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

Abstract

The application discloses a preparation method of modified graphene super-hydrophobic self-cleaning anticorrosive paint and relates to the technical field of paint preparation. The modified graphene super-hydrophobic self-cleaning anticorrosive paint is prepared by mixing graphene oxide and hydroxyl silicone oil in an organic solvent, adding diisocyanate into the organic solvent to generate a reaction, obtaining a modified graphene dispersion liquid, and finally mixing the modified graphene dispersion liquid with silicone resin and an additive. The paint has excellent hydrophobicity and anticorrosion property, has a self-cleaning effect, and can meet the protection requirements in various severe environments.

Description

Technical Field

[0001] This application relates to the field of coating preparation technology, and in particular to a method for preparing a modified graphene superhydrophobic self-cleaning anti-corrosion coating. Background Technology

[0002] In recent years, graphene, as a novel two-dimensional nanomaterial, 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 dispersibility of graphene in coatings and insufficient interfacial compatibility with matrix resins limit its practical application. Through chemical modification, the dispersibility and interfacial compatibility of graphene can be significantly improved, while endowing it with new functional properties such as superhydrophobicity and self-cleaning properties.

[0003] Chinese patent application CN 113292902A discloses a modified graphene oxide anticorrosive coating, comprising the following components by mass: 40-60% epoxy resin, functionalized SiO2@AlH2P3O 10 The composition comprises 0.3-1% graphene oxide nanocomposite material, 20-40% curing agent, 1-3% additives, and the balance being water. This application uses silica-coated aluminum tripolyphosphate attached to the surface of dopamine-modified graphene oxide to improve dispersibility and prevent agglomeration. The silica-coated aluminum tripolyphosphate acts as a barrier against corrosive media and also improves the wear resistance and hydrophobicity of the coating. When the coating is damaged, a passivation film is formed, covering the damaged areas and preventing further corrosion. This application significantly enhances the anti-corrosion performance of epoxy resin composite coatings, exhibiting high wear resistance, good hydrophobicity, strong impact resistance, and strong corrosion resistance. However, the preparation method of this anti-corrosion coating is relatively cumbersome, and the anti-corrosion performance (salt spray resistance) and hydrophobicity of the obtained coating still need improvement. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this application provides a method for preparing a modified graphene superhydrophobic self-cleaning anti-corrosion coating. The method involves mixing graphene oxide and hydroxyl silicone oil in an organic solvent; then adding diisocyanate to the organic solvent to react and obtain a modified graphene dispersion; finally, mixing the modified graphene dispersion with organosilicon resin and additives to obtain the modified graphene superhydrophobic self-cleaning anti-corrosion coating. This coating exhibits excellent hydrophobicity and anti-corrosion properties, and possesses a self-cleaning effect, meeting the protection requirements of various harsh environments.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] A method for preparing a modified graphene superhydrophobic self-cleaning anti-corrosion coating includes:

[0007] Graphene oxide and hydroxyl silicone oil are added to an organic solvent and stirred at a set temperature for a first preset time to obtain a mixture.

[0008] At the same set temperature, diisocyanate was added to the mixture, and the mixture was stirred for a second preset time to react and obtain a modified graphene dispersion.

[0009] The modified graphene dispersion was mixed with organosilicon resin and additives and stirred for a third preset time to obtain a modified graphene superhydrophobic self-cleaning anti-corrosion coating.

[0010] Beneficial technical effects:

[0011] In an organic solvent, a modified graphene dispersion is prepared by chemically bonding the isocyanate groups in diisocyanate with the hydroxyl or carboxyl groups on the surface of graphene oxide, and the isocyanate groups with the hydroxyl groups in hydroxyl silicone oil. The resulting modified graphene dispersion contains numerous segments rich in silicon-oxygen bonds (Si-O-Si), improving its compatibility with silicone resins and resulting in a more homogeneous and stable mixture with significantly enhanced corrosion resistance. Simultaneously, the side chains of the silicon-oxygen bonds (Si-O-Si) are connected to nonpolar methyl groups, which contribute to the low surface energy of the coating, improving its hydrophobicity and self-cleaning properties. Furthermore, the nanofillers in the additives form micro- and nano-scale rough structures in the more homogeneous and stable mixture. These structures trap air, forming a stable gas film on the coating surface, isolating the coating from water or contaminants, further enhancing its hydrophobicity and self-cleaning properties. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the process for preparing modified graphene superhydrophobic self-cleaning anti-corrosion coatings.

