Preparation method of acid-resistant water-based environment-friendly intelligent epoxy anticorrosive paint

Abstract

The invention discloses a preparation method of an acid-resistant water-based environment-friendly intelligent epoxy anticorrosive paint, and relates to the field of epoxy anticorrosive paints.The preparation method comprises the following intelligent anticorrosive corrosion inhibitor reaction steps that S1, graphene oxide is used as a raw material, rutin is used for reducing graphene oxide, and rutin-reduced graphene oxide is obtained; the self-repairing intelligent anti-corrosion coating capable of releasing the corrosion inhibitor in an acid environment is prepared by combining an in-situ reaction compounding method with an intelligent nano controlled release technology, taking graphene as a carrier and loading the corrosion inhibitor with a nano container, the graphene / silicon dioxide loaded corrosion inhibitor can be stably dispersed in a water medium and has good compatibility with polymer emulsion, and the corrosion inhibitor can be used as a self-repairing intelligent anti-corrosion coating capable of releasing the corrosion inhibitor in the acid environment. When a modified coating prepared by adding the corrosion inhibitor into a polymer emulsion is soaked in a corrosive medium, excellent barrier performance can be provided, meanwhile, when the coating is damaged, a corrosion inhibitor can be released, a passive film is formed with metal, and a protective self-repairing effect on the damaged part is achieved.

Description

Technical Field

[0001] The invention relates to the field of epoxy anticorrosion coatings, and in particular to a method for preparing an acid-resistant water-based environmentally friendly intelligent epoxy anticorrosion coating. Background Art

[0002] Anti-corrosion coatings are generally divided into conventional anti-corrosion coatings and heavy-duty anti-corrosion coatings. They are an indispensable type of coating in paint coatings. Conventional anti-corrosion coatings play an anti-corrosion role on metals under general conditions and protect the service life of non-ferrous metals. Heavy-duty anti-corrosion coatings refer to a type of anti-corrosion coating that can be used in relatively harsh corrosive environments and has a longer protection period than conventional anti-corrosion coatings. Traditional solvent-based coatings need to be converted to water-based due to environmental protection, quality and application scope. However, the anti-corrosion performance of water-based epoxy coatings still has a lot of room for improvement, especially its acid resistance needs to be improved urgently.

[0003] Therefore, it is necessary to invent a method for preparing an acid-resistant water-based environmentally friendly intelligent epoxy anti-corrosion coating to solve the above problems. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing an acid-resistant water-based environmentally friendly intelligent epoxy anti-corrosion coating to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for preparing an acid-resistant water-based environmentally friendly intelligent epoxy anticorrosive coating, comprising the following intelligent anticorrosive inhibitor reaction steps: S1: using graphene oxide as a raw material and using rutin to reduce the graphene oxide, thereby obtaining rutin-reduced graphene oxide; S2: Using the rutin adsorbed on the surface of rutin-reduced graphene oxide to provide affinity sites, the sustained-release agents benzotriazole, hexadecyltrimethylammonium bromide and ethyl orthosilicate were directly introduced into the rutin-reduced graphene oxide as precursors to carry out a sol-gel reaction; S3: Hexadecyltrimethylammonium bromide, as a cationic surfactant, plays the role of a multifunctional auxiliary agent: it acts as a soft template for sol-gel reactions to form silica nanocontainers; and realizes the solubilization of benzotriazole in the silica nanocontainers through hydrophobic microregions, so that benzotriazole is loaded onto the silica nanocontainers; the positive charge it carries undergoes electrostatic adsorption with rutin-reduced graphene oxide, driving the silica nanocontainers loaded with benzotriazole to in situ composite onto the surface of reduced graphene oxide, thereby constructing a graphene / silica-loaded corrosion inhibitor ternary nanocomposite material.

