Organic graphene oxide antifriction agent and preparation method thereof

Abstract

The preparation method comprises the following steps: firstly, taking graphite as a base to react with concentrated hydrochloric acid, sodium sulfate and potassium permanganate, then adding sodium hypochlorite, monoethanolamine and o-chloro-p-nitroaniline, and adopting a method of adjusting the pH value to obtain graphene oxide beneficial to a good reaction in the next step; then reacting with phosphorus pentoxide, methanol and oil-based primary amine, and adopting a two-step pressure-dividing and pressure-reducing method, so as to prepare the organic graphene oxide friction reducer with good oil solubility and excellent friction reducing property. The production method is simple, low in cost, good in oil solubility and high in yield.

Description

Technical Field

[0001] The invention belongs to the field of chemical synthesis, and in particular relates to an oil-soluble organic graphene oxide friction reducer and a preparation method thereof. Background Art

[0002] Carbon has three allotropes: graphite, diamond and fullerene. A single layer of graphite, called graphene, can last for more than 6,500 "wear cycles", a significant improvement over traditional lubricants such as graphite or molybdenum disulfide. In contrast, a lubricant with 1,000 layers of traditional graphite can only last for about 1,000 wear cycles.

[0003] The nano friction between graphene layers mainly depends on the lattice commensurability between graphene layers. Among them, the sliding friction between non-commensurately stacked graphene layers is very small, and even super lubrication occurs. Some literature suggests that under "vacuum" conditions, the friction and friction coefficient decrease with the increase in the number of layers. After the seventh layer, the friction no longer changes within the error range, and its friction coefficient tends to zero. Basically, as the number of layers increases, the interaction with the substrate gradually weakens and is worn away.

[0004] Fewer layers have better wear resistance, but the friction coefficient decreases with more layers. Generally speaking, the introduction of defects will increase its compatibility, thereby increasing the friction between layers.

[0005] If graphene is applied to lubricating oil, the friction coefficient of the lubricating oil can be greatly reduced, which can save fuel, reduce noise and improve power. However, since graphene is a solid, how to solve its oil solubility is the most critical issue, and people have been exploring this issue for many years. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide an organic graphene oxide friction reducer with simple production method, low cost, good oil solubility and high yield and a preparation method thereof. The additive is an oil-soluble organic graphene oxide friction reducer, which is a friction modifier and anti-wear agent for lubricating oil, especially lubricating oil for internal combustion engines, and has a significant fuel-saving effect.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for preparing an organic graphene oxide friction reducer, the steps are as follows:

[0008] 1) Synthesis of graphene oxide

[0009] Put graphite and concentrated hydrochloric acid in a container, stir evenly, add sodium sulfate and potassium permanganate, react at 90°C to 100°C under vacuum for 2 to 3 hours, add sodium hypochlorite and monoethanolamine, adjust the pH value to 7, continue stirring for not less than 20 minutes, add o-chloro-p-nitroaniline, stir, continue to react at 100 to 120°C for 3 to 4 hours, cool down, and obtain a brown graphene oxide mixture;

[0010] 2) Synthesis of organic graphene oxide friction reducer

[0011] The prepared graphene oxide mixture is mixed with phosphorus pentoxide and methanol, stirred evenly, and reacted for 4 to 5 hours at a temperature of 100 to 120° C. and a pressure of 0.1 MPa; cooled to 40 to 50° C., added with an oleyl primary amine, the temperature is increased to 200 to 210° C., and the reaction is continued for 3 to 4 hours under the condition of constant pressure, then cooled to 100° C., and vacuumed to a pressure of 0.1 MPa; finally filtered to obtain a yellow organic graphene oxide friction reducer.

[0012] In the step 1), the mass ratio of graphite: concentrated hydrochloric acid: sodium sulfate: potassium permanganate: sodium hypochlorite: monoethanolamine: o-chloro-p-nitroaniline is 1:10-14:10-14:5-7:5-7:20-25:20-25.

