Nanometer modified polysiloxane heavy-duty anticorrosive coating and preparation method thereof

Abstract

The present application relates to the technical field of anticorrosive paint, in particular to a kind of nano-modified polysiloxane heavy-duty anticorrosive paint and preparation method thereof, comprising the following raw materials by weight: 100 parts of polysiloxane resin, 5-15 parts of amino silane coupling agent, 20-40 parts of mica iron oxide, 1-5 parts of auxiliary agent, 10-30 parts of solvent, 3-10 parts of biomimetic mineralization enhancer, 1-5 parts of additive, the biomimetic mineralization enhancer in the present application is made by dopamine modification and nano diatomite mineralization treatment with ethyl silicate, which significantly improves the compactness, adhesion and physical shielding performance of the coating, can effectively block the penetration of corrosive medium, and the additive made of silver nanowire and polyvinylidene fluoride by electrospinning gives the coating conductivity, realizes damage self-sensing and early warning, so that the prepared paint has excellent salt spray resistance, wear resistance, impact resistance and long-acting anticorrosive performance, is suitable for metal protection in severe corrosive environment, and has broad application prospect.

Description

Technical Field

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

[0002] Heavy-duty anti-corrosion coatings are key materials for protecting metal substrates from corrosion in harsh environments. Traditional anti-corrosion coatings include epoxy and polyurethane. In recent years, polysiloxane resins have gradually become the base resins for the new generation of anti-corrosion coatings due to their excellent heat resistance, weather resistance and chemical stability.

[0003] In the prior art, there is still room for improvement in the film density, adhesion and impermeability of pure resin systems. Based on this, the present invention provides a nano-modified polysiloxane heavy-duty anti-corrosion coating and its preparation method. Summary of the Invention

[0004] The purpose of this invention is to provide a nano-modified polysiloxane heavy-duty anti-corrosion coating and its preparation method. This invention has excellent comprehensive performance and can effectively resist chemical corrosion, salt spray erosion and physical wear in harsh environments, solving the problems of insufficient long-term protection and low mechanical strength of traditional heavy-duty anti-corrosion coatings.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] In a first aspect, the present invention provides a nano-modified polysiloxane heavy-duty anti-corrosion coating, characterized in that it comprises the following raw materials in parts by weight: 100 parts polysiloxane resin, 5-15 parts aminosilane coupling agent, 20-40 parts mica iron oxide, 1-5 parts additives, 10-30 parts solvent, 3-10 parts biomimetic mineralization enhancer, and 1-5 parts additives.

[0007] Furthermore, the biomimetic mineralization enhancer is prepared by the following method:

[0008] S1: Mix nano-diatomaceous earth powder with deionized water at a solid-liquid ratio of 1:(8-12), stir and react to obtain the first suspension;

[0009] S2: Heat the first suspension to 55-65℃, add dopamine hydrochloride to the first suspension, add 1-2 drops of 0.1mol / L tris(hydroxymethyl)aminomethane buffer, adjust the pH to 8.5, and continue the reaction for 12 hours to obtain a mixture, wherein the mass of dopamine hydrochloride is 1-3% of the mass of the first suspension;

[0010] S3: Centrifuge the mixture to obtain a precipitate. Wash the precipitate three times each with deionized water and ethanol. Dry the washed precipitate under vacuum at 55-65℃ to obtain the intermediate product.

[0011] S4: Disperse the intermediate product in an ethanol solution, add tetraethyl orthosilicate and ammonia, and stir the reaction at 35-45℃ for 5.5-6.5 h. After the reaction is completed, centrifuge, wash and dry the product to obtain the biomimetic mineralization enhancer.

[0012] Further, the nano-diatomite powder is prepared by the following method: diatomite is added to a 10% hydrochloric acid solution and acid-washed at 75-85℃ for 1.5-2.5h. The acid-washed diatomite is washed with deionized water until neutral and filtered to obtain a filter cake. The filter cake is dried at 90-110℃ to constant weight to obtain purified diatomite. The purified diatomite and zirconia grinding balls are placed in a planetary ball mill at a mass ratio of 1:(8-12) and ball-milled at 200-400rpm for 5.5-6.5h. After ball milling, the powder is passed through an 800-mesh sieve to obtain nano-diatomite powder, wherein the mass ratio of diatomite to hydrochloric acid solution is 1:(3-4).

