A low surface energy multifunctional lubricating protective coating based on polysilazane and its coating and application

Abstract

The application provides a polysilazane-based low-surface-energy multifunctional lubricating protective coating and a coating and application thereof, and relates to the technical field of protective coatings.The polysilazane-based low-surface-energy multifunctional lubricating protective coating provided by the application comprises the following components in mass percentage: 10-30% of polysilazane, 0.4-4% of long-chain flexible high-molecular compound, 0.1-2% of modified two-dimensional nanosheet, 65-89% of solvent, 0.1-0.5% of defoaming agent, 0.1-0.5% of dispersing agent and 0.1-0.5% of leveling agent; the long-chain flexible high-molecular compound comprises a long-chain flexible high-molecular compound containing silicon and / or fluorine.The coating formed by the coating can effectively prevent biofouling, has good corrosion resistance, and can improve the drag reduction and wear resistance of the surface of the coating, and can be applied to the protection of the surface of a sea-going body, effectively reduces the adhesion of marine organisms, prevents seawater corrosion, reduces the sailing resistance, and improves the surface wear resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of protective coatings, and in particular to a low-surface-energy multifunctional lubricating protective coating based on polysilazane, a coating thereof, and an application thereof. Background Art

[0002] The use of marine resources is often accompanied by biofouling. The growth of fouling organisms on the hull increases surface roughness, leading to increased resistance. Biofouling can also cause coating degradation, increase coating conductivity, and thus increase corrosion. Marine navigational bodies such as ships, warships, and torpedoes play an important role in marine economic development and marine defense. The operating speed and energy consumption rate of navigational bodies are important indicators for evaluating their performance. In addition to being related to engine efficiency, the most important factor affecting the operating speed and energy consumption rate is the resistance of the navigation body in seawater. Therefore, for the development of the global marine industry, it is of great significance to take measures to minimize the impact of marine biofouling and corrosion and reduce navigation resistance.

[0003] In recent years, surface coating technology has shown broad promise as an effective strategy for protecting surfaces from biofouling and corrosion. However, conventional coatings typically offer a single function: antifouling or anticorrosion, with little consideration given to drag reduction. In practical applications, a multilayer composite coating is typically formed by coupling multiple functional coatings. However, this requires addressing compatibility and interfacial bonding issues between the individual coatings, which reduces coating efficiency and increases maintenance costs.

[0004] In order to improve the comprehensive performance of protective technology and ensure the life and stability of the coating, it is necessary to develop a lubricating protective coating that integrates anti-fouling, anti-corrosion and drag reduction functions. Summary of the Invention

[0005] In light of this, the present invention aims to provide a polysilazane-based, low-surface-energy, multifunctional lubricating protective coating, its coating, and its application. The protective coating formed by the polysilazane-based, low-surface-energy, multifunctional lubricating protective coating can effectively prevent biofouling, exhibit excellent corrosion resistance, and enhance the drag-reducing and wear-resistant properties of the coating surface.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a low-surface-energy multifunctional lubricating protective coating based on polysilazane, comprising the following components in percentage by weight: 10-30% polysilazane, 0.4-4% long-chain flexible polymer compound, 0.1-2% modified two-dimensional nanosheets, 65-89% solvent, 0.1-0.5% defoaming agent, 0.1-0.5% dispersant, and 0.1-0.5% leveling agent; the long-chain flexible polymer compound comprises a silicon-containing long-chain flexible polymer compound and / or a fluorine-containing long-chain flexible polymer compound.

[0008] Preferably, the number average molecular weights of the silicon-containing long-chain flexible polymer compound and the fluorine-containing long-chain flexible polymer compound are 1000~3000 respectively; the silicon-containing long-chain flexible polymer compound is a silicone oil containing hydroxyl groups at the end group or the side chain, and the fluorine-containing long-chain flexible polymer compound is a fluorine-containing polyether polyol.

[0009] Preferably, the silicon-containing long-chain flexible polymer compound includes one or more of hydroxy silicone oil, polydiethylsiloxane, polymethylphenylsiloxane and terminal hydroxy fluorosilicone oil, and the fluorine-containing long-chain flexible polymer compound includes one or more of perfluoropolyether alcohol, fluorine-containing polyether diol and perfluoropolyether diol.

