Modified graphene nanoplatelet heavy-duty anticorrosive coating and preparation method thereof

Abstract

The application relates to the technical field of metal anticorrosion coating, and discloses a modified graphene nanosheet heavy-duty anticorrosion coating and a preparation method thereof.The preparation method is as follows: modified graphene nanosheets are uniformly mixed with acetone and a dispersing agent BYK-110, ultrasonic treatment is carried out for 1-1.5 hours, then ball milling is carried out for 2-3 hours under the conditions of 400-450 rpm and zirconium oxide beads with a particle size of 0.5 mm, a uniform dispersion liquid is obtained, bisphenol A epoxy resin and modified polyurethane are added into the dispersion liquid, stirring is carried out at 60-65 DEG C for 30-40 minutes until complete dissolution, high-speed shearing emulsification is carried out at 1200-1300 rpm for 1-2 hours, cooling is carried out to 35-40 DEG C, m-phenylenediamine is added, and light-proof stirring is carried out for 15-20 minutes, so that the modified graphene nanosheet heavy-duty anticorrosion coating is obtained.The heavy-duty anticorrosion coating prepared by the application has good anticorrosion performance and wear resistance.

Description

Technical Field

[0001] This invention relates to the field of metal anti-corrosion coating technology, specifically to a modified graphene nanosheet heavy-duty anti-corrosion coating and its preparation method. Background Technology

[0002] The ocean is a vast treasure trove of resources. With the rapid development of science and technology in recent years and the depletion of various land-based resources, the development of deep-sea materials and resources has become a crucial national strategic goal. my country's marine development industry has enormous potential, but a significant challenge arises: corrosion protection for marine engineering materials. The marine corrosive environment is extremely harsh and demanding. The most damaging factors are the various saline corrosive agents contained in seawater and marine air, which rapidly corrode various marine engineering structures, causing them to decompose and fracture. Furthermore, the diverse marine microorganisms and high exposure to the elements also accelerate corrosion. Conventional anti-corrosion coatings, due to their high porosity and poor impermeability, are ineffective in extreme environments. The coating is prone to cracking and peeling, exhibiting poor corrosion resistance. Therefore, avoiding this phenomenon is key to solving the problem. For example, patent CN118142821A discloses a heavy-duty anti-corrosion coating for oil pipes and its preparation method, including the following steps: pre-treating the substrate, then performing laser modification treatment on the surface of the substrate to obtain a substrate with a surface-modified layer; applying a liquid primer to the substrate with the surface-modified layer using high-pressure airless spraying, followed by curing to obtain a substrate with both primer and surface-modified layer; when the surface temperature of the substrate with primer and surface-modified layer reaches a set temperature, applying a powder topcoat, followed by curing to obtain a heavy-duty anti-corrosion coating for oil pipes. This invention improves the compatibility of various interfaces, enhances the service performance of the coating system, and effectively extends the service life of oil pipes in environments containing H2S / CO2 / Cl. - It has a long service life in harsh environments, but its wear resistance needs to be improved. Summary of the Invention

[0003] (a) Technical problems to be solved

[0004] To address the shortcomings of existing technologies, this invention provides a modified graphene nanosheet heavy-duty anti-corrosion coating and its preparation method. The heavy-duty anti-corrosion coating prepared by this invention has excellent anti-corrosion and wear-resistant properties.

[0005] (II) Technical Solution

[0006] To achieve the above objectives, the present invention provides the following technical solution: a modified graphene nanosheet heavy-duty anti-corrosion coating, comprising the following weight components: 45-50 parts by weight of bisphenol A epoxy resin, 0.6-1 parts by weight of modified graphene nanosheets, 4-6 parts by weight of modified polyurethane, 20-25 parts by weight of acetone, 1-2 parts by weight of m-phenylenediamine, and 0.8-1 parts by weight of dispersant BYK-110.

[0007] Furthermore, the method for preparing the modified graphene nanosheets is as follows:

[0008] Step 1: Add silane coupling agent KH-560 and deionized water to a round-mouth flask and mix them together. Adjust the pH to 3-4 with acetic acid and stir for 30-40 minutes to hydrolyze and obtain KH-560 hydrolysate.