[0013] Further, the additive is prepared by the following method: an ethanol dispersion of silver nanowires is mixed with N,N-dimethylformamide solvent at a mass ratio of 1:1, and ultrasonically treated for 30 min to obtain a second dispersion. Polyvinylidene fluoride powder is added to the second dispersion, and the mixture is stirred in a water bath at 55-65℃ for 3.5-4.5 h to obtain a third mixture. The third mixture is spun using an electrospinning device, and then dried in a vacuum oven at 76-85℃ for 12 h. After drying, it is pulverized to obtain the additive.

[0014] Further, the ethanol dispersion of silver nanowires is prepared by the following method: silver nitrate and ethylene glycol solution are mixed at a mass ratio of (1.2-1.8):100 to obtain a fourth solution; polyvinylpyrrolidone and sodium chloride are dissolved in ethylene glycol solution to obtain a fifth solution; the fifth solution is heated to 150-170℃, and the fourth solution is added dropwise to the fifth solution within 5 min under magnetic stirring; the reaction is continued at 150-170℃ for 0.5-1.5 h to obtain a silver nanowire dispersion; after cooling to room temperature, an equal volume of acetone is added, and centrifugation is performed to obtain a silver nanowire precipitate; the silver nanowire precipitate is washed three times with ethanol solution, and the silver nanowires are redispersed in ethanol solution to obtain the ethanol dispersion of silver nanowires.

[0015] Furthermore, the parameters of the electrospinning device are set as follows: receiving roller speed is 150-250 rpm, spinning voltage is 15 kV, receiving distance is 15 cm, and the mass of the polyvinylidene fluoride powder is 8-12% of the mass of N,N-dimethylformamide solvent.

[0016] Furthermore, the mass of the polyvinylpyrrolidone is 3.0-3.5 times the mass of silver nitrate, the mass of sodium chloride is 3.0-3.5% of the mass of silver nitrate, the mass of the ethylene glycol solution used to prepare the fifth solution is 65-75 times the mass of silver nitrate, the concentration of the ethanol solution is above 95%, and the mass ratio of ethanol solution to silver nanowires in the dispersion is 19:1.

[0017] Furthermore, in S4, the mass concentration of the ethanol solution is 40-60%, and the mass of the ethanol solution is 10 times the mass of the intermediate product; the mass concentration of tetraethyl orthosilicate is 10-20%, and the mass of tetraethyl orthosilicate is 1.5-2.5 times the mass of the intermediate product; the mass concentration of ammonia is 25-28%, and the mass of ammonia is 30-40% of the mass of the intermediate product.

[0018] Furthermore, the additive is silicone oil.

[0019] Secondly, the present invention also provides a method for preparing a nano-modified polysiloxane heavy-duty anti-corrosion coating, comprising the following steps:

[0020] Step 1: Add polysiloxane resin, aminosilane coupling agent, solvent and additives to a high-speed disperser and disperse at high speed under circulating water cooling. Maintain the material temperature below 40℃ and stir at 450-550 rpm for 10 minutes to obtain the base material.

[0021] Step 2: Add mica iron oxide, biomimetic mineralization enhancer and self-sensing additive to the base material, increase the rotation speed to 1000-2000 rpm, and disperse at high speed for 30 minutes to obtain slurry;

[0022] Step 3: Transfer the slurry to a sand mill and grind it to a fineness of ≤25μm. After grinding, filter and package to obtain nano-modified polysiloxane heavy-duty anti-corrosion coating.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] 1. This invention, through the introduction of a biomimetic mineralization enhancer, namely dopamine-modified and tetraethyl orthosilicate-mineralized nanodiatomite, greatly improves the density and physical shielding effect of the coating, effectively blocking the penetration of corrosive media such as water, oxygen, and chloride ions, and improving salt spray resistance, which is significantly better than traditional anti-corrosion coatings.

[0025] 2. This invention utilizes the synergistic effect of nano-diatomite and mica iron oxide, as well as the strong bond between the biomimetic mineralization layer and the resin matrix, to give the coating excellent wear resistance, impact resistance, and adhesion to metal substrates, thus significantly extending its service life.

[0026] 3. This invention, by adding an additive made of silver nanowires and polyvinylidene fluoride through electrospinning, endows the anti-corrosion coating with a conductive network. When the coating is damaged or corroded, the changes in the conductive path can be monitored in time, realizing real-time online monitoring and early warning of the coating's health status, thus solving the pain point that traditional coatings cannot detect internal damage. Attached Figure Description

[0027] Figure 1 A flowchart is provided for the invention of a nano-modified polysiloxane heavy-duty anti-corrosion coating. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0029] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application are described clearly and completely below.

