A core-shell structure composite material, its preparation method and application, a resin-based composite lubricating coating and coating

Abstract

The present invention belongs to the technical field of lubricating coatings, and specifically relates to a core-shell structure composite material, a preparation method and application thereof, and a resin-based composite lubricating coating and coating. The core-shell structure composite material provided by the present invention includes a spherical flower-shaped MoS2 core; a polymer intermediate modification layer coated on its surface, the material forming the polymer intermediate modification layer contains hydroxyl groups; and a cage-type silsesquioxane shell layer chemically modified on the surface of the polymer intermediate modification layer. As a lubricating filler, the core-shell structure composite material provided by the present invention shows good dispersibility and high hardness in the resin matrix, and can effectively alleviate the oxidation phenomenon of MoS2 in the MoS2 / resin coating under high humidity conditions (80±2%); compared with MoS2 / epoxy coating, the resin composite lubricating coating obtained after adding the core-shell structure composite material provided by the present invention can effectively reduce the friction coefficient and wear rate under a humid environment.

Description

Technical Field

[0001] The present invention belongs to the technical field of lubricating coatings, and in particular relates to a core-shell structure composite material, a preparation method and application thereof, and a resin-based composite lubricating coating and coating. Background Art

[0002] In complex service environments, lubrication failure of materials can easily lead to serious damage to the lubricating coating, shortening the service life of key components. Therefore, high requirements are placed on the long-term and stable lubrication of lubricating coatings applicable to various equipment.

[0003] Studies have shown that most solid lubricants are selective for working conditions and environments, that is, they only play a lubricating role within a certain operating range. Among them, molybdenum disulfide (MoS2) has been widely used in various fields as a lubricating and protective material due to its low friction coefficient, high hardness, and high wear resistance. Recently, researchers have obtained various forms of MoS2 nanomaterials, such as nanosheets, micro / nanospheres, micro / nanospheres, and nanowires, through a hydrothermal method. Friction tests have confirmed that the tribological properties of MoS2 nanospheres are far superior to those of traditional layered MoS2 materials. The reason is the excellent chemical stability given by the layered closed spherical structure of the nanosphere MoS2. This apparently closed structure of MoS2 (such as spherical or tubular) not only has the chemical structure and physical properties of traditional MoS2, but also under large loads, the spherical MoS2 is prone to rolling, elastic deformation, and shell peeling at the friction interface, which significantly improves its wear resistance and lubrication performance.

[0004] Although MoS2 can maintain a low friction coefficient and wear rate under vacuum / inert gas conditions, its structural defects, moisture and oxygen intrusion produce hard oxides that act as abrasive phases, increasing friction resistance and seriously hindering its practical application in atmospheric humidity environments. Summary of the Invention

[0005] The purpose of the present invention is to provide a core-shell structure composite material, a preparation method and application thereof, a resin-based composite lubricating coating and a coating. The core-shell structure composite material provided by the present invention exhibits good dispersibility and high hardness in the resin matrix as a lubricating filler, and can effectively alleviate the oxidation phenomenon of MoS2 in the MoS2 / resin coating under high humidity conditions; compared with the MoS2 / epoxy coating obtained by direct mixing, the resin composite lubricating coating obtained after adding the core-shell structure composite material provided by the present invention can effectively reduce the friction coefficient and wear rate under a humid environment.

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

[0007] The present invention provides a core-shell structure composite material, comprising a spherical flower-shaped MoS2 core; a polymer intermediate modification layer coated on the surface of the core, wherein the material forming the polymer intermediate modification layer contains hydroxyl groups; and a cage-type silsesquioxane shell layer chemically modified on the surface of the polymer intermediate modification layer.

[0008] Preferably, the material forming the polymer intermediate modified layer includes one or more of polydopamine, polyethylene glycol and polyvinyl alcohol.

[0009] Preferably, the weight average molecular weight of the polyethylene glycol is 20,000; the weight average molecular weight of the polyvinyl alcohol is 10,000 to 26,000.

[0010] Preferably, the particle size of the spherical flower-shaped MoS2 core is 180-190 nm.

[0011] Preferably, the thickness of the polymer intermediate modified layer is 45 to 55 nm.

[0012] The present invention provides a method for preparing the core-shell structure composite material described in the above technical solution, comprising the following steps:

[0013] The surface of the spherical flower-shaped MoS2 is coated with a polymer layer to obtain an intermediate product; the intermediate product includes a spherical flower-shaped MoS2 core and a polymer intermediate modified layer coated on the surface thereof;

[0014] The alkaline dispersion of the intermediate product and amino-type cage-type silsesquioxane are mixed to carry out Michael addition and Schiff base reaction to obtain the core-shell structure composite material.

[0015] The present invention provides the use of the core-shell structure composite material described in the above technical solution or the core-shell structure composite material prepared by the preparation method described in the above technical solution as a lubricating filler.

[0016] The present invention provides a resin-based composite lubricating coating, comprising independently packaged resin components and a curing agent, wherein the resin components include a resin matrix and a lubricating filler; the lubricating filler includes the core-shell structure composite material described in the above technical solution or the core-shell structure composite material prepared by the preparation method described in the above technical solution.

[0017] Preferably, the resin matrix is a water-based epoxy resin, and the mass of the lubricating filler accounts for 1 to 4% of the mass of the resin matrix.