[0009] Step 2: Add graphene nanosheets to anhydrous ethanol and ultrasonically disperse for 30-35 minutes to obtain a graphene nanosheet dispersion.

[0010] Step 3: Add the graphene nanosheet dispersion obtained in Step 2 to the KH-560 hydrolysate obtained in Step 1, stir and react at 80-85℃ for 6-8 hours. After the reaction is completed, vacuum filter, dry at 60-65℃ for 20-24 hours, and repeatedly grind and pulverize until the fineness is less than 200 mesh to obtain modified graphene nanosheets.

[0011] Furthermore, in step one, the ratio of silane coupling agent KH-560 to deionized water is 4.02-4.05g:78-80mL.

[0012] Furthermore, in step two, the ratio of graphene nanosheets to anhydrous ethanol is 1.13-1.17g:80-82mL.

[0013] Furthermore, the method for preparing the modified polyurethane is as follows:

[0014] S1: Add butyric acid, toluene, and aluminum oxide to a three-necked flask, stir and mix, then add diethylenetriamine, and react at 140-160℃ for 4-6 hours. Continue to raise the temperature to 200-220℃ and react for 3-5 hours. After the reaction is completed, remove toluene by rotary evaporation to obtain intermediate 1.

[0015] S2: Add intermediate 1 and 1,4-dibromobutane to acetone solvent, stir at 75-80℃ for 12-14 h, remove acetone by rotary evaporation after the reaction is complete, and wash with n-hexane to obtain intermediate 2.

[0016] S3: Add ethanol, glutaraldehyde, and intermediate 2 to a three-necked flask equipped with a reflux condenser, stir well, and reflux at 75-85℃ for 18-24h. After the reaction is complete, cool, precipitate, filter, wash and dry to obtain intermediate 3.

[0017] S4: Add polypropylene glycol-2000, isophorone diisocyanate, 2,2-bis(hydroxymethyl)propionic acid, and dibutyltin dilaurate catalyst to the reactor. React at 75-80℃ for 2-3 hours. After cooling the system to 65-70℃, add intermediate 3 and continue the reaction for 1-2 hours. After the reaction is complete, cool to 35-40℃, add triethylamine and deionized water to the system, and stir for 30-40 minutes to obtain modified polyurethane.

[0018] Furthermore, the ratio of butyric acid, toluene, aluminum oxide, and diethylenetriamine in S1 is 4.32-4.35g: 12-15mL: 0.5-0.6g: 2.14-2.16g.

[0019] Furthermore, the ratio of acetone, intermediate 1, 1,4-dibromobutane, and n-hexane in S2 is 15-20 mL: 1.52-1.55 g: 1.26-1.28 g: 10-12 mL.

[0020] Furthermore, the ratio of ethanol, glutaraldehyde, and intermediate 2 in S3 is 20-25 mL: 2.45-2.48 g: 2.03-2.06 g.

[0021] Further, the ratio of polypropylene glycol-2000, isophorone diisocyanate, 2,2-bis(hydroxymethyl)propionic acid, dibutyltin dilaurate, intermediate 3, triethylamine, and deionized water in S4 is 2.63-2.66g:3.24-3.28g:0.46-0.48g:0.03-0.04g:2.04-2.08g:0.01-0.02g:15-20mL.

[0022] Further, the preparation method of the modified graphene nanosheet heavy-duty anti-corrosion coating is as follows: the modified graphene nanosheets are mixed evenly with acetone and dispersant BYK-110, ultrasonically treated for 1-1.5h, and then ball-milled at 400-450rpm with zirconia beads of 0.5mm particle size for 2-3h to obtain a uniform dispersion. Bisphenol A epoxy resin and modified polyurethane are added to the dispersion, and stirred at 60-65℃ for 30-40min until completely dissolved. Then, high-speed shear emulsification is carried out at 1200-1300rpm for 1-2h, the temperature is lowered to 35-40℃, m-phenylenediamine is added, and the mixture is stirred in the dark for 15-20min to obtain the modified graphene nanosheet heavy-duty anti-corrosion coating.