[0030] Example 1

[0031] Preparation of nano-diatomaceous earth powder: Diatomaceous earth was added to a 10% hydrochloric acid solution and acid-washed at 75°C for 1.5 h. The acid-washed diatomaceous earth was washed with deionized water until neutral and then filtered to obtain a filter cake. The filter cake was dried at 90°C to constant weight to obtain purified diatomaceous earth. The purified diatomaceous earth and zirconia grinding balls were placed in a planetary ball mill at a mass ratio of 1:8 and ball-milled at 200 rpm for 5.5 h. After ball milling, the powder was passed through an 800-mesh sieve to obtain nano-diatomaceous earth powder. The mass ratio of diatomaceous earth to hydrochloric acid solution was 1:3.

[0032] Preparation of biomimetic mineralization enhancers:

[0033] S1: Mix nano-diatomaceous earth powder with deionized water at a solid-liquid ratio of 1:8, stir and react to obtain the first suspension;

[0034] S2: Heat the first suspension to 55°C, add dopamine hydrochloride to the first suspension, add 1-2 drops of 0.1 mol / L tris(hydroxymethyl)aminomethane buffer, adjust the pH to 8.5, and continue the reaction for 12 hours to obtain a mixture, wherein the mass of dopamine hydrochloride is 1% of the mass of the first suspension;

[0035] S3: Centrifuge the mixture to obtain a precipitate. Wash the precipitate three times each with deionized water and ethanol. Dry the washed precipitate under vacuum at 55°C to obtain the intermediate product.

[0036] S4: The intermediate product was dispersed in an ethanol solution, and tetraethyl orthosilicate and ammonia were added. The mixture was stirred at 35°C for 5.5 h. After the reaction was completed, the product was centrifuged, washed and dried again to obtain the biomimetic mineralization enhancer.

[0037] Furthermore, the ethanol solution has a mass concentration of 40%, and the mass of the ethanol solution is 10 times the mass of the intermediate product; the tetraethyl orthosilicate has a mass concentration of 10%, and the mass of the tetraethyl orthosilicate is 1.5 times the mass of the intermediate product; the ammonia solution has a mass concentration of 25%, and the mass of the ammonia solution is 30% of the mass of the intermediate product.

[0038] Preparation of ethanol dispersion of silver nanowires: Silver nitrate and ethylene glycol solution were mixed at a mass ratio of 1.2:100 to obtain a fourth solution. Polyvinylpyrrolidone and sodium chloride were dissolved in ethylene glycol solution to obtain a fifth solution. The fifth solution was heated to 150℃, and the fourth solution was added dropwise to the fifth solution over 5 min under magnetic stirring. The reaction was continued at 150℃ for 0.5 h to obtain a silver nanowire dispersion. After cooling to room temperature, an equal volume of acetone was added, and centrifugation was performed to obtain silver nanowire precipitate. The silver nanowire precipitate was washed three times with ethanol solution, and the silver nanowires were redispersed in ethanol solution to obtain the ethanol dispersion of silver nanowires.

[0039] Furthermore, the mass of polyvinylpyrrolidone is 3.0 times the mass of silver nitrate, the mass of sodium chloride is 3.0% of the mass of silver nitrate, the mass of the ethylene glycol solution used to prepare the fifth solution is 65 times the mass of silver nitrate, the concentration of the ethanol solution is above 95%, and the mass ratio of ethanol solution to silver nanowires in the dispersion is 19:1.

[0040] Preparation of the additive: The ethanol dispersion of silver nanowires was mixed with N,N-dimethylformamide solvent at a mass ratio of 1:1 and ultrasonically treated for 30 min to obtain a second dispersion. Polyvinylidene fluoride powder was added to the second dispersion and stirred in a water bath at 55℃ for 3.5 h to obtain a third mixture. The third mixture was spun using an electrospinning device with the receiving roller speed set at 150 rpm, the spinning voltage at 15 kV, and the receiving distance at 15 cm. After drying, it was placed in a vacuum oven at 76℃ for 12 h and then pulverized to obtain the additive. The mass of polyvinylidene fluoride powder was 8% of the mass of N,N-dimethylformamide solvent.

[0041] Raw material preparation: 100 parts polysiloxane resin, 5 parts aminosilane coupling agent, 20 parts mica iron oxide, 1 part additive, 10 parts solvent, 3 parts biomimetic mineralization enhancer, and 1 part additive.

