formyl-L-histidine, 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, then couples with aminopropyltriethoxysilane, and finally is compounded with silicotungstate, the amino group on the histidine can undergo ring-opening reaction with the epoxy group of the epoxy resin to form a strong covalent bond connection, significantly enhancing the interfacial bonding force and compatibility of the modifier and the resin matrix, effectively reducing the interfacial defects and phase separation, the long-chain alkane introduced by 1-palmitoyl-2-oleoyl ethanolamine can strengthen the interaction with the epoxy resin matrix through physical entanglement, and the unsaturated double bond at the end can participate in the free radical reaction during the curing process, and crosslinking with the epoxy resin matrix, especially with the graphene nanocomposite modified filler, further improving the crosslinking density and network compactness of the whole system.

[0024] The graphene nanocomposite modified filler is constructed by intercalating the sodium-based bentonite and graphene oxide, and then modified by allyltrimethoxysilane. The bentonite sheet effectively prevents the stacking of graphene, increases its effective barrier area, and silanization introduces reactive allyl double bonds. The modified filler can form highly dispersed and randomly oriented sheet barriers in the coating. These sheets greatly extend and tortuous the penetration path of corrosive media such as water, oxygen, corrosive ions and the like to the metal substrate, and the physical barrier effect is significant.

[0025] The quaternary ammonium salt structure in the histidine modifier has a rigid tetraoxaspiro ring structure, and the long-chain hydrophobic alkyl of 1-palmitoyl-2-oleoyl ethanolamine cooperates to form a hydrophobic region inside the coating and at the interface with the metal substrate, effectively preventing the adsorption and infiltration of water molecules. The cationic center of the quaternary ammonium salt carries a strong positive charge, which can form a stable ionic bond with the heteropoly acid with strong negative charge through electrostatic attraction. This composite structure enhances the mechanical properties and stability of the coating. The cationic center can be strongly adsorbed on the surface of the metal substrate with negative charge, significantly improving the adhesion of the coating, and helping to passivate the metal surface and slow down the initiation of electrochemical corrosion. The introduction of heteropoly acid not only stabilizes the quaternary ammonium salt structure through electrostatic interaction, but also has good catalytic activity and passivation ability, which can further enhance the protection of the coating on the metal substrate. This high-density cross-linked network, combined with the physical filling effect of the modifier and the filler, effectively fills the micro-gaps and micro-cracks generated during the curing and shrinkage of the epoxy resin, significantly reducing the permeation channels inside the coating.

[0026] The long-chain alkane and specific spiro / heterocyclic structure introduced in the modifier, as well as the reinforcing effect of graphene / bentonite nanosheet layer, together contribute to the improvement of the toughness of the coating, making it have better impact resistance and ability to resist physical damage, avoiding the loss of protective function of the coating due to mechanical damage. The high density, strong adhesion, excellent barrier property and hydrophobicity of the modifier and graphene / bentonite nanosheet layer together give the coating excellent corrosion resistance and long-term protection ability. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The adhesion test results column chart of the heavy-duty anticorrosive coating prepared for the embodiments and comparative examples of the present application;

[0028] Figure 2 The impact resistance test results column chart of the heavy-duty anticorrosive coating prepared for the embodiments and comparative examples of the present application.

[0029] The accompanying drawings are used to provide a further understanding of the present application, and constitute a part of the specification, together with the embodiments of the present application, to explain the present application, and do not constitute a limitation on the present application. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application are described below in a clear and complete manner. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments, and all other embodiments obtained by those skilled in the art without creative labor based on the embodiments in the present application belong to the scope of protection of the present application.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Methods and materials similar or equivalent to those described herein can be used in the practice of the present application. The preferred materials and methods are described herein, although any method and material similar or equivalent to those described herein can be used. The materials, methods, and examples are illustrative only and not intended to be limiting.

[0032] The experimental methods in the following examples are all conventional methods unless otherwise specified. The experimental materials used in the following examples are all commercially available unless otherwise specified.

