Wear-resistant antioxidant lubricating oil and preparation method thereof

Abstract

The invention relates to the field of lubricating oil, and particularly discloses wear-resistant antioxidant lubricating oil and a preparation method thereof. The wear-resistant antioxidant lubricating oil is prepared from the following raw materials in parts by weight: 50 to 70 parts of base oil, 30 to 50 parts of graphene / aluminum oxide coated powder, 5 to 10 parts of a friction modifier, 2 to 4 parts of an antioxidant, 0.5 to 1 part of a de-foaming agent, 0.5 to 1.2 parts of an anti-rust agent and 10 to 15 parts of a friction self-repairing nano material, the graphene / aluminum oxide coated powder comprises a graphene core material and an aluminum oxide wall material, the aluminum oxide wall material contains aluminum oxide and 3-aminopropyltriethoxysilane, and the mass ratio of the graphene to the aluminum oxide to the 3-aminopropyltriethoxysilane is 1: (2-3): (1-2). The lubricating oil disclosed by the invention contains the graphene / aluminum oxide coated powder, so that the lubricating oil not only has a relatively strong lubricating effect, but also is not easy to oxidize at a high temperature, has good high-temperature-resistant stability, and also has an excellent anti-corrosion effect.

Description

Technical Field

[0001] This application relates to the technical field of lubricating oils. More specifically, it relates to a wear-resistant and antioxidant lubricating oil and a preparation method thereof. Background Art

[0002] Lubricating oil is a liquid or semi-solid lubricant used in various types of automobiles and mechanical equipment to reduce friction, protect machinery and workpieces, and mainly plays roles such as lubrication, cooling, rust prevention, cleaning, sealing, and buffering. Lubricating oil generally consists of two parts: base oil and additives. The base oil is the main component of lubricating oil and can determine the basic properties of lubricating oil. However, additives can make up for and improve the deficiencies in the performance of the base oil, endow some new properties, and are an important part of synthetic lubricating oil. Graphene is a good choice among additives. Graphene is a traditional solid lubricating material. Due to its special layered crystal structure, graphene has good lubricating properties.

[0003] In the prior art, the Chinese invention patent document with the application number CN201710438720X discloses a graphene lubricating oil, which includes a base oil, and also includes a modified graphene additive and an auxiliary agent. The weight ratio of the base oil, the modified graphene additive, and the auxiliary agent is 1:0.05 - 0.2:0.05 - 0.15. The preparation method of the modified graphene additive is: mixing graphene with dimethylformamide, sodium alkylbenzenesulfonate, and arabic gum, performing ultrasonic dispersion treatment for 30 - 50 min, and the ultrasonic power is 800 - 1000 W to obtain a dispersed graphene solution; then mixing the dispersed graphene solution with aminobenzoic acid and stirring evenly.

[0004] The above graphene lubricating oil carboxylates graphene using dimethylformamide, sodium alkylbenzenesulfonate, arabic gum, and aminobenzoic acid to increase the dispersibility of graphene in the base oil. In view of the related technology above, the inventor found that in a high-temperature environment, graphene in the lubricating oil is more likely to react with oxygen molecules or oxide substances, causing graphene to be oxidized, thereby leading to a decline in the lubricating effect and an increase in friction and wear. Summary of the Invention

[0005] In order to increase the antioxidant ability of graphene-containing lubricating oil, this application provides a wear-resistant and antioxidant lubricating oil and a preparation method thereof.

[0006] In the first aspect, this application provides a wear-resistant and antioxidant lubricating oil, adopting the following technical scheme:

[0007] An abrasion-resistant and antioxidant lubricating oil, comprising the following raw materials in parts by weight: 50-70 parts of base oil, 30-50 parts of graphene / aluminum oxide-coated powder, 5-10 parts of friction improver, 2-4 parts of antioxidant, 0.5-1 part of defoamer, 0.5-1.2 parts of rust inhibitor, and 10-15 parts of friction self-repairing nanomaterial;

[0008] The graphene / aluminum oxide-coated powder includes a graphene core material and an aluminum oxide wall material. The aluminum oxide wall material contains aluminum oxide and 3-aminopropyltriethoxysilane. The mass ratio of graphene, aluminum oxide, and 3-aminopropyltriethoxysilane is 1:2-3:1-2.

[0009] By adopting the above technical solution, the graphene / aluminum oxide-coated powder is used in the base oil. Using aluminum oxide and 3-aminopropyltriethoxysilane as the wall material and graphene as the core material, the wall material coats the core material to obtain a coated body. After hydrolysis, 3-aminopropyltriethoxysilane can react with the hydroxyl groups on the surface of aluminum oxide to modify its surface. Moreover, it can react with the hydroxyl groups on the surface of aluminum oxide at one end to form covalent bonds or hydrogen bonds, and at the other end, it can also form hydrogen bonds or covalent bonds with graphene, organically connecting the interface between aluminum oxide and graphene. In addition, the surface energy of 3-aminopropyltriethoxysilane is relatively low, and its wetting ability is relatively strong, which can be evenly distributed on the surface of aluminum oxide, improving the compatibility and dispersibility of the wall material in the base oil. The aluminum oxide coats the graphene, which can form an effective antioxidant coating, isolating the graphene from the oxidizing gas and preventing the gas from entering the interior, thereby improving the antioxidant property of the graphene material. At the same time, aluminum oxide also has good lubricating ability. During the friction process, the friction self-repairing nanomaterial forms a specific repair layer on the surface through the energy and material exchange between the friction pair surface, the lubricating medium, and the self-repairing material. When the wear rate of the friction pair is less than the repair rate, the dynamic self-repair of the friction surface can be realized. The friction improver can reduce friction through mutual sliding and cooperate with the friction self-repairing material to improve the integrity of the repair layer formed by the friction self-repairing material, thereby improving the lubrication, friction reduction, and anti-wear effects.