[0010] Preferably, the hydroxy silicone oil includes one or more of dimethyl hydroxy silicone oil, hydroxyl-terminated polysiloxane and hydroxypropyl silicone oil.

[0011] Preferably, the polysilazane includes organic polysilazane and / or inorganic polysilazane.

[0012] Preferably, the modified two-dimensional nanosheets are two-dimensional nanosheets modified by a silane coupling agent, and the two-dimensional nanosheets are one or more of graphene oxide, hexagonal boron nitride nanosheets, Mxene nanosheets, single-layer montmorillonite and flaky magnesium hydroxysulfate.

[0013] The present invention provides a method for preparing a low surface energy multifunctional lubricating protective coating based on polysilazane as described in the above technical solution, comprising the following steps:

[0014] mixing the long-chain flexible polymer compound with polysilazane to obtain a long-chain flexible polymer-modified polysilazane solution;

[0015] The long-chain flexible polymer-modified polysilazane solution is mixed with modified two-dimensional nanosheets, a solvent, a defoamer, a dispersant, and a leveling agent to obtain the polysilazane-based low-surface-energy multifunctional lubricating protective coating.

[0016] The present invention provides a polysilazane-based low-surface-energy multifunctional lubricating protective coating, which is obtained by coating the polysilazane-based low-surface-energy multifunctional lubricating protective coating described in the above technical solution or the polysilazane-based low-surface-energy multifunctional lubricating protective coating obtained by the preparation method described in the above technical solution onto the surface of a substrate and curing the coating.

[0017] Preferably, the coating thickness is 15-40 μm; the curing temperature is room temperature, and the curing time is 3-7 days.

[0018] The present invention provides the use of the low surface energy multifunctional lubricating protective coating based on polysilazane described in the above technical solution in the surface protection of marine navigation bodies.

[0019] The present invention provides a low-surface-energy multifunctional lubricating protective coating based on polysilazane, comprising the following components in percentage by weight: 10-30% polysilazane, 0.4-4% long-chain flexible polymer compound, 0.1-2% modified two-dimensional nanosheets, 65-89% solvent, 0.1-0.5% defoaming agent, 0.1-0.5% dispersant, and 0.1-0.5% leveling agent; the long-chain flexible polymer compound comprises a silicon-containing long-chain flexible polymer compound and / or a fluorine-containing long-chain flexible polymer compound. The present invention uses polysilazane with Si-NH-Si bond as repeating unit as the main structural body. Polysilazane is rich in Si-N-Si bond, easily combines with -OH on the surface of the substrate, and can form Si-O-Si, Si-O-Cr, Si-O-Fe covalent structures with metal atoms such as Cr and Fe, thereby having strong bonding strength with the metal substrate; the present invention introduces long-chain flexible polymer compounds containing silicon and / or fluorine to modify polysilazane. The long-chain flexible polymer has liquid-like properties, which can significantly reduce the surface energy of the polysilazane coating, improve the surface smoothness, improve the toughness of the polysilazane, and give the coating drag reduction, anti-fouling and anti-corrosion functions; in addition, the present invention adds modified two-dimensional nanosheets to the coating to further improve the corrosion resistance and wear resistance of the coating. The coating formed by the low surface energy multifunctional lubricating protective coating provided by the present invention can be used for the protection of the surface of marine navigation bodies such as ships and underwater vehicles, and can effectively reduce the attachment of marine organisms, prevent seawater corrosion, reduce navigation resistance, and improve surface wear resistance. DETAILED DESCRIPTION

[0020] The present invention provides a low-surface-energy multifunctional lubricating protective coating based on polysilazane, comprising the following components in percentage by weight: 10-30% polysilazane, 0.4-4% long-chain flexible polymer compound, 0.1-2% modified two-dimensional nanosheets, 65-89% solvent, 0.1-0.5% defoaming agent, 0.1-0.5% dispersant, and 0.1-0.5% leveling agent; the long-chain flexible polymer compound comprises a silicon-containing long-chain flexible polymer compound and / or a fluorine-containing long-chain flexible polymer compound.

[0021] In the present invention, unless otherwise specified, the raw materials involved are commercially available products well known to those skilled in the art.

