Corrosion-resistant self-repairing polyurea coating material for ships and preparation method thereof

Abstract

The invention discloses a corrosion-resistant self-repairing polyurea coating material for ships and a preparation method thereof.The preparation method comprises the following steps that modified zirconium hydrogen phosphate is prepared, and the modified zirconium hydrogen phosphate comprises alkylated zirconium hydrogen phosphate; the preparation method comprises the following steps: preparing a UPy group curing agent UPy-IPDA-NH2 containing quadruple hydrogen bonds; and mixing the modified zirconium hydrogen phosphate with polyurea in proportion, and adding a curing agent IPDA and a UPy group curing agent UPy-IPDA-NH2 containing quadruple hydrogen bonds, which are mixed in proportion, to obtain the self-repairing polyurea coating material. The corrosion resistance of the coating material is improved by introducing modified zirconium hydrogen phosphate, the coating is rapidly repaired after being damaged by using a quadruple hydrogen bond repair technology, the service life of the coating is remarkably prolonged, and the reliability of the coating is remarkably improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of self-repairing anti-corrosion materials, and specifically to a corrosion-resistant self-repairing polyurea coating material for ships and a preparation method thereof. The self-repairing polyurea coating material manufactured by the preparation method is suitable for the protection of ships, especially for protection applications in high-salinity corrosion environments. Background Art

[0002] Ships operate in marine environments for long periods of time, and their surfaces are susceptible to erosion by seawater, salt spray, microorganisms, and mechanical wear, leading to serious corrosion problems. Currently, ship protection mainly relies on traditional epoxy resin coatings, polyurethane coatings, and anti-corrosion primers. Although these coatings can provide anti-corrosion protection to a certain extent, their corrosion resistance is limited, and they are prone to cracking, peeling, and other problems during long-term use, resulting in a decrease in protective effectiveness. To address this problem, anti-corrosion coatings have become a common protection method, using coating materials to block direct contact between corrosive media and the ship's surface, thereby delaying or preventing the occurrence of corrosion. Common anti-corrosion coatings include epoxy resin coatings, polyurethane coatings, acrylic coatings, etc. These coatings have good corrosion resistance and are widely used in petrochemicals, marine engineering, construction facilities and other fields. However, these traditional anti-corrosion coatings have many problems during use, mainly reflected in the durability of the coating itself, the difficulty of repair, and environmental adaptability.

[0003] Specifically, while traditional anti-corrosion coatings can effectively isolate corrosive media, they often suffer from inherent flaws. For example, over the long term, coatings can easily develop microcracks or peeling due to factors such as external impact, temperature fluctuations, mechanical wear, or environmental corrosion. These damages often allow corrosive media to penetrate the metal surface through the cracks, thereby destroying the coating's protective function and causing corrosion of the metal substrate. Therefore, the problem of coating damage repair has become a key factor limiting its long-term effectiveness. Summary of the Invention

[0004] Some embodiments of the present disclosure provide a method for preparing a corrosion-resistant self-repairing polyurea coating material for ships, comprising the following steps:

[0005] preparing modified zirconium hydrogen phosphate, wherein the modified zirconium hydrogen phosphate comprises alkylated zirconium hydrogen phosphate;

[0006] Preparation of UP containing quadruple hydrogen bonds y Group Curing Agent UP y -IPDA-NH2; and

[0007] The modified zirconium hydrogen phosphate and polyurea are mixed in proportion, and the curing agent IPDA and UP containing quadruple hydrogen bonds are added in proportion. yGroup Curing Agent UP y -IPDA-NH2, to obtain a self-repairing polyurea coating material.

[0008] In some embodiments, preparing the modified zirconium hydrogen phosphate comprises the following steps:

[0009] preparing zirconium hydrogen phosphate using zirconium chloride and phosphoric acid solution; and

[0010] Zirconium hydrogen phosphate is modified by methyl chloride to obtain modified zirconium hydrogen phosphate.

[0011] In some embodiments, preparing zirconium hydrogen phosphate using zirconium chloride and phosphoric acid solution comprises the following steps:

[0012] Add zirconium chloride to deionized water, heat and stir to dissolve to form a zirconium chloride solution;

[0013] adding the zirconium chloride solution to the phosphoric acid solution, and stirring the mixture in a fume hood to react to obtain a first reactant; and

[0014] The first reactant is subjected to a centrifugal operation, washed with deionized water, and dried to obtain zirconium hydrogen phosphate powder.

[0015] In some embodiments, modifying zirconium hydrogen phosphate with methyl chloride to obtain modified zirconium hydrogen phosphate comprises the following steps:

[0016] dissolving zirconium hydrogen phosphate in isopropyl alcohol solvent to obtain a zirconium hydrogen phosphate solution;

[0017] adding methyl chloride to the zirconium hydrogen phosphate solution, and stirring the mixture in a fume hood to react to obtain a second reactant;

[0018] The second reactant is subjected to a centrifugal operation, washed with deionized water, and dried to obtain modified zirconium hydrogen phosphate powder.

[0019] In some embodiments, UP containing quadruple hydrogen bonds is prepared y Group Curing Agent UP y -IPDA-NH2 includes the following steps:

[0020] The intermediate UP was obtained by reacting 2-amino-4-hydroxy-6-methylpyrimidine with N, N'-carbonyldiimidazole. y -CDI; and

[0021] The intermediate UP y -CDI reacts with the curing agent IPDA to obtain UP containing quadruple hydrogen bonds y Group Curing Agent UP y -IPDA-NH2.