[0006] Preferably, the preparation process includes the following: S1: 711 g of reduced graphene oxide dispersion was transferred to a three-necked flask with a condenser fixed in a heat-collecting constant temperature heating magnetic stirrer, and the temperature was raised to 80°C; S2: Add 0.42g sodium hydroxide, 1.5g hexadecyltrimethylammonium bromide and 2.5g benzotriazole under magnetic stirring and condensation reflux, and then slowly add 7g of ethyl orthosilicate dropwise after uniform dispersion, and react at 80°C for 2h to obtain a black dispersion product; S3: The black dispersion product is centrifuged at a high speed of 5000 rpm, and then centrifuged and washed twice with deionized water to obtain a graphene / silicon dioxide-loaded corrosion inhibitor; S4: Blending the graphene / silicon dioxide loaded corrosion inhibitor ternary nanocomposite material with a waterborne epoxy anti-corrosion coating to obtain an acid-resistant waterborne environmentally friendly intelligent epoxy anti-corrosion coating.

[0007] Preferably, the reduced graphene oxide accounts for 14.07 mg·g -1 .

[0008] Preferably, the aromatic structural unit in the rutin molecule can be adsorbed on the surface of the reduced graphene oxide to form a π-π interaction, thereby stabilizing the rutin-reduced graphene oxide.

[0009] Preferably, rutin is 3',4',5,7-tetrahydroxyflavone-3β-D-rutin, which is a natural product.

[0010] Preferably, the pH response release includes the following: In acidic medium, H + Ion exchange with positively charged hexadecyltrimethylammonium bromide results in matrix destruction, so release is rapid; There is no H in a neutral environment. + Ion exchange with hexadecyltrimethylammonium bromide; The release in an alkaline environment starts with the hydrolysis of the silica nanocontainer, which is slow in the early stage. Later, the hexadecyltrimethylammonium bromide micelles dissolve and the release rate of benzotriazole becomes faster.

[0011] Technical effects and advantages of the present invention: The present invention adopts an in-situ reaction composite method in combination with intelligent nano controlled release technology, uses graphene as a carrier, and uses a nano container to load a corrosion inhibitor to prepare a self-repairing intelligent anti-corrosion coating that releases the corrosion inhibitor in an acidic environment. The graphene / silicon dioxide loaded corrosion inhibitor can be stably dispersed in an aqueous medium and has good compatibility with a polymer emulsion. When the modified coating prepared by adding the graphene / silicon dioxide to a polymer emulsion is immersed in a corrosive medium, it can provide excellent barrier properties. At the same time, when the coating is damaged, the corrosion inhibitor can also be released to form a passivation film with the metal, which has a protective self-repairing effect on the damaged area. The corrosion inhibitor of the graphene / silicon dioxide loaded corrosion inhibitor is quickly released under acidic conditions, which plays an important role in improving the acid resistance of the water-based epoxy resin anti-corrosion coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the experiment of different quality R-rGO and BTA of the present invention; Figure 2 Schematic diagram of the release curve of BTA@SN-IGO of the present invention under different pH conditions. DETAILED DESCRIPTION

[0013] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0014] A method for preparing an acid-resistant water-based environmentally friendly intelligent epoxy anticorrosive coating comprises the following intelligent anticorrosive inhibitor reaction steps: S1: using graphene oxide as a raw material and using rutin to reduce the graphene oxide, thereby obtaining rutin-reduced graphene oxide; S2: Using the rutin adsorbed on the surface of rutin-reduced graphene oxide to provide affinity sites, the sustained-release agents benzotriazole, hexadecyltrimethylammonium bromide and ethyl orthosilicate were directly introduced into the rutin-reduced graphene oxide as precursors to carry out a sol-gel reaction; S3: Hexadecyltrimethylammonium bromide, as a cationic surfactant, plays the role of a multifunctional auxiliary agent: it acts as a soft template for sol-gel reactions to form silica nanocontainers; and it achieves solubilization of benzotriazole in silica nanocontainers through hydrophobic microregions, allowing benzotriazole to be loaded onto silica nanocontainers; the positive charge it carries undergoes electrostatic adsorption with rutin-reduced graphene oxide, driving the silica nanocontainers loaded with benzotriazole to in situ composite onto the surface of reduced graphene oxide, thereby constructing a graphene-silica-loaded corrosion inhibitor ternary nanocomposite material.

