Preparation method of modified graphene super-hydrophobic self-cleaning anticorrosive paint

Abstract

The invention discloses a preparation method of a modified graphene super-hydrophobic self-cleaning anticorrosive coating, and relates to the technical field of coating preparation. Graphene oxide and hydroxyl silicone oil are mixed in an organic solvent; adding diisocyanate into an organic solvent for reaction to obtain a modified graphene dispersion liquid; finally, the modified graphene dispersion liquid is mixed with organic silicon resin and auxiliaries, and the modified graphene super-hydrophobic self-cleaning anti-corrosion coating is prepared. The coating is excellent in hydrophobicity and corrosion resistance, has a self-cleaning effect, and can meet the protection requirements in various harsh environments.

Description

Technical Field

[0001] The present application relates to the technical field of coating preparation, and particularly relates to a preparation method of a modified graphene superhydrophobic self-cleaning anti-corrosion coating. Background Art

[0002] In recent years, as a new type of two-dimensional nanomaterial, graphene has shown great application potential in the field of anti-corrosion coatings due to its excellent mechanical properties, electrical conductivity, chemical stability, and barrier properties. However, problems such as poor dispersion of graphene in coatings and insufficient interfacial compatibility with matrix resins have limited its practical applications. Through chemical modification, the dispersion and interfacial compatibility of graphene can be significantly improved, and at the same time, new functional characteristics such as superhydrophobicity and self-cleaning can be imparted.

[0003] Chinese patent application with publication number CN 113292902A discloses a modified graphene oxide anti-corrosion coating, which includes the following mass components: 40 - 60% of epoxy resin, 0.3 - 1% of functionalized SiO2 @AlH2 P3O 10 supported graphene oxide nanocomposite, 20 - 40% of curing agent, 1 - 3% of additives, and the balance is water. In this application, aluminum tripolyphosphate coated with silica is attached to the surface of dopamine-modified graphene oxide to improve dispersion and avoid agglomeration. The aluminum tripolyphosphate coated with silica plays a role in blocking corrosive media, and can also improve the wear resistance and hydrophobicity of the coating. When the coating is damaged, a passivation film can be formed to cover the damaged part of the coating and prevent the continued corrosion of the coating by corrosive substances. This application has a great enhancing effect on the anti-corrosion performance of the epoxy resin composite coating, and has characteristics such as high wear resistance, good hydrophobicity, strong impact resistance, and strong corrosion resistance. However, the preparation method of the anti-corrosion coating in this application is relatively cumbersome, and the anti-corrosion performance (salt spray resistance) and hydrophobicity of the prepared anti-corrosion coating still need to be improved. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present application provides a preparation method of a modified graphene superhydrophobic self-cleaning anti-corrosion coating. By mixing graphene oxide and hydroxy silicone oil in an organic solvent; then adding diisocyanate to the organic solvent to react to obtain a modified graphene dispersion; finally, mixing the modified graphene dispersion with an organosilicon resin and additives to prepare a modified graphene superhydrophobic self-cleaning anti-corrosion coating. This coating has excellent hydrophobicity and anti-corrosion properties, and has a self-cleaning effect, and can meet the protection requirements under various harsh environments.

[0005] To achieve the above object, the present application adopts the following technical solutions: A preparation method of a modified graphene superhydrophobic self-cleaning anti-corrosion coating, comprising: Graphene oxide and hydroxy silicone oil are added to an organic solvent, and stirred for a first preset time at a set temperature to obtain a mixed solution; At the same set temperature, diisocyanate is added to the mixed solution and stirred for a second preset time to undergo a reaction to obtain a modified graphene dispersion; The modified graphene dispersion, silicone resin and additives are mixed and stirred for a third preset time to prepare a modified graphene superhydrophobic self-cleaning anti-corrosion coating.

[0006] Beneficial technical effects: In an organic solvent, through the reaction of the isocyanate group in diisocyanate with the hydroxyl or carboxyl group on the surface of graphene oxide, and the reaction of the isocyanate group with the hydroxyl group in hydroxy silicone oil, the three are tightly connected together in a chemical bond binding manner, thereby obtaining a modified graphene dispersion. Moreover, there are many segments rich in silicon-oxygen bonds (Si-O-Si) in the prepared modified graphene dispersion, which improves the compatibility of the modified graphene dispersion with the silicone resin, makes the entire mixed system more uniform and stable, and greatly improves the anti-corrosion performance. At the same time, the side chains of the silicon-oxygen bonds (Si-O-Si) are connected with non-polar methyl groups, and these groups make the coating have a low surface energy, improving the hydrophobicity and self-cleaning performance of the coating. In addition, the nano-fillers in the additives better form a micro-nano rough structure in a more uniform and stable mixed system, and these structures can capture air, forming a stable gas film on the surface of the coating to isolate the water or pollutants on the coating surface, further improving the hydrophobicity and self-cleaning performance of the coating. Description of the drawings

[0007] Figure 1 is a process schematic diagram for preparing a modified graphene superhydrophobic self-cleaning anti-corrosion coating.