[0022] In some embodiments, 2-amino-4-hydroxy-6-methylpyrimidine is reacted with N, N'-carbonyldiimidazole to obtain the intermediate UP. y -CDI includes the following steps:

[0023] 2-amino-4-hydroxy-6-methylpyrimidine and N, N'-carbonyldiimidazole are dispersed in dimethyl sulfoxide solvent, and a solid product is obtained by stirring and filtering.

[0024] The solid product is washed and dried to obtain the intermediate UP y -CDI.

[0025] In some embodiments, the intermediate UP y -CDI reacts with the curing agent IPDA to obtain UP containing quadruple hydrogen bonds y Group Curing Agent UP y -IPDA-NH2 includes the following steps:

[0026] The intermediate UP y -CDI and curing agent IPDA are mixed, and added into n-hexane and stirred to obtain a mixture; and

[0027] The lower layer solution of the mixture is dissolved in dichloromethane, and the UP containing quadruple hydrogen bonds is obtained by washing, drying, rotary evaporation and vacuum drying. y Group Curing Agent UP y -IPDA-NH2.

[0028] In some embodiments, the modified zirconium hydrogen phosphate and polyurea are mixed in proportion to form a composite material, and a curing agent IPDA and a UP containing a quadruple hydrogen bond are added in proportion. y Group Curing Agent UP y -IPDA-NH2, obtaining a self-repairing polyurea coating comprises the following steps:

[0029] The modified zirconium hydrogen phosphate and polyurea are mixed in proportion, and ultrasonic treatment is performed to obtain a composite material;

[0030] Mix the curing agent IPDA and UP containing quadruple hydrogen bonds in proportion y Group Curing Agent UP y -IPDA-NH2 to obtain a curing agent mixture;

[0031] The composite material and the curing agent mixture are mixed in a xylene solvent in proportion, and the self-repairing polyurea coating material is obtained through stirring, degassing, evaporation and heating.

[0032] In some embodiments, the curing agent IPDA and UP containing quadruple hydrogen bonds yGroup Curing Agent UP y -IPDA-NH2 were mixed at a molar ratio of 8:2.

[0033] Some embodiments of the present disclosure provide a corrosion-resistant self-healing polyurea coating material for ships, wherein the self-healing polyurea coating material is manufactured using the preparation method described in the aforementioned embodiments.

[0034] Compared with the related art, the above solution of the embodiment of the present disclosure has at least the following beneficial effects:

[0035] The present invention discloses a corrosion-resistant, self-healing polyurea coating material for ships, which is prepared by mixing modified zirconium hydrogen phosphate with polyurea and adding a curing agent having quadruple hydrogen bonds. The corrosion resistance of the coating material is improved by introducing modified zirconium hydrogen phosphate, which effectively prevents the penetration of corrosive media and provides longer-lasting protection. At the same time, the addition of modified zirconium hydrogen phosphate gives the coating material stronger mechanical properties, improves the coating's scratch and damage resistance, and makes it more reliable in harsh environments. The quadruple hydrogen bond repair technology is used to achieve rapid repair of the coating after damage, significantly enhancing the coating's service life and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A flow chart showing a method for preparing a corrosion-resistant self-repairing polyurea coating material for ships provided in some embodiments of the present disclosure is shown;

[0037] Figure 2 for Figure 1 Specific flow chart of step S100;

[0038] Figure 3 for Figure 2 Specific flow chart of step S110;

[0039] Figure 4 for Figure 2 Specific flow chart of step S120;

[0040] Figure 5 for Figure 1 Specific flow chart of step S200;

[0041] Figure 6 for Figure 5 Specific flow chart of step S210;

[0042] Figure 7 for Figure 5 Specific flow chart of step S220;

[0043] Figure 8 for Figure 1 Specific flow chart of step S300 in FIG. DETAILED DESCRIPTION

[0044] To make the objectives, technical solutions, and advantages of the present disclosure more clear, the present disclosure will be further described in detail below with reference to the accompanying drawings. It is apparent that the embodiments described are only a portion of the embodiments of the present disclosure, rather than all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present disclosure without creative effort are intended to fall within the scope of protection of the present disclosure.

[0045] The terms used in the embodiments of the present disclosure are for the purpose of describing specific embodiments only and are not intended to limit the present disclosure. The singular forms "a," "an," "the," and "the" used in the embodiments of the present disclosure and the appended claims are also intended to include plural forms, and unless the context clearly indicates otherwise, "a plurality" generally includes at least two.

[0046] It should be understood that the term "and / or" as used herein is merely a description of the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0047] It should be understood that although the terms "first," "second," "third," etc. may be used to describe structures in the embodiments of the present disclosure, these structures should not be limited to these terms. These terms are merely used to distinguish different structures. For example, a first component may also be referred to as a second component, and similarly, a second component may also be referred to as a first component without departing from the scope of the embodiments of the present disclosure.

[0048] As used herein, the words "if" and "if" may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to the determination" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)," depending on the context.

[0049] It should also be noted that the terms "include," "comprises," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a product or device comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such product or device. In the absence of further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the product or device comprising the element.

[0050] The present invention provides a method for preparing a corrosion-resistant self-repairing polyurea coating material for ships, comprising the following steps: preparing modified zirconium hydrogen phosphate, wherein the modified zirconium hydrogen phosphate comprises alkylated zirconium hydrogen phosphate; preparing UP containing quadruple hydrogen bonds; y Group Curing Agent UP y -IPDA-NH2; and the modified zirconium hydrogen phosphate and polyurea are mixed in proportion, and the curing agent IPDA and UP containing quadruple hydrogen bonds are added in proportion. y Group Curing Agent UP y -IPDA-NH2, to obtain a self-repairing polyurea coating material.