[0023] (III) Beneficial Technical Effects

[0024] This invention modifies the surface of graphene nanosheets with the silane coupling agent KH-560. The modified graphene nanosheets can be uniformly dispersed in epoxy resin to form a dense physical barrier layer, which delays the penetration of corrosive media and improves corrosion resistance. The silanol generated after the hydrolysis of the silane coupling agent KH-560 can form covalent bonds with the oxygen-containing groups on the graphene surface. At the same time, its epoxy groups can react with the resin matrix, significantly improving the interfacial bonding force between graphene and resin and enhancing the wear resistance of the material. Schiff bases are introduced through the synthesis of intermediate 3. The imine groups in the Schiff base can form stable coordination bonds with metal ions, forming a passivation layer on the metal surface and inhibiting the corrosion reaction of the metal substrate. The polar groups in the polyurethane molecular chain can form hydrogen bonds or chemical bonds with the metal substrate, improving the adhesion of the coating. Its soft and hard segment microphase separation structure endows the coating with excellent flexibility and wear resistance, avoiding cracking of the coating due to mechanical stress. Moreover, the low permeability of polyurethane to corrosive media such as water, salt, and acid / alkali can delay substrate corrosion. It works synergistically with the physical barrier effect of graphene to effectively improve the anti-corrosion performance of the material. Attached Figure Description

[0025] Figure 1 This is the synthesis reaction formula for intermediate 3. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific embodiments.

[0028] Example 1

[0029] (1) Add 4.02g of silane coupling agent KH-560 and 78mL of deionized water to a round-mouth flask and mix them together. Adjust the pH to 3 with acetic acid and stir for 30min to hydrolyze and obtain KH-560 hydrolysate.

[0030] (2) 1.13 g of graphene nanosheets were added to 80 mL of anhydrous ethanol and ultrasonically dispersed for 30 min to obtain a graphene nanosheet dispersion.

[0031] (3) Add the graphene nanosheet dispersion obtained in (2) to the KH-560 hydrolysate obtained in (1), stir and react at 80°C for 6 hours. After the reaction is completed, vacuum filter, dry at 60°C for 20 hours, and repeatedly grind and pulverize until the fineness is less than 200 mesh to obtain modified graphene nanosheets.

[0032] (4) Add 4.32 g of butyric acid, 12 mL of toluene, and 0.5 g of aluminum oxide to a three-necked flask, stir and mix, then add 2.14 g of diethylenetriamine, react at 140 °C for 4 h, continue to heat to 200 °C and react for 3 h, after the reaction is completed, remove toluene by rotary evaporation to obtain intermediate 1.

[0033] (5) Add 1.52 g of intermediate 1 and 1.26 g of 1,4-dibromobutane to 15 mL of acetone solvent, stir at 75 °C for 12 h, remove acetone by rotary evaporation after the reaction is completed, and wash with 10 mL of n-hexane to obtain intermediate 2.

[0034] (6) Add 20 mL of ethanol, 2.45 g of glutaraldehyde and 2.03 g of intermediate 2 to a three-necked flask equipped with a reflux condenser, stir well, reflux at 75 °C for 18 h, after the reaction is complete, cool, precipitate, filter, wash and dry to obtain intermediate 3.

[0035] (7) Add 2.63g of polypropylene glycol-2000, 3.24g of isophorone diisocyanate, 0.46g of 2,2-bis(hydroxymethyl)propionic acid, and 0.03g of dibutyltin dilaurate catalyst to the reactor. React at 75°C for 2h. After cooling the system to 65°C, add 2.04g of intermediate 3 and continue the reaction for 1h. After the reaction is completed, cool to 35°C and add 0.01g of triethylamine and 15mL of deionized water to the system. Stir for 30min to obtain modified polyurethane.