[0022] The polysilazane-based low-surface-energy multifunctional lubricating protective coating provided herein comprises, by weight percentage, 10-30% polysilazane, preferably 10-15%, and more preferably 10-11%. In the present invention, the polysilazane preferably comprises an organopolysilazane and / or an inorganic polysilazane (i.e., perhydropolysilazane), wherein the side chains of the organopolysilazane are organic groups such as methyl or ethylene. The organopolysilazane is preferably an organopolysilazane modeled IOTA-OPSZ-9150, produced by Anhui Iota Silicone Oil Co., Ltd., and the inorganic polysilazane is preferably an inorganic polysilazane modeled IOTA-PHPS, produced by Anhui Iota Silicone Oil Co., Ltd.

[0023] In terms of mass percentage, the low surface energy multifunctional lubricating protective coating based on polysilazane provided by the present invention includes 0.4~4% of a long-chain flexible polymer compound, and the mass ratio of the long-chain flexible polymer compound to polysilazane is preferably 8~12:100, more preferably 10:100. In the present invention, the long-chain flexible polymer compound includes a silicon-containing long-chain flexible polymer compound and / or a fluorine-containing long-chain flexible polymer compound. In the present invention, when the long-chain flexible polymer compound includes a silicon-containing long-chain flexible polymer compound and a fluorine-containing long-chain flexible polymer compound, the present invention has no special requirements for the ratio of the silicon-containing long-chain flexible polymer compound and the fluorine-containing long-chain flexible polymer compound, and they can be mixed in any proportion. In the present invention, the number of main atoms in the main chain segment of the long-chain flexible polymer compound is preferably more than 12, and the flexibility of the long-chain flexible polymer refers to the freedom of the polymer chain to rotate around a single bond, and internal rotation can lead to changes in the conformation of the polymer chain. In the present invention, the number average molecular weights of the silicon-containing long-chain flexible polymer compound and the fluorine-containing long-chain flexible polymer compound are preferably 1000-3000, more preferably 1000-2000, respectively.

[0024] In the present invention, the silicon-containing long-chain flexible polymer compound is preferably a silicone oil containing a hydroxyl group at the end or a hydroxyl group at the side chain, more preferably one or more of hydroxy silicone oil, polydiethylsiloxane, polymethylphenylsiloxane and terminal hydroxyl fluorosilicone oil, and the hydroxy silicone oil preferably includes one or more of dimethyl hydroxy silicone oil, hydroxyl-terminated polysiloxane and hydroxypropyl silicone oil. In the embodiment of the present invention, the dimethyl hydroxy silicone oil was purchased from Nanjing Bermuda Biotechnology Co., Ltd., CAS: 68554-71-2; the hydroxyl-terminated polysiloxane was purchased from Shenzhen Haisian Company, item number: 30088876, CAS: 102782-86-5; the hydroxypropyl silicone oil was purchased from Maclean, product number: C934546, CAS: 58130-04-4.

[0025] In the present invention, the fluorinated long-chain flexible polymer compound is preferably a fluorinated polyether polyol, more preferably one or more of a perfluoropolyether alcohol, a fluorinated polyether diol, and a perfluoropolyether diol, and further preferably a perfluoropolyether alcohol. In the embodiment of the present invention, the perfluoropolyether alcohol is produced by Changsha Fumeiduo New Materials Co., Ltd. and is model OH-7200.

[0026] The polysilazane-based low-surface-energy multifunctional lubricating protective coating provided by the present invention comprises, by weight percentage, 0.1-2%, preferably 0.1-0.5%, of modified two-dimensional nanosheets. In the present invention, the modified two-dimensional nanosheets are preferably two-dimensional nanosheets modified with a silane coupling agent, and the two-dimensional nanosheets are preferably one or more of graphene oxide, hexagonal boron nitride nanosheets, MXene nanosheets, monolayer montmorillonite, and flaky magnesium hydroxysulfate. In the present invention, the method for preparing the silane coupling agent-modified two-dimensional nanosheets preferably comprises the following steps:

[0027] dispersing the two-dimensional nanosheets in anhydrous ethanol to obtain a two-dimensional nanosheet dispersion;

[0028] mixing a silane coupling agent solution with the two-dimensional nanosheet dispersion to perform a modification reaction to obtain a modified solution;

[0029] The modified liquid is filtered, solid phase washed and dried in sequence to obtain the silane coupling agent modified two-dimensional nanosheets.

