Preparation method of lubricating oil friction reducer and application thereof

Abstract

The application discloses a preparation method of a lubricating oil friction-reducing agent and application of the lubricating oil friction-reducing agent, and the lubricating oil friction-reducing agent has the following structure: wherein the R1 group is selected from a methyl group and a trifluoromethyl group, and the R2 group is a straight-chain alkyl group. The specific preparation method is as follows: under the condition of nitrogen, a Mannich reaction of a certain molar ratio of phenol, alkylamine and polyformaldehyde is carried out in a solvent toluene at high temperature, and the product is obtained after reduced pressure distillation to obtain the lubricating oil friction-reducing agent. The synthetic preparation method is simple, the reaction condition is mild, raw materials are easy to obtain, and the yield is relatively high. The prepared friction-reducing agent has good oil solubility, and the molecular structure has active elements of nitrogen and sulfur which are beneficial to friction reduction, can effectively reduce the friction coefficient of lubricating oil, and improve the effectiveness and reliability of oil.

Description

Technical Field

[0001] This invention relates to a method for preparing a lubricating oil friction reducer and its application, belonging to the field of lubrication technology. Background Technology

[0002] Friction is a physical phenomenon that is widespread in daily life and industrial processes. Energy loss and equipment failure caused by friction and wear are unavoidable. Lubricating materials are an effective means to reduce friction and wear, improve the working efficiency of machinery, and reduce energy consumption.

[0003] Lubricating materials mainly consist of two parts: base oil and lubricating oil additives. Among these, lubricating oil additives are a key factor affecting oil performance. In recent years, some heterocyclic compounds, especially those with compact and stable structures containing nitrogen or sulfur elements, such as benzotriazole, benzothiazole, benzimidazole, benzoxazole, thiadiazole, and triazine derivatives, have attracted widespread attention due to their excellent tribological properties. However, some solid heterocyclic compounds have poor oil solubility and compatibility with other additives. Therefore, researchers both domestically and internationally have conducted extensive research on such additives. For example, CN 101205216 discloses a benzotriazole ammonium salt lubricating oil additive; patent CN 114507556 prepared a class of dimerized thiadiazole dimer compounds with significant anti-wear effects; and patent CN 114763337 synthesized a polysulfide compound of benzotriazole for use as an extreme pressure additive for lubricating oils.

[0004] To address the problems of poor oil solubility and instability of heterocyclic compounds as lubricating oil additives in existing technologies, this invention provides a nitrogen-containing heterocyclic lubricating oil friction reducer. Compared with traditional organic additives, this invention has a simple preparation method, excellent thermal stability, and is easily soluble in lubricating oil, achieving significant results in improving the tribological properties of oils. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing a lubricating oil friction reducer and its application, so as to overcome the defect of poor oil solubility of nitrogen-containing heterocyclic compounds in the prior art. When applied to polyalphaolefin (PAO6), this friction reducer can effectively reduce the friction coefficient of the base oil.

[0006] The technical solution of this invention is:

[0007] The lubricating oil friction reducer of the present invention has the structural formula of formula (1):

[0008]

[0009] In this configuration, R1 is a methyl or trifluoromethyl group, and R2 is a straight-chain alkyl group.

[0010] Furthermore, the straight-chain alkyl group R2 contains 2-35 carbon atoms, preferably 4-30 carbon atoms, more preferably 6-25 carbon atoms, for example 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 18, 20, 22, 24 or 25 carbon atoms.

[0011] A method for preparing the lubricating oil friction reducer as described above, the method comprising: mixing a phenol source, an amine source and paraformaldehyde in a solvent toluene under nitrogen conditions, reacting at 80-110°C for 4-8 hours, and obtaining the lubricating oil friction reducer by vacuum distillation.

[0012] Furthermore, the molar ratio of phenolic source, amine source, and paraformaldehyde is 0.8–1.5:0.8–1.5:2.2; for example, the molar ratio of phenolic source, amine source, and paraformaldehyde is 0.8:0.8–1.5:2.2, 0.9:0.8–1.5:2.2, 1:0.8–1.5:2.2, 1.1:0.8–1.5:2.2, 1.2:0.8–1.5:2.2, 1.3:0.8–1.5:2.2, 1.4:0.8–1.5:2.2, 1.5:0.8–1.5:2.2, or 1–1.5:1–1.5:2.2.

[0013] Furthermore, the amine source is octylamine or hexadecylamine.

[0014] Furthermore, the phenol source is 4-methylthiophenol or 4-trifluoromethylthiophenol.

[0015] Furthermore, the molar ratio of phenolic source, amine source and paraformaldehyde is 1:1:2.2.