[0036] (8) Mix 0.6 parts by weight of modified graphene nanosheets with 20 parts by weight of acetone and 0.8 parts by weight of dispersant BYK-110 evenly, sonicate for 1 hour, and then ball mill at 400 rpm with zirconia beads of 0.5 mm particle size for 2 hours to obtain a uniform dispersion. Add 45 parts by weight of bisphenol A epoxy resin and 4 parts by weight of modified polyurethane to the dispersion, stir at 60°C for 30 minutes until completely dissolved, then emulsify at 1200 rpm for 1 hour, cool to 35°C, add 1 part by weight of m-phenylenediamine, stir in the dark for 15 minutes to obtain a modified graphene nanosheet heavy-duty anti-corrosion coating.

[0037] Example 2

[0038] (1) Add 4.05g of silane coupling agent KH-560 and 80mL of deionized water to a round-mouth flask and mix them together. Adjust the pH to 4 with acetic acid and stir for 40min to hydrolyze and obtain KH-560 hydrolysate.

[0039] (2) 1.17 g of graphene nanosheets were added to 82 mL of anhydrous ethanol and ultrasonically dispersed for 35 min to obtain a graphene nanosheet dispersion.

[0040] (3) Add the graphene nanosheet dispersion obtained in (2) to the KH-560 hydrolysate obtained in (1), stir and react at 85°C for 8 hours. After the reaction is completed, vacuum filter, dry at 65°C for 24 hours, and repeatedly grind and pulverize until the fineness is less than 200 mesh to obtain modified graphene nanosheets.

[0041] (4) Add 4.35g of butyric acid, 15mL of toluene and 0.6g of aluminum oxide to a three-necked flask, stir and mix, then add 2.16g of diethylenetriamine, react at 160℃ for 6h, continue to heat to 220℃ and react for 5h, after the reaction is completed, remove toluene by rotary evaporation to obtain intermediate 1.

[0042] (5) Add 1.55 g of intermediate 1 and 1.28 g of 1,4-dibromobutane to 20 mL of acetone solvent, stir at 80 °C for 14 h, remove acetone by rotary evaporation after the reaction is completed, and wash with 12 mL of n-hexane to obtain intermediate 2.

[0043] (6) Add 25 mL of ethanol, 2.48 g of glutaraldehyde and 2.06 g of intermediate 2 to a three-necked flask equipped with a reflux condenser, stir well, reflux at 85 °C for 24 h, after the reaction is completed, cool, precipitate, filter, wash and dry to obtain intermediate 3.

[0044] (7) Add 2.66g of polypropylene glycol-2000, 3.28g of isophorone diisocyanate, 0.48g of 2,2-bis(hydroxymethyl)propionic acid, and 0.04g of dibutyltin dilaurate catalyst to the reactor. React at 80℃ for 3h. After cooling the system to 70℃, add 2.08g of intermediate 3 and continue the reaction for 2h. After the reaction is completed, cool to 40℃ and add 0.02g of triethylamine and 20mL of deionized water to the system. Stir for 40min to obtain modified polyurethane.

[0045] (8) Mix 1 part by weight of modified graphene nanosheets with 25 parts by weight of acetone and 1 part by weight of dispersant BYK-110 evenly, sonicate for 1.5 h, and then ball mill at 450 rpm and zirconia beads with a particle size of 0.5 mm for 3 h to obtain a uniform dispersion. Add 50 parts by weight of bisphenol A epoxy resin and 6 parts by weight of modified polyurethane to the dispersion, stir at 65°C for 40 min until completely dissolved, then emulsify at 1300 rpm for 2 h, cool to 40°C, add 2 parts by weight of m-phenylenediamine, stir in the dark for 20 min to obtain a modified graphene nanosheet heavy anti-corrosion coating.

[0046] Example 3

[0047] (1) Add 4.03g of silane coupling agent KH-560 and 79mL of deionized water to a round-mouth flask and mix them together. Adjust the pH to 3 with acetic acid and stir for 30-40min to hydrolyze and obtain KH-560 hydrolysate.