[0030] In the present invention, the ratio of the two-dimensional nanosheets to anhydrous ethanol is preferably 1 g:500 mL; the dispersion is preferably ultrasonic dispersion, and the ultrasonic dispersion time is preferably 20 minutes. In the present invention, the silane coupling agent solution is specifically an ethanol solution of a silane coupling agent, the mass concentration of the silane coupling agent in the silane coupling agent solution is preferably 4%, and the silane coupling agent is preferably hexadecyltrimethoxysilane, octadecyltrimethoxysilane, or vinyltriethoxysilane; the ratio of the two-dimensional nanosheets to the silane coupling agent solution is preferably 1 g:30 mL. In the present invention, the modification reaction time is preferably 2-4 hours, and the modification reaction is preferably carried out under stirring. In the present invention, the filtration is preferably performed using filter paper; the washing agent for the solid phase washing is preferably ethanol, and the number of washes is preferably three or more, to remove excess silane coupling agent. In the present invention, the drying temperature is preferably 80°C, and the drying time is preferably 4 hours, and the ethanol is completely evaporated during the drying process. The present invention modifies the two-dimensional nanosheets by using a silane coupling agent, which is beneficial to the uniform dispersion of the two-dimensional nanosheets in the coating.

[0031] The polysilazane-based low-surface-energy multifunctional lubricating protective coating provided by the present invention comprises 65-89% by mass, preferably 80-88% by mass of a solvent. In the present invention, the solvent is preferably trichlorotrifluoroethane.

[0032] The polysilazane-based low-surface-energy multifunctional lubricating protective coating provided herein includes, by weight percentage, 0.1-0.5%, preferably 0.1-0.3%, of a defoamer. In the present invention, the defoamer is preferably Tech-386N defoamer (produced by Shanghai Tiger Polymer Technology Co., Ltd.).

[0033] The polysilazane-based low-surface-energy multifunctional lubricating protective coating provided herein comprises, by weight percentage, 0.1-0.5% dispersant, preferably 0.1-0.3%. In the present invention, the dispersant is preferably Tech-5063 wetting and dispersing agent (produced by Shanghai Tiger Polymer Technology Co., Ltd.).

[0034] The polysilazane-based low-surface-energy multifunctional lubricating protective coating provided herein includes, by weight percentage, 0.1-0.5%, preferably 0.1-0.3%, of a leveling agent. In the present invention, the leveling agent is preferably Tech-2733 leveling agent (produced by Shanghai Tiger Polymer Technology Co., Ltd.).

[0035] The present invention provides a method for preparing a low surface energy multifunctional lubricating protective coating based on polysilazane as described in the above technical solution, comprising the following steps:

[0036] Mixing the long-chain flexible polymer compound with polysilazane (referred to as the first mixing) to obtain a long-chain flexible polymer-modified polysilazane solution;

[0037] The long-chain flexible polymer-modified polysilazane solution is mixed with modified two-dimensional nanosheets, a solvent, a defoamer, a dispersant, and a leveling agent (referred to as the second mixing) to obtain the polysilazane-based low-surface-energy multifunctional lubricating protective coating.

[0038] In the present invention, the first mixing and the second mixing are preferably carried out under stirring, and the stirring speed is preferably 600r / min. The present invention has no special requirements for the time of the first mixing, as long as the long-chain flexible polymer compound and the polysilazane are evenly mixed. During the first mixing process, the long-chain flexible polymer compound and the polysilazane undergo alcoholysis reaction. The present invention preferably adds the modified two-dimensional nanosheet, solvent, defoamer, dispersant and leveling agent to the long-chain flexible polymer-modified polysilazane solution under stirring. In the present invention, the time of the second mixing is preferably 10min, and the time of the second mixing is calculated from the completion of the addition of the two-dimensional nanosheet, solvent, defoamer, dispersant and leveling agent.

[0039] The present invention provides a polysilazane-based low-surface-energy multifunctional lubricating protective coating, which is obtained by coating the polysilazane-based low-surface-energy multifunctional lubricating protective coating described in the above technical solution or the polysilazane-based low-surface-energy multifunctional lubricating protective coating obtained by the preparation method described in the above technical solution onto the surface of a substrate and curing the coating.