[0018] The present invention provides a resin-based composite lubricating coating, which is obtained by forming a film of the resin-based composite lubricating coating on the surface of a metal substrate and then curing it; the resin-based composite lubricating coating is the resin-based composite lubricating coating described in the above technical solution.

[0019] The present invention provides a core-shell structure composite material (denoted as m-MoS2@POSS), comprising a spherical flower-shaped MoS2 core; a polymer intermediate modification layer coated on the surface thereof, wherein the material forming the polymer intermediate modification layer contains hydroxyl groups; and a cage-type silsesquioxane shell layer chemically modified on the surface of the polymer intermediate modification layer. The present invention first coats the surface of the spherical flower-shaped MoS2 core with a polymer intermediate modification layer, and provides chemical reaction active sites through the hydroxyl groups contained in the polymer intermediate modification layer, thereby forming a cage-type silsesquioxane shell layer on the surface of the polymer intermediate modification layer through chemical modification. Cage-type silsesquioxane (POSS) is an organic-inorganic hybrid core-shell structure material with a silicon core. The core-shell structure composite material obtained by forming the cage-type silsesquioxane shell layer has good environmental stability, and has good stability under both humidity and oxygen conditions. In summary, the core-shell structure composite material provided by the present invention shows good dispersibility and high hardness in the resin matrix, and can effectively alleviate the oxidation phenomenon of MoS2 in the MoS2 / resin coating under high humidity conditions (80±2%); compared with the MoS2 / epoxy coating obtained by direct mixing, the resin composite lubricating coating obtained by the core-shell structure composite material provided by the present invention can effectively reduce the friction coefficient and wear rate under a humid environment. The results of the examples show that the m-MoS2@POSS provided by the present invention has good dispersibility and uniformity in the epoxy resin matrix; and improves the interfacial bonding strength of the resin-based composite lubricating coating, and the deformation resistance of the resin-based composite lubricating coating is significantly improved. The Shore hardness value of the resin-based composite lubricating coating formed by m-MoS2@POSS is also significantly improved. Meanwhile, the present invention uses ball-on-disc reciprocating friction and wear tester to carry out macroscopic tribological performance test to resin-based composite lubricating coating: adopt stainless steel small ball with diameter of 6mm as friction pair, external load is 10N, reciprocating speed is 2Hz, each group of data is tested independently three times, to ensure the true feasibility of data, test is carried out respectively under the environment of room temperature being 25±2 ℃, relative humidity is 25±2% and 80±2%, under the ambient humidity of RH~25%, the friction coefficient of resin-based composite lubricating coating formed by m-MoS2@POSS is low, under humid environment (RH~80%), the friction coefficient of resin-based composite lubricating coating formed by m-MoS2@POSS is always stable at below 0.25. Explanation: the resin-based composite lubricating coating formed by m-MoS2@POSS can well improve the problem of lubrication failure of single MoS2 under humidity environment, and has good stability under humidity environment simultaneously. Thus, m-MoS2@POSS provided by the present invention plays an important role in improving the tribological performance of the transfer film of friction interface. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1Transmission electron microscopy (TEM) characterization results of MoS2, MoS2-PDA and m-MoS2@POSS materials prepared in Example 1 of the present invention;

[0021] Figure 2 Infrared spectra of MoS2, MoS2-PDA and m-MoS2@POSS materials prepared in Example 1 of the present invention;

[0022] Figure 3 Microscopic morphology, cross-section and hardness analysis of the pure epoxy coating prepared in Comparative Example 1, the MoS2 / epoxy coating prepared in Comparative Example 2, the MoS2-PDA / epoxy coating prepared in Comparative Example 3 and the m-MoS2@POSS / epoxy coating prepared in Example;

[0023] Figure 4 These are the macro-tribological performance test results of the pure epoxy coating prepared in Comparative Example 1, the MoS2 / epoxy coating prepared in Comparative Example 2, the MoS2-PDA / epoxy coating prepared in Comparative Example 3, and the m-MoS2@POSS / epoxy coating prepared in Example 1. DETAILED DESCRIPTION

[0024] The present invention provides a core-shell structure composite material, comprising a spherical flower-shaped MoS2 core; a polymer intermediate modification layer coated on the surface of the spherical flower-shaped MoS2 core, wherein the material forming the polymer intermediate modification layer contains hydroxyl groups; and a cage-type silsesquioxane shell layer chemically modified on the surface of the polymer intermediate modification layer.

[0025] In the present invention, unless otherwise specified, all preparation raw materials / components are commercially available products well known to those skilled in the art.