[0051] The present invention discloses a corrosion-resistant, self-healing polyurea coating material for ships, which is prepared by mixing modified zirconium hydrogen phosphate with polyurea and adding a curing agent having quadruple hydrogen bonds. The corrosion resistance of the coating material is improved by introducing modified zirconium hydrogen phosphate, which effectively prevents the penetration of corrosive media and provides longer-lasting protection. At the same time, the addition of modified zirconium hydrogen phosphate gives the coating material stronger mechanical properties, improves the coating's scratch and damage resistance, and makes it more reliable in harsh environments. The quadruple hydrogen bond repair technology is used to achieve rapid repair of the coating after damage, significantly enhancing the coating's service life and reliability.

[0052] Optional embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0053] Figure 1 The flowchart of the preparation method of the corrosion-resistant self-repairing polyurea coating material for ships provided by some embodiments of the present disclosure is shown. Figure 1 As shown, some embodiments of the present disclosure provide a method for preparing a corrosion-resistant self-repairing polyurea coating material for ships, the preparation method comprising the following steps:

[0054] S100: preparing modified zirconium hydrogen phosphate, wherein the modified zirconium hydrogen phosphate includes alkylated zirconium hydrogen phosphate;

[0055] S200: Preparation of UPs containing quadruple hydrogen bonds y Group Curing Agent UP y -IPDA-NH2; and

[0056] S300: The modified zirconium hydrogen phosphate and polyurea are mixed in proportion, and the curing agent IPDA and UP containing quadruple hydrogen bonds are added in proportion. y Group Curing Agent UP y -IPDA-NH2, to obtain a self-repairing polyurea coating material.

[0057] The above-mentioned preparation method involves the preparation of modified zirconium hydrogen phosphate and a self-healing polyurea elastomer. The self-healing polyurea coating material prepared using this method is then applied to the metal surface via spray or spin coating and cured at room temperature for 48 hours, ultimately forming a composite coating with excellent corrosion resistance and self-healing capabilities. This preparation method enhances the coating's corrosion resistance by introducing modified zirconium hydrogen phosphate and utilizes quadruple hydrogen bonding technology to rapidly repair the coating after damage, significantly extending its service life and reliability.

[0058] Figure 2 for Figure 1 In the specific flow chart of step S100, in some embodiments, as Figure 2 As shown, step S100: preparing modified zirconium hydrogen phosphate includes the following steps:

[0059] S110: preparing zirconium hydrogen phosphate using zirconium chloride and phosphoric acid solution;

[0060] Specifically, zirconium hydrogen phosphate is obtained by reacting zirconium chloride with phosphoric acid, with the molecular formula being Zr(HPO4)2.

[0061] S120: Modifying zirconium hydrogen phosphate with methyl chloride to obtain modified zirconium hydrogen phosphate.

[0062] Specifically, zirconium hydrogen phosphate is modified using chloromethane, which reacts with phosphoric acid groups on the surface of the zirconium hydrogen phosphate to generate alkylated zirconium hydrogen phosphate, namely methyl zirconium hydrogen phosphate Zr(OH)(HPO4)(OCH3).

[0063] Figure 3 for Figure 2 In the specific flow chart of step S110, in some embodiments, as Figure 3 As shown, step S110: preparing zirconium hydrogen phosphate using zirconium chloride and phosphoric acid solution includes the following steps:

[0064] S111: adding zirconium chloride to deionized water, heating and stirring to dissolve to form a zirconium chloride solution;

[0065] Specifically, an appropriate amount of zirconium chloride is weighed and added to an appropriate amount of deionized water, and the water is heated to a set temperature and slowly stirred to dissolve the water, thereby obtaining a zirconium chloride solution.

[0066] S112: adding the zirconium chloride solution to the phosphoric acid solution, stirring and reacting in a fume hood to obtain a first reactant;

[0067] Specifically, the dissolved zirconium chloride solution is slowly poured into the phosphoric acid solution with continuous stirring. The reaction is carried out in a fume hood, and a cooling device is used to capture hydrogen chloride gas to prevent toxic gas leakage. This produces a zirconium hydrogen phosphate precipitate, the first reactant. The reaction molar ratio of zirconium chloride to phosphoric acid is 1:2, meaning 1 mol of zirconium chloride reacts with 2 mol of phosphoric acid.

[0068] S113: The first reactant is subjected to a centrifugal operation, washed with deionized water, and dried to obtain zirconium hydrogen phosphate powder.

[0069] Specifically, the first reactant is subjected to centrifugal operation, deionized water washing and other filtering operations to remove impurities, and then transferred to an oven for drying to obtain zirconium hydrogen phosphate powder.

[0070] Figure 4 for Figure 2 In the specific flow chart of step S120, in some embodiments, as Figure 2 As shown, step S120: using methyl chloride to modify zirconium hydrogen phosphate to obtain modified zirconium hydrogen phosphate includes the following steps:

[0071] S121: dissolving zirconium hydrogen phosphate in isopropyl alcohol solvent to obtain a zirconium hydrogen phosphate solution;

[0072] Specifically, zirconium hydrogen phosphate powder is dissolved in isopropyl alcohol solution to form a zirconium hydrogen phosphate solution.