[0013] Figure 2 This is a schematic diagram of the reaction for preparing a modified graphene dispersion.

[0014] Figure 3 This is a schematic diagram of the structure of the modified graphene dispersion prepared in Example 1. Detailed Implementation

[0015] The following embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent transformations or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

[0016] In this application, the terminology used is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0017] The singular forms “for,” “or,” “a,” “any,” and “the” used in this application are intended to include the plural forms unless the context clearly indicates otherwise.

[0018] This application adopts the following... Figure 1 The technical solution shown is as follows:

[0019] A method for preparing a modified graphene superhydrophobic self-cleaning anti-corrosion coating includes:

[0020] Graphene oxide and hydroxyl silicone oil are added to an organic solvent and stirred at a set temperature for a first preset time to obtain a mixture.

[0021] At the same set temperature, diisocyanate was added to the mixture, and the mixture was stirred for a second preset time to react and obtain a modified graphene dispersion. A schematic diagram of the reaction is shown below. Figure 2 As shown;

[0022] The modified graphene dispersion was mixed with organosilicon resin and additives and stirred for a third preset time to obtain a modified graphene superhydrophobic self-cleaning anti-corrosion coating.

[0023] In one feasible embodiment, the structure of the hydroxyl silicone oil includes:

[0024] Where x is an integer between 10 and 50.

[0025] In one feasible embodiment, the organic solvent includes one or more of ethyl acetate, butyl acetate, toluene, xylene, dichloromethane, and tetrahydrofuran.

[0026] In one feasible implementation, the set temperature is 60~80℃; the first preset time is 30~60min; the second preset time is 4~6h; and the third preset time is 1~2h.

[0027] In one feasible embodiment, the diisocyanate includes at least one of hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, and toluene diisocyanate.

[0028] In one feasible embodiment, the structure of the modified graphene dispersion includes:

[0029]

[0030] or

[0031] ,in, For graphene oxide; R includes , and Any one of the following; x is an integer between 10 and 50.

[0032] In one feasible embodiment, the silicone resin includes at least one of methyl silicone resin and phenyl silicone resin.

[0033] In one feasible implementation, the additives include nanofillers, dispersants, and defoamers.

[0034] In one feasible embodiment, the nanofiller includes at least one of nano-silica and nano-alumina.

[0035] In one feasible implementation, the particle size range of both the nano-silica and nano-alumina is 10~100nm.

[0036] In one feasible implementation, the dispersant comprises at least one of sodium dodecyl sulfate and sodium dodecylbenzenesulfonate.

[0037] In one feasible implementation, the defoamer includes at least one of BYK-052 and BYK-053.

[0038] In one 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).

[0039] In one feasible embodiment, the mass ratio of the modified graphene dispersion, organosilicon resin, nanofiller, dispersant and defoamer is (30~40):(40~60):(5~10):(0.1~1):(0.1~1).

[0040] The following describes in detail, with reference to different embodiments, a method for preparing a modified graphene superhydrophobic self-cleaning anti-corrosion coating provided in this application.