[0008] Figure 2 is a reaction schematic diagram for preparing a modified graphene dispersion.

[0009] Figure 3 is a structural schematic diagram of the modified graphene dispersion prepared in Example 1. Detailed implementation manners

[0010] The following examples are only for illustrating the technical concept and characteristics of the present invention, and their purpose is to enable those who are familiar with this technology to understand the content of the present invention and implement it accordingly, and cannot be used to limit the protection scope of the present invention. All equivalent transformations or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

[0011] In this application, the terms used in this application are only for the purpose of describing specific embodiments, and are not intended to limit this application.

[0012] As used in this application, the singular forms "is", "or", "a", "any one", and "the" are intended to include the plural forms unless the context clearly dictates otherwise.

[0013] This application adopts the technical solution as Figure 1 shown below: A method for preparing a modified graphene superhydrophobic self-cleaning and anti-corrosion coating, comprising: Adding graphene oxide and hydroxy silicone oil into an organic solvent, and stirring for a first preset time at a set temperature to obtain a mixed solution; At the same set temperature, adding diisocyanate into the mixed solution, stirring for a second preset time, and reacting to obtain a modified graphene dispersion liquid. The schematic diagram of the reaction is as Figure 2 shown; Mixing and stirring the modified graphene dispersion liquid with an organosilicon resin and an auxiliary agent for a third preset time to prepare a modified graphene superhydrophobic self-cleaning and anti-corrosion coating.

[0014] In a feasible embodiment, the structure of the hydroxy silicone oil includes: ; wherein, x is an integer between 10 and 50.

[0015] In a feasible embodiment, the organic solvent includes one or more of ethyl acetate, butyl acetate, toluene, xylene, dichloromethane, and tetrahydrofuran.

[0016] In a feasible embodiment, the set temperature is 60 - 80 °C; the first preset time is 30 - 60 min; the second preset time is 4 - 6 h; the third preset time is 1 - 2 h.

[0017] In a feasible embodiment, the diisocyanate includes at least one of hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, and toluene diisocyanate.

[0018] In a feasible embodiment, the structure of the modified graphene dispersion liquid includes:

[0019] or , wherein, is graphene oxide; R includes , and any one of; x is an integer between 10 and 50.

[0020] In a feasible embodiment, the organosilicon resin includes at least one of methyl silicone resin and phenyl silicone resin.

[0021] In a feasible embodiment, the auxiliary agent includes a nano filler, a dispersant, and an antifoaming agent.

[0022] In a feasible embodiment, the nano filler includes at least one of nano silica and nano alumina.

[0023] In a feasible embodiment, the particle size ranges of the nano silica and the nano alumina are both 10 - 100 nm.

[0024] In a feasible embodiment, the dispersant includes at least one of sodium dodecyl sulfate and sodium dodecylbenzenesulfonate.

[0025] In a feasible embodiment, the antifoaming agent includes at least one of BYK - 052 and BYK - 053.

[0026] In a feasible embodiment, the mass ratio of the organic solvent, graphene oxide, hydroxyl silicone oil, and diisocyanate is (40 - 60):(5 - 10):(20 - 30):(10 - 20).

[0027] In a feasible embodiment, the mass ratio of the modified graphene dispersion liquid, silicone resin, nano filler, dispersant, and antifoaming agent is (30 - 40):(40 - 60):(5 - 10):(0.1 - 1):(0.1 - 1).

[0028] The following will specifically describe a preparation method of a modified graphene superhydrophobic self - cleaning and anti - corrosion coating provided by the present application in combination with different embodiments.