[0013] In the step 2), the mass ratio of graphene oxide, phosphorus pentoxide, methanol and oleyl primary amine is 1:2-3:20-25:20-25.

[0014] Preferably, in step 1), the mass ratio of graphite:concentrated hydrochloric acid:sodium sulfate:potassium permanganate:sodium hypochlorite:monoethanolamine:o-chloro-p-nitroaniline is 1:10:10:5:5:20:20.

[0015] Preferably, in the step 2), the mass ratio of graphene oxide, phosphorus pentoxide, methanol and oleyl primary amine is 1:2:20:20.

[0016] The organic graphene oxide friction reducer prepared by the above preparation method.

[0017] The beneficial effects of the present invention are as follows: the prepared organic graphene oxide friction reducer is a friction modifier and anti-wear agent for lubricating oil, especially lubricating oil for internal combustion engines, and has significant friction reduction and fuel saving effects. Due to low sulfur and low phosphorus, the additive also has the advantages of energy saving and environmental protection. The production method is simple, the cost is low, the oil solubility is good, and the yield is high. DETAILED DESCRIPTION

[0018] The present invention is further described in detail below in conjunction with specific embodiments:

[0019] The preparation method of the organic graphene oxide friction reducer of the present invention comprises the following steps:

[0020] 1) Synthesis of graphene oxide

[0021] Put graphite and concentrated hydrochloric acid in a container, stir evenly, add sodium sulfate and potassium permanganate, react at 90°C to 100°C under vacuum for 2 to 3 hours, add sodium hypochlorite and monoethanolamine, adjust the pH value to 7, continue stirring for not less than 20 minutes, add o-chloro-p-nitroaniline, stir, continue to react at 100 to 120°C for 3 to 4 hours, cool down, and obtain a brown graphene oxide mixture;

[0022] 2) Synthesis of organic graphene oxide friction reducer

[0023] The prepared graphene oxide mixture is mixed with phosphorus pentoxide and methanol, stirred evenly, and reacted for 4 to 5 hours at a temperature of 100 to 120° C. and a pressure of 0.1 MPa; cooled to 40 to 50° C., added with an oleyl primary amine, the temperature is increased to 200 to 210° C., and the reaction is continued for 3 to 4 hours under the condition of constant pressure, then cooled to 100° C., and vacuumed to a pressure of 0.1 MPa; finally filtered to obtain a yellow organic graphene oxide friction reducer.

[0024] In the step 1), the mass ratio of graphite: concentrated hydrochloric acid: sodium sulfate: potassium permanganate: sodium hypochlorite: monoethanolamine: o-chloro-p-nitroaniline is 1:10-14:10-14:5-7:5-7:20-25:20-25.

[0025] In the step 2), the mass ratio of graphene oxide, phosphorus pentoxide, methanol and oleyl primary amine is 1:2-3:20-25:20-25.

[0026] Preferably, in step 1), the mass ratio of graphite:concentrated hydrochloric acid:sodium sulfate:potassium permanganate:sodium hypochlorite:monoethanolamine:o-chloro-p-nitroaniline is 1:10:10:5:5:20:20.

[0027] Preferably, in the step 2), the mass ratio of graphene oxide, phosphorus pentoxide, methanol and oleyl primary amine is 1:2:20:20.

[0028] The organic graphene oxide friction reducer prepared by the above preparation method.

[0029] The present invention first performs polarity modification and oxidation on graphene and then effectively cooperates with long-chain amines; the surface energy of the modified graphene is greatly reduced, and a single molecule adsorption layer and a multi-molecule structure layer are formed. Under the action of high temperature and pressure, the multi-layer structure will decompose to reduce the friction coefficient, and at the same time, the decomposed single molecular layer will exert better wear resistance.