[0073] S122: adding methyl chloride to the zirconium hydrogen phosphate solution, stirring and reacting in a fume hood to obtain a second reactant;

[0074] Specifically, an excess amount of methyl chloride is slowly added dropwise to the isopropyl tone solution in which zirconium hydrogen phosphate is dissolved, and the mixture is continuously stirred to generate a modified zirconium hydrogen phosphate precipitate, namely the second reactant.

[0075] S123: The second reactant is subjected to a centrifugal operation, washed with deionized water, and dried to obtain modified zirconium hydrogen phosphate powder.

[0076] Specifically, the second reactant is subjected to centrifugal operation, deionized water washing and other filtering operations to remove impurities, and then transferred to an oven for drying to obtain modified zirconium hydrogen phosphate powder.

[0077] Figure 5 for Figure 1 In the specific flow chart of step S200, in some embodiments, as Figure 5 As shown, step S200: preparing UP containing quadruple hydrogen bonds y Group Curing Agent UP y -IPDA-NH2 includes the following steps:

[0078] S210: 2-amino-4-hydroxy-6-methylpyrimidine reacts with N, N'-carbonyldiimidazole to obtain intermediate UP y -CDI;

[0079] S220: The intermediate UP y -CDI reacts with the curing agent IPDA to obtain UP containing quadruple hydrogen bonds y Group Curing Agent UP y -IPDA-NH2.

[0080] Figure 6 for Figure 5 In the specific flow chart of step S210, in some embodiments, as Figure 6 As shown, step S210: using 2-amino-4-hydroxy-6-methylpyrimidine to react with N, N'-carbonyldiimidazole to obtain intermediate UP y -CDI includes the following steps:

[0081] S211: dispersing 2-amino-4-hydroxy-6-methylpyrimidine and N, N'-carbonyldiimidazole in dimethyl sulfoxide solvent, stirring, and filtering to obtain a solid product;

[0082] Specifically, the molar ratio of 2-amino-4-hydroxy-6-methylpyrimidine to N, N'-carbonyldiimidazole is 2:3, and the two are dispersed and dissolved in dimethyl sulfoxide solvent, stirred at high temperature, and then filtered and purified to obtain a solid product.

[0083] S212: Washing and drying the solid product to obtain the intermediate UP y -CDI.

[0084] Specifically, the solid product was washed with cold acetone for several times and dried in vacuum to obtain the intermediate UP. y -CDI.

[0085] Figure 7 for Figure 5 In the specific flow chart of step S220, in some embodiments, as Figure 7 As shown, step S200: the intermediate UP y -CDI reacts with the curing agent IPDA to obtain UP containing quadruple hydrogen bonds y Group Curing Agent UP y -IPDA-NH2 includes the following steps:

[0086] S221 the intermediate UP y -CDI is mixed with the curing agent IPDA, and added into n-hexane and stirred to obtain a mixture;

[0087] Specifically, the intermediate UPy -CDI, stirred and dissolved in the curing agent IPDA, i.e. isophorone diamine, the intermediate UP y The molar ratio of -CDI to curing agent IPDA was 1:10, and then added into n-hexane and stirred thoroughly.

[0088] S222: dissolving the lower layer of the mixture in dichloromethane, washing, drying, rotary evaporation, and vacuum drying to obtain the UP containing quadruple hydrogen bonds. y Group Curing Agent UP y -IPDA-NH2.

[0089] Specifically, the lower layer of the mixture was dissolved in dichloromethane and washed thoroughly with brine and deionized water, and then the mixture was dried with Na2SO4 and the dichloromethane was removed by rotary evaporation. Finally, the mixture was dried in vacuum to obtain UP containing quadruple hydrogen bonds. y Group Curing Agent UP y -IPDA-NH2.

[0090] Figure 8 for Figure 1 In the specific flow chart of step S300, in some embodiments, as Figure 8 As shown, step S300: the modified zirconium hydrogen phosphate and polyurea are mixed in proportion to form a composite material, and the curing agent IPDA and UP containing quadruple hydrogen bonds are added in proportion. y Group Curing Agent UP y -IPDA-NH2, obtaining a self-repairing polyurea coating comprises the following steps:

[0091] S310: mixing the modified zirconium hydrogen phosphate and polyurea in proportion, and performing ultrasonic treatment to obtain a composite material;

[0092] The modified zirconium hydrogen phosphate and polyurea are mixed at a mass ratio of 1:20, and ultrasonic treatment technology is used to ensure that the modified zirconium hydrogen phosphate is evenly dispersed in the polyurea to ensure the uniformity of the coating material.

[0093] S320: Curing agent IPDA mixed with UP containing quadruple hydrogen bonds in proportion y Group Curing Agent UP y -IPDA-NH2 to obtain a curing agent mixture;

[0094] Specifically, the curing agent IPDA and UP containing quadruple hydrogen bonds y Group Curing Agent UP y -IPDA-NH2 ratio, that is, the molar ratio is 6:4 to 9:1, by adjusting the curing agent IPDA and UP containing quadruple hydrogen bonds yDifferent self-healing polyurea elastomers can be prepared by adjusting the content ratio of the group curing agent UPy-IPDA-NH2.

[0095] S330: The composite material and the curing agent mixture are mixed in a xylene solvent in proportion, and the self-repairing polyurea coating material is obtained by stirring, removing bubbles, evaporating, and heating.