[0026] The core-shell structure composite material provided herein comprises a spherical flower-shaped MoS2 core. In the present invention, the spherical flower-shaped MoS2 is assembled from nanosheets. The particle size of the spherical flower-shaped MoS2 core is preferably 180 to 190 nm, more preferably 185 nm. In the present invention, the spherical flower-shaped MoS2 is preferably prepared by a hydrothermal method. In a specific embodiment of the present invention, the preparation method of the spherical flower-shaped MoS2 comprises the following steps: mixing molybdate, thiourea, a surfactant, and water, followed by a hydrothermal reaction to obtain the spherical flower-shaped MoS2. The molybdate is preferably ammonium molybdate. The surfactant comprises a first surfactant and a second surfactant, the first surfactant being preferably ethylene glycol and the second surfactant being preferably polyvinyl pyrrolidone. The water is preferably deionized water. The mass ratio of molybdate to thiourea is preferably 1.12:2.32. The mixing preferably comprises the following steps: mixing the molybdate, the first surfactant, and a portion of the water to obtain a molybdate solution; mixing the thiourea, the second surfactant, and the remaining water to obtain a thiourea solution; and mixing the molybdate solution with the thiourea solution. The amount ratio of the molybdate and the first surfactant is preferably 1.12g:30mL. The mass ratio of the thiourea and the second surfactant is preferably 2.32:0.76. The present invention has no special requirements for the amount of water, as long as the hydrothermal reaction is carried out smoothly. The hydrothermal reaction is carried out in a blast drying oven, the temperature of the hydrothermal reaction is preferably 200°C, and the time is preferably 24 hours. After the hydrothermal reaction is completed, the present invention preferably washes the obtained solid product to obtain the spherical flower-shaped MoS2. The washing is preferably centrifugal washing. The washing preferably includes water washing and ethanol washing in sequence, the water washing is preferably deionized water washing, the number of water washings is preferably 3 to 4 times, and the number of ethanol washings is preferably 3 to 4 times.

[0027] The core-shell structure composite material provided by the present invention includes a polymer intermediate modification layer coated on the surface of the spherical flower-shaped MoS2 core, and the material forming the polymer intermediate modification layer contains a hydroxyl group. In the present invention, the material forming the polymer intermediate modification layer preferably includes one or more of polydopamine (PDA), polyethylene glycol (PEG) and polyvinyl alcohol (PVA). The weight average molecular weight of the polyethylene glycol is preferably 20,000; the weight average molecular weight of the polyvinyl alcohol is preferably 10,000 to 26,000. The thickness of the polymer intermediate modification layer is preferably 45 to 55 nm. The present invention uses a polymer with strong adhesion as the intermediate layer modification, and the above polymer adheres to the surface of the spherical flower-shaped MoS2 core through adhesion.

[0028] The core-shell structure composite material provided by the present invention includes a cage-type silsesquioxane (POSS) shell layer chemically modified on the surface of the polymer intermediate modification layer. The chemical modification connects the polymer intermediate modification layer and the cage-type silsesquioxane shell layer through a chemical bond. The polymer in the polymer intermediate modification layer chemically reacts with an amino-type cage-type silsesquioxane (NH2-POSS) to obtain the cage-type silsesquioxane shell layer.

[0029] The particle size of the core-shell structure composite material provided by the present invention is preferably 240 to 290 nm, specifically preferably 260 nm, 242 nm or 290 nm.

[0030] The present invention provides a method for preparing the core-shell structure composite material described in the above technical solution, comprising the following steps:

[0031] The surface of the spherical flower-shaped MoS2 is coated with a polymer layer to obtain an intermediate product; the intermediate product includes a spherical flower-shaped MoS2 core and a polymer intermediate modified layer coated on the surface thereof;

[0032] The alkaline dispersion of the intermediate product and amino-type cage-type silsesquioxane are mixed to carry out Michael addition and Schiff base reaction to obtain the core-shell structure composite material.

[0033] The present invention coats the surface of a spherical flower-shaped MoS2 with a polymer layer to obtain an intermediate product; the intermediate product includes a spherical flower-shaped MoS2 core and a polymer intermediate modification layer coated on its surface. In the present invention, the specific implementation method of coating the spherical flower-shaped MoS2 surface with a polymer layer is preferably: a spherical flower-shaped MoS2 aqueous dispersion and a polymer layer raw material are mixed for coating. The mass concentration of the spherical flower-shaped MoS2 in the spherical flower-shaped MoS2 aqueous dispersion is preferably 1.5 mg / mL. In the present invention, the polymer layer raw material preferably includes one or more of dopamine, polyethylene glycol (PEG), and polyvinyl alcohol (PVA). In a specific embodiment of the present invention, when the polymer intermediate modification layer is a polydopamine layer, the polymer layer raw material used in the present invention is preferably dopamine, and dopamine reacts to form polydopamine during the coating process to form the polymer intermediate modification layer. In a specific embodiment of the present invention, when the polymer intermediate modification layer is a polyethylene glycol (PEG) layer or a polyvinyl alcohol (PVA) layer, the polymer layer raw material used in the present invention is polyethylene glycol (PEG) or polyvinyl alcohol (PVA).

[0034] In a specific embodiment of the present invention, when the polymer is preferably PDA, the coating raw material also includes Tris base. The mass ratio of spherical flower-shaped MoS2 to the PDA is preferably 75:200. The mass ratio of spherical flower-shaped MoS2 to the Tris base is preferably 0.075:0.121. The mixing preferably includes adding the Tris base to the spherical flower-shaped MoS2 aqueous dispersion, ultrasonically mixing for 10 minutes, and then adding the PDA. The coating is performed at room temperature, in the dark, and for a period of 48 hours.

[0035] In a specific embodiment of the present invention, when the polymer layer raw material is preferably PEG or PVA, the polymer layer raw material is preferably used in the form of an aqueous polymer solution. The mass concentration of PEG in the PEG solution is preferably 5 mg / mL. The mass concentration of PVA in the PVA solution is preferably 5 mg / mL. The mass ratio of the spherical flower-shaped MoS2 to the dopamine is preferably 75:50. The coating temperature is preferably room temperature, and the coating is carried out under stirring, preferably magnetic stirring, for preferably 5 hours.