[0030] Organic graphene oxide friction reducer is dissolved in various lubricating oils in liquid form, and the minimum friction coefficient can be reduced to 0.0187; it can significantly improve the film-forming and load-bearing capacity of lubricating oils. Under normal working conditions of lubricating parts, a physical and chemical adsorption film with friction reduction and anti-wear effects is formed on the friction surface. This adsorption film is sliding friction; it further protects the engine.

[0031] The organic graphene oxide friction reducer of the present invention is an ionic liquid compound with good oil solubility and will never precipitate. It is also low in sulfur and phosphorus, has a small dosage and high performance, and is a rare environmentally friendly lubricant. Therefore, the use of organic graphene oxide friction reducer can achieve the following effects:

[0032] 1. Reduce friction coefficient: can be reduced by more than 50%.

[0033] 2. Save fuel: can save more than 10% of fuel.

[0034] 3. Effectively improve engine power.

[0035] Example 1

[0036] 1) Synthesis of graphene oxide

[0037] Graphite and concentrated hydrochloric acid are placed in a container, stirred evenly, sodium sulfate and potassium permanganate are added, reacted at 100° C. under vacuum (pressure = 0.10 MPa) for 2 hours, sodium hypochlorite and monoethanolamine are added, pH value is adjusted to 7, stirring is continued for 20 minutes, o-chloro-p-nitroaniline is added, stirred, and the reaction is continued at 120° C. for 3 hours, and the temperature is lowered to obtain a brown graphene oxide mixture;

[0038] In terms of mass ratio, the mass ratio of graphite: concentrated hydrochloric acid: sodium sulfate: potassium permanganate: sodium hypochlorite: monoethanolamine: o-chloro-p-nitroaniline is 1:10:10:5:5:20:20.

[0039] 2) Synthesis of organic graphene oxide friction reducer

[0040] 5 g of the graphene oxide mixture prepared above was mixed with 10 g of phosphorus pentoxide and 100 g of methanol, stirred evenly, and reacted for 4 hours at a temperature of 100° C. and a pressure of 0.1 MPa; cooled to 40° C., 100 g of oleyl primary amine was added, the temperature was increased to 200° C., and the reaction was continued for 3 hours under the condition of constant pressure, then cooled to 100° C., and vacuumed to a pressure of 0.1 MPa; finally filtered to obtain a yellow organic graphene oxide friction reducer.

[0041] The friction and anti-wear performance and load-bearing capacity of the product were investigated by using a four-ball tester to measure the extreme pressure and friction and anti-wear performance under a set load (temperature 20°C, load 392N, speed 1200R / min, time 60min). The steel ball used in the four-ball test was a GCR steel ball with a diameter of 12.7mm. The test showed that the product had good extreme pressure and friction and anti-wear performance. By comparison, when lubricating oil was directly used, the wear spot diameter reached 0.9mm. When 1% (by mass) of the product prepared in this embodiment was added to API SP0W / 40 lubricating oil, the wear spot diameter reached 0.32mm and the friction coefficient was 0.0117.

[0042] Example 2

[0043] 1) Synthesis of graphene oxide

[0044] Graphite and concentrated hydrochloric acid are placed in a container, stirred evenly, sodium sulfate and potassium permanganate are added, reacted at 90° C. under vacuum (pressure = 0.10 MPa) for 3 hours, sodium hypochlorite and monoethanolamine are added, pH value is adjusted to 7, stirring is continued for 20 minutes, o-chloro-p-nitroaniline is added, stirred, and the reaction is continued at 110° C. for 4 hours, and the temperature is lowered to obtain a brown graphene oxide mixture;

[0045] In terms of mass ratio, graphite: concentrated hydrochloric acid: sodium sulfate: potassium permanganate: sodium hypochlorite: monoethanolamine: o-chloro-p-nitroaniline = 1:14:14:7:7:25:25.