[0042] Preparation of nano-modified polysiloxane heavy-duty anti-corrosion coating:

[0043] Step 1: Add polysiloxane resin, aminosilane coupling agent, solvent and additives to a high-speed disperser and disperse at high speed under circulating water cooling. Maintain the material temperature below 40℃ and stir at 450-550 rpm for 10 minutes to obtain the base material.

[0044] Step 2: Add mica iron oxide, biomimetic mineralization enhancer and self-sensing additive to the base material, increase the rotation speed to 1000 rpm, and disperse at high speed for 30 minutes to obtain slurry;

[0045] Step 3: Transfer the slurry to a sand mill and grind it to a fineness of ≤25μm. After grinding, filter and package to obtain nano-modified polysiloxane heavy-duty anti-corrosion coating.

[0046] Example 2

[0047] Preparation of nano-diatomaceous earth powder: Diatomaceous earth was added to a 10% hydrochloric acid solution and acid-washed at 80°C for 2 hours. The acid-washed diatomaceous earth was washed with deionized water until neutral and then filtered to obtain a filter cake. The filter cake was dried at 100°C to constant weight to obtain purified diatomaceous earth. The purified diatomaceous earth and zirconia grinding balls were placed in a planetary ball mill at a mass ratio of 1:10 and ball-milled at 300 rpm for 6 hours. After ball milling, the powder was passed through an 800-mesh sieve to obtain nano-diatomaceous earth powder. The mass ratio of diatomaceous earth to hydrochloric acid solution was 1:3.5.

[0048] Preparation of biomimetic mineralization enhancers:

[0049] S1: Mix nano-diatomaceous earth powder with deionized water at a solid-liquid ratio of 1:10, stir and react to obtain the first suspension;

[0050] S2: Heat the first suspension to 60°C, add dopamine hydrochloride to the first suspension, add 1-2 drops of 0.1 mol / L tris(hydroxymethyl)aminomethane buffer, adjust the pH to 8.5, and continue the reaction for 12 hours to obtain a mixture, wherein the mass of dopamine hydrochloride is 2% of the mass of the first suspension;

[0051] S3: The mixture is centrifuged to obtain a precipitate. The precipitate is washed three times each with deionized water and ethanol. The washed precipitate is then vacuum dried at 60°C to obtain the intermediate product.

[0052] S4: The intermediate product was dispersed in an ethanol solution, and tetraethyl orthosilicate and ammonia were added. The mixture was stirred at 40°C for 6 hours. After the reaction was completed, the product was centrifuged, washed and dried again to obtain the biomimetic mineralization enhancer.

[0053] Furthermore, the ethanol solution has a mass concentration of 50%, and the mass of the ethanol solution is 10 times the mass of the intermediate product; the tetraethyl orthosilicate has a mass concentration of 15%, and the mass of the tetraethyl orthosilicate is 2 times the mass of the intermediate product; the ammonia solution has a mass concentration of 27%, and the mass of the ammonia solution is 35% of the mass of the intermediate product.

[0054] Preparation of ethanol dispersion of silver nanowires: Silver nitrate and ethylene glycol solution were mixed at a mass ratio of 1.6:100 to obtain a fourth solution. Polyvinylpyrrolidone and sodium chloride were dissolved in ethylene glycol solution to obtain a fifth solution. The fifth solution was heated to 160℃, and the fourth solution was added dropwise to the fifth solution over 5 min under magnetic stirring. The reaction was continued at 160℃ for 1 h to obtain a silver nanowire dispersion. After cooling to room temperature, an equal volume of acetone was added, and centrifugation was performed to obtain silver nanowire precipitate. The silver nanowire precipitate was washed three times with ethanol solution, and the silver nanowires were redispersed in ethanol solution to obtain the ethanol dispersion of silver nanowires.

[0055] Furthermore, the mass of polyvinylpyrrolidone is 3.3 times the mass of silver nitrate, the mass of sodium chloride is 3.3% of the mass of silver nitrate, the mass of the ethylene glycol solution used to prepare the fifth solution is 70 times the mass of silver nitrate, the concentration of the ethanol solution is above 95%, and the mass ratio of ethanol solution to silver nanowires in the dispersion is 19:1.