[0036] After obtaining the intermediate product, the present invention mixes an alkaline dispersion of the intermediate product with an amino-type cage-type silsesquioxane to perform Michael addition and Schiff base reactions to obtain the core-shell composite material. The alkaline dispersion of the intermediate product preferably comprises the intermediate product and a Tris buffer solution, the pH of the Tris buffer solution preferably being 8.5. The mass ratio of the intermediate product to the amino-type cage-type silsesquioxane (NH2-POSS) is preferably 50:(200-1000), specifically preferably 50:200, 50:500, or 50:1000. The amount ratio of the intermediate product to the Tris buffer solution is preferably 50 mg:100 mL. The Michael addition and Schiff base reactions are preferably carried out at room temperature for 20 hours. The Michael addition and Schiff base reactions are carried out under stirring. After the Michael addition and Schiff base reactions, a solid reaction product is obtained. The present invention preferably washes the obtained solid reaction product to obtain the core-shell composite material. The washing is preferably centrifugal washing. The washing preferably includes water washing and ethanol washing in sequence, the water washing is preferably deionized water washing, the number of water washings is preferably 3 times, and the number of ethanol washings is preferably 3 times.

[0037] The present invention provides the use of the core-shell structure composite material described in the above technical solution or the core-shell structure composite material prepared by the preparation method described in the above technical solution as a lubricating filler.

[0038] The present invention provides a resin-based composite lubricating coating, comprising independently packaged resin components and a curing agent, wherein the resin components include a resin matrix and a lubricating filler; the lubricating filler includes the core-shell structure composite material described in the above technical solution or the core-shell structure composite material prepared by the preparation method described in the above technical solution.

[0039] In the present invention, the resin matrix is preferably an epoxy resin, more preferably a water-based epoxy resin, and more preferably an F0704 water-based epoxy resin. The resin curing agent is preferably an epoxy resin curing agent, and more preferably an F0705 water-based epoxy curing agent. The mass ratio of the resin matrix to the resin curing agent is preferably 2:1. The mass percentage of the lubricating filler to the mass of the resin matrix is preferably 1-4%, and more preferably 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, or 4%.

[0040] The present invention provides a mixing method before use of the resin-based composite lubricating coating described in the above technical solution, which preferably includes the following steps: stirring and mixing the resin matrix, resin curing agent and lubricating filler to obtain the resin-based composite lubricating coating; the stirring and mixing temperature is preferably room temperature, and the time is preferably 30 minutes.

[0041] The present invention provides a resin-based composite lubricating coating, which is obtained by forming a film of the resin-based composite lubricating coating on the surface of a metal substrate and then curing it; the resin-based composite lubricating coating is the resin-based composite lubricating coating described in the above technical solution.

[0042] In the present invention, the thickness of the resin-based composite lubricating coating is preferably 0.3 mm to 0.4 mm. The metal substrate is preferably made of Q235 steel sheet. When the metal substrate is preferably 2 cm × 2 cm × 0.1 cm in size, the amount of the resin-based composite lubricating coating used is preferably 5 mL. The film-forming method preferably includes cast film formation, spin coating, or dip coating. The curing temperature is preferably 70°C.

[0043] In order to further illustrate the present invention, the technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0044] In the following examples: Tris base and dopamine were purchased from Sigma-Aldrich (Shanghai) Trading Co., Ltd.; amino-modified POSS was purchased from Changsha Baxi Instrument Co., Ltd.; F0704 water epoxy resin and F0705 water epoxy curing agent were purchased from Shenzhen Yoshida Chemical Co., Ltd.; and homemade deionized water was used.

[0045] The products prepared in the following examples and comparative examples are: MoS2 / epoxy composite coating: a composite coating prepared by adding molybdenum disulfide balls to epoxy resin; m-MoS2 / epoxy composite coating: a composite coating prepared by adding modified molybdenum disulfide (including MoS2-PDA, MoS2-PVA and MoS2-PEG) to epoxy resin; m-MoS2@POSS / epoxy composite coating: a composite coating prepared by adding amino-POSS-coated molybdenum disulfide to epoxy resin.

[0046] Example 1

[0047] Dissolve 1.12g of ammonium molybdate in 30mL of ethylene glycol and 100mL of deionized water and stir for 10 minutes. At the same time, dissolve 2.32g of thiourea and 0.76g of polyvinyl pyrrolidone in 20mL of deionized water and stir for 10 minutes. Mix the two solutions and continue stirring for 30 minutes. Take 30mL of the mixed solution into a 50mL reactor and place it in a blast drying oven at 200℃ for 24 hours. After the reaction is completed, centrifuge and wash with deionized water and ethanol for 3 to 4 times respectively to obtain spherical flower-shaped MoS2. The transmission electron microscopy (TEM) characterization results are as follows: Figure 1 As shown in (a) in .

[0048] 0.121 g of Tris base was added to 50 mL of spherical flower-shaped MoS2 aqueous dispersion (1.5 mg / mL), and 200 mg of dopamine was slowly added after ultrasonication for 10 minutes. The mixture was stirred in the dark at room temperature for 48 hours. After the reaction was completed, the modified m-MoS2 was prepared by centrifugation and washing three times with deionized water and ethanol, and was recorded as MoS2-PDA. The transmission electron microscopy (TEM) characterization results of MoS2-PDA are shown in Figure 2. Figure 1 As shown in (b) in .

