Graphene oxide anti-wear lubricant and preparation method thereof
Through the preparation method of modified graphene oxide, the problem of weak antioxidant ability of existing lubricants at high temperatures is solved, and the stable performance and long life of lubricants at high temperatures are achieved.
Patent Information
- Application Number
- CN202510132362.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-06
- Publication Date
- 2025-05-13
AI Technical Summary
Existing lubricants have weak oxidation resistance at high temperatures, resulting in poor lubricating performance and short service life.
Through the preparation method of modified graphene oxide, bimolecular nucleophilic substitution reaction is carried out using raw materials such as 4-aminodiphenylamine and octane chloride to obtain intermediate 1, and react with graphene oxide, and finally react with hydrazine hydrate to obtain modified graphene oxide. This modified graphene oxide significantly improves antioxidant properties and lubricating properties in lubricants.
Modified graphene oxide lubricants have significant antioxidant ability at high temperatures, extending the service life of the lubricant and forming a stable lubricating film on the friction surface to reduce friction and wear.
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of lubricants, and in particular relates to a graphene oxide anti-wear lubricant and a preparation method thereof. Background Art
[0002] Lubricant is a material that can reduce friction and wear between two friction surfaces. Traditional lubricants, such as mineral oil, synthetic oil, etc., have problems such as poor lubrication, easy aging, and environmental pollution. With the rapid development of industry, the industry has higher and higher performance requirements for lubricants, and nanomaterials have received more and more attention as new lubricants. Graphene oxide (GO) is considered to be a potential lubricant material due to its excellent mechanical properties, chemical properties and lubrication characteristics. However, the GO-based lubricants reported in existing literature usually only show good lubrication effects under specific friction conditions and have weak antioxidant ability at high temperatures. Summary of the invention
[0003] In order to solve the problems of weak anti-oxidation ability and poor lubrication performance of existing lubricants, the present invention provides a graphene oxide anti-wear lubricant and a preparation method thereof.
[0004] The purpose of the present invention can be achieved through the following technical solutions:
[0005] A method for preparing a graphene oxide anti-wear lubricant, the method for preparing the lubricant comprising the following mass fractions: 0.01-0.05% modified graphene oxide, 0.5-5% ascorbic acid, 50-70% polyethylene glycol, and 24.98-49.45% deionized water;
[0006] (1) first adding polyethylene glycol to deionized water to obtain a first solution, then adding modified graphene oxide to the first solution and stirring to obtain a second solution, and ultrasonically dispersing the second solution to obtain a graphene oxide dispersion;
[0007] (2) Add ascorbic acid to the graphene oxide dispersion, heat it in a water bath, and adjust the pH value to 8-10 to obtain a graphene oxide anti-wear lubricant.
[0008] Further, the modified graphene oxide is prepared by the following steps:
[0009] Step 1: Under the protection of argon, add 4-aminodiphenylamine, N,N-dimethylformamide and sodium hydride into a flask, stir at room temperature for 1-3 hours, then add octadecane chloride, react for 1-3 hours, cool to 0-2°C, add deionized water to terminate the reaction, extract with ethyl acetate to obtain an organic phase, adjust the pH value of the organic phase to neutral, dry, and filter to obtain intermediate 1;
[0010] Step 2: Add graphene oxide and N-methylpyrrolidone into a conical flask, stir for 30-60 min at room temperature, and ultrasonicate for 30-60 min. Then, add 1-hydroxy-7-azobenzotriazole and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, stir for 30-60 min, and then add intermediate 1. Heat to 90-95° C., stir for 28-36 h, wash with ethanol, filter and dry to obtain intermediate 2.
[0011] The third step is to add the intermediate 2, anhydrous ethanol and hydrazine hydrate into a flask, stir at 75-85° C. for 24-36 hours, then centrifuge and wash, filter and dry to obtain modified graphene oxide.
[0012] Furthermore, the mass ratio of the 4-aminodiphenylamine, sodium hydride and octadecane chloride is 1:0.2-0.4:1.8-2.4.
[0013] Furthermore, the mass ratio of the graphene oxide, 1-hydroxy-7-azobenzotriazole, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and intermediate 1 is 1:0.08-0.12:1-1.2:0.3-0.6.
[0014] Furthermore, the usage ratio of the graphene oxide and hydrazine hydrate is 0.3-0.5 g:5 mL.
[0015] Furthermore, the temperature of the first solution is maintained at 36-45°C.