[0056] Preparation of the additive: The ethanol dispersion of silver nanowires was mixed with N,N-dimethylformamide solvent at a mass ratio of 1:1 and ultrasonically treated for 30 min to obtain a second dispersion. Polyvinylidene fluoride powder was added to the second dispersion and stirred in a water bath at 60℃ for 4 h to obtain a third mixture. The third mixture was spun using an electrospinning device with the receiving roller speed set at 200 rpm, the spinning voltage at 15 kV, and the receiving distance at 15 cm. After drying, it was placed in an 80℃ vacuum oven for 12 h and then pulverized to obtain the additive. The mass of polyvinylidene fluoride powder was 10% of the mass of N,N-dimethylformamide solvent.

[0057] Raw material preparation: 100 parts polysiloxane resin, 10 parts aminosilane coupling agent, 30 parts mica iron oxide, 3 parts additives, 20 parts solvent, 7 parts biomimetic mineralization enhancer, and 3 parts additives.

[0058] Preparation of nano-modified polysiloxane heavy-duty anti-corrosion coating: Step 1: Add polysiloxane resin, aminosilane coupling agent, solvent and additives to a high-speed disperser, disperse at high speed under circulating water cooling, keep the material temperature below 40℃, stir at 500rpm for 10min to obtain the base material.

[0059] Step 2: Add mica iron oxide, biomimetic mineralization enhancer and self-sensing additive to the base material, increase the rotation speed to 1500 rpm, and disperse at high speed for 30 minutes to obtain slurry;

[0060] Step 3: Transfer the slurry to a sand mill and grind it to a fineness of ≤25μm. After grinding, filter and package to obtain nano-modified polysiloxane heavy-duty anti-corrosion coating.

[0061] Example 3

[0062] Preparation of nano-diatomaceous earth powder: Diatomaceous earth was added to a 10% hydrochloric acid solution and acid-washed at 85°C for 2.5 h. The acid-washed diatomaceous earth was washed with deionized water until neutral and then filtered to obtain a filter cake. The filter cake was dried at 110°C to constant weight to obtain purified diatomaceous earth. The purified diatomaceous earth and zirconia grinding balls were placed in a planetary ball mill at a mass ratio of 1:12 and ball-milled at 400 rpm for 6.5 h. After ball milling, the powder was passed through an 800-mesh sieve to obtain nano-diatomaceous earth powder. The mass ratio of diatomaceous earth to hydrochloric acid solution was 1:4.

[0063] Preparation of biomimetic mineralization enhancers:

[0064] S1: Mix nano-diatomaceous earth powder with deionized water at a solid-liquid ratio of 1:12, stir and react to obtain the first suspension;

[0065] S2: Heat the first suspension to 65°C, add dopamine hydrochloride to the first suspension, add 1-2 drops of 0.1 mol / L tris(hydroxymethyl)aminomethane buffer, adjust the pH to 8.5, and continue the reaction for 12 hours to obtain a mixture, wherein the mass of dopamine hydrochloride is 3% of the mass of the first suspension;

[0066] S3: The mixture is centrifuged to obtain a precipitate. The precipitate is washed three times each with deionized water and ethanol. The washed precipitate is then vacuum dried at 65°C to obtain an intermediate product.

[0067] S4: The intermediate product was dispersed in an ethanol solution, and tetraethyl orthosilicate and ammonia were added. The mixture was stirred at 45°C for 6.5 h. After the reaction was completed, the product was centrifuged, washed and dried again to obtain the biomimetic mineralization enhancer.

[0068] Furthermore, the ethanol solution has a mass concentration of 60%, and the mass of the ethanol solution is 10 times the mass of the intermediate product; the tetraethyl orthosilicate has a mass concentration of 20%, and the mass of the tetraethyl orthosilicate is 2.5 times the mass of the intermediate product; the ammonia solution has a mass concentration of 28%, and the mass of the ammonia solution is 40% of the mass of the intermediate product.

[0069] Preparation of ethanol dispersion of silver nanowires: Silver nitrate and ethylene glycol solution were mixed at a mass ratio of 1.8:100 to obtain a fourth solution. Polyvinylpyrrolidone and sodium chloride were dissolved in ethylene glycol solution to obtain a fifth solution. The fifth solution was heated to 170℃, and the fourth solution was added dropwise to the fifth solution over 5 min under magnetic stirring. The reaction was continued at 170℃ for 1.5 h to obtain a silver nanowire dispersion. After cooling to room temperature, an equal volume of acetone was added, and centrifugation was performed to obtain silver nanowire precipitate. The silver nanowire precipitate was washed three times with ethanol solution, and the silver nanowires were redispersed in ethanol solution to obtain the ethanol dispersion of silver nanowires.