[0041] Example 1:

[0042] like Figure 1 As shown, a method for preparing a modified graphene superhydrophobic self-cleaning anti-corrosion coating includes the following steps:

[0043] Step 1: Add 50g ethyl acetate, 8g graphene oxide and 25g hydroxyl silicone oil to the reactor and stir at 70℃ for 45min to obtain a mixture;

[0044] Step 2: At 70℃, 17g of hexamethylene diisocyanate was added to the mixture and stirred for 5 hours to obtain a modified graphene dispersion. The structural diagram of the modified graphene dispersion is shown below. Figure 3 As shown;

[0045] Step 3: Mix 35g of modified graphene dispersion, 56g of methyl silicone resin, 8g of nano silica, 0.5g of sodium dodecyl sulfate and 0.5g of BYK-052 and stir for 1.5h to obtain modified graphene superhydrophobic self-cleaning anti-corrosion coating.

[0046] Example 2:

[0047] like Figure 1 As shown, a method for preparing a modified graphene superhydrophobic self-cleaning anti-corrosion coating includes the following steps:

[0048] Step 1: Add 45g butyl acetate, 7g graphene oxide and 28g hydroxyl silicone oil to the reactor and stir at 65°C for 50 minutes to obtain a mixture;

[0049] Step 2: At 65℃, add 20g of dicyclohexylmethane diisocyanate to the mixture and stir for 4.5 hours to react and obtain a modified graphene dispersion.

[0050] Step 3: Mix 38g of modified graphene dispersion, 55g of phenyl silicone resin, 6.4g of nano alumina, 0.3g of sodium dodecylbenzenesulfonate and 0.3g of BYK-053 and stir for 1.8 hours to obtain modified graphene superhydrophobic self-cleaning anti-corrosion coating.

[0051] Example 3:

[0052] like Figure 1 As shown, a method for preparing a modified graphene superhydrophobic self-cleaning anti-corrosion coating includes the following steps:

[0053] Step 1: Add 55g toluene, 6g graphene oxide and 23g hydroxyl silicone oil to the reactor and stir at 75°C for 40 minutes to obtain a mixture;

[0054] Step 2: At 75°C, 16g of toluene diisocyanate was added to the mixture and stirred for 5.5 hours to react and obtain a modified graphene dispersion.

[0055] Step 3: Mix 38g of modified graphene dispersion, 50g of methyl silicone resin, 10g of nano silica, 1g of sodium dodecyl sulfate and 1g of BYK-052 and stir for 1.2 hours to obtain modified graphene superhydrophobic self-cleaning anti-corrosion coating.

[0056] Example 4:

[0057] like Figure 1 As shown, a method for preparing a modified graphene superhydrophobic self-cleaning anti-corrosion coating includes the following steps:

[0058] Step 1: Add 60g xylene, 5g graphene oxide and 22g hydroxyl silicone oil to the reactor and stir at 80℃ for 30 minutes to obtain a mixture;

[0059] Step 2: At 80℃, 13g of hexamethylene diisocyanate was added to the mixture and stirred for 6 hours to react and obtain a modified graphene dispersion.

[0060] Step 3: Mix 40g of modified graphene dispersion, 53g of phenyl silicone resin, 6.8g of nano alumina, 0.1g of sodium dodecylbenzenesulfonate and 0.1g of BYK-053 and stir for 2 hours to obtain modified graphene superhydrophobic self-cleaning anti-corrosion coating.

[0061] Example 5:

[0062] like Figure 1 As shown, a method for preparing a modified graphene superhydrophobic self-cleaning anti-corrosion coating includes the following steps:

[0063] Step 1: Add 40g dichloromethane, 10g graphene oxide and 30g hydroxyl silicone oil to the reactor and stir at 60℃ for 60 minutes to obtain a mixture;

[0064] Step 2: At 60℃, add 20g of dicyclohexylmethane diisocyanate to the mixture and stir for 4 hours to react and obtain a modified graphene dispersion.

[0065] Step 3: Mix 30g of modified graphene dispersion, 60g of methyl silicone resin, 9g of nano silica, 0.5g of sodium dodecyl sulfate and 0.5g of BYK-052 and stir for 1 hour to obtain modified graphene superhydrophobic self-cleaning anti-corrosion coating.