[0016] An application of a lubricating oil friction reducer as described above, wherein the lubricating oil friction reducer is added to a base oil at an amount of 0.25 wt% to 4 wt%, based on a base oil mass of 100 wt%. For example, the lubricating oil additive is added to a base oil at amounts of 0.25 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, or 4 wt%.

[0017] Furthermore, the lubricating oil friction reducer is applied to polyalphaolefin base oil.

[0018] Technical features and beneficial effects of the present invention:

[0019] This invention provides a nitrogen-containing heterocyclic lubricating oil friction reducer. By introducing long-chain alkyl groups, it has excellent oil solubility. At the same time, the presence of nitrogen and sulfur elements can effectively reduce the friction coefficient between friction pairs, achieving significant results in improving the tribological properties of oil. Attached Figure Description

[0020] Figure 1 This is the infrared spectrum of the lubricating oil friction reducer of the present invention;

[0021] Figure 2 This is a thermogravimetric diagram of the lubricating oil friction reducer of the present invention. Detailed Implementation

[0022] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. However, the following embodiments are only for explaining the present invention, and the scope of protection of the present invention should include all the contents of the claims. Moreover, through the description of the following embodiments, those skilled in the art can fully implement all the contents of the claims of the present invention.

[0023] In the following embodiments of the present invention, some of the raw materials are as follows: paraformaldehyde (Sinopharm Chemical Reagent Co., Ltd., 80096618).

[0024] Example 1

[0025] 0.02 mol (2.8 g) of 4-methylthiophenol, 0.02 mol (4.82 g) of hexadecylamine, 0.044 mol (1.32 g) of paraformaldehyde and 25 g of toluene were added to a 100 ml three-necked flask. The mixture was heated to 95 °C under nitrogen atmosphere and stirred for 6 h. After the reaction was completed, the solvent and small molecule impurities were removed by vacuum distillation at 80 °C and 0.095 MPa for 2 h. After cooling, a yellow liquid was obtained.

[0026] Example 2

[0027] 0.02 mol (2.8 g) of 4-methylthiophenol, 0.02 mol (2.58 g) of octylamine, 0.044 mol (1.32 g) of paraformaldehyde and 15 g of toluene were added to a 100 ml three-necked flask. The mixture was heated to 90 °C under nitrogen atmosphere and stirred for 5 h. After the reaction was completed, the solvent and small molecule impurities were removed by vacuum distillation at 80 °C and a vacuum degree of 0.095 MPa for 2 h. After cooling, a yellow liquid was obtained.

[0028] Example 3

[0029] 0.02 mol (3.88 g) of 4-trifluoromethylthiophenol, 0.02 mol (4.82 g) of hexadecylamine, 0.044 mol (1.32 g) of paraformaldehyde and 20 g of toluene were added to a 100 ml three-necked flask. The mixture was heated to 95 °C under nitrogen atmosphere and stirred for 6 h. After the reaction was completed, the solvent and small molecule impurities were removed by vacuum distillation at 80 °C and a vacuum degree of 0.095 MPa for 2 h. After cooling, a reddish-brown liquid was obtained.

[0030] Infrared spectroscopy analysis:

[0031] The lubricating oil friction reducers prepared in Examples 1-3 were characterized using Fourier transform infrared spectroscopy. Instrument parameters were set as follows: scanning range 500-4000 cm⁻¹. -1 4cm resolution -1 Infrared spectrum, such as Figure 1 As shown, 2925cm -1 and 2854cm -1 Absorption peaks at 1585 cm⁻¹, attributed to the asymmetric and symmetric stretching vibrations of the methylene group, respectively. -1 and 1458cm -1 The characteristic peak of the benzene ring skeleton is 928 cm⁻¹. -1 The characteristic absorption peak of the oxazine ring is 1226 cm⁻¹. -1 The peak value for the stretching vibration of COC is 631 cm⁻¹. -1 This is a characteristic absorption peak for the CS bond, at 1310 cm⁻¹. -1 The infrared spectroscopy analysis above confirms that the lubricating oil friction reducer described in this invention was successfully prepared, as indicated by the characteristic absorption peak of the CF bond.

[0032] Thermogravimetric analysis:

[0033] Thermal stability of Examples 1-3 was evaluated using a Netzsch STA449F3 simultaneous thermal analyzer. Test conditions: N2 atmosphere, temperature range 50-600℃, heating rate 10℃ / min. Experimental results are shown below. Figure 2 The initial thermal decomposition temperatures of Examples 1-3 were 303.7℃, 272.1℃, and 287.1℃, respectively. It can be seen that the above three lubricating oil friction reducers all have excellent thermal stability and are suitable for use as lubricating oil additives.