[0070] Furthermore, the mass of polyvinylpyrrolidone is 3.5 times the mass of silver nitrate, the mass of sodium chloride is 3.5% of the mass of silver nitrate, the mass of the ethylene glycol solution used to prepare the fifth solution is 75 times the mass of silver nitrate, the concentration of the ethanol solution is above 95%, and the mass ratio of ethanol solution to silver nanowires in the dispersion is 19:1.

[0071] Preparation of the additive: The ethanol dispersion of silver nanowires was mixed with N,N-dimethylformamide solvent at a mass ratio of 1:1 and ultrasonically treated for 30 min to obtain a second dispersion. Polyvinylidene fluoride powder was added to the second dispersion and stirred in a water bath at 65℃ for 4.5 h to obtain a third mixture. The third mixture was spun using an electrospinning device with the receiving roller speed set at 250 rpm, the spinning voltage at 15 kV, and the receiving distance at 15 cm. After drying, it was placed in a vacuum oven at 85℃ for 12 h and then pulverized to obtain the additive. The mass of polyvinylidene fluoride powder was 12% of the mass of N,N-dimethylformamide solvent.

[0072] Raw material preparation: 100 parts polysiloxane resin, 15 parts aminosilane coupling agent, 40 parts mica iron oxide, 5 parts additives, 30 parts solvent, 10 parts biomimetic mineralization enhancer, and 5 parts additives.

[0073] Preparation of nano-modified polysiloxane heavy-duty anti-corrosion coating: Step 1: Add polysiloxane resin, aminosilane coupling agent, solvent and additives to a high-speed disperser, disperse at high speed under circulating water cooling, keep the material temperature below 40℃, stir at 550rpm for 10min to obtain the base material.

[0074] Step 2: Add mica iron oxide, biomimetic mineralization enhancer and self-sensing additive to the base material, increase the rotation speed to 2000 rpm, and disperse at high speed for 30 minutes to obtain slurry;

[0075] Step 3: Transfer the slurry to a sand mill and grind it to a fineness of ≤25μm. After grinding, filter and package to obtain nano-modified polysiloxane heavy-duty anti-corrosion coating.

[0076] Comparative Example 1:

[0077] The difference between this comparative example and Example 1 is that it does not contain biomimetic mineralization enhancers.

[0078] Comparative Example 2:

[0079] The difference between this comparative example and Example 1 is that it does not contain any additives.

[0080] Comparative Example 3:

[0081] The difference between this comparative example and Example 1 is that the nano-diatomite in the biomimetic mineralization enhancer is not modified with dopamine or treated with tetraethyl orthosilicate mineralization, but directly uses an equal amount of purified nano-diatomite powder.

[0082] Comparative Example 4:

[0083] The difference between this comparative example and Example 1 is that the conductive material in the additive is replaced with an equal mass of untreated multi-walled carbon nanotubes.

[0084] Performance testing: The high-strength corrosion-resistant composite materials prepared in Experiments 1, 2, 3, Comparative Examples 1, 2, 3, and 4 were subjected to performance testing. The test data are recorded in the table below:

[0085] sample Salt spray tolerance time (h) Adhesion (MPa) Rate of change in resistance (%) Example 1 2800 18.5 95.2 Example 2 3000 19.5 96.5 Example 3 2850 18.2 95.8 Comparative Example 1 960 14.3 92.1 Comparative Example 2 2500 18.0 3.5 Comparative Example 3 1500 15.6 93.8 Comparative Example 4 2400 17.8 28.4

[0086] Performance testing methods:

[0087] Salt spray resistance was tested according to the neutral salt spray test (NSS) in GB / T10125-2021. After the sample was marked with a cross, it was placed in a salt spray chamber and continuously sprayed with a 5% sodium chloride solution. The temperature inside the chamber was kept constant at 35℃±2℃. The sample was observed every 24 hours, and phenomena such as coating blistering and substrate corrosion were recorded. The time when the corrosion width on one side of the marked part of the sample reached or exceeded 2mm was taken as the final salt spray resistance time, which was used to evaluate the long-term protective ability of the coating in harsh corrosive environments.

[0088] The adhesion was tested in accordance with GBT5210-2006 to determine the bonding strength between the coating and the metal substrate.

[0089] Conductivity and damage self-sensing sensitivity: Referring to the GB / T351-2019 standard, the resistance change rate of the coating before and after artificial scratch (simulating mechanical damage) is measured by a customized circuit continuity monitoring device to evaluate its damage self-sensing ability. The larger the resistance change rate (ΔR / R0), the higher the sensitivity.