[0048] (2) 1.15g of graphene nanosheets were added to 81mL of anhydrous ethanol and ultrasonically dispersed for 33min to obtain a graphene nanosheet dispersion.

[0049] (3) Add the graphene nanosheet dispersion obtained in (2) to the KH-560 hydrolysate obtained in (1), stir and react at 82°C for 7 hours. After the reaction is completed, vacuum filter, dry at 62°C for 22 hours, and repeatedly grind and pulverize until the fineness is less than 200 mesh to obtain modified graphene nanosheets.

[0050] (4) Add 4.33 g of butyric acid, 13 mL of toluene, and 0.5 g of aluminum oxide to a three-necked flask, stir and mix, then add 2.15 g of diethylenetriamine, react at 150 °C for 5 h, continue to heat to 210 °C and react for 4 h, after the reaction is completed, remove toluene by rotary evaporation to obtain intermediate 1.

[0051] (5) Add 1.53 g of intermediate 1 and 1.27 g of 1,4-dibromobutane to 17 mL of acetone solvent, stir at 78 °C for 13 h, remove acetone by rotary evaporation after the reaction is complete, and wash with 11 mL of n-hexane to obtain intermediate 2.

[0052] (6) Add 22 mL of ethanol, 2.46 g of glutaraldehyde and 2.04 g of intermediate 2 to a three-necked flask equipped with a reflux condenser, stir well, reflux at 80 °C for 21 h, after the reaction is completed, cool, precipitate, filter, wash and dry to obtain intermediate 3.

[0053] (7) Add 2.64g of polypropylene glycol-2000, 3.26g of isophorone diisocyanate, 0.47g of 2,2-bis(hydroxymethyl)propionic acid, and 0.03g of dibutyltin dilaurate catalyst to the reactor. React at 78°C for 2h. After cooling the system to 68°C, add 2.06g of intermediate 3 and continue the reaction for 1h. After the reaction is completed, cool to 38°C and add 0.01g of triethylamine and 18mL of deionized water to the system. Stir for 35min to obtain modified polyurethane.

[0054] (8) Mix 0.8 parts by weight of modified graphene nanosheets with 22 parts by weight of acetone and 0.9 parts by weight of dispersant BYK-110 evenly, sonicate for 1.2 h, and then ball mill at 425 rpm and zirconia beads with a particle size of 0.5 mm for 2.5 h to obtain a uniform dispersion. Add 48 parts by weight of bisphenol A epoxy resin and 5 parts by weight of modified polyurethane to the dispersion, stir at 62 °C for 35 min until completely dissolved, then emulsify at 1250 rpm for 1.5 h, cool to 38 °C, add 1.5 parts by weight of m-phenylenediamine, stir in the dark for 18 min to obtain a modified graphene nanosheet heavy-duty anti-corrosion coating.

[0055] Example 4

[0056] (1) Add 4.04 g of silane coupling agent KH-560 and 78 mL of deionized water to a round-mouth flask and mix them together. Adjust the pH to 3 with acetic acid and stir for 32 min to hydrolyze and obtain KH-560 hydrolysate.

[0057] (2) 1.14 g of graphene nanosheets were added to 80 mL of anhydrous ethanol and ultrasonically dispersed for 31 min to obtain a graphene nanosheet dispersion.

[0058] (3) Add the graphene nanosheet dispersion obtained in (2) to the KH-560 hydrolysate obtained in (1), stir and react at 81°C for 6.5 h, after the reaction is completed, vacuum filter, dry at 62°C for 21 h, and repeatedly grind and pulverize until the fineness is less than 200 mesh to obtain modified graphene nanosheets.

[0059] (4) Add 4.33 g of butyric acid, 12 mL of toluene, and 0.5 g of aluminum oxide to a three-necked flask, stir and mix, then add 2.15 g of diethylenetriamine, react at 145 °C for 4 h, continue to heat to 205 °C and react for 3.5 h, after the reaction is completed, remove toluene by rotary evaporation to obtain intermediate 1;

[0060] (5) Add 1.53 g of intermediate 1 and 1.26 g of 1,4-dibromobutane to 16 mL of acetone solvent, stir at 76 °C for 13 h, remove acetone by rotary evaporation after the reaction is complete, and wash with 10 mL of n-hexane to obtain intermediate 2.