[0046] 2) Synthesis of organic graphene oxide friction reducer

[0047] 10 g of the graphene oxide mixture prepared above was mixed with 25 g of phosphorus pentoxide and 250 g of methanol, stirred evenly, and reacted for 5 hours at a temperature of 120° C. and a pressure of 0.1 MPa; cooled to 40° C., 250 g of oleyl primary amine was added, the temperature was increased to 210° C., and the reaction was continued for 4 hours under the condition of constant pressure, then cooled to 100° C., and vacuumed to a pressure of 0.1 MPa; finally filtered to obtain a yellow organic graphene oxide friction reducer.

[0048] The friction and anti-wear performance and load-bearing capacity of the product were investigated by using a four-ball tester to measure the extreme pressure and friction and anti-wear performance under a set load (temperature 25°C, load 392N, speed 1200R / min, time 60min). The steel ball used in the four-ball test was a GCR steel ball with a diameter of 12.7mm. The test showed that the product had good extreme pressure and friction and anti-wear performance. By comparison, when lubricating oil was directly used, the wear spot diameter reached 0.9mm. When 1% (by mass) of the product prepared in this embodiment was added to API SP0W / 40 lubricating oil, the wear spot diameter reached 0.31mm and the friction coefficient was 0.0127.

[0049] Example 3

[0050] 1) Synthesis of graphene oxide

[0051] Graphite and concentrated hydrochloric acid are placed in a container and stirred evenly. Sodium sulfate and potassium permanganate are added to react at 95° C. under vacuum (pressure = 0.10 MPa) for 2.5 hours. Sodium hypochlorite and monoethanolamine are added to adjust the pH value to 7. The stirring is continued for 20 minutes. O-chloro-p-nitroaniline is added and stirred. The reaction is continued at 110° C. for 3.5 hours. The temperature is lowered to obtain a brown graphene oxide mixture.

[0052] By mass ratio, graphite: concentrated hydrochloric acid: sodium sulfate: potassium permanganate: sodium hypochlorite: monoethanolamine: o-chloro-p-nitroaniline = 1:12:12:6:6:21:21.

[0053] 2) Synthesis of organic graphene oxide friction reducer

[0054] 8 g of the graphene oxide mixture prepared above was mixed with 20 g of phosphorus pentoxide and 180 g of methanol, stirred evenly, and reacted at a temperature of 110° C. and a pressure of 0.1 MPa for 4.5 hours; cooled to 40° C., 180 g of oleyl primary amine was added, the temperature was increased to 205° C., and the reaction was continued for 3.5 hours under the condition of constant pressure, then cooled to 100° C., and vacuumed to a pressure of 0.1 MPa; finally filtered to obtain a yellow organic graphene oxide friction reducer.

[0055] The friction and anti-wear performance and load-bearing capacity of the product were investigated by using a four-ball tester to measure the extreme pressure and friction and anti-wear performance under a set load (temperature 25°C, load 392N, speed 1200R / min, time 60min). The steel ball used in the four-ball test was a GCR steel ball with a diameter of 12.7mm. The test showed that the product had good extreme pressure and friction and anti-wear performance. By comparison, when lubricating oil was directly used, the wear spot diameter reached 0.9mm. When 1% (by mass) of the product prepared in this embodiment was added to API SP0W / 40 lubricating oil, the wear spot diameter reached 0.35mm and the friction coefficient was 0.0121.

[0056] Example 4

[0057] 1) Synthesis of graphene oxide

[0058] Graphite and concentrated hydrochloric acid are placed in a container and stirred evenly. Sodium sulfate and potassium permanganate are added to react at 98° C. under vacuum (pressure = 0.10 MPa) for 2.5 hours. Sodium hypochlorite and monoethanolamine are added to adjust the pH value to 7. The stirring is continued for 20 minutes. O-chloro-p-nitroaniline is added and stirred. The reaction is continued at 100° C. for 4 hours. The temperature is lowered to obtain a brown graphene oxide mixture.

