A kind of graphene lubricating oil and preparation method thereof

Abstract

The invention belongs to the technical field of lubricating oils, discloses a graphene lubricating oil and a preparation method thereof, the graphene lubricating oil comprises 85-100 parts of base oil; 4-6 parts of modified graphene powder; 1-2 parts of polymer thickener; 1-2 parts of additive, and the raw material is simple, the dispersibility is good, the sedimentation is not easy to occur, the stability is good, and the practicability is strong. The preparation method is to mix the base oil, the graphene powder, the polymer thickener and the additive, and then disperse. The preparation method of the present invention is easy to operate and is suitable for large-scale production.

Description

Technical Field

[0001] The present invention relates to the technical field of lubricating oils, and in particular to a graphene lubricating oil and a preparation method thereof. Background Art

[0002] In the mechanical field, lubricating oil is usually used on mechanical parts to reduce friction and wear between mechanical parts and increase the service life of mechanical parts. Currently, the lubricating oil on the market is mainly composed of base oil and additives. The base oil mainly plays a lubricating role, and the additives are mainly used to improve the properties of the base oil.

[0003] Compared with ordinary lubricants, graphene lubricants have better lubrication performance, stronger adaptability, and better high temperature resistance. Specifically, graphene has super lubrication performance and can effectively reduce the friction resistance of mechanical equipment, engines, etc., making graphene lubricants perform well in reducing friction and wear, thereby extending the service life of equipment; graphene lubricants can play a good role in both wet and dry environments, and can maintain a stable lubrication effect in both wet and dry environments, and have a wider range of applicability; graphene lubricants can also maintain lubrication effects in high temperature environments, are not easy to oxidize and decompose, and can still play an excellent lubricating role under high temperature conditions to protect equipment from high temperature damage.

[0004] Although graphene lubricants have many good properties, they still have certain defects. For example, graphene itself is neither soluble in water nor in oil, and it is difficult to disperse evenly in the base oil, and it is easy to aggregate and settle. Long-term use may cause graphene to deposit inside the engine, which will not only increase the wear of mechanical components and affect the overall performance and life of the engine; it may also cause mechanical components to overheat or fail, affecting the normal use of the equipment and even causing safety accidents. Summary of the invention

[0005] The object of the present invention is to provide a graphene lubricant, which has simple raw materials, good dispersibility, is not prone to sedimentation, has good stability and is highly practical.

[0006] The technical solution adopted to achieve the purpose of the present invention is:

[0007] A graphene lubricant specifically comprises the following raw materials in parts by weight: 85-100 parts of base oil; 4-6 parts of modified graphene powder; 1-2 parts of polymer thickener; and 1-2 parts of additives.

[0008] Furthermore, the base oil is a mineral base oil or a synthetic base oil.

[0009] Furthermore, the polymer thickener is one or more of polyacrylate, polyurethane, hydroxyethyl cellulose or sodium carboxymethyl cellulose.

[0010] Further, the additives include tristearin, polymethacrylate, octylphenol, a fluorine surfactant, a silane coupling agent and diisocyanate.

[0011] In the graphene lubricant of the present invention, the base oil can form a protective oil film on the surface of mechanical devices, reducing friction and wear between devices. Graphene powder is a non-polar substance that can be miscible with the base oil, thereby enhancing the strength and stability of the oil film; and the nanoscale size and excellent mechanical properties of graphene enable it to form a uniform and firm lubricating film on the metal surface, further reducing the friction coefficient and wear rate. The synergistic effect of the base oil of the invention and graphene can significantly improve the lubrication effect.

[0012] In actual selection, the base oil can be selected from mineral base oil or synthetic base oil, wherein the mineral base oil is derived from the petroleum refining process, and common mineral base oils include Shell Red Helix HX3, Yellow Helix HX5 and Mobil Lipo. The overall cost of mineral base oil is relatively low, and the stability is good, which is suitable for general lubrication needs, but it may contain certain impurities and aromatic hydrocarbons, which have a certain impact on environmental performance. Synthetic base oil is mainly synthesized by chemical reaction, and common synthetic base oils include poly alpha-olefin (PAO) and polyether compound (PAG). Synthetic base oil has excellent physical and chemical properties, outstanding antioxidant performance and high temperature resistance, is suitable for lubrication needs under extreme conditions, and has good environmental performance and less impact on the environment. Compared with mineral base oil, synthetic base oil has more stable physical and chemical properties, better lubrication performance, wider temperature adaptability, stronger corrosion resistance, longer oil change cycle and better environmental performance. Therefore, the invention preferably base oil is synthetic base oil.