[0049] 50 mg of MoS2-PDA was dispersed in 100 mL of Tris buffer at pH 8.5, and 500 mg of NH2-POSS was added thereto. After stirring at room temperature for 20 hours, m-MoS2@POSS-1 was prepared after centrifugal washing three times with deionized water and ethanol. The transmission electron microscopy (TEM) characterization results of m-MoS2@POSS-1 are shown in FIG. Figure 1 As shown in (c) in .

[0050] 0.04 g of m-MoS2@POSS-1 was added to 4.0 g of F0704 water-based epoxy resin and 2.0 g of F0705 water-based epoxy curing agent, where m-MoS2@POSS-1 accounted for 1.0% of the mass of F0704 water-based epoxy resin. After stirring and dispersing for 30 minutes, 5 mL was taken and coated on a Q235 steel sheet (2 cm × 2 cm × 0.1 cm) substrate, and cured in a 70 ° C oven to obtain the m-MoS2@POSS-1 epoxy composite coating.

[0051] Figure 1 These are the transmission electron microscopy (TEM) characterization results of MoS2, MoS2-PDA and m-MoS2@POSS materials prepared in Example 1 of the present invention. Figure 1 (a) is the spherical flower-shaped MoS2 (particle size is ~185nm) assembled from nanosheets prepared in Example 1; Figure 1 (b) is a MoS2-PDA core-shell material with a particle size of ~235nm (shell thickness is about 50nm); the shell edge of the m-MoS2@POSS composite material is clearer, as shown in Figure 2. Figure 1 As shown in (c) in . Figure 1 The transmission electron microscopy characterization results demonstrated the successful preparation of MoS2-PDA core-shell structure and m-MoS2@POSS core-shell-shell composite material.

[0052] Figure 2 The infrared spectrum of the m-MoS2@POSS material prepared in Example 1 of the present invention; Figure 2 As shown in the infrared spectrum of the spherical flower-shaped MoS2 prepared in Example 1, 3430 cm -1 and 1630cm -1 Corresponding to the stretching vibration and bending vibration of OH, respectively, at 905cm -1 The stretching vibration of SS bond appears. In the infrared spectrum of MoS2-PDA, 1267cm -1 and 1720cm -1 The characteristic peaks correspond to the stretching vibrations of the C-O bond and the C=O bond, 3228 cm -1 , 2900cm -1 and 1620cm -1 The peaks at 1100cm correspond to the stretching vibrations of NH, CH and CN bonds, which confirms the successful coating of PDA on the MoS2 surface. The stretching vibration of Si-O bond (1100cm -1 ) confirmed the presence of POSS and at 1270 cm -1 The C=N bond stretching vibration was observed at 1620 cm -1 The C-N bond at the position also indicates the occurrence of Michael addition reaction. Figure 2 The FTIR results shown confirm the successful preparation of the m-MoS2@POSS core-shell-shell structure.

[0053] Example 2

[0054] The preparation method of spherical flower-shaped MoS2 is the same as that in Example 1.

[0055] 10 mL of 5 mg / mL PVA (Mw = 10000-26000) solution was added to 50 mL of spherical flower-shaped MoS2 aqueous dispersion (1.5 mg / mL), and m-MoS2 was prepared by magnetic stirring for 5 hours, which was recorded as MoS2-PVA.

[0056] 50 mg of MoS2-PVA was dispersed in 100 mL of Tris buffer, and 500 mg of NH2-POSS was added thereto. After stirring at room temperature for 20 hours, m-MoS2@POSS-2 was prepared by centrifugation and washing three times with deionized water and ethanol.

[0057] 0.04 g of m-MoS2@POSS-2 was added to 4.0 g of F0704 water-based epoxy resin and 2.0 g of F0705 water-based epoxy curing agent, where m-MoS2@POSS-2 accounted for 1.0% of the mass of F0704 water-based epoxy resin. After stirring and dispersing for 30 minutes, 5 mL was taken and coated on a Q235 steel sheet (2 cm × 2 cm × 0.1 cm) substrate, and cured in a 70 ° C oven to obtain the m-MoS2@POSS-2 epoxy composite coating.

[0058] Example 3

[0059] The preparation method of spherical flower-shaped MoS2 is the same as that in Example 1.

[0060] 10 mL of 5 mg / mL PEG (Mw=20000) solution was added to 50 mL of spherical flower-shaped MoS2 aqueous dispersion (1.5 mg / mL), and m-MoS2 was prepared by magnetic stirring for 5 hours, which was recorded as MoS2-PEG.

[0061] 50 mg of MoS2-PEG was dispersed in 100 mL of Tris buffer, and 500 mg of NH2-POSS was added thereto. After stirring at room temperature for 20 hours, m-MoS2@POSS-3 was prepared after centrifugal washing three times with deionized water and ethanol.

[0062] 0.04 g of m-MoS2@POSS-3 was added to 4.0 g of F0704 water-based epoxy resin and 2.0 g of F0705 water-based epoxy curing agent, where m-MoS2@POSS-3 accounted for 1.0% of the mass of F0704 water-based epoxy resin. After stirring and dispersing for 30 minutes, 5 mL was taken and coated on a Q235 steel sheet (2 cm × 2 cm × 0.1 cm) substrate, and cured in a 70 ° C oven to obtain the m-MoS2@POSS-3 epoxy composite coating.