[0010] Optionally, the preparation method of the graphene / aluminum oxide-coated powder is as follows:

[0011] Add an aluminum nitrate solution to a graphene suspension with a concentration of 0.5-1 wt%. After stirring evenly, dropwise add ammonia water until neutral, then let it stand, centrifuge, wash, and sinter to obtain a coated body;

[0012] Disperse the coated body in an anhydrous ethanol solution, ultrasonically homogenize it, heat it to 60-70 °C, add 3-aminopropyltriethoxysilane, react for 5-6 h, centrifuge, wash, and freeze-dry.

[0013] By adopting the above technical solution, aluminum ions are generated by the hydrolysis of aluminum nitrate during dissolution. Then, by dropping ammonia water, the amount of generated hydroxide ions is controlled to complete the neutralization reaction. Finally, aluminum hydroxide precipitate is formed in the solution. Aluminum hydroxide is non-uniformly formed with graphene as the substrate. After sintering, aluminum hydroxide is dehydrated by heating to form alumina. Then, 3-aminopropyltriethoxysilane is hydrolyzed and spreads on the surface of alumina nanoparticles to complete the surface modification of alumina particles, making the surface of alumina particles easily wetted. Furthermore, the dispersion of alumina-coated graphene in lubricating oil is improved, the agglomeration of graphene / alumina-coated powder is reduced, and thus the lubrication and friction reduction effects of graphene / alumina-coated powder are improved.

[0014] Optionally, the friction self-repairing nanomaterial has a two-dimensional layered structure and is selected from at least one of molybdenum disulfide, hexagonal boron nitride, and zirconium phosphate nanosheets.

[0015] By adopting the above technical solution, the above materials all have a two-dimensional layered structure and can form a dense friction protection film on the friction surface during the friction process, having excellent lubrication and friction reduction capabilities and playing good anti-wear, friction reduction, and repair performances. The lamellar structure of the friction self-repairing material has excellent barrier properties, can prevent corrosive media from penetrating into the coating, and plays a labyrinth effect to extend the diffusion path of corrosive media, making the lubricating oil have good anti-corrosion performance.

[0016] Optionally, the friction self-repairing material is a zinc oxide nanoring-modified friction self-repairing material.

[0017] By adopting the above technical solutions, although the friction self-repairing material has good anti-friction lubrication and anti-corrosion capabilities, there is a strong interaction and high specific surface energy between its particles, making it prone to agglomeration and difficult to disperse in the lubricating oil, which is not conducive to improving the continuity and compactness of the lubricating oil. Utilizing the steric hindrance effect generated by the nanoparticles to prevent the agglomeration between the two-dimensional nanosheet layers, making it easier for the friction self-repairing material to disperse in the base oil. The zinc oxide nanoring is modified on the surface of the friction self-repairing material to generate a steric hindrance effect, blocking the agglomeration of the friction self-repairing material nanosheets in the coating. At the same time, the loading of the zinc oxide nanoring increases the contact area between the friction self-repairing material, the base oil, and the friction surface, improving the interfacial compatibility between the friction self-repairing material and the base oil. Moreover, the zinc oxide nanoring can also fill the microcracks and defects in the friction protection film formed on the friction surface, making the friction protection film present a denser morphology and obtaining better lubrication and protection effects. The modification of the zinc oxide nanoring extends the diffusion path of the corrosive medium in the friction protection film, enhancing the barrier ability of the friction self-repairing material on the friction surface. The zinc oxide nanoring makes the friction self-repairing material evenly distributed in the base oil, thus evenly distributed on the friction surface, increasing the contact area between the friction self-repairing material and the friction surface, filling the microholes and cracks, and endowing the friction self-repairing material with more excellent anti-corrosion performance. The zinc oxide nanoring is made from zinc acetate dihydrate as the raw material. After it is dispersed in deionized water, it reacts to form zinc hydroxide and acetic acid, and then zinc hydroxide reacts to form zinc oxide and water, thus forming zinc oxide nanoparticles. Then, dimethyl sulfoxide is hydrolyzed to produce hydroxide ions, which adsorb on the zinc ions to form a zinc complex, causing the zinc oxide nanoparticles to gradually transform from nanospheres into zinc oxide nanobowl structures.