[0033] Example 1: A graphene nanometer heavy-duty anticorrosive coating, comprising the following components by mass fraction: diene allyl bisphenol A type epoxy resin 50 parts, histidine modifier 8 parts, graphene nanometer composite modified filler 12 parts, curing agent diethylene triamine 5 parts, leveling agent BYK333 0.5 parts, defoaming agent tributyl phosphate 0.3 parts.

[0034] The histidine modifier is prepared by the following steps:

[0035] (1) 1-palmitoyl-2-oleoyl ethanolamine and N-formyl-L-histidine are added to anhydrous ethanol at a mass volume ratio of 1:10 g / mL, after stirring and dissolving, 1.0% of acetic acid based on the total mass of the reaction system is added, and stirring is carried out at 60°C for 5h; after the reaction is completed, it is cooled to room temperature, and the solid product is obtained by suction filtration, washed with anhydrous ethanol for 3 times, and dried at 70°C under vacuum for 6h to obtain the histidine modification intermediate A;

[0036] (2) The histidine modification intermediate A and (6CI,7CI,8CI,9CI)-3,9-bis(2-chloroethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane are added to acetonitrile at a mass volume ratio of 1:12 g / mL, and the reaction is carried out under nitrogen protection at 90°C for 8h; after the reaction is completed, 80% of acetonitrile is removed by distillation under reduced pressure, and after cooling to room temperature, the product is precipitated by adding anhydrous diethyl ether at a volume ratio of 1:1 with the remaining reaction liquid, and after suction filtration, the precipitate is washed with anhydrous diethyl ether for 3 times, and dried at 60°C under vacuum for 6h to obtain the histidine modification intermediate B;

[0037] (3) The histidine modification intermediate B and aminopropyl triethoxysilane are added to toluene at a mass volume ratio of 1:15 g / mL, 0.5% of dibutyltin dilaurate based on the total mass of the reaction system is added, and the reaction is carried out at 80°C under nitrogen protection for 4h, followed by the addition of silicotungstate, and the reaction is continued at 70°C for 3h; after the reaction is completed, it is cooled to room temperature, and the solid product is obtained by suction filtration, washed with toluene for 3 times, and dried at 80°C under vacuum for 8h to obtain the histidine modifier.

[0038] The graphene nanometer composite modified filler is prepared by the following steps:

[0039] S1, the sodium bentonite is dispersed into deionized water according to the mass volume ratio 1:25 g / mL, ultrasonic dispersion is carried out for 40 min under the power of 400 W, the sodium bentonite dispersion liquid is obtained, the graphene oxide is dispersed into deionized water according to the mass volume ratio 1:60 g / mL, ultrasonic dispersion is carried out for 50 min under the power of 500 W, the graphene oxide dispersion liquid is obtained, the sodium bentonite dispersion liquid and the graphene oxide dispersion liquid are mixed according to the volume ratio 1:1, 0.3% sodium dodecyl sulfate is added, accounting for the total mass of the mixed liquid, it is magnetically stirred at 400 r / min under 35℃ for 3 h, and then vacuum drying is carried out at 70℃ for 15 h, and grinding is carried out through 200 mesh screen, and the graphene oxide / bentonite intercalation material is obtained;

[0040] S2, the graphene oxide / bentonite intercalation material is added into anhydrous toluene according to the mass volume ratio 1:20 g / mL, ultrasonic dispersion is carried out for 30 min under the power of 300 W, then allyl trimethoxysilane is added, 0.8% triethylamine is added, accounting for the total mass of the reaction system, and the reaction is carried out under the protection of nitrogen at 90℃ for 6 h; after the reaction is completed, it is cooled to room temperature, and the solid product is obtained by suction filtration, and then it is washed with toluene and anhydrous ethanol respectively for 2 times, vacuum drying is carried out at 90℃ for 10 h, and grinding is carried out through 300 mesh screen, and the graphene nanocomposite modified filler is obtained.