[0040] The present invention has no particular requirements for the substrate; any substrate familiar to those skilled in the art can be used. In the embodiments of the present invention, the substrate is a carbon steel substrate (Q235 carbon steel). In the present invention, the substrate is preferably sandblasted before coating, and the surface roughness of the substrate after sandblasting is preferably 1-3 μm. In the present invention, the coating method is preferably spraying, and the coating thickness is preferably 15-40 μm. In the present invention, the curing temperature is preferably room temperature, and the curing time is preferably 3-7 days. In the present invention, curing is preferably performed after the coating has dried to the touch.

[0041] The present invention mainly uses polysilazane with Si-NH-Si bond as repeating unit as the main structural body, utilizes Si-NH-Si bond to combine with -OH on the surface of the substrate, and forms covalent structures such as Si-O-Si, Si-O-Cr, and Si-O-Fe with metal atoms Cr and Fe, thereby having good bonding with the substrate. The present invention introduces long-chain flexible polymers containing silicon and fluorine, taking perfluoropolyether alcohol as an example: improving the flexibility of polysilazane, increasing the mechanical matching performance between the coating and the substrate, reducing the cohesive force of the coating, and thus greatly increasing the bonding strength between the substrate and the coating; and perfluoropolyether alcohol has a high fluorine content. During the curing process, the fluorocarbon segments of the perfluoropolyether alcohol have a tendency to migrate and enrich toward the surface of the coating, and will be arranged and distributed toward the outside of the coating surface, greatly reducing the surface energy of the coating and weakening the interaction force between the object and the coating surface, thereby improving the lubrication and drag reduction performance and reducing the adhesion of organisms to the coating surface. The addition of modified two-dimensional nanosheets further enhances the coating's corrosion resistance. The addition of the two-dimensional nanosheets not only blocks the entry of corrosive substances into the coating but also prolongs the path for corrosive ions to enter the substrate. The complementary advantages of each component ensure that the coating exhibits excellent antifouling, drag reduction, and corrosion resistance even at a relatively thin thickness, while also providing good mechanical compatibility between the coating and the substrate.

[0042] In the present invention, the polysilazane-based low-surface-energy multifunctional lubricating protective coating is formed by an organic polysilazane modified with a silicon-containing or fluorine-containing long-chain flexible polymer. Several typical chemical structures of the film-forming material are shown in Formulas I to III, wherein Formula I is the chemical structure of a film-forming material formed by modifying a polysilazane with dimethylhydroxy silicone oil as a long-chain flexible polymer compound, Formula II is the chemical structure of a film-forming material formed by modifying a polysilazane with perfluoropolyether alcohol as a long-chain flexible polymer compound, and Formula III is the chemical structure of a film-forming material formed by modifying a polysilazane with a mixture of perfluoropolyether alcohol and dimethylhydroxy silicone oil as a long-chain flexible polymer compound.

[0043] Formula I, Formula II,

[0044] Formula III.

[0045] The present invention provides the use of the polysilazane-based low-surface-energy, multifunctional lubricating protective coating described in the above technical solution for surface protection of marine vessels. The low-surface-energy, multifunctional lubricating coating provided by the present invention can be applied to marine vessels, such as ships, underwater vehicles, underwater sensors, marine aquaculture equipment, and other infrastructure, effectively preventing biofouling, seawater erosion, increased navigation energy consumption, and coating wear, offering broad application prospects.

[0046] To further illustrate the present invention, the polysilazane-based low surface energy multifunctional lubricating protective coating, its coating, and its application provided by the present invention are described in detail below with reference to examples. However, these examples should not be construed as limiting the scope of protection of the present invention.