[0013] In terms of extreme pressure performance and load-bearing capacity, PAG may have more advantages, while in terms of viscosity-temperature performance, thermal stability and oxidation stability, PAO performs well, can maintain stable lubrication performance in a wide temperature range, and resist high temperature and oxidation. In addition, in terms of additive sensitivity, PAO also has more advantages, can work in conjunction with more additives, and improve the comprehensive performance of lubricating oil. Therefore, the base oil of the present invention is preferably a composite of PAO and PAG on the basis of selecting a synthetic base oil, and the two can complement each other in and out of the composite as a base oil, play a synergistic effect, significantly improve the quality of the base oil, balance the performance of the lubricating oil, and have better comprehensive performance.

[0014] The polymer thickener in the present invention can effectively increase the viscosity of the lubricating oil, thereby increasing the suspension stability of the graphene particles in the lubricating oil and preventing them from settling. In the present invention, the polymer thickener can be one or more of polyacrylate, polyurethane, hydroxyethyl cellulose or sodium carboxymethyl cellulose. Polyacrylate, as the raw material of the graphene lubricating oil of the present invention, can effectively disperse the graphene particles in the oil through the adsorption and bridging effect of its polymer chain, reduce the agglomeration between particles, and thus improve the dispersibility. Polyurethane can stably disperse the graphene particles in the oil through the entanglement and adsorption of its molecular chain, and polyurethane can also form chemical bonds with the graphene particles through its unique chemical structure, further enhancing the dispersion stability. Hydroxyethyl cellulose can increase the viscosity of the lubricating oil through the adsorption and expansion of its molecular chain, while improving the dispersibility of the graphene particles, and hydroxyethyl cellulose can also prevent the agglomeration and sedimentation of the graphene particles through its steric hindrance effect. Sodium carboxymethyl cellulose can be used as a dispersant, and graphene particles can be effectively dispersed in oil through the adsorption and electrostatic repulsion of its polymer chain. Sodium carboxymethyl cellulose can also increase the viscosity of the lubricating oil and increase the stability of the system. The addition of additives can make the graphene lubricating oil of the present invention have a higher annual index, stability, excellent anti-wear and antifreeze properties, etc.

[0015] Another object of the present invention is to provide a method for preparing graphene lubricant oil, wherein the product prepared by the method has good dispersibility and stability, and the method is easy to prepare and suitable for large-scale production.

[0016] The technical solution adopted to achieve another purpose of the present invention is:

[0017] A method for preparing graphene lubricating oil comprises the following specific steps: mixing base oil, graphene powder, polymer thickener and additives, and then dispersing them.

[0018] Furthermore, the specific preparation steps of the graphene lubricant are:

[0019] Step S1, adding additives to the modified graphene powder and dispersing them evenly to obtain a mixture A;

[0020] Step S2, mixing the base oil and the polymer thickener and stirring them thoroughly to obtain a mixture B;

[0021] Step S3, slowly adding mixture A into mixture B and stirring evenly.

[0022] Furthermore, in step S1, the preparation method of the modified graphene powder is specifically as follows: firstly, the graphene powder raw material is subjected to oxidation treatment, oxygen-containing groups are introduced on the surface of the graphene, and then the modified graphene powder is obtained by reduction treatment.

[0023] The beneficial effects of the present invention are as follows: the raw materials of the present invention are simple and easy to obtain, the graphene lubricating oil prepared by using the raw materials of the present invention has a small friction coefficient and wear rate, and is uniformly dispersed as a whole and is not easy to settle. In addition, the preparation method of the present invention is easy to operate and is suitable for large-scale production. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the following will be described clearly and completely in combination with the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are partial embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention.

[0025] A graphene lubricant specifically comprises the following raw materials in parts by weight: 85 parts of base oil; 4 parts of modified graphene powder; 1 part of polymer thickener; and 1 part of additive.

[0026] In the above raw materials, the base oil is a synthetic base oil, and the synthetic base oil is a compound of PAO and PAG in a ratio of 1:1.

[0027] The preparation method of modified graphene powder is specifically as follows:

[0028] The first step is to oxidize the graphene material, introduce oxygen-containing groups to oxidize the surface of the graphene powder, such as introducing epoxy groups, carboxyl groups and hydroxyl groups. During the treatment, a compound containing a single alkylamine group is selected as a surface treatment agent so that it is easy to react with the oxygen-containing groups on the surface of the graphene. In actual selection, in order to ensure the dispersibility of the graphene powder in the lubricating oil, the above-mentioned surface treatment agent can be selected from 1-aminoundecane, dodecylamine, tridecylamine, tetradecylamine, 1-aminopentadecane, hexadecylamine, 1-aminoheptadecane, octadecylamine or 1-aminononadecane. The present invention preferably uses hexadecylamine, 1-aminoheptadecane, octadecylamine or 1-aminononadecane to improve the dispersion stability of the graphene powder in the lubricating oil.

[0029] The second step is to reduce the oxidized graphene powder. After the graphene powder is treated with the above-mentioned surface treatment agent, it is reduced to obtain modified graphene powder. This process is to ensure that the graphene modified by the surface treatment agent has a suitable atomic ratio of oxygen element / carbon element.