[0041] The mass ratio of 1-palmitoyl-2-oleoyl ethanolamine to N-formyl-L-histidine in the step (1) is 1.0:1.3; 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 in the step (2) is 1.0:1.5; the mass ratio of the modified intermediate B to aminopropyl triethoxysilane in the step (3) is 1.0:1.0; the mass ratio of the modified intermediate B to silicotungstate in the step (3) is 1.0:0.5; the mass ratio of the sodium bentonite to the graphene oxide in the step S1 is 1.0:0.5; and the mass ratio of the graphene oxide / bentonite intercalation material to allyl trimethoxysilane in the step S2 is 1.0:0.6.

[0042] A method for preparing the graphene nanometer heavy-duty anticorrosive coating, comprising the following steps: weighing each component according to the mass fraction, adding the diallyl bisphenol A type epoxy resin into a reaction kettle, heating to 70℃, stirring at 500 r / min for 15 min, then adding the histidine modifier and the graphene nanometer composite modified filler, increasing the temperature to 90℃, high-speed dispersing for 40 min at 1000 r / min, reducing the temperature to 60℃, adding the leveling agent and the defoaming agent, stirring at 600 r / min for 30 min, continuously reducing the temperature to 30℃, adding the curing agent, stirring at 300 r / min for 15 min, filtering the material, and obtaining the graphene nanometer heavy-duty anticorrosive coating.

[0043] Example 2: A graphene nanometer heavy-duty anticorrosive coating, comprising the following components by mass fraction: 70 parts of diallyl bisphenol A type epoxy resin, 15 parts of histidine modifier, 20 parts of graphene nanometer composite modified filler, 5 parts of triethylene tetramine, 5 parts of Jeffamine D-230, 1 part of BYK381, 1 part of TEGO-410, 0.5 part of methyl silicone oil, and 0.5 part of BYK-021.

[0044] The histidine modifier is prepared by the following steps:

[0045] (1) 1-palmitoyl-2-oleoyl ethanolamine and N-formyl-L-histidine are added to anhydrous ethanol in a mass volume ratio of 1:8 g / mL, and after stirring and dissolving, 0.5% of acetic acid based on the total mass of the reaction system is added, and stirring is carried out at 50°C for 4h; after the reaction is completed, it is cooled to room temperature, and the solid product is extracted by filtration, washed with anhydrous ethanol 3 times, and dried at 60°C under vacuum for 4h to obtain the histidine modified intermediate A;

[0046] (2) The histidine modified intermediate A and (6CI, 7CI, 8CI, 9CI)-3, 9-bis(2-chloroethyl)-2, 4, 8, 10-tetraoxaspiro[5.5]undecane are added to acetonitrile in a mass volume ratio of 1:10 g / mL, and under nitrogen protection, the temperature is raised to 80°C to reflux for 7h; after the reaction is completed, 80% of acetonitrile is removed by distillation under reduced pressure, and after cooling to room temperature, the product is precipitated by adding anhydrous diethyl ether in a volume ratio of 1:1 with the remaining reaction liquid, and after filtration, the precipitate is washed with anhydrous diethyl ether 3 times, and dried at 50°C under vacuum for 5h to obtain the histidine modified intermediate B;

[0047] (3) The histidine modified intermediate B and aminopropyl triethoxysilane are added to toluene in a mass volume ratio of 1:12 g / mL, and 0.3% of dibutyltin dilaurate based on the total mass of the reaction system is added, and under nitrogen protection, stirring is carried out at 70°C for 3h, and then silicotungstate is added, and the reaction is continued at 60°C for 2h; after the reaction is completed, it is cooled to room temperature, and the solid product is extracted by filtration, washed with toluene 3 times, and dried at 70°C under vacuum for 6h to obtain the histidine modifier.

[0048] The graphene nanometer composite modified filler is prepared by the following steps:

[0049] S1, the sodium bentonite is dispersed into deionized water according to the mass-volume ratio of 1:20 g / mL, ultrasonic dispersion is carried out for 30 min under the power of 300 W, a sodium bentonite dispersion liquid is obtained, the graphene oxide is dispersed into deionized water according to the mass-volume ratio of 1:50 g / mL, ultrasonic dispersion is carried out for 40 min under the power of 400 W, a graphene oxide dispersion liquid is obtained, the sodium bentonite dispersion liquid and the graphene oxide dispersion liquid are mixed according to the volume ratio of 1:1, 0.2% of sodium dodecyl sulfate is added to the total mass of the mixed liquid, magnetic stirring is carried out at 300 r / min under 30℃ for 2 h, and then vacuum drying is carried out at 60℃ for 12 h, and grinding is carried out through a 200 mesh screen, so that the graphene oxide / bentonite intercalation material is obtained;