[0016] Furthermore, the stirring time is maintained at 40-60 min.
[0017] Furthermore, the ultrasonic power is 500-1000w, the ultrasonic temperature is 20-30°C, and the ultrasonic time is 1-2h.
[0018] Furthermore, the water bath heating temperature is 80-100° C., and the water bath time is 1-2 h.
[0019] Beneficial effects of the present invention:
[0020] 1. The present invention uses 4-aminodiphenylamine and octadecane chloride as raw materials to undergo a bimolecular nucleophilic substitution reaction to obtain an intermediate 1, and then reacts the intermediate 1 with graphene oxide. The carboxyl groups on the graphene oxide and the epoxy groups on the basal plane respectively undergo an amidation reaction and a nucleophilic substitution reaction with the amino groups in the intermediate 1 to obtain an intermediate 2, and finally undergoes a reduction reaction with hydrazine hydrate to obtain a modified graphene oxide. Diphenylamine can significantly improve the anti-oxidation performance of lubricants, and can effectively prevent graphene oxide and base oil from oxidative decomposition under adverse conditions such as high temperature and high pressure, thereby extending the service life of the lubricant. The benzene ring in its molecular structure can increase the polarity of the lubricant, making it easier to form a stable lubricating film on the metal surface, thereby reducing friction and wear; the hydrophobicity of the 18-carbon chain makes it easier to dissolve in oil, with better oil solubility, and also significantly improves the dispersibility of graphene oxide in lubricants and reduces the friction between lubricant molecules, making it easier to form a lubricating film on the friction surface, thereby reducing friction and wear; the reduced graphene sheet structure is more complete and the mechanical properties are restored, which helps to improve its lubricating performance as a lubricant. DETAILED DESCRIPTION
[0021] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0022] The molecular weight of polyethylene glycol is 200-800.
[0023] Example 1
[0024] A modified graphene oxide is prepared by the following steps:
[0025] Step 1: Under the protection of argon, 12 g of 4-aminodiphenylamine, 100 mL of N,N-dimethylformamide and 2.4 g of sodium hydride were added to a flask, stirred at 25°C for 1 h, and then 21.6 g of octadecane chloride was added, reacted for 1 h, cooled to 0°C, 250 mL of deionized water was added to terminate the reaction, and extracted with 250 mL of ethyl acetate to obtain an organic phase, the organic phase was adjusted to pH 7, dried, and filtered to obtain intermediate 1;
[0026] Step 2: Add 20 g of graphene oxide and 400 mL of N-methylpyrrolidone into a conical flask, stir for 30 min at 25 °C, and ultrasonicate for 30 min. Then, add 1.6 g of 1-hydroxy-7-azobenzotriazole and 20 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, stir for 30 min, and then add 6 g of intermediate 1. Heat to 90 °C, stir for 28 h, wash with ethanol, filter and dry to obtain intermediate 2.
[0027] Step 3: Add 3 g of intermediate 2, anhydrous ethanol and 50 mL of hydrazine hydrate into a flask, stir at 75° C. for 24 h, then centrifuge, wash, filter and dry to obtain modified graphene oxide.
[0028] Example 2
[0029] A modified graphene oxide is prepared by the following steps:
[0030] Step 1: Under the protection of argon, add 12 g of 4-aminodiphenylamine, 100 mL of N,N-dimethylformamide and 4 g of sodium hydride into a flask, stir at 25°C for 1-3 h, then add 24 g of octadecane chloride, react for 2 h, cool to 1°C, add 250 mL of deionized water to terminate the reaction, extract with 250 mL of ethyl acetate to obtain an organic phase, adjust the pH value of the organic phase to 7, dry, and filter to obtain intermediate 1;
[0031] Step 2: Add 20 g of graphene oxide and 400 mL of N-methylpyrrolidone into a conical flask, stir for 40 min at 25 °C, and ultrasonicate for 50 min. Then, add 2 g of 1-hydroxy-7-azobenzotriazole and 22 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, stir for 40 min, and then add 8 g of intermediate 1. Heat to 92 °C, stir for 32 h, wash with ethanol, filter and dry to obtain intermediate 2.
[0032] Step 3: Add 4 g of intermediate 2, anhydrous ethanol and 50 mL of hydrazine hydrate into a flask, stir at 80° C. for 30 h, then centrifuge, wash, filter and dry to obtain modified graphene oxide.