[0018] Optionally, the friction improver is a castor oil-polysulfone resin microcapsule. The core material of the castor oil-polysulfone resin microcapsule includes castor oil, and the wall material includes polysulfone resin and multi-walled carbon nanotubes. The mass ratio of the polysulfone resin to the multi-walled carbon nanotubes is 1:0.03 - 0.04.

[0019] By adopting the above technical solution, multi-walled carbon nanotubes are used as the wall material and mixed with polysulfone resin to form the wall material, with castor oil coated inside. The multi-walled carbon nanotubes and polysulfone resin can form a lubricating film on the friction surface, reducing the friction coefficient, and can also resist corrosive moisture, playing an anti-corrosion protection role. Polysulfone resin has excellent antioxidant and thermal stability, and can form a uniform and dense film, effectively coating the core material, remaining stable at high temperatures, not easily decomposing or degrading, ensuring the stability and durability of the microcapsules in a high-temperature environment. In addition, it also has good corrosion resistance and can resist the erosion of chemical substances such as acids, alkalis, and salts. When used as the microcapsule wall material, when lubrication generates friction and the wall material is damaged, the microcapsules rupture, and the castor oil flows out from the microcapsules and fills between the friction pairs, forming a lubricating film, which plays an auxiliary role in the friction self-repairing material. The multi-walled carbon nanotubes can timely fill the wear marks and play a synergistic role with the castor oil. Moreover, the high viscosity of the castor oil enables it to form a persistent lubricating film on the friction surface when filling the friction pairs, improving the adhesion ability of the lubricating oil, and can also effectively slow down the corrosion rate of the friction surface and improve the anti-corrosion ability of the lubricating oil. Using the microcapsule repair technology to further protect the friction surface, when the rupture of the microcapsules causes the castor oil to fill the cracks, the castor oil forms a film layer at the friction surface, supplementing or repairing the friction protection film formed by the friction self-repairing material. The two cooperate with each other, effectively preventing the contact between the corrosive medium and the friction surface, and at the same time improving the lubrication effect.

[0020] Optionally, the mass ratio of the friction improver to the friction self-repairing material is 1:1.5 - 2.

[0021] By adopting the above technical solution, an appropriate proportion of the friction improver and the friction self-repairing material can endow the lubricating oil with certain repair ability, enabling it to reform a film layer at the worn area, effectively preventing the contact between the corrosive medium and the metal matrix, not only enhancing the compactness and integrity of the lubricating film, but also enhancing its self-repairing performance and corrosion resistance.

[0022] Optionally, the antioxidant is composed of an amine antioxidant, a phenolic antioxidant, and a phosphate antioxidant compounded in a mass ratio of 1:0.5 - 2:0.5 - 2.

[0023] By adopting the above technical solution, the cooperation of multiple antioxidants can endow the lubricating oil with excellent antioxidant ability.

[0024] Optionally, the amine antioxidant is at least one of diphenylamine, naphthylamine, N-phenyl-α-naphthylamine, and p-phenylenediamine;

[0025] The phenolic antioxidant is at least one of 2,6-di-tert-butyl-4-methylphenol, bis(3,5-di-tert-butyl-4-hydroxyphenyl)sulfide, 4,4'-methylenebis(2,6-di-tert-butylphenol), and 2,6-di-tert-butyl-α-dimethylaminop-cresol;

[0026] The phosphate antioxidant is at least one of triethyl phosphite, tributyl phosphite, trioctyl phosphite, tris(nonylphenyl) phosphite, and triisopropyl phosphite.

[0027] Optionally, the rust inhibitor is selected from at least one of isononylphenoxyacetic acid, sorbitan monooleate, alkenyl succinic acid, and barium dinonylnaphthalene sulfonate.

[0028] In a second aspect, the present application provides a method for preparing a wear-resistant and antioxidant lubricating oil, adopting the following technical solution:

[0029] A method for preparing a wear-resistant and antioxidant lubricating oil includes the following steps:

[0030] Heat the base oil to 50 - 80 °C, and while stirring, add the antioxidant and the friction self-repairing material, and mix evenly to obtain a first mixture;

[0031] Heat the first mixture to 100 - 110 °C, stir for 1 - 2 h, then add the graphene / aluminum oxide-coated powder, friction modifier, rust inhibitor, and defoamer. After dispersing evenly, filter and package to obtain the wear-resistant and antioxidant lubricating oil.

[0032] By adopting the above technical solution, the lubricating oil is prepared by a simple method of heating and blending. It not only has excellent antioxidant, rust prevention, and corrosion prevention properties, but also has super lubricity, greatly reducing the mechanical friction coefficient and improving the extreme pressure performance. Moreover, the preparation process is simple and suitable for industrial production.

[0033] In summary, the present application has the following beneficial effects:

[0034] 1. Since the present application uses the method of alumina coating to provide antioxidant protection for graphene, with graphene as the core material, alumina and 3-aminopropyltriethoxysilane as the wall materials, 3-aminopropyltriethoxysilane can improve the dispersion of the coated powder in the base oil, reduce agglomeration, and improve the lubrication effect, while alumina can reduce the oxidation of graphene by high temperature and oxidation gases, thereby enhancing the oxidation resistance of the lubricating oil containing graphene at high temperatures and improving the high-temperature usage effect of the lubricating oil.