[0050] S2, the graphene oxide / bentonite intercalation material is added into anhydrous toluene according to the mass-volume ratio of 1:15 g / mL, ultrasonic dispersion is carried out for 20 min under the power of 300 W, then allyl trimethoxysilane is added, 0.5% of triethylamine is added to the total mass of the reaction system, and reflux reaction is carried out at 80℃ for 5 h under nitrogen protection; after the reaction is completed, cooling is carried out to room temperature, and solid products are obtained by filtration, and then the solid products are washed with toluene and anhydrous ethanol respectively for 2 times, vacuum drying is carried out at 80℃ for 8 h, and grinding is carried out through a 300 mesh screen, so that the graphene nanocomposite modified filler is obtained.

[0051] The mass ratio of 1-palmitoyl-2-oleoyl ethanolamine to N-formyl-L-histidine in the step (1) is 1.0:1.1; 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 in the step (2) is 1.0:1.2; the mass ratio of the modified intermediate B to aminopropyl triethoxysilane in the step (3) is 1.0:0.8; the mass ratio of the modified intermediate B to silicotungstate is 1.0:0.3; the mass ratio of the sodium bentonite to the graphene oxide in the step S1 is 1.0:0.3; and the mass ratio of the graphene oxide / bentonite intercalation material to allyl trimethoxysilane in the step S2 is 1.0:0.4.

[0052] A method for preparing the graphene nanometer heavy-duty anticorrosive coating, comprising the following steps: weighing each component according to the mass fraction, adding the diallyl bisphenol A type epoxy resin into a reaction kettle, heating to 60℃, stirring at 300 r / min for 10 min, then adding the histidine modifier and the graphene nanometer composite modified filler, increasing the temperature to 80℃, high-speed dispersing for 30 min at 800 r / min, reducing the temperature to 50℃, adding the leveling agent and the defoaming agent, stirring at 400 r / min for 20 min, continuously reducing the temperature to 25℃, adding the curing agent, stirring at 200 r / min for 10 min, and filtering the material to obtain the graphene nanometer heavy-duty anticorrosive coating.

[0053] Example 3: A graphene nanometer heavy-duty anticorrosive coating, comprising the following components in parts by mass: a diallyl bisphenol A type epoxy resin 60 parts, a histidine modifier 12 parts, a graphene nanometer composite modified filler 15 parts, Jeffamine D-230 3 parts, Jeffamine T-403 3 parts, Aradur-42 2 parts, TEGO-410 0.5 parts, TEGO-440 0.3 parts, TEGO-450 0.2 parts, BYK-021 0.2 parts, BYK-024 0.2 parts, and BYK-028 0.2 parts.

[0054] The histidine modifier is prepared by the following steps:

[0055] (1) 1-palmitoyl-2-oleoyl ethanolamine and N-formyl-L-histidine are added to anhydrous ethanol in a mass-volume ratio of 1:9 g / mL, after stirring and dissolving, 0.75% of acetic acid based on the total mass of the reaction system is added, and stirring is carried out at 55°C for 4.5h; after the reaction is completed, it is cooled to room temperature, and the solid product is obtained by suction filtration, washed with anhydrous ethanol 3 times, and dried at 65°C under vacuum for 5h to obtain the histidine modification intermediate A;

[0056] (2) The histidine modification intermediate A and (6CI, 7CI, 8CI, 9CI)-3, 9-bis(2-chloroethyl)-2, 4, 8, 10-tetraoxaspiro[5.5]undecane are added to acetonitrile in a mass-volume ratio of 1:11 g / mL, and the reaction is carried out under nitrogen protection at 85°C reflux for 7.5h; after the reaction is completed, 80% of acetonitrile is removed by reduced pressure distillation, and after cooling to room temperature, the product is precipitated by adding anhydrous diethyl ether in a volume ratio of 1:1 with the remaining reaction liquid, and after suction filtration, the precipitate is washed with anhydrous diethyl ether 3 times, and dried at 55°C under vacuum for 5.5h to obtain the histidine modification intermediate B;