[0090] The performance test data shows that the salt spray resistance and adhesion of the nano-modified polysiloxane heavy-duty anti-corrosion coatings prepared in Examples 1, 2, and 3 are significantly better than those in Comparative Examples 1, 2, 3, and 4. This fully demonstrates that the biomimetic mineralization enhancer, through the synergistic effect of the biomimetic adhesion properties of dopamine and the rigid reinforcement of silica formed by the hydrolysis of tetraethyl orthosilicate, constructs a robust organic-inorganic hybrid structure within the coating. This structure greatly enhances the interfacial chemical bonding and physical entanglement between the nanofiller and the polysiloxane resin matrix, thereby significantly improving the density of the coating and its adhesion to the substrate. At the same time, the synergistic effect of the nano-diatomite sheets and the surface mineralization layer effectively blocks the penetration of corrosive media such as water, oxygen, and chloride ions. Compared with the comparative examples, the salt spray resistance of the examples is extended several times. Its mechanism of action originates from the biomimetic design of the multi-level structure of the nacreous layer of seashells. By constructing a micro-nano scale enhanced interface, it successfully solves the problem of early failure caused by insufficient physical shielding and weakened interfacial bonding in traditional anti-corrosion coatings.

[0091] Furthermore, the additive, made by electrospinning silver nanowires and polyvinylidene fluoride, forms a stable and continuous three-dimensional conductive network in the coating. This network not only provides a sensitive signal pathway for damage self-sensing in the coating, but its metallic silver component also preferentially reacts with the corrosive medium at the scratch site through the sacrificial anode protection mechanism to generate an inert protective film, thereby inhibiting the electrochemical corrosion propagation of the base metal. The corrosion rate and resistance change rate data of Comparative Examples 2 and 4 are far inferior to those of the Example, which shows that the unique one-dimensional morphology of silver nanowires and their uniform dispersion in the polyvinylidene fluoride skeleton are crucial for constructing a highly efficient conductive anti-corrosion network, and its effect is unmatched by aggregated zero-dimensional nanoparticles or carbon materials.

[0092] By comparing and analyzing the data in the table, it can be seen that the nano-modified polysiloxane heavy-duty anti-corrosion coating prepared by this invention, through the innovative synergistic design of biomimetic mineralization enhancers and additives, enables the coating to simultaneously achieve a dual protective effect of passive long-term shielding and active intelligent early warning. The fine pretreatment of nano-diatomite and the electrospinning process further ensure the stability and effectiveness of the functional components in the system. This indicates that the nano-modified polysiloxane heavy-duty anti-corrosion coating and its preparation method provided by this invention have superior performance and broader application prospects in the field of metal protection under harsh corrosive environments.

[0093] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0094] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A nano-modified polysiloxane heavy-duty anti-corrosion coating, characterized in that, The ingredients, by weight, include the following: 100 parts polysiloxane resin, 5-15 parts aminosilane coupling agent, 20-40 parts mica iron oxide, 1-5 parts additives, 10-30 parts solvent, 3-10 parts biomimetic mineralization enhancer, and 1-5 parts additives. The biomimetic mineralization enhancer is prepared by the following method: S1: Mix nano-diatomite powder with deionized water at a solid-liquid ratio of 1:(8-12), stir and react to obtain the first suspension; S2: Heat the first suspension to 55-65℃, add dopamine hydrochloride to the first suspension, add 1-2 drops of 0.1mol / L tris(hydroxymethyl)aminomethane buffer, adjust the pH to 8.5, and continue the reaction for 12 hours to obtain a mixture, wherein the mass of dopamine hydrochloride is 1-3% of the mass of the first suspension; S3: Centrifuge the mixture to obtain a precipitate. Wash the precipitate three times each with deionized water and ethanol. Dry the washed precipitate under vacuum at 55-65℃ to obtain the intermediate product. S4: Disperse the intermediate product in an ethanol solution, add tetraethyl orthosilicate and ammonia, and stir the reaction at 35-45℃ for 5.5-6.5h. After the reaction is completed, centrifuge, wash and dry the product obtained to obtain the biomimetic mineralization enhancer. The additive is prepared by the following method: an ethanol dispersion of silver nanowires is mixed with N,N-dimethylformamide solvent at a mass ratio of 1:1, and ultrasonically treated for 30 min to obtain a second dispersion. Polyvinylidene fluoride powder is added to the second dispersion, and the mixture is stirred in a water bath at 55-65℃ for 3.5-4.5 h to obtain a third mixture. The third mixture is spun using an electrospinning device, and then dried in a vacuum oven at 76-85℃ for 12 h. After drying, the mixture is pulverized to obtain the additive.