[0035] 2. In the present application, a friction self-repairing material with a two-dimensional sheet-like structure is preferably used, and zinc oxide nanorings are used to modify the friction self-repairing material. The loading of zinc oxide nanorings can increase the dispersion effect of the friction self-repairing material in the base oil, and at the same time increase the contact area between the friction self-repairing material and the friction surface, enhancing the lubrication and repair ability of the friction self-repairing material, and at the same time further enhancing the anti-corrosion performance of the friction self-repairing material.

[0036] 3. In this application, castor oil-polysulfone resin microcapsules are preferably used as friction improvers. With castor oil as the core material and polysulfone resin and multi-walled carbon nanotubes as the wall materials, the microcapsules can form a lubricating film on the surface, reducing the friction coefficient. Under the action of friction, the microcapsules rupture, and the castor oil flows out and fills the friction surface, forming a lubricating film, which produces a cooperative effect with the friction self-repairing material, increases the adhesion strength between the friction self-repairing material and the friction surface, and improves the long-term lubricity of the lubricating film. Detailed Embodiments

[0037] The following examples further illustrate this application in detail.

[0038] Preparation Examples 1-3 of Graphene / Aluminum Oxide Coated Powders

[0039] Preparation Example 1: Add 10 g of graphene to deionized water and ultrasonically disperse it for 3 h to form a graphene suspension with a concentration of 1 wt%. Add an aluminum nitrate solution with a concentration of 0.3 mol / l to the graphene suspension, stir evenly, and then dropwise add ammonia water until the pH of the solution is neutral. After standing for 4 h, centrifuge and wash with deionized water, and sinter at 850 °C for 120 min to obtain a coated body. Adjust the addition amount of the aluminum nitrate solution so that the mass ratio of graphene to aluminum oxide in the coated body is 1:3.

[0040] Disperse the coated body in an anhydrous ethanol solution formed by 45 ml of anhydrous ethanol and 5 ml of deionized water. After ultrasonically dispersing evenly, raise the temperature to 70 °C, add 20 g of 3-aminopropyltriethoxysilane, react for 5 h, then centrifuge, collect the precipitate, wash with deionized water, and freeze-dry at -35 °C to obtain graphene / aluminum oxide coated powder.

[0041] Preparation Example 2: Add 10 g of graphene to deionized water and ultrasonically disperse it for 3 h to form a graphene suspension with a concentration of 0.5 wt%. Add an aluminum nitrate solution with a concentration of 0.3 mol / l to the graphene suspension, stir evenly, and then dropwise add ammonia water until the pH of the solution is neutral. After standing for 4 h, centrifuge and wash with deionized water, and sinter at 850 °C for 120 min to obtain a coated body. Adjust the addition amount of the aluminum nitrate solution so that the mass ratio of graphene to aluminum oxide in the coated body is 1:2.

[0042] Disperse the coated body in an anhydrous ethanol solution formed by 45 ml of anhydrous ethanol and 5 ml of deionized water. After ultrasonically dispersing evenly, raise the temperature to 60 °C, add 10 g of 3-aminopropyltriethoxysilane, react for 6 h, then centrifuge, collect the precipitate, wash with deionized water, and freeze-dry at -35 °C to obtain graphene / aluminum oxide coated powder.

[0043] Preparation Example 3: 10 g of graphene was added to deionized water and ultrasonically dispersed for 3 h to form a graphene suspension with a concentration of 1 wt%. An aluminum nitrate solution with a concentration of 0.3 mol / l was added to the graphene suspension, and after stirring evenly, ammonia water was added dropwise until the pH of the solution was neutral. After standing for 4 h, it was centrifuged and washed with deionized water, and then sintered at 850 °C for 120 min to obtain graphene / aluminum oxide-coated powder. The addition amount of the aluminum nitrate solution was adjusted so that the mass ratio of graphene to aluminum oxide in the graphene / aluminum oxide-coated powder was 1:3.

[0044] Example

[0045] Example 1: A wear-resistant and antioxidant lubricating oil, the amounts of its raw materials are shown in Table 1. Among them, the base oil is polyalphaolefin, selected from Shenzhen Hua'aode Petroleum Technology, model PA040; the graphene / aluminum oxide coating is made from Preparation Example 1; the friction improver is molybdenum dialkyldithiocarbamate, selected from Hangzhou Shi'an Chemical Industry, model F1510; the antioxidant is composed of an amine antioxidant, a phenolic antioxidant, and a phosphoric acid ester antioxidant with a mass ratio of 1:0.5:2. The amine antioxidant is diphenylamine, the phenolic antioxidant is 2,6-di-tert-butyl-4-methylphenol, and the phosphoric acid ester antioxidant is triethyl phosphite; the defoamer is an oil-based non-silicon defoamer, selected from Dongguan Defeng Defoamer, model DF-520; the rust inhibitor is sorbitan monooleate; the friction self-repairing material has a two-dimensional layered structure, specifically molybdenum disulfide.