[0015] The preparation process includes the following: S1: 711 g of reduced graphene oxide dispersion was transferred into a three-necked flask with a condenser fixed in a heat-collecting constant temperature heating magnetic stirrer, and the temperature was raised to 80°C; S2: Add 0.42g sodium hydroxide, 1.5g hexadecyltrimethylammonium bromide and 2.5g benzotriazole under magnetic stirring and condensation reflux, and then slowly add 7g of ethyl orthosilicate dropwise after uniform dispersion, and react at 80°C for 2h to obtain a black dispersion product; S3: The black dispersion product is centrifuged at a high speed of 5000 rpm, and then centrifuged and washed twice with deionized water to obtain a graphene / silicon dioxide-loaded corrosion inhibitor; S4: Blending the graphene / silicon dioxide loaded corrosion inhibitor ternary nanocomposite material with a waterborne epoxy anti-corrosion coating to obtain an acid-resistant waterborne environmentally friendly intelligent epoxy anti-corrosion coating.

[0016] The effective protection days of waterborne epoxy anticorrosive coatings in acid, alkali, salt and deionized water media are 9, 67, 22, 45 days, and 21, 116, 69, 63 days after adding graphene / silicon dioxide loaded corrosion inhibitors for intelligent anticorrosion. The waterborne epoxy acrylic coatings are 32, 65, 52, 19 days, and 50, 96, 90, 65 days after adding graphene / silicon dioxide loaded corrosion inhibitors for intelligent anticorrosion. It can be seen that after intelligent anticorrosion, the acid, alkali, salt and deionized water resistance of the coatings are improved, especially the acid anticorrosion effect is the most obvious. This is because the ternary nanocomposite material can provide shielding protection in the early stage of the coating's service, and can release corrosion inhibitors in the later stage of the coating's service to form a protective film. This combined effect effectively improves the coating's resistance to acid, alkali, salt and deionized water; it is particularly important to note that the ternary nanocomposite material releases corrosion inhibitors faster and in greater amounts under acidic conditions, so the coating's acid resistance and anticorrosion effect are most significantly improved.

[0017] In order to optimize the preparation formula of graphene / silicon dioxide-loaded corrosion inhibitor, a series of experiments were conducted with the addition of different masses of rutin-reduced graphene oxide and benzotriazole, such as Figure 1 As shown in columns 1 to 9, for comparison, SN-rGO binary nanocomposites were prepared by a similar method, but without the addition of benzotriazole; similarly, silica-loaded corrosion inhibitors were prepared without the addition of rutin-reduced graphene oxide, and a series of experiments were conducted to explore the effect of the added mass of benzotriazole on the loading amount of benzotriazole in the silica-loaded corrosion inhibitor, such as Figure 1 As shown, columns 10 to 14; thereafter, SN-GO was prepared by replacing rutin-reduced graphene oxide with graphene oxide; finally, silica nanocontainers were prepared without adding rutin-reduced graphene oxide and benzotriazole.

[0018] The proportion of reduced graphene oxide in the dispersion is 14.07 mg g -1 .

[0019] Reduced graphene oxide is obtained by reducing graphene oxide with the natural product rutin, which has obvious advantages over conventional reducing agents such as hydrazine hydrate and sodium borohydride, which are toxic, explosive, and easy to agglomerate after reduction.

[0020] Rutin is 3',4',5,7-tetrahydroxyflavone-3β-D-rutin. The aromatic structural unit in the rutin molecule can be adsorbed on the surface of reduced graphene oxide to form a π-π interaction, making the rutin-reduced graphene oxide stable.

[0021] pH responsive release including: In acidic medium, H + Ion exchange with positively charged hexadecyltrimethylammonium bromide results in matrix destruction, so release is rapid; There is no H in a neutral environment. + Ion exchange with hexadecyltrimethylammonium bromide; The release in an alkaline environment starts with the hydrolysis of the silica nanocontainer, which is slow in the early stage. Later, the hexadecyltrimethylammonium bromide micelles dissolve and the release rate of benzotriazole becomes faster.