[0061] (6) Add 21 mL of ethanol, 2.46 g of glutaraldehyde and 2.04 g of intermediate 2 to a three-necked flask equipped with a reflux condenser, stir well, reflux at 78 °C for 20 h, after the reaction is completed, cool, precipitate, filter, wash and dry to obtain intermediate 3.

[0062] (7) Add 2.64g of polypropylene glycol-2000, 3.25g of isophorone diisocyanate, 0.46g of 2,2-bis(hydroxymethyl)propionic acid, and 0.03g of dibutyltin dilaurate catalyst to the reactor. React at 76℃ for 2h. After cooling the system to 66℃, add 2.05g of intermediate 3 and continue the reaction for 1h. After the reaction is completed, cool to 35℃ and add 0.01g of triethylamine and 16mL of deionized water to the system. Stir for 32min to obtain modified polyurethane.

[0063] (8) Mix 0.7 parts by weight of modified graphene nanosheets with 22 parts by weight of acetone and 0.8 parts by weight of dispersant BYK-110 evenly, sonicate for 1 hour, and then ball mill at 410 rpm and zirconia beads with a particle size of 0.5 mm for 2 hours to obtain a uniform dispersion. Add 46 parts by weight of bisphenol A epoxy resin and 4 parts by weight of modified polyurethane to the dispersion, stir at 60°C for 32 minutes until completely dissolved, then emulsify at 1200 rpm for 1 hour, cool to 35°C, add 1 part by weight of m-phenylenediamine, stir in the dark for 15 minutes to obtain a modified graphene nanosheet heavy-duty anti-corrosion coating.

[0064] Example 5

[0065] (1) Add 4.04 g of silane coupling agent KH-560 and 79 mL of deionized water to a round-mouth flask and mix them together. Adjust the pH to 4 with acetic acid and stir for 38 min to hydrolyze and obtain KH-560 hydrolysate.

[0066] (2) 1.16 g of graphene nanosheets were added to 82 mL of anhydrous ethanol and ultrasonically dispersed for 34 min to obtain a graphene nanosheet dispersion.

[0067] (3) Add the graphene nanosheet dispersion obtained in (2) to the KH-560 hydrolysate obtained in (1), stir and react at 84°C for 8 hours. After the reaction is completed, vacuum filter, dry at 65°C for 23 hours, and repeatedly grind and pulverize until the fineness is less than 200 mesh to obtain modified graphene nanosheets.

[0068] (4) Add 4.34 g of butyric acid, 15 mL of toluene, and 0.6 g of aluminum oxide to a three-necked flask, stir and mix, then add 2.16 g of diethylenetriamine, react at 155 °C for 6 h, continue to heat to 215 °C and react for 5 h, after the reaction is completed, remove toluene by rotary evaporation to obtain intermediate 1.

[0069] (5) Add 1.54 g of intermediate 1 and 1.27 g of 1,4-dibromobutane to 20 mL of acetone solvent, stir at 78 °C for 14 h, remove acetone by rotary evaporation after the reaction is completed, and wash with 12 mL of n-hexane to obtain intermediate 2.

[0070] (6) Add 24 mL of ethanol, 2.47 g of glutaraldehyde and 2.05 g of intermediate 2 to a three-necked flask equipped with a reflux condenser, stir well, reflux at 82 °C for 22 h, after the reaction is completed, cool, precipitate, filter, wash and dry to obtain intermediate 3.

[0071] (7) Add 2.65g of polypropylene glycol-2000, 3.27g of isophorone diisocyanate, 0.48g of 2,2-bis(hydroxymethyl)propionic acid, and 0.04g of dibutyltin dilaurate catalyst to the reactor. React at 78°C for 3h. After cooling the system to 70°C, add 2.07g of intermediate 3 and continue the reaction for 2h. After the reaction is completed, cool to 40°C and add 0.02g of triethylamine and 18mL of deionized water to the system. Stir for 38min to obtain modified polyurethane.