[0046] The preparation method of the above wear-resistant and antioxidant lubricating oil includes the following steps:

[0047] Heat the base oil to 80 °C, and while stirring, add the antioxidant and the friction self-repairing material, and mix evenly to obtain a first mixture;

[0048] Heat the first mixture to 100 °C, stir for 2 h, then add the graphene / aluminum oxide-coated powder, the friction improver, the rust inhibitor, and the defoamer. After dispersing evenly, filter and pack to obtain the wear-resistant and antioxidant lubricating oil.

[0049] Table 1

[0050]

[0051] Example 2: A wear-resistant and antioxidant lubricating oil, the dosage of its raw materials is shown in Table 1. Among them, the base oil is polyalphaolefin, selected from Shenzhen Aode Petroleum Technology, with the model PA040. The graphene / aluminum oxide coating is made from Preparation Example 2. The friction modifier is zinc dialkyldithiophosphate. The antioxidant is composed of an amine antioxidant, a phenolic antioxidant, and a phosphoric acid ester antioxidant with a mass ratio of 1:2:0.5. The amine antioxidant is p-phenylenediamine, the phenolic antioxidant is 4,4'-methylenebis(2,6-di-tert-butylphenol), and the phosphoric acid ester antioxidant is tributyl phosphite. The defoamer is an oil-based non-silicon defoamer, selected from Dongguan Defeng Defoamer, with the model DF-520. The rust inhibitor is alkenyl succinic acid. The friction self-repairing material has a two-dimensional layered structure, specifically hexagonal boron nitride.

[0052] The preparation method of the above wear-resistant and antioxidant lubricating oil includes the following steps:

[0053] Heat the base oil to 50°C, and while stirring, add the antioxidant and the friction self-repairing material, and mix evenly to obtain the first mixture;

[0054] Heat the first mixture to 110°C, stir for 1 h, then add the graphene / aluminum oxide coated powder, the friction modifier, the rust inhibitor, and the defoamer. After dispersing evenly, filter and package to obtain the wear-resistant and antioxidant lubricating oil.

[0055] Example 3: A wear-resistant and antioxidant lubricating oil, the dosage of its raw materials is shown in Table 1. Among them, the base oil is polyalphaolefin, selected from Shenzhen Aode Petroleum Technology, with the model PA040. The graphene / aluminum oxide coating is made from Preparation Example 1. The friction modifier is zinc dialkyldithiophosphate. The antioxidant is composed of an amine antioxidant, a phenolic antioxidant, and a phosphoric acid ester antioxidant with a mass ratio of 1:1:0.5. The amine antioxidant is naphthylamine, the phenolic antioxidant is 2,6-di-tert-butyl-α-dimethylamino-p-cresol, and the phosphoric acid ester antioxidant is trioctyl phosphite. The defoamer is an oil-based non-silicon defoamer, selected from Dongguan Defeng Defoamer, with the model DF-520. The rust inhibitor is alkenyl succinic acid. The friction self-repairing material has a two-dimensional layered structure, specifically hexagonal boron nitride.

[0056] The preparation method of the above wear-resistant and antioxidant lubricating oil includes the following steps:

[0057] Heat the base oil to 70°C, and while stirring, add the antioxidant and the friction self-repairing material, and mix evenly to obtain the first mixture;

[0058] Heat the first mixture to 100°C, stir for 1 h, then add the graphene / aluminum oxide coated powder, the friction modifier, the rust inhibitor, and the defoamer. After dispersing evenly, filter and package to obtain the wear-resistant and antioxidant lubricating oil.

[0059] Example 4: An anti-wear and antioxidant lubricating oil, which is different from Example 1 in that the raw material dosages are as shown in Table 1, and the mass ratio of the friction improver to the friction self-repairing material is 1:2.

[0060] Example 5: An anti-wear and antioxidant lubricating oil, which is different from Example 1 in that the raw material dosages are as shown in Table 1, and the mass ratio of the friction improver to the friction self-repairing material is 1:1.

[0061] Example 6: An anti-wear and antioxidant lubricating oil, which is different from Example 1 in that the raw material dosages are as shown in Table 1, and the mass ratio of the friction improver to the friction self-repairing material is 1:3.

[0062] Example 7: An anti-wear and antioxidant lubricating oil, which is different from Example 1 in that the friction self-repairing material is a zinc oxide nanoring-modified friction self-repairing material, and the specific preparation method is as follows:

[0063] Disperse 100 mg of the friction self-repairing material molybdenum disulfide into 100 ml of a sodium hydroxide solution with a concentration of 5 M, stir at 35 °C for 7 h, centrifuge at a speed of 3000 rpm for 3 min to obtain molybdenum disulfide deposits, wash until neutral and then disperse into deionized water, ultrasonicate at a power of 100 W for 2 h to obtain a suspension, centrifuge at a speed of 3000 rpm for 2 min to remove the lower layer of undissociated substances, obtain a dispersion, centrifuge at a speed of 9800 rpm for 8 min, pour off the supernatant to obtain nanosheets, and freeze at -35 °C for 12 h to obtain nanosheet powder;

[0064] Disperse 20 mg of the nanosheet powder, 200 mg of cetyltrimethylammonium bromide, and 80 mg of zinc acetate dihydrate into 20 ml of deionized water, disperse under ultrasonic action for 30 min, stir at 35 °C for 1 h, add 29.2 ml of dimethyl sulfoxide, stir for 30 min and then heat to 70 °C, react for 1.5 h and then cool and stand for 4 h, centrifuge at 9000 rpm for 6 min, wash with absolute ethanol and deionized water, and freeze-dry at -35 °C to prepare the zinc oxide nanoring-modified friction self-repairing material.