[0029] Example 1:

[0030] As Figure 1 shown, a preparation method of a modified graphene superhydrophobic self - cleaning and anti - corrosion coating includes the following steps: Step 1: Add 50 g of ethyl acetate, 8 g of graphene oxide, and 25 g of hydroxyl silicone oil into a reactor, and stir at 70 °C for 45 min to obtain a mixed liquid; Step 2: At 70 °C, add 17 g of hexamethylene diisocyanate into the mixed liquid, and stir for 5 h to undergo a reaction to obtain a modified graphene dispersion liquid. The structural schematic diagram of this modified graphene dispersion liquid is as Figure 3 shown; Step 3: Mix and stir 35 g of the modified graphene dispersion liquid, 56 g of methyl silicone resin, 8 g of nano silica, 0.5 g of sodium dodecyl sulfate, and 0.5 g of BYK - 052 for 1.5 h to prepare a modified graphene superhydrophobic self - cleaning and anti - corrosion coating.

[0031] Example 2:

[0032] As Figure 1 shown, a preparation method of a modified graphene superhydrophobic self-cleaning and anti-corrosion coating includes the following steps: Step 1: Add 45 g of butyl acetate, 7 g of graphene oxide, and 28 g of hydroxyl silicone oil into a reactor, and stir at 65 °C for 50 minutes to obtain a mixed solution; Step 2: At 65 °C, add 20 g of dicyclohexylmethane diisocyanate into the mixed solution, and stir for 4.5 hours to carry out a reaction to obtain a modified graphene dispersion; Step 3: Mix and stir 38 g of the modified graphene dispersion, 55 g of phenyl silicone resin, 6.4 g of nano-aluminum oxide, 0.3 g of sodium dodecylbenzenesulfonate, and 0.3 g of BYK-053 for 1.8 hours to prepare the modified graphene superhydrophobic self-cleaning and anti-corrosion coating.

[0033] Example 3:

[0034] As Figure 1 shown, a preparation method of a modified graphene superhydrophobic self-cleaning and anti-corrosion coating includes the following steps: Step 1: Add 55 g of toluene, 6 g of graphene oxide, and 23 g of hydroxyl silicone oil into a reactor, and stir at 75 °C for 40 minutes to obtain a mixed solution; Step 2: At 75 °C, add 16 g of toluene diisocyanate into the mixed solution, and stir for 5.5 hours to carry out a reaction to obtain a modified graphene dispersion; Step 3: Mix and stir 38 g of the modified graphene dispersion, 50 g of methyl silicone resin, 10 g of nano-silica, 1 g of sodium dodecyl sulfate, and 1 g of BYK-052 for 1.2 hours to prepare the modified graphene superhydrophobic self-cleaning and anti-corrosion coating.

[0035] Example 4:

[0036] As Figure 1 shown, a preparation method of a modified graphene superhydrophobic self-cleaning and anti-corrosion coating includes the following steps: Step 1: Add 60 g of xylene, 5 g of graphene oxide, and 22 g of hydroxyl silicone oil into a reactor, and stir at 80 °C for 30 minutes to obtain a mixed solution; Step 2: At 80 °C, add 13 g of hexamethylene diisocyanate into the mixed solution, and stir for 6 hours to carry out a reaction to obtain a modified graphene dispersion; Step 3: Mix and stir 40 g of the modified graphene dispersion, 53 g of phenyl silicone resin, 6.8 g of nano-aluminum oxide, 0.1 g of sodium dodecylbenzenesulfonate, and 0.1 g of BYK-053 for 2 hours to prepare the modified graphene superhydrophobic self-cleaning and anti-corrosion coating.

[0037] Example 5:

[0038] As Figure 1 shown, a preparation method of a modified graphene superhydrophobic self-cleaning and anti-corrosion coating includes the following steps: Step 1: Add 40 g of dichloromethane, 10 g of graphene oxide, and 30 g of hydroxy silicone oil into a reactor, and stir at 60 °C for 60 minutes to obtain a mixed solution; Step 2: At 60 °C, add 20 g of dicyclohexylmethane diisocyanate into the mixed solution, and stir for 4 hours to carry out a reaction to obtain a modified graphene dispersion; Step 3: Mix and stir 30 g of the modified graphene dispersion, 60 g of methyl silicone resin, 9 g of nano-silica, 0.5 g of sodium dodecyl sulfate, and 0.5 g of BYK-052 for 1 hour to prepare the modified graphene superhydrophobic self-cleaning and anti-corrosion coating.