[0072] (8) Mix 0.9 parts by weight of modified graphene nanosheets with 24 parts by weight of acetone and 1 part by weight of dispersant BYK-110 evenly, sonicate for 1.5 h, and then ball mill at 450 rpm and zirconia beads with a particle size of 0.5 mm for 3 h to obtain a uniform dispersion. Add 48 parts by weight of bisphenol A epoxy resin and 6 parts by weight of modified polyurethane to the dispersion, stir at 65°C for 35 min until completely dissolved, then emulsify at 1300 rpm for 2 h, cool to 38°C, add 2 parts by weight of m-phenylenediamine, stir in the dark for 18 min to obtain a modified graphene nanosheet heavy-duty anti-corrosion coating.

[0073] Comparative Example 1

[0074] The difference between this comparative example and Example 5 is that graphene nanosheets were used instead of modified graphene nanosheets.

[0075] Comparative Example 2

[0076] The difference between this comparative example and Example 5 is that no modified polyurethane was added.

[0077] Performance testing:

[0078] The performance of the heavy-duty anti-corrosion coatings prepared in Examples 1-5 and Comparative Examples 1-2 was tested.

[0079] (1) The corrosion resistance test method is as follows:

[0080] The heavy-duty anti-corrosion coatings prepared in Examples 1-5 and Comparative Examples 1-2 were subjected to anti-corrosion tests under the following conditions: immersion in 20% sulfuric acid, immersion in 20% sodium hydroxide, and salt spray test with 5% sodium chloride. The test results are shown in Table 1.

[0081] Table 1: Corrosion resistance test.

[0082]

[0083]

[0084] As can be seen from Table 1, the heavy-duty anti-corrosion coatings prepared in Examples 1-5 have better anti-corrosion performance than the heavy-duty anti-corrosion coatings prepared in Comparative Examples 1-2.

[0085] (2) The abrasion resistance test method is as follows: Abrasion resistance test was conducted according to GB / T 1768-2006 "Determination of Abrasion Resistance of Paints and Varnishes". The test results are shown in Table 2.

[0086] Table 2: Abrasion resistance test.

[0087] project Abrasion resistance / mg Example 1 9.3 Example 2 8.4 Example 3 8.7 Example 4 9.1 Example 5 8.5 Comparative Example 1 13.1 Comparative Example 2 12.6

[0088] As can be seen from Table 2, the heavy-duty anti-corrosion coatings prepared in Examples 1-5 have better wear resistance than the heavy-duty anti-corrosion coatings prepared in Comparative Examples 1-2.

[0089] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0090] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0091] Those skilled in the art should understand that the above descriptions are merely several specific embodiments of the present invention, and not all embodiments. It should be noted that many modifications and improvements can be made by those skilled in the art, and all modifications or improvements not exceeding the scope of the claims should be considered within the protection scope of the present invention.