[0065] Example 8: An anti-wear and antioxidant lubricating oil, which is different from Example 1 in that the friction improver is a castor oil-polysulfone resin microcapsule. The core material of the castor oil-polysulfone resin microcapsule includes castor oil, and the wall material includes polysulfone resin and multi-walled carbon nanotubes with a mass ratio of 1:0.04. The castor oil is selected from Jinan Zeshuen Chemical Industry, with the product number 001, and the multi-walled carbon nanotubes are selected from Jiangsu Xianfeng Nano Materials Technology Co., Ltd., with the model 100234. The preparation method of the castor oil-polysulfone microcapsule is as follows:

[0066] Add 1 g of polysulfone resin to 20 ml of dichloromethane, stir to dissolve, add multi-walled carbon nanotubes, and mix evenly to obtain Solution A. The mass ratio of multi-walled carbon nanotubes to polysulfone resin is 0.04:1;

[0067] Add 0.1 g of castor oil to Solution A, after ultrasonic oscillation, add Solution B prepared by mixing 0.5 g of gelatin, 0.4 g of PVA-1788 and 20 ml of deionized water until the dichloromethane has completely evaporated, filter by suction, and dry in vacuum at 50 °C to obtain castor oil-polysulfone resin microcapsules.

[0068] Example 9: An anti-wear and antioxidant lubricating oil, which is different from Example 1 in that the friction modifier is castor oil-polysulfone resin microcapsules. The core material of the castor oil-polysulfone resin microcapsules includes castor oil, and the wall material includes polysulfone resin and multi-walled carbon nanotubes with a mass ratio of 1:0.03. The castor oil is selected from Jinan Zeshu Chemical Industry, with the product number 001, and the multi-walled carbon nanotubes are selected from Jiangsu Xianfeng Nano Materials Technology Co., Ltd., with the model 100234. The preparation method of the castor oil-polysulfone microcapsules is as follows:

[0069] Add 1 g of polysulfone resin to 20 ml of dichloromethane, stir to dissolve, add multi-walled carbon nanotubes, and mix evenly to obtain Solution A. The mass ratio of multi-walled carbon nanotubes to polysulfone resin is 0.03:1;

[0070] Add 0.1 g of castor oil to Solution A, after ultrasonic oscillation, add Solution B prepared by mixing 0.5 g of gelatin, 0.4 g of PVA-1788 and 20 ml of deionized water until the dichloromethane has completely evaporated, filter by suction, and dry in vacuum at 50 °C to obtain castor oil-polysulfone resin microcapsules.

[0071] Example 10: An anti-wear and antioxidant lubricating oil, which is different from Example 8 in that multi-walled carbon nanotubes are not added to the wall material.

[0072] Example 11: An anti-wear and antioxidant lubricating oil, which is different from Example 8 in that white oil is used to replace castor oil in equal amount. The white oil is selected from Jinan Baijiang New Materials, with the product number 10.

[0073] Example 12: An anti-wear and antioxidant lubricating oil, which is different from Example 1 in that the friction self-repairing material is zinc oxide nanoring modified friction self-repairing material, and the friction modifier is castor oil-polysulfone resin microcapsules. The core material of the castor oil-polysulfone resin microcapsules includes castor oil, and the wall material includes polysulfone resin and multi-walled carbon nanotubes with a mass ratio of 1:0.04. The castor oil is selected from Jinan Zeshu Chemical Industry, with the product number 001, and the multi-walled carbon nanotubes are selected from Jiangsu Xianfeng Nano Materials Technology Co., Ltd., with the model 100234;

[0074] The specific preparation method of the zinc oxide nanoring modified friction self-repairing material is as follows:

[0075] Disperse 100 mg of molybdenum disulfide, a friction self-repairing material, into 100 ml of a sodium hydroxide solution with a concentration of 5 M, stir at 35 °C for 7 h, centrifuge at a speed of 3000 rpm for 3 min to obtain molybdenum disulfide deposits. After washing to neutrality, disperse them into deionized water, ultrasonicate at a power of 100 W for 2 h to obtain a suspension, centrifuge at a speed of 3000 rpm for 2 min to remove the undelaminated material in the lower layer, obtain a dispersion, centrifuge at a speed of 9800 rpm for 8 min, pour off the supernatant to obtain nanosheets, and freeze at -35 °C for 12 h to obtain nanosheet powder;

[0076] Disperse 20 mg of nanosheet powder, 200 mg of cetyltrimethylammonium bromide, and 80 mg of zinc acetate dihydrate in 20 ml of deionized water, disperse under ultrasonic action for 30 min, stir at 35 °C for 1 h, add 29.2 ml of dimethyl sulfoxide, stir for 30 min and then heat up to 70 °C, react for 1.5 h and then cool and let stand for 4 h, centrifuge at 9000 rpm for 6 min, wash with absolute ethanol and deionized water, and freeze-dry at -35 °C to prepare a zinc oxide nanoring-modified friction self-repairing material.