[0096] Specifically, the composite material and the curing agent mixture are thoroughly mixed and stirred in a xylene solvent at a mass ratio of 10:1, and bubbles in the mixture solution are removed using a vacuum drying oven. The solution is applied to polytetrafluoroethylene (PTFE) and dried under vacuum to ensure complete evaporation of the solvent. The solution is then heated to obtain a self-healing polyurea elastomer, i.e., a self-healing polyurea coating material.

[0097] The self-repairing polyurea coating material prepared by the preparation method of the self-repairing polyurea coating material provided by the present disclosure has significant advantages over traditional anti-corrosion coatings. First, it has a self-repairing function, which can automatically repair the damaged area when microcracks or damage occur in the coating, restore the anti-corrosion performance, and extend the service life of the coating. Specifically, by embedding 2-ureido-4[1H]-pyrimidinone (UP) with a quadruple hydrogen bond, y ) unit, giving the material excellent self-repair properties. When the material is mechanically damaged, UP y The units can restore their original structure through reversible hydrogen bond interactions, achieving self-healing of the material; secondly, by introducing modified zirconium hydrogen phosphate, the material significantly improves the corrosion resistance of the coating, effectively preventing the penetration of corrosive media and providing longer-lasting protection; finally, due to the addition of modified zirconium hydrogen phosphate, the material has stronger mechanical properties, improving the coating's scratch and damage resistance, making it more reliable in harsh environments.

[0098] The following describes specific examples and comparative examples of the present disclosure.

[0099] Example 1

[0100] In Example 1, a method for preparing a corrosion-resistant self-repairing polyurea coating material for ships is provided, which specifically comprises the following steps:

[0101] Step S100: preparing modified zirconium hydrogen phosphate, wherein the modified zirconium hydrogen phosphate includes alkylated zirconium hydrogen phosphate.

[0102] Specifically, 5g of zirconium chloride was added to 100ml of deionized water, heated to 60°C, and stirred continuously until dissolved. The zirconium chloride solution was then slowly poured into a 0.5mol / L phosphoric acid solution and stirred continuously for 2 hours to form a zirconium hydrogen phosphate precipitate. The above reaction was carried out in a fume hood, and a cooling device was used to capture the hydrogen chloride gas to prevent toxic gas leakage.

[0103] The reaction mixture was transferred to a centrifuge tube and centrifuged at 3000 rpm for 15 minutes. The zirconium hydrogen phosphate precipitate was then transferred to a test tube and repeatedly washed with deionized water. The solution was dried at 60°C to remove moisture, yielding a light yellow zirconium hydrogen phosphate powder.

[0104] Weigh 5g of zirconium hydrogen phosphate and add it to 100ml of isopropanol. Heat the solution to 60°C and stir with a magnetic stirrer until the zirconium hydrogen phosphate is completely dissolved. Slowly add 0.03mol of chloromethane dropwise to the isopropanol solution containing the zirconium hydrogen phosphate and continue stirring for 2h. Perform the above reaction in a fume hood.

[0105] The reactants were transferred to a centrifuge tube and centrifuged at 3000 rpm for 15 minutes. The modified zirconium hydrogen phosphate precipitate was transferred to a test tube, washed repeatedly with deionized water, and dried at 60°C for 12 hours to remove moisture, thereby obtaining a powdered modified zirconium hydrogen phosphate.

[0106] S200: Preparation of UPs containing quadruple hydrogen bonds y Group Curing Agent UP y -IPDA-NH2;

[0107] Specifically, 15.0 g (0.12 mol) of 2-amino-4-hydroxy-6-methylpyrimidine and 29.187 g (0.18 mol) of N,N'-carbonyldiimidazole (CDI) were dispersed and dissolved in 500 mL of dimethyl sulfoxide (DMSO). The mixture was stirred at 80°C for 2 h. The solid product was then filtered and purified.

[0108] The solid product was washed three times with cold acetone and dried in vacuum at an ambient temperature of 30°C for 12 h to obtain 21.82 g of white powder with a yield of 83%. The compound was named UP y -CDI, called intermediate UP y -CDI.

[0109] 10.0 g, 0.0456 mol of intermediate UP y -CDI was mixed with 78.49 g (0.456 mol) of the curing agent IPDA (i.e., isophorol diamine) and stirred at 45°C for 48 h. Subsequently, n-hexane at 0°C was added and stirred thoroughly to obtain a mixture.

[0110] The lower layer of the mixture was then dissolved in 30 mL of dichloromethane (DCM) and washed three times with 30 mL of brine and 30 mL of deionized water. The mixture was then dried with Na2SO4 and the dichloromethane was removed by rotary evaporation. Finally, the mixture was dried in a vacuum overnight to obtain UP containing quadruple hydrogen bonds. y Group Curing Agent UP y -IPDA-NH2.

[0111] S300: The modified zirconium hydrogen phosphate and polyurea are mixed in proportion, and the curing agent IPDA and UP containing quadruple hydrogen bonds are added in proportion. y Group Curing Agent UP y -IPDA-NH2, to obtain a self-repairing polyurea coating material.

[0112] Specifically, the modified zirconium hydrogen phosphate is mixed with polyurea at a mass ratio of 1:20. Ultrasonic treatment technology is used to ensure that the modified zirconium hydrogen phosphate is evenly dispersed in the polyurea, thereby ensuring the uniformity of the coating material and obtaining a uniform composite material.

[0113] Mix the curing agent IPDA and UP containing quadruple hydrogen bonds in a molar ratio of 9:1. y Group Curing Agent UP y -IPDA-NH2 to obtain a curing agent mixture.