[0066] Example 6:

[0067] like Figure 1 As shown, a method for preparing a modified graphene superhydrophobic self-cleaning anti-corrosion coating includes the following steps:

[0068] Step 1: Add 52g tetrahydrofuran, 9g graphene oxide and 24g hydroxyl silicone oil to the reactor and stir at 68°C for 55 minutes to obtain a mixture;

[0069] Step 2: At 68℃, 15g of toluene diisocyanate was added to the mixture and stirred for 5.2 hours to obtain a modified graphene dispersion.

[0070] Step 3: Mix 36g of modified graphene dispersion, 56.4g of phenyl silicone resin, 6.8g of nano alumina, 0.4g of sodium dodecylbenzenesulfonate and 0.4g of BYK-053 and stir for 1.7 hours to obtain modified graphene superhydrophobic self-cleaning anti-corrosion coating.

[0071] Comparative Example 1:

[0072] A method for preparing a modified graphene superhydrophobic self-cleaning anti-corrosion coating includes the following steps:

[0073] Step 1: Add 50g ethyl acetate, 8g graphene oxide and 25g hydroxyl silicone oil to the reactor and stir at 70℃ for 45min to obtain a mixture;

[0074] Step 2: Add 17g of ethylene glycol to the mixture at 70℃ and stir for 5 hours to obtain a modified graphene dispersion.

[0075] Step 3: Mix 35g of modified graphene dispersion, 56g of methyl silicone resin, 8g of nano silica, 0.5g of sodium dodecyl sulfate and 0.5g of BYK-052 and stir for 1.5h to obtain modified graphene superhydrophobic self-cleaning anti-corrosion coating.

[0076] Comparative Example 2:

[0077] A method for preparing a modified graphene superhydrophobic self-cleaning anti-corrosion coating includes the following steps:

[0078] Step 1: Add 55g toluene, 6g graphene oxide and 23g silicone oil to the reactor and stir at 75°C for 40 minutes to obtain a mixture;

[0079] Step 2: At 75°C, 16g of toluene diisocyanate was added to the mixture and stirred for 5.5 hours to react and obtain a modified graphene dispersion.

[0080] Step 3: Mix 38g of modified graphene dispersion, 50g of methyl silicone resin, 10g of nano silica, 1g of sodium dodecyl sulfate and 1g of BYK-052 and stir for 1.2 hours to obtain modified graphene superhydrophobic self-cleaning anti-corrosion coating.

[0081] Comparative Example 3:

[0082] A method for preparing a modified graphene superhydrophobic self-cleaning anti-corrosion coating includes the following steps:

[0083] Step 1: Add 40g dichloromethane, 10g graphene oxide and 30g hydroxyl silicone oil to the reactor and stir at 60℃ for 60 minutes to obtain a mixture;

[0084] Step 2: At 60℃, add 20g of dicyclohexylmethane diisocyanate to the mixture and stir for 4 hours to react and obtain a modified graphene dispersion.

[0085] Step 3: Mix 30g of modified graphene dispersion, 60g of acrylic resin, 9g of nano-silica, 0.5g of sodium dodecyl sulfate and 0.5g of BYK-052 and stir for 1 hour to obtain modified graphene superhydrophobic self-cleaning anti-corrosion coating.

[0086] The modified graphene superhydrophobic self-cleaning anti-corrosion coatings prepared in Examples 1-6 and Comparative Examples 1-3 were tested.

[0087] According to GB / T 30447-2013, the hydrophobicity of the prepared coating is reflected by testing the size of the water contact angle.

[0088] Referring to GB / T 1771-2007, the corrosion resistance of the prepared coating is demonstrated by testing the duration of salt spray resistance. The test results are shown in Table 1.

[0089] Table 1. Test results of the modified graphene superhydrophobic self-cleaning anti-corrosion coatings prepared in the examples and comparative examples.

[0090]

[0091] As shown in Table 1, the data of Examples 1-6 are generally better than those of Comparative Examples 1-3.