[0077] The preparation method of castor oil-polysulfone microcapsules is as follows:

[0078] Add 1 g of polysulfone resin to 20 ml of dichloromethane, stir to dissolve, add multi-walled carbon nanotubes, and mix evenly to obtain solution A. The mass ratio of multi-walled carbon nanotubes to polysulfone resin is 0.04:1;

[0079] Add 0.1 g of castor oil to solution A, after ultrasonic oscillation, add solution B made of 0.5 g of gelatin, 0.4 g of PVA-1788, and 20 ml of deionized water until the dichloromethane volatilizes completely, filter by suction, and dry in vacuum at 50 °C to obtain castor oil-polysulfone resin microcapsules.

[0080] Comparative example

[0081] Comparative example 1: An anti-wear and antioxidant lubricating oil, the difference from Example 1 is that the graphene / aluminum oxide-coated powder is made from Preparation Example 3.

[0082] Comparative example 2: An anti-wear and antioxidant lubricating oil, the difference from Example 1 is that graphene is not coated with aluminum oxide, and only 3-aminopropyltriethoxysilane is used to treat graphene. The specific preparation method is as follows: Add 10 g of graphene to deionized water, ultrasonically disperse for 3 h to form a graphene suspension with a concentration of 1 wt%, heat up to 60 °C, add 10 g of 3-aminopropyltriethoxysilane, react for 6 h and then centrifuge, collect the precipitate, wash with deionized water, and freeze-dry at -35 °C.

[0083] Comparative Example 3: An anti-wear and antioxidant lubricating oil, which is different from Example 1 in that an equal amount of graphene is used to replace the graphene / aluminum oxide coated powder.

[0084] Comparative Example 4: An anti-wear and antioxidant lubricating oil, which is different from Example 1 in that an equal amount of friction improver is used to replace the friction self-repairing material.

[0085] Performance detection test

[0086] Prepare the lubricating oil according to the methods in the examples and comparative examples, and carry out performance detection with reference to the following methods. Record the detection results in Table 2.

[0087] 1. Coefficient of friction and wear scar diameter: Detect according to GB / T3142-1982 "Method for Determining the Load-Carrying Capacity of Lubricants (Four-Ball Method)".

[0088] 2. Viscosity index: Detect according to GB / T2541-1981 "Calculation Table for Viscosity Index of Petroleum Products".

[0089] 3. Corrosion resistance: Detect according to GB / T5096-2017 "Copper Strip Corrosion Test Method for Petroleum Products".

[0090] Table 2 Performance detection results of anti-wear and antioxidant lubricating oil

[0091]

[0092]

[0093] Combined with the data in Table 2 and the raw material usage in Examples 1-3, it can be seen that in Examples 1-3, the graphene / aluminum oxide coated powder is used, and the lubricating oil prepared has a small coefficient of friction and wear scar diameter, has high lubricity, and has little change in the coefficient of friction and wear scar diameter at 200 °C, has good high-temperature oxidation resistance, and has a large viscosity index, has good high-temperature viscosity stability, is not easily decomposed at high temperatures, and reduces wear.

[0094] In Example 4, a friction improver and a friction self-repairing material with a mass ratio of 1:2 are used. It can be seen that the lubricating oil prepared therefrom has a low coefficient of friction and wear scar diameter, and has little change in the coefficient of friction and wear scar diameter at high temperatures, and has lubrication and high-temperature oxidation resistance similar to those of Example 1.

[0095] In Example 5, the mass ratio of the friction improver to the friction self-repairing material is 1:1, and in Example 6, the mass ratio of the friction improver to the friction self-repairing material is 1:3. Compared with Example 1, for the lubricating oils prepared in Example 5 and Example 6, the wear scar diameter and the coefficient of friction increase slightly, and the lubrication effect at high temperatures weakens slightly. It can be seen that the friction self-repairing material and the friction improver can achieve a better lubrication effect when combined in an appropriate mass ratio.

[0096] Compared with Example 1, in Example 7, zinc oxide nanorings were used to modify the friction self-repairing material molybdenum disulfide, and zinc oxide nanorings were loaded on the molybdenum disulfide nanosheets. It can be seen that the friction coefficient of the lubricating oil decreased, the high-temperature resistance ability was improved, and its anti-corrosion ability was enhanced.

[0097] Compared with Example 1, in Examples 8 and 9, castor oil-polysulfone resin microcapsules were used as friction improvers. As shown in Table 2, the surface friction coefficient and wear scar diameter of the lubricating oil prepared in Examples 8-9 decreased, and the high-temperature resistance ability was slightly enhanced.

[0098] Compared with Example 8, in Example 10, multi-walled carbon nanotubes were not added to the wall material. It can be seen that the lubrication performance and high-temperature resistance ability of the prepared lubricating oil decreased slightly; compared with Example 8, in Example 11, white oil was used as the core material, and the prepared microcapsules were used as friction improvers. For the lubricating oil thus prepared, the lubrication ability decreased slightly.