[0034] Tribological performance testing:

[0035] Based on the mass of ExxonMobil polyalphaolefin (PAO 6), the lubricating oil friction reducer prepared in Example 1 was added to ExxonMobil polyalphaolefin (PAO 6) at concentrations of 0.25 wt%, 1 wt%, 2 wt%, 3 wt%, and 4 wt%, respectively, until completely dissolved to prepare the corresponding lubricating oils. Tribological properties were tested using an Optimal-SRV-V friction and wear testing machine. Bearing steel balls (AISI 52100) with a diameter of 10 mm and a hardness of 62 ± 3 HRC were clamped in the upper fixture, and the lower part used... A steel disc with a hardness of 62±3 HRC (AISI 52100) was used. The experimental conditions were: experimental load 100 N, experimental temperature 30 °C, frequency 25 Hz, stroke 1 cm, and running time 1800 s. The experimental results are shown in Table 1.

[0036] Table 1. Tribological property test results of Example 1

[0037] Sample Name Average coefficient of friction PAO 6 0.288 PAO 6+0.25wt% Example 1 0.177 PAO 6+1wt% Example 1 0.132 PAO 6+2wt% Example 1 0.123 PAO 6+3wt% Example 1 0.115 PAO 6+4wt% Example 1 0.111

[0038] Experimental results show that Example 1 can effectively improve the tribological properties of PAO 6. When the addition amount is 0.25 wt%, the coefficient of friction decreases from 0.288 to 0.177, indicating that only a small amount of lubricating oil friction reducer is needed to significantly reduce the coefficient of friction of the oil. As the amount of friction reducer added increases, the coefficient of friction of the oil also decreases. When the addition amount is 4 wt%, the coefficient of friction reaches a minimum of 0.111, which is 61.5% lower than that of the base oil. This is because the nitrogen and sulfur elements in the friction reducer undergo physical and chemical adsorption on the surface of the friction pair, forming a friction protective film and exerting an excellent friction-reducing effect.

[0039] 1 wt% of the friction reducers prepared in Examples 1-3 were dissolved in PAO 6 to prepare corresponding lubricating oils, and their tribological properties were tested using the same method. The experimental results are shown in Table 2. The results show that Examples 1-3 all exhibit good friction-reducing properties, with Example 2 showing a lower coefficient of friction than Example 1. This indicates that the additive structure has a certain influence on friction-reducing performance; for this type of lubricating oil friction reducer, shorter alkyl chain lengths result in better tribological performance. Furthermore, Example 3 has the lowest coefficient of friction, only 0.113, suggesting that the introduction of fluorine may alter the composition of the friction film, further improving the tribological properties of the oil.

[0040] Table 2. Tribological property test results of Examples 1-3

[0041] Sample Name Average coefficient of friction PAO 6 0.288 PAO 6+1wt% Example 1 0.132 PAO 6+1wt% Example 2 0.125 PAO 6+1wt% Example 3 0.113

[0042] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. Use of a lubricating oil friction reducer, characterized in that The additive amount of the lubricating oil friction reducer in base oil is 0.2wt%-5wt%, based on 100wt% of the mass of the base oil; the lubricating oil friction reducer has a structural formula of formula (1): （1） Wherein, R1 is trifluoromethyl, R2 is a linear alkyl; the structural formula of the lubricating oil friction reducer, the linear alkyl R2 contains 2-24 carbon atoms.

2. Use according to claim 1, characterized in that, The structural formula of the lubricating oil friction reducer, the linear alkyl R2 contains 4-22 carbon atoms.

3. Use according to claim 1, characterized in that, The structural formula of the lubricating oil friction reducer, the linear alkyl R2 contains 6-20 carbon atoms.

4. Use according to claim 1, characterized in that, The lubricating oil friction reducer is prepared by mixing a phenol source, an amine source and paraformaldehyde in a solvent toluene under nitrogen condition, reacting at 80-110 DEG C for 4-8 hours, and obtaining the lubricating oil friction reducer after reduced pressure distillation.

5. Use according to claim 4, characterized in that, The amine source is octylamine or hexadecylamine.

6. Use according to claim 4, characterized in that, The phenol source is 4-trifluoromethylthiophenol.

7. Use according to claim 4, characterized in that, The molar ratio of the phenol source, the amine source and the paraformaldehyde is 0.8-1.5:0.8-1.5:2.

2.

8. The use according to claim 1, characterized in that, The additive amount of the lubricating oil friction reducer in base oil is 0.25wt%-4wt%, based on 100wt% of the mass of the base oil.

9. The use according to claim 1, characterized in that, The base oil is poly-alpha-olefin.

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