[0022] Benzotriazole loaded in the nanocontainer can be released under appropriate conditions. In an aqueous environment, the responsive release curves of graphene / silica loaded corrosion inhibitors to different pH values ​​are shown in Figure 2. Figure 2 As shown in the figure, it can be seen that the release rate of graphene / silica loaded corrosion inhibitor under acidic conditions is much higher than that under neutral and alkaline conditions. At a pH value of 3.0, the release of benzotriazole within 2 hours reaches 58%; when the pH value is 7.0 or 10.0, the release time is 24 hours to achieve the same release amount. When the release time is 24 hours, at a pH value of 3, the cumulative release of benzotriazole is as high as 89%; and at a pH value of 7.0 or 10.0, the cumulative release is 62% or 55%. The above results show that the release of graphene / silica loaded corrosion inhibitor is pH responsive, and the release rate is fastest at a pH value of 3.

[0023] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing an acid-resistant water-based environmentally friendly intelligent epoxy anticorrosive coating, characterized in that: The method comprises the following intelligent corrosion inhibitor reaction steps: S1: using graphene oxide as a raw material and using rutin to reduce the graphene oxide, thereby obtaining rutin-reduced graphene oxide; S2: Using the rutin adsorbed on the surface of rutin-reduced graphene oxide to provide affinity sites, the sustained-release agents benzotriazole, hexadecyltrimethylammonium bromide and ethyl orthosilicate were directly introduced into the rutin-reduced graphene oxide as precursors to carry out a sol-gel reaction; S3: Hexadecyltrimethylammonium bromide, as a cationic surfactant, plays the role of a multifunctional auxiliary agent: it acts as a soft template for sol-gel reactions to form silica nanocontainers; and realizes the solubilization of benzotriazole in the silica nanocontainers through hydrophobic microregions, so that benzotriazole is loaded onto the silica nanocontainers; the positive charge it carries undergoes electrostatic adsorption with rutin-reduced graphene oxide, driving the silica nanocontainers loaded with benzotriazole to in situ composite onto the surface of reduced graphene oxide, thereby constructing a graphene / silica-loaded corrosion inhibitor ternary nanocomposite material.

2. The method for preparing an acid-resistant water-based environmentally friendly intelligent epoxy anticorrosive coating according to claim 1, characterized in that: The preparation process includes the following: S1: 711 g of reduced graphene oxide dispersion was transferred to a three-necked flask with a condenser fixed in a heat-collecting constant temperature heating magnetic stirrer, and the temperature was raised to 80°C; S2: Add 0.42g sodium hydroxide, 1.5g hexadecyltrimethylammonium bromide and 2.5g benzotriazole under magnetic stirring and condensation reflux, and then slowly add 7g of ethyl orthosilicate dropwise after uniform dispersion, and react at 80°C for 2h to obtain a black dispersion product; S3: The black dispersion product is centrifuged at a high speed of 5000 rpm, and then centrifuged and washed twice with deionized water to obtain a graphene / silicon dioxide-loaded corrosion inhibitor; S4: Blending the graphene / silicon dioxide loaded corrosion inhibitor ternary nanocomposite material with a waterborne epoxy anti-corrosion coating to obtain an acid-resistant waterborne environmentally friendly intelligent epoxy anti-corrosion coating.

3. The method for preparing an acid-resistant water-based environmentally friendly intelligent epoxy anticorrosive coating according to claim 2, characterized in that: The proportion of reduced graphene oxide in the dispersion is 14.07 mg g -1 .

4. The method for preparing an acid-resistant water-based environmentally friendly intelligent epoxy anticorrosive coating according to claim 3, characterized in that: The aromatic structural units in the rutin molecule can be adsorbed on the surface of reduced graphene oxide to form π-π interactions, making the rutin-reduced graphene oxide stable.

5. The method for preparing an acid-resistant water-based environmentally friendly intelligent epoxy anticorrosive coating according to claim 4, characterized in that: Rutin is 3',4',5,7-tetrahydroxyflavone-3β-D-rutin, a natural product.

6. The method for preparing an acid-resistant water-based environmentally friendly intelligent epoxy anticorrosive coating according to claim 5, characterized in that: pH responsive release including: In acidic medium, H + Ion exchange with positively charged hexadecyltrimethylammonium bromide results in matrix destruction, so release is rapid; There is no H in a neutral environment. + Ion exchange with hexadecyltrimethylammonium bromide; The release in an alkaline environment starts with the hydrolysis of the silica nanocontainer, which is slow in the early stage. Later, the hexadecyltrimethylammonium bromide micelles dissolve and the release rate of benzotriazole becomes faster.

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