[0057] (3) The histidine modification intermediate B and aminopropyl triethoxysilane are added to toluene in a mass-volume ratio of 1:13.5 g / mL, and 0.4% of dibutyltin dilaurate based on the total mass of the reaction system is added, and the reaction is carried out at 75°C under nitrogen protection for 3.5h, and then silicotungstate is added, and the reaction is continued at 65°C for 2.5h; after the reaction is completed, it is cooled to room temperature, and the solid product is obtained by suction filtration, washed with toluene 3 times, and dried at 75°C under vacuum for 7h to obtain the histidine modifier.

[0058] The graphene nanometer composite modified filler is prepared by the following steps:

[0059] S1, the sodium bentonite is dispersed into deionized water according to the mass-volume ratio of 1:22.5 g / mL, ultrasonic dispersion is carried out for 35 min under the power of 350 W, a sodium bentonite dispersion liquid is obtained, the graphene oxide is dispersed into deionized water according to the mass-volume ratio of 1:55 g / mL, ultrasonic dispersion is carried out for 45 min under the power of 450 W, a graphene oxide dispersion liquid is obtained, the sodium bentonite dispersion liquid and the graphene oxide dispersion liquid are mixed according to the volume ratio of 1:1, 0.25% of sodium dodecyl sulfate is added to the total mass of the mixed liquid, magnetic stirring is carried out at 350 r / min under 32.5℃ for 2.5 h, then vacuum drying is carried out at 65℃ for 13.5 h, and grinding is carried out through a 200 mesh screen, so that the graphene oxide / bentonite intercalation material is obtained;

[0060] S2, the graphene oxide / bentonite intercalation material is added into anhydrous toluene according to the mass-volume ratio of 1:17.5 g / mL, ultrasonic dispersion is carried out for 25 min under the power of 300 W, then allyl trimethoxysilane is added, 0.65% of triethylamine is added to the total mass of the reaction system, and reflux reaction is carried out at 85℃ for 5.5 h under nitrogen protection; after the reaction is completed, the temperature is cooled to room temperature, and solid products are obtained by suction filtration, which are washed with toluene and anhydrous ethanol respectively for 2 times, vacuum drying is carried out at 85℃ for 9 h, and grinding is carried out through a 300 mesh screen, so that the graphene nanocomposite modified filler is obtained.

[0061] The mass ratio of 1-palmitoyl-2-oleoyl ethanolamine to N-formyl-L-histidine in the step (1) is 1.0:1.2; 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 in the step (2) is 1.0:1.35; the mass ratio of the modified intermediate B to aminopropyl triethoxysilane in the step (3) is 1.0:0.9; the mass ratio of the modified intermediate B to silicotungstate is 1.0:0.4; the mass ratio of the sodium bentonite to the graphene oxide in the step S1 is 1.0:0.4; and the mass ratio of the graphene oxide / bentonite intercalation material to allyl trimethoxysilane in the step S2 is 1.0:0.5.

[0062] A method for preparing the graphene nanometer heavy-duty anticorrosive coating, comprising the following steps: weighing each component according to the mass fraction, adding the diallyl bisphenol A type epoxy resin into a reaction kettle, heating to 65℃, stirring at 400 r / min for 12.5 min, then adding the histidine modifier and the graphene nanometer composite modified filler, increasing the temperature to 85℃, high-speed dispersing for 35 min at 900 r / min, reducing the temperature to 55℃, adding the leveling agent and the defoaming agent, stirring at 500 r / min for 25 min, continuously reducing the temperature to 27.5℃, adding the curing agent, stirring at 250 r / min for 12.5 min, filtering the material, and obtaining the graphene nanometer heavy-duty anticorrosive coating.