[0114] 4.5 g of the composite material, 0.452 g of the curing agent mixture, and 150 mL of xylene solvent were thoroughly mixed and stirred for 20 minutes. Air bubbles were removed from the mixture using a vacuum drying oven. The mixture was then applied to polytetrafluoroethylene (PTFE) and vacuum-dried at 60°C for 24 hours to ensure complete evaporation of the solvent. The resulting self-healing polyurea elastomer, designated NEU0.1, was then heated at 80°C for 24 hours.

[0115] Example 2:

[0116] The preparation method of the self-repairing polyurea coating material in Example 2 is substantially the same as that in Example 1, except that in step S300, the curing agent IPDA and the UP containing quadruple hydrogen bonds are mixed in a molar ratio of 8:2. y Group Curing Agent UP y -IPDA-NH2 was used to obtain a curing agent mixture, and the self-healing polyurea elastomer prepared according to the preparation method of Example 2 was named NEU0.2.

[0117] Example 3:

[0118] The preparation method of the self-repairing polyurea coating material in Example 3 is substantially the same as that in Example 1, except that in step S300, the curing agent IPDA and the UP containing quadruple hydrogen bonds are mixed in a molar ratio of 7:3. y Group Curing Agent UP y -IPDA-NH2 was used to obtain a curing agent mixture, and the self-healing polyurea elastomer prepared according to the preparation method of Example 3 was named NEU0.3.

[0119] Example 4:

[0120] The preparation method of the self-repairing polyurea coating material in Example 4 is substantially the same as that in Example 1, except that in step S300, the curing agent IPDA and the UP containing quadruple hydrogen bonds are mixed in a molar ratio of 6:4. y Group Curing Agent UP y -IPDA-NH2 was used to obtain a curing agent mixture, and the self-healing polyurea elastomer prepared according to the preparation method of Example 4 was named NEU0.4.

[0121] Comparative Example 1:

[0122] The preparation method of the self-repairing polyurea coating material in the comparative example is substantially the same as that in Example 1, except that in step S300, the curing agent mixture only uses the curing agent IPDA, and does not contain the UP containing quadruple hydrogen bonds. y Group Curing Agent UP y -IPDA-NH2, a polyurea elastomer prepared by the preparation method of the comparative example, named NEP1.

[0123] As described above, in the preparation method of the self-repairing polyurea coating material provided by the present disclosure, different polyurea elastomers can be prepared by adding curing agent mixtures in different mixing ratios. First, UP containing quadruple hydrogen bonds is not used at all. y Group Curing Agent UP y -IPDA-NH2, only using curing agent IPDA, corresponding to the ratio 1, then changing the amount of curing agent IPDA added, adding different amounts of UP containing quadruple hydrogen bonds y Group Curing Agent UP y -IPDA-NH2 curing agent, corresponding to Example 1 to Example 4, four different UP y In order to distinguish them, NEPx and NEUx are used to name polyurea elastomers. NEP is used to represent polyurea elastomers, and NEU represents polyurea elastomers with UP units. y The "x" is used to distinguish the different proportions of added curing agent.

[0124] The polyurea elastomers prepared by the preparation methods of Examples 1 to 4 and the comparative example were tested respectively, and the test results are shown in Table 1.

[0125] Table 1

[0126]

[0127] As shown in Table 1, the glass transition temperatures Tg of NEP1, NEU0.1, NEU0.2, NEU0.3, and NEU0.4 are similar, their elongation at break increases, their tensile strength decreases, and their recovery rate increases. Although NEU0.1 sample has the best tensile strength, its strength-elongation recovery effect only recovers 68% of the initial state. This phenomenon is caused by the UP y The limited self-recovery ability cannot guarantee the stability and safety of the material during service. For the NEU0.2 sample, the self-recovery efficiency has been significantly improved, about 89%, which shows that UP y Increasing the unit content improves the coating material's repair efficiency. Furthermore, NEU0.3 and NEU0.4 samples achieved repair efficiencies exceeding 90%, but their tensile strengths were only half that of the NEU0.2 sample, or even lower. Based on these tests, it can be confirmed that the polyurea elastomer in the NEU0.2 sample exhibits strong tensile strength, high elongation at break, and excellent self-healing properties, offering the best overall performance.

[0128] In order to further verify the protective effect of the elastomer coating, EDS analysis was performed on the polyurea elastomers prepared by the preparation methods of Examples 1 to 4 and the comparative example after peeling and immersion. The analysis results are shown in Table 2, which reflect the atomic percentages of various elements in the polyurea elastomer.

[0129] Table 2

[0130]

[0131] As shown in Table 2, for samples NEP1, NEU0.1, NEU0.3, and NEU0.4, a large amount of corrosion products, such as iron oxide, were present on the metal surfaces at the coating scratches, indicating that the substrate had been severely corroded. This damage was irreparable, leading to the accumulation of corrosion products. For sample NEU0.2, a small amount of corrosion products was observed on its surface, indicating early corrosion of the metal caused by the initial stage of damage repair, but this was significantly less than that of the other three coatings. This indicates that NEU0.2 did not experience significant penetration of the corrosive medium during the immersion process. This performance of NEU0.2 is attributed to the repair of micro-defects within the coating by multiple hydrogen bonds and the reconstruction of the molecular shielding network. The intact coating molecular network has a good barrier effect, increasing the corrosion resistance of the coating and providing excellent corrosion protection for the metal beneath.