[0063] Example 4

[0064] The preparation method of spherical flower-shaped MoS2 is the same as that in Example 1.

[0065] To 50 mL of a 1.5 mg / mL aqueous dispersion of spherical flower-shaped MoS₂ was added 0.121 g of Tris base. After 10 minutes of sonication, 200 mg of dopamine was slowly added and stirred in the dark at room temperature for 48 hours. After the reaction, the modified m-MoS₂ was prepared by washing three times with deionized water and ethanol by centrifugation, designated MoS₂-PDA.

[0066] 50 mg of MoS2-PDA was dispersed in 100 mL of Tris buffer, and 200 mg of NH2-POSS was added thereto. After stirring at room temperature for 20 hours, m-MoS2@POSS-4 was prepared after centrifugal washing three times with deionized water and ethanol.

[0067] 0.04 g of m-MoS2@POSS-4 was added to 4.0 g of F0704 water-based epoxy resin and 2.0 g of F0705 water-based epoxy curing agent, where m-MoS2@POSS-4 accounted for 1.0% of the mass of F0704 water-based epoxy resin. After stirring and dispersing for 30 minutes, 5 mL was taken and coated on a Q235 steel sheet (2 cm × 2 cm × 0.1 cm) substrate, and cured in a 70 ° C oven to obtain the m-MoS2@POSS-4 epoxy composite coating.

[0068] Example 5

[0069] The preparation method of spherical flower-shaped MoS2 is the same as that in Example 1.

[0070] To 50 mL of a 1.5 mg / mL aqueous dispersion of spherical flower-shaped MoS2 was added 0.121 g of Tris base. After 10 minutes of sonication, 200 mg of dopamine was slowly added and stirred in the dark at room temperature for 48 hours. After the reaction, the modified m-MoS2, designated MoS2-PDA, was prepared by washing three times with deionized water and ethanol by centrifugation.

[0071] 50 mg of MoS2-PDA was dispersed in 100 mL of Tris buffer, and 1000 mg of NH2-POSS was added thereto. After stirring at room temperature for 20 hours, m-MoS2@POSS-5 was prepared after centrifugal washing three times with deionized water and ethanol.

[0072] 0.04 g of m-MoS2@POSS-5 was added to 4.0 g of F0704 water-based epoxy resin and 2.0 g of F0705 water-based epoxy curing agent, where m-MoS2@POSS-5 accounted for 1.0% of the mass of F0704 water-based epoxy resin. After stirring and dispersing for 30 minutes, 5 mL was taken and coated on a Q235 steel sheet (2 cm × 2 cm × 0.1 cm) substrate, and cured in a 70 ° C oven to obtain the m-MoS2@POSS-5 epoxy composite coating.

[0073] Example 6

[0074] The preparation method of spherical flower-shaped MoS2 is the same as that in Example 1.

[0075] To 50 mL of a 1.5 mg / mL aqueous dispersion of spherical flower-shaped MoS2 was added 0.121 g of Tris base. After 10 minutes of sonication, 200 mg of dopamine was slowly added and stirred in the dark at room temperature for 48 hours. After the reaction, the modified m-MoS2, designated MoS2-PDA, was prepared by washing three times with deionized water and ethanol by centrifugation.

[0076] 50 mg of MoS2-PDA was dispersed in 100 mL of Tris buffer, and 500 mg of NH2-POSS was added thereto. After stirring at room temperature for 20 hours, m-MoS2@POSS-6 was prepared after centrifugal washing three times with deionized water and ethanol.

[0077] 0.08 g of m-MoS2@POSS-6 was added to 4.0 g of F0704 water-based epoxy resin and 2.0 g of F0705 water-based epoxy curing agent, where m-MoS2@POSS-6 accounted for 2.0% of the mass of F0704 water-based epoxy resin. After stirring and dispersing for 30 minutes, 5 mL was taken and coated on a Q235 steel sheet (2 cm × 2 cm × 0.1 cm) substrate, and cured in a 70 ° C oven to obtain the m-MoS2@POSS-6 epoxy composite coating.

[0078] Example 7

[0079] The preparation method of spherical flower-shaped MoS2 is the same as that in Example 1.

[0080] To 50 mL of a 1.5 mg / mL aqueous dispersion of spherical flower-shaped MoS2 was added 0.121 g of Tris base. After 10 minutes of sonication, 200 mg of dopamine was slowly added and stirred in the dark at room temperature for 48 hours. After the reaction, the modified m-MoS2, designated MoS2-PDA, was prepared by washing three times with deionized water and ethanol by centrifugation.

[0081] 50 mg of MoS2-PDA was dispersed in 100 mL of Tris buffer, and 500 mg of NH2-POSS was added thereto. After stirring at room temperature for 20 hours, m-MoS2@POSS-7 was prepared after centrifugal washing three times with deionized water and ethanol.

[0082] 0.16 g of m-MoS2@POSS-7 was added to 4.0 g of F0704 water-based epoxy resin and 2.0 g of F0705 water-based epoxy curing agent, where m-MoS2@POSS-7 accounted for 4.0% of the mass of F0704 water-based epoxy resin. After stirring and dispersing for 30 minutes, 5 mL was taken and coated on a Q235 steel sheet (2 cm × 2 cm × 0.1 cm) substrate, and cured in a 70 ° C oven to obtain the m-MoS2@POSS-7 epoxy composite coating.