[0033] Example 3
[0034] A modified graphene oxide is prepared by the following steps:
[0035] Step 1: Under the protection of argon, 12 g of 4-aminodiphenylamine, 100 mL of N,N-dimethylformamide and 4.8 g of sodium hydride were added to a flask, stirred at 25°C for 3 h, and then 28.8 g of octadecane chloride was added, reacted for 3 h, cooled to 2°C, 250 mL of deionized water was added to terminate the reaction, and extracted with 250 mL of ethyl acetate to obtain an organic phase, the organic phase was adjusted to pH 7, dried, and filtered to obtain intermediate 1;
[0036] Step 2: Add 20 g of graphene oxide and 400 mL of N-methylpyrrolidone into a conical flask, stir for 60 min at 25 °C, and ultrasonicate for 60 min. Then, add 2.4 g of 1-hydroxy-7-azobenzotriazole and 24 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, stir for 60 min, and then add 12 g of intermediate 1. Heat to 95 °C, stir for 36 h, wash with ethanol, filter and dry to obtain intermediate 2.
[0037] Step 3: Add 5 g of intermediate 2, anhydrous ethanol and 50 mL of hydrazine hydrate into a flask, stir at 85° C. for 36 h, then centrifuge, wash, filter and dry to obtain modified graphene oxide.
[0038] Example 4
[0039] (1) First, 50 g of polyethylene glycol was added to 24.98 mL of deionized water to obtain a first solution, and the temperature of the first solution was maintained at 36 ° C. Then, 0.01 g of modified graphene oxide of Example 3 was added to the first solution and stirred for 40 min to obtain a second solution. The second solution was ultrasonically dispersed at an ultrasonic power of 500 w, an ultrasonic temperature of 20 ° C, and an ultrasonic time of 1 h to obtain a graphene oxide dispersion;
[0040] (2) Add 0.5 g of ascorbic acid to the graphene oxide dispersion and heat it in a water bath at 80° C. for 1 h. Adjust the pH value to 8 to obtain a graphene oxide anti-wear lubricant.
[0041] Example 5
[0042] (1) First, 70 g of polyethylene glycol was added to 49.45 mL of deionized water to obtain a first solution, the temperature of the first solution was maintained at 45 ° C, and then 0.05 g of modified graphene oxide in Example 2 was added to the first solution and stirred, and the stirring time was maintained at 60 min to obtain a second solution, and the second solution was ultrasonically dispersed at an ultrasonic power of 1000 w, an ultrasonic temperature of 30 ° C, and an ultrasonic time of 2 h to obtain a graphene oxide dispersion;
[0043] (2) Add 5 g of ascorbic acid to the graphene oxide dispersion and heat it in a water bath at a temperature of 100° C. for 2 h. Adjust the pH value to 10 to obtain a graphene oxide anti-wear lubricant.
[0044] Example 6
[0045] (1) First, 60 g of polyethylene glycol was added to 30 mL of deionized water to obtain a first solution, the temperature of the first solution was maintained at 40 ° C, and then 0.04 g of modified graphene oxide in Example 2 was added to the first solution and stirred, and the stirring time was maintained at 50 min to obtain a second solution, and the second solution was ultrasonically dispersed at an ultrasonic power of 800 w, an ultrasonic temperature of 25 ° C, and an ultrasonic time of 1.5 h to obtain a graphene oxide dispersion;
[0046] (2) Add 4 g of ascorbic acid to the graphene oxide dispersion and heat it in a water bath at 90° C. for 1.2 h. Adjust the pH value to 9 to obtain a graphene oxide anti-wear lubricant.
[0047] Comparative Example 1
[0048] Compared with Example 6, the modified graphene oxide in Example 6 is replaced by graphene oxide, and the remaining raw materials and preparation process are the same as Example 5.
[0049] The results of Examples 4 to 6 and Comparative Example 1 were subjected to 1. Antioxidation performance: The antioxidation performance of the lubricant to be tested at constant temperature and programmed temperature was tested using a NETZSCH-DSC-204HP high pressure differential scanning calorimeter. A cover-pierced aluminum crucible was used in the NETZSCH-DSC-204HP high pressure differential scanning calorimeter. The constant temperature test temperature was 210°C, the oxygen pressure was 3.5 MPa, and the oxygen flow rate was 100 mL / min; the programmed temperature was increased from room temperature to 300°C at a heating rate of 10°C / min, the oxygen pressure was 3.5 MPa, and the oxygen flow rate was 50 mL / min. Friction test: The conditions of this friction test are as follows: test apparatus: MMW-1 vertical universal friction and wear testing machine, MQL precision oil injection system; test method: four-ball friction test; test ball material: AISI52100 steel ball (hardness 59-61HRC), test ball diameter 12.7mm; MQL flow rate: 20 ml / h; MQL air pressure: 0.3 MPa; load: 40N; rotation speed: 800 rpm; test duration: 30 minutes.