[0047] The sources of raw materials in the embodiment are as follows:

[0048] Organopolysilazane: produced by Anhui IOTA Silicone Oil Co., Ltd., model number IOTA-OPSZ-9150;

[0049] Inorganic polysilazane: produced by Anhui IOTA Silicone Oil Co., Ltd., model number is IOTA-PHPS;

[0050] Dimethylhydroxysilicone oil: purchased from Nanjing Bermuda Biotechnology Co., Ltd., CAS: 68554-71-2;

[0051] Hydroxyl-terminated polysiloxane: purchased from Shenzhen Haisian Company, product number: 30088876, CAS: 102782-86-5;

[0052] Hydroxypropyl silicone oil: purchased from Maclean, product number: C934546, CAS: 58130-04-4;

[0053] Perfluoropolyether alcohol: produced by Changsha Fumeiduo New Materials Co., Ltd., model OH-7200;

[0054] Tech-386N defoamer, Tech-5063 wetting and dispersing agent, and Tech-2733 leveling agent: produced by Shanghai Tiger Polymer Technology Co., Ltd.

[0055] Example 1

[0056] 1g of graphene oxide was dispersed in 500mL of anhydrous ethanol and ultrasonically dispersed for 20 minutes; then 98wt% of hexadecyltrimethoxysilane was diluted with ethanol to 4wt%, mixed with the ultrasonically dispersed graphene oxide, 1g of graphene oxide corresponding to 30mL of the diluted solution, and reacted under stirring for 2h; after the reaction, the mixed solution was filtered with filter paper and washed with ethanol for more than 3 times to wash away excess hexadecyltrimethoxysilane; the filtered graphene was dried in an 80°C oven for 4h until the ethanol was completely evaporated to obtain modified graphene oxide.

[0057] 1.0 g of perfluoropolyether alcohol and 10 g of organopolysilazane were mixed and stirred at 600 r / min to obtain a mixed solution; 80 g of trichlorotrifluoroethane was added to the above mixed solution while stirring, and then 0.1 g of Tech-5063 wetting and dispersing agent, 0.1 g of Tech-2733 leveling agent, 0.1 g of Tech-386N defoaming agent and 0.1 g of modified graphene oxide were added, and stirring was continued for 10 minutes to obtain a low surface energy multifunctional lubricating coating based on polysilazane.

[0058] The metal substrate (Q235 carbon steel) was sandblasted to achieve a surface roughness of 2.4 μm. The low surface energy multifunctional lubricating coating was sprayed on the surface of the metal substrate and cured at room temperature for 3 days to obtain a low surface energy multifunctional lubricating coating.

[0059] Example 2

[0060] The modified hexagonal boron nitride nanosheets were prepared by using the method for preparing modified graphene oxide in Example 1, except that the graphene oxide was replaced by hexagonal boron nitride nanosheets.

[0061] 1.0 g of perfluoropolyether alcohol and 10 g of organopolysilazane were mixed and uniformly stirred at 600 r / min to obtain a mixed solution; 80 g of trichlorotrifluoroethane was added to the above mixed solution while stirring, and then 0.1 g of Tech-5063 wetting and dispersing agent, 0.1 g of Tech-2733 leveling agent, 0.1 g of Tech-386N defoaming agent and 0.1 g of modified hexagonal boron nitride nanosheets were added, and stirring was continued for 10 minutes to obtain a low surface energy multifunctional lubricating coating based on polysilazane.

[0062] The metal substrate (Q235 carbon steel) was sandblasted to achieve a surface roughness of 1.8 μm. The low surface energy multifunctional lubricating coating was sprayed on the surface of the metal substrate and cured at room temperature for 3 days to obtain a low surface energy multifunctional lubricating coating.

[0063] Example 3

[0064] The modified graphene oxide is the same as that in Example 1.

[0065] 0.6 g of perfluoropolyether alcohol, 0.6 g of dimethylhydroxysilicone oil and 10 g of organopolysilazane were mixed and uniformly stirred at 600 r / min to obtain a mixed solution; 80 g of solvent trichlorotrifluoroethane was added to the above mixed solution while stirring, and then 0.1 g of Tech-5063 wetting and dispersing agent, 0.2 g of Tech-2733 leveling agent, 0.2 g of Tech-386N defoaming agent and 0.1 g of modified graphene oxide were added, and stirring was continued for 10 minutes to obtain a low surface energy multifunctional lubricating coating based on polysilazane.

[0066] The metal substrate (Q235 carbon steel) was sandblasted to achieve a surface roughness of 2.1 μm. The low surface energy multifunctional lubricating coating was sprayed on the surface of the metal substrate and cured at room temperature for 3 days to obtain a low surface energy multifunctional lubricating coating.