[0039] Example 6:

[0040] As Figure 1 shown, a preparation method of a modified graphene superhydrophobic self-cleaning and anti-corrosion coating includes the following steps: Step 1: Add 52 g of tetrahydrofuran, 9 g of graphene oxide, and 24 g of hydroxy silicone oil into a reactor, and stir at 68 °C for 55 minutes to obtain a mixed solution; Step 2: At 68 °C, add 15 g of toluene diisocyanate into the mixed solution, and stir for 5.2 hours to carry out a reaction to obtain a modified graphene dispersion; Step 3: Mix and stir 36 g of the modified graphene dispersion, 56.4 g of phenyl silicone resin, 6.8 g of nano-alumina, 0.4 g of sodium dodecylbenzenesulfonate, and 0.4 g of BYK-053 for 1.7 hours to prepare the modified graphene superhydrophobic self-cleaning and anti-corrosion coating.

[0041] Comparative Example 1: A preparation method of a modified graphene superhydrophobic self-cleaning and anti-corrosion coating includes the following steps: Step 1: Add 50 g of ethyl acetate, 8 g of graphene oxide, and 25 g of hydroxy silicone oil into a reactor, and stir at 70 °C for 45 min to obtain a mixed solution; Step 2: At 70 °C, add 17 g of ethylene glycol into the mixed solution, and stir for 5 h to obtain a modified graphene dispersion Step 3: Mix and stir 35 g of the modified graphene dispersion, 56 g of methyl silicone resin, 8 g of nano-silica, 0.5 g of sodium dodecyl sulfate, and 0.5 g of BYK-052 for 1.5 h to prepare the modified graphene superhydrophobic self-cleaning and anti-corrosion coating.

[0042] Comparative Example 2: Preparation method of a modified graphene superhydrophobic self-cleaning and anti-corrosion coating, comprising the following steps: Step 1: Add 55 g of toluene, 6 g of graphene oxide and 23 g of silicone oil into a reactor, stir at 75 °C for 40 minutes to obtain a mixed solution; Step 2: At 75 °C, add 16 g of toluene diisocyanate into the mixed solution, stir for 5.5 hours to carry out a reaction to obtain a modified graphene dispersion; Step 3: Mix and stir 38 g of the modified graphene dispersion, 50 g of methyl silicone resin, 10 g of nano-silica, 1 g of sodium dodecyl sulfate and 1 g of BYK-052 for 1.2 hours to prepare the modified graphene superhydrophobic self-cleaning and anti-corrosion coating.

[0043] Comparative Example 3: Preparation method of a modified graphene superhydrophobic self-cleaning and anti-corrosion coating, comprising the following steps: Step 1: Add 40 g of dichloromethane, 10 g of graphene oxide and 30 g of hydroxyl silicone oil into a reactor, stir at 60 °C for 60 minutes to obtain a mixed solution; Step 2: At 60 °C, add 20 g of dicyclohexylmethane diisocyanate into the mixed solution, stir for 4 hours to carry out a reaction to obtain a modified graphene dispersion; Step 3: Mix and stir 30 g of the modified graphene dispersion, 60 g of acrylic resin, 9 g of nano-silica, 0.5 g of sodium dodecyl sulfate and 0.5 g of BYK-052 for 1 hour to prepare the modified graphene superhydrophobic self-cleaning and anti-corrosion coating.

[0044] Test the modified graphene superhydrophobic self-cleaning and anti-corrosion coatings prepared in Examples 1 to 6 and Comparative Examples 1 to 3.

[0045] Referring to GB / T 30447-2013, the hydrophobicity of the prepared coating is reflected by testing the size of the water contact angle.

[0046] Referring to GB / T 1771-2007, the anti-corrosion property of the prepared coating is reflected by testing the length of the salt spray resistance time. The test results are shown in Table 1.

[0047] Table 1 Test results of the modified graphene superhydrophobic self-cleaning and anti-corrosion coatings prepared in Examples and Comparative Examples

[0048] As can be seen from Table 1, the various data of Examples 1 to 6 are overall better than those of Comparative Examples 1 to 3.

[0049] The reason is that in Examples 1 to 6, in an organic solvent, through the reaction of the isocyanate groups in the diisocyanate with the hydroxyl or carboxyl groups on the surface of graphene oxide, and the reaction of the isocyanate groups with the hydroxyl groups in the hydroxyl silicone oil, the three are tightly connected together in a chemical bond combination manner, thus obtaining a modified graphene dispersion. Moreover, there are many segments rich in silicon-oxygen bonds (Si-O-Si) in the obtained modified graphene dispersion, which improves the compatibility of the modified graphene dispersion with the silicone resin, makes the entire mixed system more uniform and stable, and greatly improves the anti-corrosion performance. At the same time, the side chains of the silicon-oxygen bonds (Si-O-Si) are connected with non-polar methyl groups, and these groups make the coating have a low surface energy, improving the hydrophobicity and self-cleaning performance of the coating. In addition, the nano-fillers in the additives better form a micro-nano level rough structure in a more uniform and stable mixed system. These structures can capture air, form a stable air film on the surface of the coating, isolate the coating from water or pollutants on the coating surface, and further improve the hydrophobicity and self-cleaning performance of the coating.