[0063] Example 4: A graphene nanometer heavy-duty anticorrosive coating, comprising the following components by mass fraction: diallyl bisphenol A type epoxy resin 60 parts, histidine modifier 12 parts, graphene nanometer composite modified filler 15 parts, triethylene tetramine 3 parts, Jeffamine T-403 3 parts, Aradur-42 2 parts, BYK333 0.5 parts, BYK381 0.3 parts, TEGO-450 0.2 parts, tributyl phosphate 0.2 parts, BYK-024 0.2 parts, BYK-028 0.2 parts.

[0064] Example 5: A graphene nanometer heavy-duty anticorrosive coating, comprising the following components by mass fraction: diallyl bisphenol A type epoxy resin 60 parts, histidine modifier 12 parts, graphene nanometer composite modified filler 15 parts, diethylene triamine 3 parts, Jeffamine T-403 3 parts, Jeffamine D-230 2 parts, BYK333 0.5 parts, BYK381 0.3 parts, TEGO-450 0.2 parts, tributyl phosphate 0.2 parts, BYK-021 0.2 parts, BYK-024 0.1 parts, BYK-028 0.1 parts.

[0065] Comparative Example 1: In this comparative example, an equal amount of aminopropyl triethoxysilane is used instead of the histidine modifier, and the rest is the same as Example 3.

[0066] Comparative Example 2: In this comparative example, an equal amount of graphene oxide is used instead of the graphene nanometer composite modified filler, and the rest is the same as Example 3.

[0067] Test Example 1: Heavy-duty anticorrosive coating corrosion resistance test

[0068] The heavy-duty anticorrosive coatings prepared in each example and comparative example of the application were tested for neutral salt spray resistance time according to GB / T1771-2007 Color Paint and Varnish Determination of Resistance to Neutral Salt Spray. The heavy-duty anticorrosive coatings were coated on 0.8mm cold rolled steel plates, and then immersed in 20% sulfuric acid and 20% sodium hydroxide respectively at 25°C for 60d, and the coating was observed for cracks, blistering, peeling, rusting and other phenomena to evaluate its corrosion resistance. The results are shown in the table below.

[0069] Table 1 Comparison of heavy-duty anticorrosive coating corrosion resistance test results

[0070] Number Neutral salt spray resistance time Acid corrosion resistance Alkali corrosion resistance Example 1 ＞3000h No cracks, blistering, peeling, rusting No cracks, blistering, peeling, rusting Example 2 ＞3000h No cracks, blistering, peeling, rusting No cracks, blistering, peeling, rusting Example 3 ＞3000h No cracks, blistering, peeling, rusting No cracks, blistering, peeling, rusting Example 4 ＞3000h No cracks, blistering, peeling, rusting No cracks, blistering, peeling, rusting Example 5 ＞3000h No cracks, blistering, peeling, rusting No cracks, blistering, peeling, rusting Comparative Example 1 ＜2000h Cracks, blistering, no peeling, rusting Cracks, blistering, peeling, no rusting Comparative Example 2 ＜2000h Cracks, blistering, no peeling, rusting Cracks, blistering, no peeling, rusting

[0071] As can be seen from Table 1, the heavy-duty anticorrosive coatings prepared in each embodiment have a neutral salt spray resistance time of >3000h, and no cracking, blistering, peeling, rusting phenomenon occurs in the acid corrosion resistance and alkali corrosion resistance tests, indicating that the heavy-duty anticorrosive coatings prepared in the application have excellent corrosion resistance and can resist salt spray, acid and alkali.

[0072] Test Example 2: Comparison of heavy-duty anticorrosive coating aging resistance test results

[0073] The heavy-duty anticorrosive coatings prepared in each embodiment and the comparative example of the application were tested for aging resistance according to “GB / T 23987-2009 Paints and Varnishes Exposure of Coatings to Artificial Weathering Exposure to Fluorescent UV and Water”, UVA-340 lamp was used, the test period was 3000h, the cycle conditions were 60℃ UV irradiation for 4h + 50℃ condensation for 4h, whether cracking, blistering, peeling and other phenomena occurred was observed, the powdering grade was evaluated according to “GBT_1766-2008 Rating Method for Aging of Paint and Varnish Coatings”, and the results are shown in the following table.