[0092] The reason for this is that, in Examples 1-6, in an organic solvent, the isocyanate groups in the diisocyanate react with the hydroxyl or carboxyl groups on the surface of graphene oxide, and the isocyanate groups react with the hydroxyl groups in the hydroxyl silicone oil, thus tightly linking the three together through chemical bonds, thereby obtaining a modified graphene dispersion. Furthermore, the obtained modified graphene dispersion contains many segments rich in silicon-oxygen bonds (Si-O-Si), improving the compatibility between the modified graphene dispersion and the organosilicon resin, making the entire mixture system more homogeneous and stable, and significantly improving its anti-corrosion performance. Simultaneously, the side chains of the silicon-oxygen bonds (Si-O-Si) are connected to non-polar methyl groups, which give the coating low surface energy, improving its hydrophobicity and self-cleaning properties. In addition, the nanofillers in the additives better form micro- and nano-scale rough structures in a more homogeneous and stable mixture system. These structures can trap air, forming a stable gas film on the coating surface, isolating the coating from water or contaminants on the coating surface, further improving the coating's hydrophobicity and self-cleaning properties.

[0093] In Comparative Example 1, no diisocyanate was used, so graphene oxide and hydroxyl silicone oil could not be chemically bonded together. Therefore, the modification of graphene oxide was unsuccessful, and its compatibility with organosilicon resin was poor, resulting in poor hydrophobicity and corrosion resistance. For the same reason, silicone oil was used in Comparative Example 2 instead of hydroxyl silicone oil. Therefore, although diisocyanate was used, graphene oxide and silicone oil could not be chemically bonded together. In Comparative Example 3, although both diisocyanate and hydroxyl silicone oil were used, and the corresponding modified graphene dispersion could be successfully prepared, the compatibility between the two was also poor because acrylic resin was finally mixed with the modified graphene dispersion. Therefore, the hydrophobicity and corrosion resistance were also poor.

[0094] The above results demonstrate and describe the basic principles and main features of this application, as well as its advantages.

[0095] Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this application. Various changes and modifications can be made to this application without departing from the spirit and scope thereof, and all such changes and modifications fall within the scope of this application as claimed. The scope of protection of this application is defined by the equivalents of the appended claims.

Claims

1. A method for preparing a modified graphene superhydrophobic self-cleaning anti-corrosion coating, characterized in that, include: Graphene oxide and hydroxyl silicone oil are added to an organic solvent and stirred at a set temperature for a first preset time to obtain a mixture. At the same set temperature, diisocyanate was added to the mixture, and the mixture was stirred for a second preset time to react and obtain a modified graphene dispersion. The modified graphene dispersion was mixed with organosilicon resin and additives and stirred for a third preset time to obtain a modified graphene superhydrophobic self-cleaning anti-corrosion coating. The set temperature is 60~80℃; the first preset time is 30~60min; the second preset time is 4~6h; and the third preset time is 1~2h. The diisocyanate includes at least one of hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, and toluene diisocyanate; The structure of the hydroxyl silicone oil includes: x is an integer between 10 and 50; The organosilicon resin includes at least one of methyl silicone resin and phenyl silicone resin; the additives include nanofillers, dispersants and defoamers; the mass ratio of the organic solvent, graphene oxide, hydroxyl silicone oil and diisocyanate is (40~60):(5~10):(20~30):(10~20); the mass ratio of the modified graphene dispersion, organosilicon resin, nanofillers, dispersants and defoamers is (30~40):(40~60):(5~10):(0.1~1):(0.1~1).

2. The preparation method of the modified graphene superhydrophobic self-cleaning 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.

3. The preparation method of the modified graphene superhydrophobic self-cleaning anti-corrosion coating according to claim 1, characterized in that, The nanofiller includes at least one of nano-silica and nano-alumina; the dispersant includes at least one of sodium dodecyl sulfate and sodium dodecylbenzene sulfonate; and the defoamer includes at least one of BYK-052 and BYK-053.

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