[0050] The test results are shown in Table 1:
[0051] Table 1
[0052] project Example 4 Example 5 Example 6 Comparative Example 1 Friction coefficient 0.114 0.118 0.112 0.128 Oxidation induction period / min 36.82 42.56 44.82 6.28 Initial oxidation temperature / ℃ 260.2 232.4 246.8 164.2
[0053] It can be seen from Table 1 that, compared with Comparative Example 1, the friction coefficient prepared in Examples 4-6 is between 0.112 and 0.118, and the oxidation induction period is 36.82-44.82 min, and the initial oxidation temperature is 232.4-260.2°C. It can be seen that the lubricant prepared by the present invention has not only good lubrication performance under modified graphene oxide, but also good antioxidant ability.
[0054] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.
[0055] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A method for preparing a graphene oxide anti-wear lubricant, characterized in that: The preparation method of the lubricant comprises the following components in mass fractions: 0.01-0.05% of modified graphene oxide, 0.5-5% of ascorbic acid, 50-70% of polyethylene glycol, and 24.95-49.89% of deionized water; (1) first adding polyethylene glycol to deionized water to obtain a first solution, then adding modified graphene oxide to the first solution and stirring to obtain a second solution, and ultrasonically dispersing the second solution to obtain a graphene oxide dispersion; (2) Add ascorbic acid to the graphene oxide dispersion, heat it in a water bath, and adjust the pH value to 8-10 to obtain a graphene oxide anti-wear lubricant.
2. A method for preparing a graphene oxide anti-wear lubricant according to claim 1, characterized in that: Modified graphene oxide is prepared by the following steps: Step 1: Under the protection of argon, add 4-aminodiphenylamine, N,N-dimethylformamide and sodium hydride into a flask, stir at room temperature for 1-3 hours, then add octadecane chloride, react for 1-3 hours, cool to 0-2°C, add deionized water to terminate the reaction, extract with ethyl acetate to obtain an organic phase, adjust the pH value of the organic phase to neutral, dry, and filter to obtain intermediate 1; Step 2: Add graphene oxide and N-methylpyrrolidone into a conical flask, stir for 30-60 min at room temperature, and ultrasonicate for 30-60 min. Then, add 1-hydroxy-7-azobenzotriazole and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, stir for 30-60 min, and then add intermediate 1. Heat to 90-95° C., stir for 28-36 h, wash with ethanol, filter and dry to obtain intermediate 2. Step 3: Add intermediate 2, anhydrous ethanol and hydrazine hydrate into a flask, stir at 75-85° C. for 24-36 hours, then centrifuge, wash, filter and dry to obtain modified graphene oxide.
3. A method for preparing a graphene oxide anti-wear lubricant according to claim 2, characterized in that: The mass ratio of the 4-aminodiphenylamine, sodium hydride and octadecane chloride is 1:0.2-0.4:1.8-2.
4.
4. A method for preparing a graphene oxide anti-wear lubricant according to claim 2, characterized in that: The mass ratio of the graphene oxide, 1-hydroxy-7-azobenzotriazole, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and intermediate 1 is 1:0.08-0.12:1-1.2:0.3-0.
6.
5. A method for preparing a graphene oxide anti-wear lubricant according to claim 2, characterized in that: The usage ratio of the graphene oxide and hydrazine hydrate is 0.3-0.5 g:5 mL.
6. A method for preparing a graphene oxide anti-wear lubricant according to claim 1, characterized in that: The temperature of the first solution was maintained at 36-45°C.
7. A method for preparing a graphene oxide anti-wear lubricant according to claim 1, characterized in that: The stirring time is maintained at 40-60 min.
8. A method for preparing a graphene oxide anti-wear lubricant according to claim 1, characterized in that: The ultrasonic power is 500-1000w, the ultrasonic temperature is 20-30°C, and the ultrasonic time is 1-2h.
9. A method for preparing a graphene oxide anti-wear lubricant according to claim 1, characterized in that: The water bath heating temperature is 80-100° C., and the water bath time is 1-2 hours.