[0074] Table 2: Heavy-duty anticorrosive coating aging resistance test

[0075] As can be seen from Table 2, the heavy-duty anticorrosive coatings prepared in each embodiment also have excellent aging resistance.

[0076] Test Example 3: Heavy-duty anticorrosive coating adhesion test

[0077] The heavy-duty anticorrosive coatings prepared in each embodiment and the comparative example of the application were tested for adhesion according to “GB / T 5210-2006 Paints and Varnishes Adhesion Test by Tensile Stripping”, a tensile testing machine was used to vertically stretch the test column, the rate was 1.0 MPa / s, the force (MPa) at which the coating was pulled off was recorded, which was the adhesion, and the results are shown in Figure 1 .

[0078] As can be seen from Figure 1 , the adhesion of the heavy-duty anticorrosive coatings prepared in each embodiment is significantly higher than that of the comparative example, and has good adhesion.

[0079] Test Example 4: Heavy-duty anticorrosive coating impact resistance test

[0080] The heavy-duty anticorrosive coatings prepared in each embodiment and the comparative example of the application were tested for impact resistance according to “GB / T1732-2020 Paint Film Impact Resistance Test Method”, and the results are shown in Figure 2 .

[0081] As can be seen from Figure 2 , the impact strength of the heavy-duty anticorrosive coatings prepared in each embodiment is >65cm, while the impact strength of the heavy-duty anticorrosive coating prepared in the comparative example is between 50-60cm, indicating that the heavy-duty anticorrosive coatings prepared in the application have good impact resistance.

[0082] While embodiments of the application have been shown and described, it is to be understood that the application is not limited to the details of the embodiments described, since various modifications can be made by those skilled in the art, without departing from the spirit and scope of the application, which is defined by the appended claims and their equivalents.

[0083] The above description of the application and its embodiments is not restrictive, and the embodiments shown are only one of the embodiments of the application, and the actual application is not limited thereto. In general, if a person skilled in the art is inspired by it, without departing from the purpose of the application, without creative design, similar ways and embodiments of the technical solution should belong to the protection scope of the application.