[0099] Compared with Examples 1, 7 and 8, the prepared lubricating oil in Example 12 not only has strong lubrication, anti-friction and anti-wear effects, but also has excellent high-temperature oxidation resistance ability, and at the same time has strong anti-corrosion performance.

[0100] In Comparative Example 1, the graphene / aluminum oxide-coated powder prepared in Preparation Example 3 was used. In Preparation Example 3, 3-aminopropyltriethoxysilane was not used to treat the coated body. As can be seen from the data in Table 2, the lubrication and anti-friction effects of the prepared lubricating oil decreased.

[0101] Compared with Example 1, in Comparative Example 2, only 3-aminopropyltriethoxysilane was used to treat graphene, and alumina was not used for coating. As shown in Table 2, the initial lubrication effect of the prepared grease changed little, but after high temperature, the friction coefficient and wear scar diameter increased significantly, and the high-temperature oxidation resistance ability decreased significantly.

[0102] In Comparative Example 3, graphene was used to replace the graphene / aluminum oxide-coated powder in equal amount. Compared with Example 1, its lubrication ability decreased and the high-temperature oxidation resistance ability weakened.

[0103] Compared with Example 1, in Comparative Example 4, a friction improver was used to replace the friction self-repairing material. It can be seen that the overall friction coefficient of the lubricating oil increased and the lubrication ability decreased.

[0104] This specific embodiment is only an interpretation of the present application, and it is not a limitation of the present application. Those skilled in the art can make modifications without creative contributions to this embodiment according to needs after reading this specification, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A wear-resistant and antioxidant lubricating oil, characterized in that: The invention comprises the following raw materials in parts by weight: 50-70 parts of base oil, 30-50 parts of graphene / alumina coated powder, 5-10 parts of friction modifier, 2-4 parts of antioxidant, 0.5-1 parts of defoamer, 0.5-1.2 parts of rust inhibitor, and 10-15 parts of friction self-repairing nanomaterial; The graphene / alumina coated powder comprises a graphene core material and an alumina wall material, wherein the alumina wall material contains alumina and 3-aminopropyltriethoxysilane, and the mass ratio of graphene, alumina and 3-aminopropyltriethoxysilane is 1:2-3:1-2.

2. The wear-resistant and antioxidant lubricating oil according to claim 1, characterized in that: The preparation method of the graphene / alumina coated powder is as follows: Aluminum nitrate solution is added to a graphene suspension having a concentration of 0.5-1wt%, and after being stirred evenly, ammonia water is added dropwise until it becomes neutral, and after standing, centrifugation, washing, and sintering are performed to obtain a coating body; The coated body is dispersed in anhydrous ethanol solution, ultrasonically homogenized, heated to 60-70°C, 3-aminopropyltriethoxysilane is added, reacted for 5-6 hours, centrifuged, washed, and freeze-dried.

3. The wear-resistant and oxidation-resistant lubricating oil according to claim 1, characterized in that: The friction self-repairing nanomaterial has a two-dimensional layered structure and is selected from at least one of molybdenum disulfide, hexagonal boron nitride, and zirconium phosphate nanosheets.

4. The wear-resistant and oxidation-resistant lubricating oil according to claim 3, characterized in that: The friction self-repairing material is a friction self-repairing material modified by zinc oxide nano-rings.

5. The wear-resistant and oxidation-resistant lubricating oil according to claim 1, characterized in that: The friction modifier is castor oil-polysulfone resin microcapsules, wherein the core material of the castor oil-polysulfone resin microcapsules includes castor oil, the wall material includes polysulfone resin and multi-walled carbon nanotubes, and the mass ratio of polysulfone resin to multi-walled carbon nanotubes is 1:0.03-0.

04.

6. The wear-resistant and oxidation-resistant lubricating oil according to claim 1, characterized in that: The mass ratio of the friction modifier to the friction self-repairing material is 1:1.5-2.

7. The wear-resistant and oxidation-resistant lubricating oil according to claim 1, characterized in that: The antioxidant is composed of an amine antioxidant, a phenolic antioxidant and a phosphate antioxidant in a mass ratio of 1:0.5-2:0.5-2.

8. The wear-resistant and antioxidant lubricating oil according to claim 1, characterized in that: The rust inhibitor is selected from at least one of isononylphenoxyacetic acid, sorbitan monooleate, alkenylsuccinic acid and barium dinonylnaphthalenesulfonate.

9. The method for preparing the wear-resistant and oxidation-resistant lubricating oil according to any one of claims 1 to 8, characterized in that: The following steps are involved: The base oil is heated to 50-80° C., and an antioxidant and a friction self-repairing material are added while stirring, and mixed evenly to obtain a first mixture; The first mixture is heated to 100-110° C., stirred for 1-2 hours, and then graphene / alumina coated powder, friction modifier, rust inhibitor and defoamer are added. After uniform dispersion, the mixture is filtered and packaged to obtain wear-resistant and antioxidant lubricating oil.

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