2. The nano-modified polysiloxane heavy-duty anti-corrosion coating according to claim 1, characterized in that, The nano-diatomaceous earth powder is prepared by the following method: Diatomaceous earth is added to a 10% hydrochloric acid solution and acid-washed at 75-85℃ for 1.5-2.5h. The acid-washed diatomaceous earth is washed with deionized water until neutral and filtered to obtain a filter cake. The filter cake is dried at 90-110℃ to constant weight to obtain purified diatomaceous earth. The purified diatomaceous earth and zirconia grinding balls are placed in a planetary ball mill at a mass ratio of 1:(8-12) and ball-milled at 200-400rpm for 5.5-6.5h. After ball milling, the powder is passed through an 800-mesh sieve to obtain nano-diatomaceous earth powder. The mass ratio of diatomaceous earth to hydrochloric acid solution is 1:(3-4).

3. The nano-modified polysiloxane heavy-duty anti-corrosion coating according to claim 1, characterized in that, The ethanol dispersion of silver nanowires was prepared by the following method: silver nitrate and ethylene glycol solution were mixed at a mass ratio of (1.2-1.8):100 to obtain a fourth solution. Polyvinylpyrrolidone and sodium chloride were dissolved in the ethylene glycol solution to obtain a fifth solution. The fifth solution was heated to 150-170℃, and the fourth solution was added dropwise to the fifth solution within 5 minutes under magnetic stirring. The reaction was continued at 150-170℃ for 0.5-1.5 hours to obtain a silver nanowire dispersion. After cooling to room temperature, an equal volume of acetone was added, and centrifugation was performed to obtain a silver nanowire precipitate. The silver nanowire precipitate was washed three times with ethanol solution, and the silver nanowires were redispersed in the ethanol solution to obtain the ethanol dispersion of silver nanowires.

4. The nano-modified polysiloxane heavy-duty anti-corrosion coating according to claim 1, characterized in that, The parameters of the electrospinning device are set as follows: receiving roller speed is 150-250 rpm, spinning voltage is 15 kV, receiving distance is 15 cm, and the mass of the polyvinylidene fluoride powder is 8-12% of the mass of N,N-dimethylformamide solvent.

5. The nano-modified polysiloxane heavy-duty anti-corrosion coating according to claim 3, characterized in that, The mass of the polyvinylpyrrolidone is 3.0-3.5 times the mass of silver nitrate, the mass of sodium chloride is 3.0-3.5% of the mass of silver nitrate, the mass of the ethylene glycol solution used to prepare the fifth solution is 65-75 times the mass of silver nitrate, the concentration of the ethanol solution is above 95%, and the mass ratio of ethanol solution to silver nanowires in the dispersion is 19:

1.

6. The nano-modified polysiloxane heavy-duty anti-corrosion coating according to claim 1, characterized in that, The ethanol solution in S4 has a mass concentration of 40-60%, and the mass of the ethanol solution is 10 times the mass of the intermediate product. The tetraethyl orthosilicate has a mass concentration of 10-20%, and the mass of the tetraethyl orthosilicate is 1.5-2.5 times the mass of the intermediate product. The ammonia solution has a mass concentration of 25-28%, and the mass of the ammonia solution is 30-40% of the mass of the intermediate product.

7. The nano-modified polysiloxane heavy-duty anti-corrosion coating according to claim 1, characterized in that: The additive is silicone oil.

8. The method for preparing the nano-modified polysiloxane heavy-duty anti-corrosion coating according to any one of claims 1-7, characterized in that, Includes the following steps: Step 1: Add polysiloxane resin, aminosilane coupling agent, solvent and additives to a high-speed disperser and disperse at high speed under circulating water cooling. Maintain the material temperature below 40℃ and stir at 450-550 rpm for 10 minutes to obtain the base material. Step 2: Add mica iron oxide, biomimetic mineralization enhancer and additives to the base material, increase the rotation speed to 1000-2000 rpm, and disperse at high speed for 30 minutes to obtain slurry; Step 3: Transfer the slurry to a sand mill and grind it to a fineness of ≤25μm. After grinding, filter and package to obtain the final product.

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