Claims

1. A modified graphene nanosheet heavy-duty anti-corrosion coating, characterized in that, It includes the following components by weight: 45-50 parts by weight of bisphenol A epoxy resin, 0.6-1 parts by weight of modified graphene nanosheets, 4-6 parts by weight of modified polyurethane, 20-25 parts by weight of acetone, 1-2 parts by weight of m-phenylenediamine, and 0.8-1 parts by weight of dispersant BYK-110. The modified polyurethane is prepared by: S1: Add butyric acid, toluene, and aluminum oxide to a three-necked flask, stir and mix, then add diethylenetriamine, and react at 140-160℃ for 4-6 hours. Continue to raise the temperature to 200-220℃ and react for 3-5 hours. After the reaction is completed, remove toluene by rotary evaporation to obtain intermediate 1. S2: Add intermediate 1 and 1,4-dibromobutane to acetone solvent, stir at 75-80℃ for 12-14 h, remove acetone by rotary evaporation after the reaction is complete, wash with n-hexane to obtain intermediate 2. S3: Add ethanol, glutaraldehyde, and intermediate 2 to a three-necked flask equipped with a reflux condenser, stir well, and reflux at 75-85℃ for 18-24h. After the reaction is complete, cool, precipitate, filter, wash and dry to obtain intermediate 3. S4: Add polypropylene glycol-2000, isophorone diisocyanate, 2,2-bis(hydroxymethyl)propionic acid, and dibutyltin dilaurate catalyst to the reactor. React at 75-80℃ for 2-3 hours. After cooling the system to 65-70℃, add intermediate 3 and continue the reaction for 1-2 hours. After the reaction is complete, cool the system to 35-40℃, add triethylamine and deionized water, and stir for 30-40 minutes to obtain modified polyurethane. In S1, the ratio of butyric acid, toluene, aluminum oxide, and diethylenetriamine is 4.32-4.35g: 12-15mL: 0.5-0.6g: 2.14-2.16g. In S2, the ratio of acetone, intermediate 1, 1,4-dibromobutane, and n-hexane is 15-20 mL: 1.52-1.55 g: 1.26-1.28 g: 10-12 mL. The method for preparing the modified graphene nanosheets is as follows: Step 1: Add silane coupling agent KH-560 and deionized water to a round-mouth flask and mix them together. Adjust the pH to 3-4 with acetic acid and stir for 30-40 minutes to hydrolyze and obtain KH-560 hydrolysate. Step 2: Add graphene nanosheets to anhydrous ethanol and ultrasonically disperse for 30-35 minutes to obtain a graphene nanosheet dispersion. Step 3: Add the graphene nanosheet dispersion obtained in Step 2 to the KH-560 hydrolysate obtained in Step 1, stir and react at 80-85℃ for 6-8 hours. After the reaction is completed, vacuum filter, dry at 60-65℃ for 20-24 hours, and repeatedly grind and pulverize until the fineness is less than 200 mesh to obtain modified graphene nanosheets.

2. The modified graphene nanosheet heavy-duty anti-corrosion coating according to claim 1, characterized in that, In step one, the ratio of silane coupling agent KH-560 to deionized water is 4.02-4.05 g: 78-80 mL.

3. The modified graphene nanosheet heavy-duty anti-corrosion coating according to claim 1, characterized in that, In step two, the ratio of graphene nanosheets to anhydrous ethanol is 1.13-1.17 g: 80-82 mL.

4. The modified graphene nanosheet heavy-duty anti-corrosion coating according to claim 1, characterized in that, The ratio of ethanol, glutaraldehyde, and intermediate 2 in S3 is 20-25 mL: 2.45-2.48 g: 2.03-2.06 g.

5. The modified graphene nanosheet heavy-duty anti-corrosion coating according to claim 1, characterized in that, The ratio of polypropylene glycol-2000, isophorone diisocyanate, 2,2-bis(hydroxymethyl)propionic acid, dibutyltin dilaurate, intermediate 3, triethylamine, and deionized water in S4 is 2.63-2.66g:3.24-3.28g:0.46-0.48g:0.03-0.04g:2.04-2.08g:0.01-0.02g:15-20mL.

6. A modified graphene nanosheet heavy-duty anti-corrosion coating as described in any one of claims 1-2, characterized in that, The preparation method of the modified graphene nanosheet heavy-duty anti-corrosion coating is as follows: Modified graphene nanosheets are mixed evenly with acetone and dispersant BYK-110, and ultrasonically treated for 1-1.5 hours. Then, the mixture is ball-milled at 400-450 rpm with zirconia beads of 0.5 mm particle size for 2-3 hours to obtain a uniform dispersion. Bisphenol A epoxy resin and modified polyurethane are added to the dispersion, and the mixture is stirred at 60-65℃ for 30-40 minutes until completely dissolved. Then, the mixture is emulsified by high-speed shearing at 1200-1300 rpm for 1-2 hours, cooled to 35-40℃, and m-phenylenediamine is added. The mixture is stirred in the dark for 15-20 minutes to obtain the modified graphene nanosheet heavy-duty anti-corrosion coating.

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