[0083] Comparative Example 1

[0084] 4.0 g of F0704 water-based epoxy resin without any additives and 2.0 g of F0705 water-based epoxy curing agent were mixed, stirred and dispersed for 30 minutes, and 5 mL was applied to a Q235 steel sheet (2 cm × 2 cm × 0.1 cm) substrate. The mixture was cured in an oven at 70°C to obtain a pure epoxy resin coating, which was marked as comparative sample 1 (pure epoxy resin coating).

[0085] Comparative Example 2

[0086] The preparation method of spherical flower-shaped MoS2 is the same as that in Example 1.

[0087] 0.04 g of MoS2 was added to 4.0 g of F0704 water-based epoxy resin and 2.0 g of F0705 water-based epoxy curing agent, where MoS2 accounted for 1.0% of the mass of the F0704 water-based epoxy resin. After stirring and dispersing for 30 minutes, 5 mL was applied to a Q235 steel sheet (2 cm × 2 cm × 0.1 cm) substrate and cured in an oven at 70°C to obtain a MoS2 / epoxy composite coating, which was marked as comparative sample 2 (MoS2 epoxy composite material).

[0088] Comparative Example 3

[0089] The preparation method of spherical flower-shaped MoS2 is the same as that in Example 1.

[0090] To 50 mL of a 1.5 mg / mL aqueous dispersion of spherical flower-shaped MoS₂ was added 0.121 g of Tris base. After 10 minutes of sonication, 200 mg of dopamine was slowly added and stirred in the dark at room temperature for 48 hours. After the reaction, the modified m-MoS₂ was prepared by washing three times with deionized water and ethanol by centrifugation, designated MoS₂-PDA.

[0091] 0.04 g of MoS2-PDA was added to 4.0 g of F0704 water-based epoxy resin and 2.0 g of F0705 water-based epoxy curing agent, where MoS2-PDA accounted for 1.0% of the mass of the F0704 water-based epoxy resin. After stirring and dispersing for 30 minutes, 5 mL was applied to a Q235 steel sheet (2 cm × 2 cm × 0.1 cm) substrate and cured in an oven at 70°C to obtain an m-MoS2 / epoxy composite coating, which was marked as comparative sample 3 (m-MoS2 epoxy composite material).

[0092] Test Example 1

[0093] Figure 3 Microscopic morphology, cross-section and hardness analysis of the pure epoxy coating prepared in Comparative Example 1, the MoS2 / epoxy coating prepared in Comparative Example 2, the MoS2-PDA / epoxy coating prepared in Comparative Example 3 and the m-MoS2@POSS / epoxy coating prepared in Example 1. Figure 3 (a) is a microscopic cross-sectional photograph of the pure epoxy coating prepared in Comparative Example 1, from which it can be clearly observed that a river-like pattern appears in the smooth fracture area, which is consistent with the typical brittle fracture of thermosetting epoxy resin. Figure 3 (b) is a microscopic cross-sectional photograph of the MoS2 / epoxy coating prepared in Comparative Example 2, as shown in FIG. Figure 3 As shown in (b), the cracks in the MoS2 / epoxy coating appear as fish scales, and the scale structure is concave and convex and orderly. Figure 3 (c) is a microscopic cross-sectional photograph of the MoS2-PDA / epoxy coating prepared in Comparative Example 3, as shown in FIG. Figure 3 As shown in (c), the cross-section of the MoS2-PDA / epoxy coating is relatively flat and smooth, but the presence of MoS2-PDA agglomerates can be observed. Figure 3 (d) is a microscopic cross-sectional photograph of the m-MoS2@POSS / epoxy coating prepared in Example 1. Figure 3 In (d), a clear pit structure can be seen, indicating that m-MoS2@POSS has good dispersion and uniformity in epoxy. In addition, due to the improvement of the interfacial bonding strength, the deformation resistance of the composite coating prepared in Example 1 has been significantly improved. Figure 3 (e) is the hardness analysis result of the coating prepared in Example 1 and Comparative Examples 1 to 3, as shown in FIG. Figure 3 As shown in (e), the Shore hardness value of the MoS2@POSS / epoxy coating is significantly higher than that of the coatings prepared in Comparative Examples 1 to 3.

[0094] Test Example 2

[0095] Testing Method: Macroscopic tribological properties of the lubricating coatings prepared in Example 1 and Comparative Examples 1-3 were tested using a ball-on-disc reciprocating friction and wear tester. A 6mm diameter stainless steel ball was used as the friction pair, with an applied load of 10N and a reciprocating speed of 2Hz. Each set of data was tested three times to ensure data authenticity. (Tests were conducted at a room temperature of 25±2°C and relative humidity of 25±2% and 80±2%).

[0096] Figure 4 The macro-tribological performance test results of pure epoxy (Comparative Example 1), MoS2 / epoxy (Comparative Example 2), MoS2-PDA / epoxy (Comparative Example 3) and m-MoS2@POSS / epoxy coating prepared in Example.