[0030] Among the above raw materials, the polymer thickener is polyacrylate, polyurethane, hydroxyethyl cellulose and sodium carboxymethyl cellulose mixed in a ratio of 1:2:0.5:1.

[0031] Among the above raw materials, the additives are tristearate glyceryl, polymethacrylate, octylphenol, fluorine surfactant, silane coupling agent and diisocyanate, which are compounded in the ratio of 4:2.5:3:1:4.5:2.

[0032] The specific steps of the preparation method of the above graphene lubricant are:

[0033] Step S1, adding tristearate glyceryl, polymethacrylate, octylphenol, fluorosurfactant, silane coupling agent and diisocyanate to modified graphene powder, and uniformly dispersing them to obtain mixture A.

[0034] Step S2, mixing the base oil and the polymer thickener and stirring them thoroughly to obtain a mixture B.

[0035] Step S3, slowly adding mixture A into mixture B and stirring evenly.

[0036] In step S1, an ultrasonic disperser is used to fully mix and disperse during dispersion to ensure that the graphene powder is evenly distributed in the base oil; in step S2, a high-speed stirrer is used for stirring to fully mix the raw materials.

[0037] The graphene lubricant product can be obtained by processing the raw materials using the preparation method of this embodiment.

[0038] Embodiment 2-5

[0039] The raw materials and processing methods of Examples 2-5 are exactly the same as those of Example 1, and the only difference is that the specific dosage ratios of the raw materials are different. The specific comparison of the raw material ratios of Examples 1-5 is shown in Table 1 below.

[0040] Table 1 Comparison of raw materials and proportions of Examples 1-5

[0041]

[0042]

[0043] The raw materials of Examples 1-5 are processed into the above-mentioned graphene lubricating oil, and then the graphene lubricating oil is subjected to stability tests, including indicators such as friction coefficient and wear rate, to ensure that it meets the use requirements.

[0044] The specific method for observing the dispersion and sedimentation conditions is as follows: each group of samples is left to stand for a period of time, and then the sedimentation of the graphene particles is observed to evaluate and judge the dispersion and sedimentation of the graphene particles, and the observation is made every 6 hours.

[0045] Choose a four-ball friction and wear tester, and the model can be MMW-10 or MRS-10. The above equipment can simulate the friction conditions in actual work and accurately measure the friction coefficient and wear rate.

[0046] The test results are shown in Table 2 below:

[0047] Table 2 Comparison of stability test results of Examples 1-5

[0048]

[0049] In the above test process, the lower the friction coefficient value, the better the anti-wear performance of the lubricant; the lower the wear rate value, the better the anti-wear performance of the lubricant.

[0050] According to the results in Table 2 above, it can be seen that the dispersion effect of Examples 2-5 of the present invention is better than that of Example 1, and the friction coefficient and wear rate are smaller. In Examples 2-5, the friction coefficient, wear rate and dispersion of Example 4 are better than those of other examples, and there is no obvious sedimentation within 96 hours. Therefore, in Examples 2-5, Example 4 of the present invention is the best example.

[0051] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the scope of the present invention should be included in the protection scope of the present invention.

Claims

1. A graphene lubricant, characterized in that: Specifically, the raw materials include the following parts by weight: 85-100 parts of base oil; 4-6 parts of modified graphene powder; 1-2 parts of polymer thickener; and 1-2 parts of additives.

2. The graphene lubricant according to claim 1, characterized in that: The base oil is a mineral base oil and / or a synthetic base oil.

3. The graphene lubricant according to claim 1 or 2, characterized in that: The polymer thickener is one or more of polyacrylate, polyurethane, hydroxyethyl cellulose or sodium carboxymethyl cellulose.

4. The graphene lubricant according to claim 1 or 2, characterized in that: The additives include tristearate, polymethacrylate, octylphenol, fluorine surfactant, silane coupling agent and diisocyanate.

5. A method for preparing the graphene lubricant according to any one of claims 1 to 4, characterized in that: The specific steps are: mixing base oil, graphene powder, polymer thickener and additives, and then dispersing to obtain the graphene lubricating oil.

6. The method for preparing graphene lubricating oil according to claim 5, characterized in that: The specific preparation steps of the graphene lubricant are: Step S1, adding additives to the modified graphene powder and dispersing them evenly to obtain a mixture A; Step S2, mixing the base oil and the polymer thickener and stirring them thoroughly to obtain a mixture B; Step S3, slowly adding mixture A into mixture B and stirring evenly.

7. The method for preparing graphene lubricating oil according to claim 6, characterized in that: In step S1, the method for preparing the modified graphene powder is specifically as follows: firstly, the graphene powder raw material is subjected to oxidation treatment to introduce oxygen-containing groups on the surface of the graphene, and then subjected to reduction treatment to obtain the modified graphene powder.

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