[0132] In the present disclosure, the curing agent IPDA is combined with UP containing quadruple hydrogen bonds. y Group Curing Agent UP y -IPDA-NH2 is used in a synergistic manner in an appropriate molar ratio to simultaneously construct a two-level crosslinking of "irreversible covalent skeleton" and "reversible multi-point hydrogen bond" in the same network. Specifically, IPDA participates in the epoxy ring-opening reaction to form a dense and continuous covalent crosslinking network, giving the material the necessary initial strength, modulus and durable shielding. y -IPDA-NH2 still forms a covalent bond with epoxy to ensure the integrity of the network. On the other hand, its side chain UP y The groups spontaneously pair to form quadruple hydrogen bonds with strength between covalent bonds and ordinary hydrogen bonds. When loaded, they can preferentially break to absorb energy and quickly reconstruct when unloaded or at room temperature, achieving both toughness and rapid self-healing. y Too low a content results in insufficient sacrificial bond density, limiting repair efficiency and elongation. Excessive content leads to sparse covalent crosslinking, reduced strength, and weakened shielding properties. Experiments demonstrate that NEU0.2 in Example 2 achieves a "mechanical-kinetic" balance between covalent and reversible crosslinking, matching segment diffusion with interfacial rebonding rates. This results in optimal combined performance in terms of tensile strength, elongation at break, 89% self-healing efficiency within 10 minutes at room temperature, and long-term corrosion resistance.

[0133] Comparative Example 2:

[0134] The preparation method of the self-healing polyurea coating material in Comparative Example 2 is basically the same as the preparation method in Example 1, except that modified zirconium hydrogen phosphate is not added to the polyurea. The self-healing polyurea elastomer prepared by the preparation method of Comparative Example 2 is named PUA0.1.

[0135] Electrochemical impedance spectroscopy was performed on NEU0.1 in Example 1 and PUA0.1 in Comparative Example 2, respectively. The test frequency range was 105 to 10 -2 Hz, the electrolyte was a 3.5 wt% NaCl solution, the coating thickness was 50 ± 5 μm, and the immersion time was 50 days. The test data are shown in Tables 3 and 4 below. Table 3 shows the change in low-frequency impedance modulus (Z f = 0.01 Hz) with immersion time, and Table 4 shows the Bode phase angle characteristic parameters.

[0136] Table 3

[0137]

[0138] Table 4

[0139]

[0140] Based on the electrochemical impedance spectroscopy test data analysis, the polyurea coating NEU0.1 modified with zirconium hydrogen phosphate modified by chloromethane exhibits significantly better corrosion resistance than the pure polyurea coating PUA0.1: in the immersion test in 3.5 wt% NaCl solution, the initial impedance value of the NEU0.1 coating reaches 3.2×10 9 Ω·cm 2 , which is higher than 2.1×10 of PUA0.1 9 Ω·cm 2 After 50 days of immersion, NEU0.1 still maintained at 1.4×10 9 Ω·cm 2 The high impedance (maintenance rate 43.75%), while PUA0.1 dropped sharply to 5.3×10 7 Ω·cm 2 (Retention rate is only 2.52%), and PUA0.1 has a second time constant after 50 days, indicating that the corrosive medium has penetrated the coating and reached the metal substrate, while NEU0.1 always maintains a single time constant and a low breakpoint frequency of 0.15 Hz, proving that the coating has good integrity; this performance improvement is mainly attributed to the ordered layered arrangement structure formed by chloromethane-modified zirconium hydrogen phosphate in the polyurea matrix, which produces a "maze effect", extending the penetration path of the corrosive medium by 3 to 5 times. At the same time, the chloromethane groups and the -NH groups of polyurea form hydrogen bonds to improve the interfacial compatibility and reduce agglomeration and interfacial defects. In addition, the interlayer ion exchange capacity of zirconium hydrogen phosphate can capture corrosive ions such as Cl⁻. The uniform dispersion of modified nanosheets also improves the density of the coating (porosity <5%). The synergistic effect of multiple mechanisms makes the long-term protection ability of the NEU0.1 coating about 26 times higher than that of PUA0.1.

[0141] Some embodiments of the present disclosure further provide a corrosion-resistant self-healing polyurea coating material for ships, wherein the self-healing polyurea coating material is manufactured using the preparation method described in the aforementioned embodiments.

[0142] The self-repairing polyurea coating material prepared by the method for preparing a corrosion-resistant self-repairing polyurea coating for ships provided by the present disclosure has the following beneficial effects:

[0143] By introducing modified zirconium hydrogen phosphate, the corrosion resistance of the coating material is improved, effectively preventing the penetration of corrosive media and providing longer-lasting protection. At the same time, the addition of modified zirconium hydrogen phosphate gives the coating material stronger mechanical properties, improves the coating's scratch and damage resistance, and makes it more reliable in harsh environments.

[0144] By UP y Thanks to the hydrogen bonding mechanism of the unit, the material can rapidly repair micro-damage such as scratches and cracks at room temperature. The repaired material not only restores its original shape but also maintains high mechanical properties. This self-healing function significantly extends the service life of the material and reduces maintenance and replacement costs.

[0145] Polyurea elastomers have high elongation and demonstrate high strength and ductility in tensile tests. After mechanical damage, the material can still recover close to its original mechanical properties, ensuring structural integrity during long-term use.