[0059] By mass ratio, graphite: concentrated hydrochloric acid: sodium sulfate: potassium permanganate: sodium hypochlorite: monoethanolamine: o-chloro-p-nitroaniline = 1:11:11:5.5:5.5:23:23.

[0060] 2) Synthesis of organic graphene oxide friction reducer

[0061] 20 g of the graphene oxide mixture prepared above was mixed with 45 g of phosphorus pentoxide and 460 g of methanol, stirred evenly, and reacted at a temperature of 120° C. and a pressure of 0.1 MPa for 5 hours; cooled to 40° C., 450 g of oleyl primary amine was added, the temperature was increased to 203° C., and the reaction was continued for 3 hours under the condition of constant pressure, then cooled to 100° C., and vacuumed to a pressure of 0.1 MPa; finally filtered to obtain a yellow organic graphene oxide friction reducer.

[0062] The friction and anti-wear performance and load-bearing capacity of the product were investigated by using a four-ball tester to measure the extreme pressure and friction and anti-wear performance under a set load (temperature 25°C, load 392N, speed 1200R / min, time 60min). The steel ball used in the four-ball test was a GCR steel ball with a diameter of 12.7mm. The test showed that the product had good extreme pressure and friction and anti-wear performance. By comparison, when lubricating oil was directly used, the wear spot diameter reached 0.9mm. When 1% (by mass) of the product prepared in this embodiment was added to API SP0W / 40 lubricating oil, the wear spot diameter reached 0.30mm and the friction coefficient was 0.0119.

[0063] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing an organic graphene oxide friction reducer, characterized in that: The following steps are involved: 1) Synthesis of graphene oxide Put graphite and concentrated hydrochloric acid in a container, stir evenly, add sodium sulfate and potassium permanganate, react for 2 to 3 hours under vacuum conditions at 90°C to 100°C, add sodium hypochlorite and monoethanolamine, adjust the pH value to 7, continue stirring for not less than 20 minutes, add o-chloro-p-nitroaniline, stir, continue to react for 3 to 4 hours at a temperature of 100 to 120°C, cool, and obtain a brown graphene oxide mixture; 2) Synthesis of organic graphene oxide friction reducer The prepared graphene oxide mixture is mixed with phosphorus pentoxide and methanol, stirred evenly, and reacted for 4 to 5 hours at a temperature of 100 to 120° C. and a pressure of 0.1 MPa; cooled to 40 to 50° C., added with an oleyl primary amine, the temperature is increased to 200 to 210° C., and the reaction is continued for 3 to 4 hours under the condition of constant pressure, then cooled to 100° C., and vacuumed to a pressure of 0.1 MPa; finally filtered to obtain a yellow organic graphene oxide friction reducer.

2. The method for preparing an organic graphene oxide friction reducer according to claim 1, wherein In the step 1), the mass ratio of graphite: concentrated hydrochloric acid: sodium sulfate: potassium permanganate: sodium hypochlorite: monoethanolamine: o-chloro-p-nitroaniline is 1:10-14:10-14:5-7:5-7:20-25:20-25.

3. The preparation method of organic graphene oxide friction reducer according to claim 1, characterized in that, In the step 2), the mass ratio of graphene oxide: phosphorus pentoxide: methanol: oleyl primary amine is 1:2-3:20-25:20-25.

4. The method for preparing an organic graphene oxide friction reducer according to claim 2, wherein: In the step 1), the mass ratio of graphite: concentrated hydrochloric acid: sodium sulfate: potassium permanganate: sodium hypochlorite: monoethanolamine: o-chloro-p-nitroaniline is 1:10:10:5:5:20:

20.

5. The method for preparing the organic graphene oxide friction reducer according to claim 3, wherein: In the step 2), the mass ratio of graphene oxide: phosphorus pentoxide: methanol: oleyl primary amine is 1:2:20:

20.

6. An organic graphene oxide friction reducer obtained by the preparation method as described in any one of claims 1 to 5.