[0097] like Figure 4 As shown in (a), under an ambient humidity of RH~25%, the friction coefficient of the m-MoS2@POSS / epoxy composite coating prepared in Example 1 is the lowest compared with the MoS2 / epoxy coating prepared in Comparative Example 2 and the MoS2-PDA / epoxy coating prepared in Comparative Example 3. The friction coefficient of the MoS2-PDA / epoxy coating of a single shell prepared in Comparative Example 3 is actually higher than that of the MoS2 / epoxy coating prepared in Comparative Example 2. Figure 4 As shown in (b), in a humid environment (RH ~ 80%), the friction coefficient of the MoS2 / epoxy coating prepared in Comparative Example 2 rises sharply when it is less than 500 cycles, and fluctuates greatly. This is because the MoO3 formed after the oxidation of MoS2 acts as abrasive particles at the friction interface, resulting in a high friction phenomenon. However, the friction coefficient of the m-MoS2@POSS / epoxy composite coating prepared in Example 1 decreases to some extent and remains stable below 0.25. This conclusion shows that the POSS shell material can well improve the problem of lubrication failure of single MoS2 in a humid environment.

[0098] like Figure 4 As shown in (c), under the ambient humidity of RH~25%, the wear rate of the m-MoS2@POSS / epoxy composite coating prepared in Example 1 is the lowest, reaching 8.91×10 -5 mm 3 ·N -1 ·m -1 , compared with MoS2 / epoxy (2.52×10 -4 mm 3 ·N -1 ·m -1 ) decreased by 64.64%. Figure 4As shown in (d), under the environment humidity of RH ~ 80%, the wear rate of different coatings will increase to varying degrees due to the increase of humidity. However, the m-MoS2@POSS / epoxy composite coating prepared in Example 1 is least affected by the environmental humidity, with a wear rate of 1.54×10 -4 mm 3 ·N -1 ·m -1 , compared with the MoS2 / epoxy coating prepared in Comparative Example 2 (1.88×10 -3 mm 3 ·N -1 ·m -1 ) decreased by 91.91%. It can be seen that the m-MoS2@POSS composite material prepared in Example 1 has good stability in a humid environment.

[0099] Table 1 Summary of micromorphology and coating properties of Examples 1 to 7 and Comparative Examples 1 to 3

[0100]

[0101]

[0102] From the above examples, it can be seen that the method provided by the present invention sequentially prepares spherical flower-shaped MoS2 by a hydrothermal method, then modifies the intermediate layer with a polymer having strong adhesion, and finally prepares the m-MoS2@POSS core-shell composite material by Michael addition and Schiff base reaction. The m-MoS2@POSS composite material obtained by the present invention shows good dispersibility and high hardness in epoxy resin; the core-shell structure can effectively alleviate the oxidation phenomenon of MoS2 in MoS2 / epoxy coating under high humidity; in a humid environment, compared with MoS2 / epoxy coating, m-MoS2@POSS / epoxy coating can effectively reduce the friction coefficient and wear rate, which plays an important role in the tribological properties of the transfer film at the friction interface.

[0103] Although the above embodiment provides a detailed description of the present invention, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. A core-shell structure composite material, characterized in that: The invention comprises a spherical flower-shaped MoS2 core; a polymer intermediate modification layer coated on the surface thereof, wherein the material forming the polymer intermediate modification layer contains a hydroxyl group; and a cage-type silsesquioxane shell layer chemically modified on the surface of the polymer intermediate modification layer.

2. The core-shell structure composite material according to claim 1, characterized in that The material forming the polymer intermediate modified layer includes one or more of polydopamine, polyethylene glycol and polyvinyl alcohol.

3. The core-shell structure composite material according to claim 2, characterized in that: The weight average molecular weight of the polyethylene glycol is 20,000; the weight average molecular weight of the polyvinyl alcohol is 10,000-26,000.

4. The core-shell structure composite material according to claim 1, characterized in that The particle size of the spherical flower-shaped MoS2 core is 180-190 nm.

5. The core-shell structure composite material according to claim 1 or 2, characterized in that: The thickness of the polymer intermediate modified layer is 45-55 nm.

6. The method for preparing the core-shell structure composite material according to any one of claims 1 to 5, characterized in that: The following steps are involved: The surface of the spherical flower-shaped MoS2 is coated with a polymer layer to obtain an intermediate product; the intermediate product includes a spherical flower-shaped MoS2 core and a polymer intermediate modified layer coated on the surface thereof; The alkaline dispersion of the intermediate product and amino-type cage-type silsesquioxane are mixed to carry out Michael addition and Schiff base reaction to obtain the core-shell structure composite material.

7. Use of the core-shell structure composite material according to any one of claims 1 to 5 or the core-shell structure composite material prepared by the preparation method according to claim 6 as a lubricating filler.

8. A resin-based composite lubricating coating, characterized in that: The invention comprises independently packaged resin components and curing agents, wherein the resin components comprise a resin matrix and a lubricating filler; the lubricating filler comprises the core-shell structure composite material according to any one of claims 1 to 5 or the core-shell structure composite material prepared by the preparation method according to claim 6.

9. The resin-based composite lubricating coating according to claim 8, characterized in that: The resin matrix is water-based epoxy resin, and the mass of the lubricating filler accounts for 1-4% of the mass of the resin matrix.

10. A resin-based composite lubricating coating, characterized in that: The resin-based composite lubricating coating is formed into a film on the surface of a metal substrate and then solidified; the resin-based composite lubricating coating is the resin-based composite lubricating coating according to claim 8 or 9.

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