[0146] Polyurea elastomer exhibits excellent anti-corrosion effect in salt spray environment. Even after damage, the coating can still effectively isolate the penetration of corrosive media and protect the substrate from corrosion, indicating that it has good corrosion resistance in marine environment.

[0147] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. References to the common and similar parts between the various embodiments will be sufficient. For the systems or devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, their descriptions are relatively simple; for relevant details, refer to the descriptions of the methods.

[0148] The above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present disclosure.

Claims

1. A method for preparing a corrosion-resistant self-repairing polyurea coating material for ships, characterized in that: The following steps are involved: preparing modified zirconium hydrogen phosphate, wherein the modified zirconium hydrogen phosphate comprises alkylated zirconium hydrogen phosphate; Preparation of UP containing quadruple hydrogen bonds y Group Curing Agent UP y -IPDA-NH2; and The modified zirconium hydrogen phosphate and polyurea are mixed in proportion, and the curing agent IPDA and UP containing quadruple hydrogen bonds are added in proportion. y Group Curing Agent UP y -IPDA-NH2, to obtain a self-repairing polyurea coating material.

2. The method for preparing the self-repairing polyurea coating material according to claim 1, characterized in that: The preparation of modified zirconium hydrogen phosphate comprises the following steps: preparing zirconium hydrogen phosphate using zirconium chloride and phosphoric acid solution; and Zirconium hydrogen phosphate is modified by methyl chloride to obtain modified zirconium hydrogen phosphate.

3. The method for preparing the self-repairing polyurea coating material according to claim 2, characterized in that: The preparation of zirconium hydrogen phosphate using zirconium chloride and phosphoric acid solution comprises the following steps: Add zirconium chloride to deionized water, heat and stir to dissolve to form a zirconium chloride solution; adding the zirconium chloride solution to the phosphoric acid solution, and stirring the mixture in a fume hood to react to obtain a first reactant; and The first reactant is subjected to a centrifugal operation, washed with deionized water, and dried to obtain zirconium hydrogen phosphate powder.

4. The method for preparing the self-repairing polyurea coating material according to claim 2, characterized in that: Modifying zirconium hydrogen phosphate with methyl chloride to obtain modified zirconium hydrogen phosphate includes the following steps: dissolving zirconium hydrogen phosphate in isopropyl alcohol solvent to obtain a zirconium hydrogen phosphate solution; adding methyl chloride to the zirconium hydrogen phosphate solution, and stirring the mixture in a fume hood to react to obtain a second reactant; The second reactant is subjected to a centrifugal operation, washed with deionized water, and dried to obtain modified zirconium hydrogen phosphate powder.

5. The method for preparing the self-repairing polyurea coating material according to claim 1, characterized in that: Preparation of UP containing quadruple hydrogen bonds y Group Curing Agent UP y -IPDA-NH2 includes the following steps: The intermediate UP was obtained by reacting 2-amino-4-hydroxy-6-methylpyrimidine with N, N'-carbonyldiimidazole. y -CDI; and The intermediate UP y -CDI reacts with the curing agent IPDA to obtain UP containing quadruple hydrogen bonds y Group Curing Agent UP y -IPDA-NH2.

6. The method for preparing the self-repairing polyurea coating material according to claim 5, characterized in that: The intermediate UP was obtained by reacting 2-amino-4-hydroxy-6-methylpyrimidine with N, N'-carbonyldiimidazole. y -CDI includes the following steps: 2-amino-4-hydroxy-6-methylpyrimidine and N, N'-carbonyldiimidazole are dispersed in dimethyl sulfoxide solvent, and a solid product is obtained by stirring and filtering. The solid product is washed and dried to obtain the intermediate UP y -CDI.

7. The method for preparing the self-repairing polyurea coating material according to claim 5, characterized in that: The intermediate UP y -CDI reacts with the curing agent IPDA to obtain UP containing quadruple hydrogen bonds y Group Curing Agent UP y -IPDA-NH2 includes the following steps: The intermediate UP y -CDI and curing agent IPDA are mixed, and added into n-hexane and stirred to obtain a mixture; and The lower layer solution of the mixture is dissolved in dichloromethane, and the UP containing quadruple hydrogen bonds is obtained by washing, drying, rotary evaporation and vacuum drying. y Group Curing Agent UP y -IPDA-NH2.

8. The method for preparing the self-repairing polyurea coating material according to claim 1, characterized in that: The modified zirconium hydrogen phosphate and polyurea are mixed in proportion to form a composite material, and a curing agent IPDA and a UP containing a quadruple hydrogen bond are added in proportion. y Group Curing Agent UP y -IPDA-NH2, obtaining a self-repairing polyurea coating comprises the following steps: The modified zirconium hydrogen phosphate and polyurea are mixed in proportion, and ultrasonic treatment is performed to obtain a composite material; Mix the curing agent IPDA and UP containing quadruple hydrogen bonds in proportion y Group Curing Agent UP y -IPDA-NH2 to obtain a curing agent mixture; The composite material and the curing agent mixture are mixed in a xylene solvent in proportion, and the self-repairing polyurea coating material is obtained through stirring, degassing, evaporation and heating.

9. The method for preparing the self-repairing polyurea coating material according to claim 8, characterized in that: The curing agent IPDA and UP containing quadruple hydrogen bonds y Group Curing Agent UP y -IPDA-NH2 were mixed at a molar ratio of 8:

2.

10. A corrosion-resistant self-repairing polyurea coating material for ships, characterized in that: The self-repairing polyurea coating material is manufactured by the preparation method according to any one of claims 1 to 9.

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