[0067] Example 4

[0068] The modified hexagonal boron nitride nanosheets are the same as those in Example 2.

[0069] 0.6 g of perfluoropolyether alcohol, 0.6 g of dimethylhydroxysilicone oil and 10 g of organopolysilazane were mixed and uniformly stirred at 600 r / min to obtain a mixed solution; 80 g of trichlorotrifluoroethane was added to the above mixed solution while stirring, and then 0.2 g of Tech-5063 wetting and dispersing agent, 0.1 g of Tech-2733 leveling agent, 0.1 g of Tech-386N defoaming agent and 0.1 g of modified hexagonal boron nitride nanosheets were added, and stirring was continued for 10 minutes to obtain a low surface energy multifunctional lubricating coating based on polysilazane.

[0070] The metal substrate (Q235 carbon steel) was sandblasted to achieve a surface roughness of 1.3 μm. The low surface energy multifunctional lubricating coating was sprayed on the surface of the metal substrate and cured at room temperature for 3 days to obtain a low surface energy multifunctional lubricating coating.

[0071] Example 5

[0072] The modified graphene oxide is the same as that in Example 1.

[0073] 1.2g of perfluoropolyether alcohol and 10g of organopolysilazane were mixed and stirred uniformly at 600 rpm to obtain a mixed solution. 80g of trichlorotrifluoroethane was added to the mixed solution while stirring. Furthermore, 0.1g of Tech-5063 wetting and dispersing agent, 0.1g of Tech-2733 leveling agent, 0.1g of Tech-386N defoaming agent, and 0.3g of modified graphene oxide were added. Stirring was continued for 10 minutes to obtain a low-surface-energy, multifunctional lubricating coating based on polysilazane.

[0074] The metal substrate (Q235 carbon steel) was sandblasted to achieve a surface roughness of 2.1 μm. The low surface energy multifunctional lubricating coating was sprayed on the surface of the metal substrate and cured at room temperature for 3 days to obtain a low surface energy multifunctional lubricating coating.

[0075] Example 6

[0076] The modified graphene oxide is the same as that in Example 1.

[0077] 1.2g of perfluoropolyether alcohol and 10g of inorganic polysilazane were mixed and stirred uniformly at 600 rpm to obtain a mixed solution. To this mixed solution, 80g of trichlorotrifluoroethane solvent was added while stirring. Furthermore, 0.1g of Tech-5063 wetting and dispersing agent, 0.1g of Tech-2733 leveling agent, 0.1g of Tech-386N defoaming agent, and 0.1g of modified graphene oxide were added. Stirring was continued for 10 minutes to obtain a low-surface-energy, multifunctional lubricating coating based on polysilazane.

[0078] The metal substrate (Q235 carbon steel) was sandblasted to achieve a surface roughness of 1.7 μm. The low surface energy multifunctional lubricating coating was sprayed on the surface of the metal substrate and cured at room temperature for 3 days to obtain a low surface energy multifunctional lubricating coating.

[0079] The coatings obtained in Examples 1 to 6 were subjected to performance tests, and the coating performance test standards were as follows:

[0080] Thickness test: Refer to GB1764-79 (89) and use a thickness gauge to test the coating thickness.

[0081] Adhesion performance test: Refer to GB / T 9286-2020 and use the cross-cut test method to test the adhesion.

[0082] Hardness test: Refer to ISO15184-2012 and use pencil hardness to test the coating hardness.

[0083] Contact angle measurement and surface energy calculation: The static water contact angle (WCA) of the modified coating was measured using a DSA-100 optical contact angle meter (Kruss company, Ltd., Germany) by dropping 3 μL of deionized water at room temperature. The surface energy of each sample was calculated using the contact angles of deionized water and diiodomethane according to the Owens-Wendt-Rabel-Kaelble method ( The average contact angle of each sample was calculated based on three data points measured for each sample.

[0084] Anti-corrosion performance test: Neutral salt spray test was carried out on bare carbon steel and coating according to the specification of GB / T 10125-2012.

[0085] Antifouling performance test: algae liquid concentration 1.5×10 6 / mL, three pieces of the same size (1cm 2) coatings were placed in sterilized glassware, and a fixed amount of algae solution (5 mL) was added. The samples were incubated statically at room temperature under a light intensity of 2000 lux for 24 hours. Artificial seawater was prepared according to ASTM D1141-98 (2013). The number of adherent organisms was determined under a 20x fluorescence microscope, and the number of fouling organisms on the sample surfaces was calculated using Image J software.