[0050] In Comparative Example 1, diisocyanate was not used. Therefore, graphene oxide and hydroxyl silicone oil could not be combined together by chemical bonds. As a result, the modification of graphene oxide was not successful, and the compatibility was poor when mixed with the silicone resin, ultimately resulting in poor hydrophobicity and anti-corrosion performance. For the same reason, in Comparative Example 2, silicone oil was used instead of hydroxyl silicone oil. Therefore, although diisocyanate was used, graphene oxide and silicone oil could not be combined together by chemical bonds. In Comparative Example 3, although both diisocyanate and hydroxyl silicone oil were used, and the corresponding modified graphene dispersion could be successfully prepared, but since the acrylic resin was mixed with the modified graphene dispersion finally, the compatibility between the two was also poor, so the hydrophobicity and anti-corrosion properties were also poor.

[0051] The above results show and describe the basic principles, main features and advantages of the present application.

[0052] Those skilled in the art of this industry should understand that the present application is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principle of the present application. Without departing from the spirit and scope of the present application, the present application will have various changes and improvements, and these changes and improvements all fall within the scope of the present application claimed. The scope of protection claimed by the present application is defined by the equivalents of the appended claims.

Claims

1. A preparation method of a modified graphene superhydrophobic self-cleaning and anti-corrosion coating, characterized in that, Including: Adding graphene oxide and hydroxy silicone oil into an organic solvent, and stirring for a first preset time at a set temperature to obtain a mixed solution; At the same set temperature, adding diisocyanate into the mixed solution, stirring for a second preset time, and reacting to obtain a modified graphene dispersion; Mixing and stirring the modified graphene dispersion, silicone resin and additives for a third preset time to prepare a modified graphene superhydrophobic self-cleaning and anti-corrosion coating.

2. The preparation method of a modified graphene superhydrophobic self-cleaning and anti-corrosion coating according to claim 1, characterized in that, The structure of the hydroxy silicone oil includes: ; wherein, x is an integer between 10 and 50.

3. The preparation method of a modified graphene superhydrophobic self-cleaning and anti-corrosion coating according to claim 1, characterized in that, The organic solvent includes one or more of ethyl acetate, butyl acetate, toluene, xylene, dichloromethane and tetrahydrofuran.

4. The preparation method of a modified graphene superhydrophobic self-cleaning and anti-corrosion coating according to claim 1, characterized in that, The set temperature is 60-80 °C; the first preset time is 30-60 min; the second preset time is 4-6 h; the third preset time is 1-2 h.

5. The preparation method of a modified graphene superhydrophobic self-cleaning and anti-corrosion coating according to claim 1, characterized in that, The diisocyanate includes at least one of hexamethylene diisocyanate, dicyclohexylmethane diisocyanate and toluene diisocyanate.

6. The preparation method of a modified graphene superhydrophobic self-cleaning and anti-corrosion coating according to claim 1, characterized in that, The structure of the modified graphene dispersion includes: ； Or ， Among them, is graphene oxide; R includes , and any one of them; x is an integer between 10 and 50.

7. The preparation method of a modified graphene superhydrophobic self-cleaning and anti-corrosion coating according to claim 1, wherein, The silicone resin includes at least one of methyl silicone resin and phenyl silicone resin.

8. The preparation method of a modified graphene superhydrophobic self-cleaning and anti-corrosion coating according to claim 1, characterized in that, The additives include nano-fillers, dispersants and defoamers.

9. The preparation method of a modified graphene superhydrophobic self-cleaning and anti-corrosion coating according to claim 8, characterized in that, The nano-fillers include at least one of nano-silica and nano-alumina; the dispersants include at least one of sodium dodecyl sulfate and sodium dodecylbenzenesulfonate; the defoamers include at least one of BYK-052 and BYK-053.

10. The preparation method of a modified graphene superhydrophobic self-cleaning and anti-corrosion coating according to claim 8, characterized in that, The mass ratio of the organic solvent, graphene oxide, hydroxy silicone oil and diisocyanate is (40-60):(5-10):(20-30):(10-20); the mass ratio of the modified graphene dispersion, silicone resin, nano-fillers, dispersants and defoamers is (30-40):(40-60):(5-10):(0.1-1):(0.1-1).

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