Claims

1. A graphene nanorebar anticorrosive coating, characterized by: The composition comprises the following components in parts by mass: 50-70 parts of a diallyl bisphenol A type epoxy resin, 8-15 parts of a histidine modifier, 12-20 parts of a graphene nanocomposite modified filler, 5-10 parts of a curing agent, 0.5-2 parts of a leveling agent, and 0.3-1 part of a defoaming agent; The histidine modifier is prepared by the following steps: (1) 1-palmitoyl-2-oleoyl ethanolamine and N-formyl-L-histidine are added into anhydrous ethanol at a mass-volume ratio of 1:8-1:10 g / mL, and after stirring and dissolving, 0.5-1.0% of acetic acid based on the total mass of the reaction system is added, and stirring is carried out at 50-60°C for 4-5h; after the reaction is completed, it is cooled to room temperature, and the solid product is obtained by suction filtration, washed with anhydrous ethanol for 3 times, and vacuum dried at 60-70°C for 4-6h to obtain a histidine modified intermediate A; (2) The histidine modified intermediate A and (6CI,7CI,8CI,9CI)-3,9-bis(2-chloroethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane are added into acetonitrile at a mass-volume ratio of 1:10-1:12, g / mL, and under nitrogen protection, the temperature is raised to 80-90°C to reflux for 7-8h; after the reaction is completed, 80% of acetonitrile is removed by distillation under reduced pressure, and after cooling to room temperature, the product is precipitated by adding anhydrous diethyl ether at a volume ratio of 1:1 with the remaining reaction liquid, and after suction filtration, the precipitate is washed with anhydrous diethyl ether for 3 times, and vacuum dried at 50-60°C for 5-6h to obtain a histidine modified intermediate B; (3) The histidine modified intermediate B and aminopropyl triethoxysilane are added into toluene at a mass-volume ratio of 1:12-1:15 g / mL, and 0.3-0.5% of dibutyltin dilaurate based on the total mass of the reaction system is added, and stirring is carried out at 70-80°C for 3-4h under nitrogen protection, and then silicotungstate is added, and the reaction is continued at 60-70°C for 2-3h; after the reaction is completed, it is cooled to room temperature, and the solid product is obtained by suction filtration, washed with toluene for 3 times, and vacuum dried at 70-80°C for 6-8h to obtain the histidine modifier; The graphene nanocomposite modified filler is prepared by the following steps: S1, sodium bentonite is dispersed into deionized water at a mass-volume ratio of 1:20-1:25 g / mL, and ultrasonic dispersion is carried out at a power of 300-400W for 30-40min to obtain a sodium bentonite dispersion liquid, and graphene oxide is dispersed into deionized water at a mass-volume ratio of 1:50-1:60 g / mL, and ultrasonic dispersion is carried out at a power of 400-500W for 40-50min to obtain a graphene oxide dispersion liquid, and the sodium bentonite dispersion liquid and the graphene oxide dispersion liquid are mixed at a volume ratio of 1:1, 0.2-0.3% of sodium dodecyl sulfate based on the total mass of the mixed liquid is added, and magnetic stirring is carried out at 300-400r / min at 30-35°C for 2-3h, and then vacuum drying is carried out at 60-70°C for 12-15h, and grinding through a 200 mesh sieve to obtain an oxidized graphene / bentonite intercalation material; S2, the graphene oxide / bentonite intercalation material is added into anhydrous toluene at a mass volume ratio of 1:15-1:20 g / mL, ultrasonic dispersion is carried out at a power of 300 W for 20-30 min, then allyl trimethoxysilane is added, 0.5-0.8% of triethylamine based on the total mass of the reaction system is added, and reflux reaction is carried out at 80-90°C under nitrogen protection for 5-6 h; after the reaction is completed, the temperature is cooled to room temperature, and solid product is obtained by filtration, which is washed with toluene and anhydrous ethanol for 2 times respectively, and dried at 80-90°C under vacuum for 8-10 h, and ground through a 300 mesh sieve to obtain the graphene nanocomposite modified filler.

2. The graphene nanorebar coating of claim 1, wherein: The mass ratio of 1-palmitoyl-2-oleoyl ethanolamine to N-formyl-L-histidine in the step (1) is 1.0:1.1-1.

3.

3. The graphene nanorebar coating of claim 1, wherein: 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 in the step (2) is 1.0:1.2-1.

5.

4. The graphene nanorebar coating of claim 1, wherein: The mass ratio of the modified intermediate B to aminopropyl triethoxysilane in the step (3) is 1.0:0.8-1.0; the mass ratio of the modified intermediate B to silicotungstate is 1.0:0.3-0.

5.

5. The graphene nanorebar coating of claim 1, wherein: The mass ratio of sodium-based bentonite to graphene oxide in the step S1 is 1.0:0.3-0.

5.

6. The graphene nanorebar coating of claim 1, wherein: The mass ratio of the graphene oxide / bentonite intercalation material to allyl trimethoxysilane in the step S2 is 1.0:0.4-0.

6.

7. The graphene nanorebar coating of claim 1, wherein: The curing agent is selected from one or more of diethylene triamine, triethylene tetramine, 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.

8. A method of preparing the graphene nanoreinforced coating according to any one of claims 1 to 7, characterized in that: The following steps are included: The components are weighed according to the mass fraction, the diallyl bisphenol A type epoxy resin is added into a reaction kettle, the temperature is raised to 60-70°C, and stirring is carried out at 300-500 r / min for 10-15 min, then the histidine modifier and the graphene nanocomposite modified filler are added, the temperature is raised to 80-90°C, high-speed dispersion is carried out at 800-1000 r / min for 30-40 min, the temperature is lowered to 50-60°C, the leveling agent and the defoaming agent are added, and stirring is carried out at 400-600 r / min for 20-30 min, the temperature is continuously lowered to 25-30°C, the curing agent is added, and stirring is carried out at 200-300 r / min for 10-15 min, and the material is filtered out to obtain the graphene nanometer heavy-duty anticorrosive coating.

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