[0086] Wear rate test: After the friction test (friction test conditions are load: 5N, frequency: 1Hz, time: 10min), the wear amount is measured using a surface profiler, and the wear rate is then calculated using the following formula:

[0087] ,

[0088] In the formula is the wear volume change, mm 3 ; S is the stroke, m; P is the load size, N.

[0089] Drag reduction rate test: The drag reduction rate of the coating surface was measured using a rheometer. The test solution was a mixture of glycerol and water with a mixing mass ratio of 1:1. The drag reduction rate at a speed of 200 r / min was then calculated using the following drag reduction rate formula:

[0090] ,

[0091] Where, is the shear stress of the blank sample, is the sample shear stress, is the drag reduction rate.

[0092] The coating test results are shown in Table 1:

[0093] Table 1 Performance parameters of coatings obtained in Examples 1 to 6

[0094]

[0095] As can be seen from Table 1, the coating formed by the low surface energy multifunctional coating based on modified polysilazane according to the present invention has excellent antifouling, anticorrosion, drag reduction and wear resistance properties.

[0096] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation thereto. It should be noted that those skilled in the art may make various improvements and modifications without departing from the principles of the present invention, and such improvements and modifications shall also be considered within the scope of protection of the present invention.

Claims

1. A low surface energy multifunctional lubricating protective coating based on polysilazane, characterized in that: The invention is composed of the following components in percentage by weight: 10-30% polysilazane, 0.4-4% long-chain flexible polymer compound, 0.1-2% modified two-dimensional nanosheets, 65-89% solvent, 0.1-0.5% defoamer, 0.1-0.5% dispersant, and 0.1-0.5% leveling agent; the long-chain flexible polymer compound is a silicon-containing long-chain flexible polymer compound and a fluorine-containing long-chain flexible polymer compound; The polysilazane is an organopolysilazane; The silicon-containing long-chain flexible polymer compound is dimethylhydroxy silicone oil, and the fluorine-containing long-chain flexible polymer compound is perfluoropolyether alcohol; The modified two-dimensional nanosheets are two-dimensional nanosheets modified by a silane coupling agent, and the two-dimensional nanosheets are one or more of graphene oxide and hexagonal boron nitride nanosheets; The method for preparing the polysilazane-based low-surface-energy multifunctional lubricating protective coating comprises the following steps: mixing the long-chain flexible polymer compound with polysilazane to obtain a long-chain flexible polymer-modified polysilazane solution; The long-chain flexible polymer-modified polysilazane solution is mixed with modified two-dimensional nanosheets, a solvent, a defoamer, a dispersant, and a leveling agent to obtain the polysilazane-based low-surface-energy multifunctional lubricating protective coating.

2. The coating according to claim 1, characterized in that The number average molecular weights of the silicon-containing long-chain flexible polymer compound and the fluorine-containing long-chain flexible polymer compound are respectively 1000-3000.

3. The method for preparing the low surface energy multifunctional lubricating protective coating based on polysilazane according to claim 1 or 2, characterized in that: The following steps are involved: mixing the long-chain flexible polymer compound with polysilazane to obtain a long-chain flexible polymer-modified polysilazane solution; The long-chain flexible polymer-modified polysilazane solution is mixed with modified two-dimensional nanosheets, a solvent, a defoamer, a dispersant, and a leveling agent to obtain the polysilazane-based low-surface-energy multifunctional lubricating protective coating.

4. A low surface energy multifunctional lubricating protective coating based on polysilazane, characterized in that: The low surface energy multifunctional lubricating protective coating based on polysilazane according to claim 1 or 2 or the low surface energy multifunctional lubricating protective coating based on polysilazane obtained by the preparation method according to claim 3 is applied to the surface of a substrate and cured.

5. The coating according to claim 4, characterized in that The coating thickness is 15-40 μm; the curing temperature is room temperature, and the curing time is 3-7 days.

6. Use of the low surface energy multifunctional lubricating protective coating based on polysilazane according to claim 4 or 5 in the surface protection of marine navigation bodies.

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