阅读说明：本技术 一种润滑油添加剂及其制备方法 (Lubricating oil additive and preparation method thereof ) 是由 刘超 于 2020-12-22 设计创作，主要内容包括：本发明公开了一种润滑油添加剂的制备方法,其特征在于,包括如下步骤：步骤S1、端羟基超支化氧化铝纳米管杂化聚合物的制备；步骤S2、苯并咪唑离子化改性；步骤S3、改性氮化硼烯纳米片；步骤S4、混合。本发明还提供了一种根据所述润滑油添加剂的制备方法制备得到的润滑油添加剂。本发明提供的润滑油添加剂综合性能更佳,掺量更小效果更显著,对设备腐蚀性及环境影响更小,能赋予润滑油优异的耐磨、极压性和抗腐蚀性,能显著改善润滑油的使用性能。(The invention discloses a preparation method of a lubricating oil additive, which is characterized by comprising the following steps: step S1, preparing a hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer; step S2, carrying out benzimidazole ionization modification; step S3, modifying boron nitride alkene nanometer sheet; and step S4, mixing. The invention also provides the lubricating oil additive prepared according to the preparation method of the lubricating oil additive. The lubricating oil additive provided by the invention has better comprehensive performance, smaller mixing amount, more obvious effect and less influence on equipment corrosivity and environment, can endow lubricating oil with excellent wear resistance, extreme pressure property and corrosion resistance, and can obviously improve the service performance of the lubricating oil.)

1. A preparation method of a lubricating oil additive is characterized by comprising the following steps:

step S1, preparation of hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer: dispersing an alumina nanotube in an organic solvent at 20-30 ℃, uniformly dispersing in an ultrasonic dispersion instrument, adding an aminosilane coupling agent, continuously and uniformly dispersing by ultrasonic, stirring and reacting at 65-85 ℃ for 6-8 hours, then adding N, N-dihydroxyethyl-3-amino-methyl propionate, continuously reacting for 3-5 hours by heat preservation, and then removing the solvent by rotary evaporation to obtain a hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer;

step S2, benzimidazole ionization modification: adding the hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer prepared in the step S1 and 2- (chloromethyl) benzimidazole into N, N-dimethylformamide, stirring and reacting at 50-60 ℃ for 3-6 hours, then adding sodium tetrakis (1-imidazolyl) borate, continuously stirring and reacting for 1-2 hours, then precipitating in water, and placing the precipitated product in a vacuum drying oven at 80-90 ℃ for drying to constant weight to obtain an intermediate product;

step S3, modifying the boron nitride alkene nano-sheet: adding boron nitride alkene nanosheets and 3-triethoxysilylpropyltrimethylammonium chloride into dimethyl sulfoxide, stirring and reacting for 3-5 hours at the temperature of 60-80 ℃, then adding carboxyl-terminated hyperbranched polyester into the mixture, continuously stirring and reacting for 1-2 hours, and then performing rotary evaporation to remove the dimethyl sulfoxide to obtain modified boron nitride alkene nanosheets;

step S4, mixing: and (4) uniformly mixing the intermediate product prepared in the step S2 and the modified boron nitride alkene nano-sheet prepared in the step S3, and grinding and sieving the mixture through a 1000-fold 1500-mesh sieve to obtain the lubricating oil additive.

2. The method for preparing the lubricating oil additive according to claim 1, wherein the mass ratio of the alumina nanotubes, the organic solvent, the aminosilane coupling agent and the N, N-dihydroxyethyl-3-amino-methyl propionate in the step S1 is 1 (5-10) to 0.2: 0.35.

3. The method for preparing the lubricating oil additive according to claim 1, wherein the organic solvent is any one of acetone, acetonitrile, tetrahydrofuran and N, N-dimethylformamide; the amino silane coupling agent is at least one of 3-aminopropyl triethoxysilane, 3-aminopropyl tri (methoxyethoxyethoxy) silane and 4-aminobutyl triethoxysilane.

4. The method for preparing the lubricating oil additive according to claim 1, wherein the mass ratio of the hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer, the 2- (chloromethyl) benzimidazole, the N, N-dimethylformamide and the sodium tetrakis (1-imidazolyl) borate in the step S2 is 1 (0.2-0.4) to (5-10) to 0.3.

5. The method for preparing the lubricating oil additive of claim 1, wherein the mass ratio of the boron nitride alkene nano-sheet, the 3-triethoxysilylpropyltrimethylammonium chloride, the dimethyl sulfoxide and the carboxyl-terminated hyperbranched polyester in the step S3 is 1 (0.1-0.3) to (5-8) to (0.5-0.8).

6. The preparation method of the lubricating oil additive according to claim 1, wherein the carboxyl-terminated hyperbranched polyester is any one of Hyper C202, Hyper C203 and Hyper C204.

7. The method for preparing the lubricating oil additive according to claim 1, wherein the mass ratio of the intermediate product to the modified boron nitride alkene nanosheets in step S4 is (2-4): 3.

8. A lubricating oil additive prepared by the method of preparing a lubricating oil additive according to any one of claims 1 to 7.

Technical Field

The invention relates to the technical field of lubricating oil, in particular to a lubricating oil additive and a preparation method thereof.

Background

Because the friction between the surface of the material and the interface can consume a large amount of mechanical energy, and the abrasion of mechanical parts is easily caused, lubricating oil needs to be added and replaced regularly in the operation process of the machine; the lubricating oil is blood for mechanical operation, and the lubricating oil additive is a key part of the lubricating oil, so that the deficiency of the base oil can be made up, various performances of the lubricating oil can be greatly improved, and even certain new performances can be endowed to the lubricating oil, the lubricating oil is an important component of the lubricating oil, and the variety, quality and addition proportion of the lubricating oil directly influence the service performance of the lubricating oil.

Most of the existing lubricating oil additives are used for coating films and coatings on the surfaces of friction pairs so as to increase the wear resistance of the friction pairs. Due to the defects of the processing technology of the metal friction pair, most of the processing technologies of the friction pair are in the micron level, so that the friction pair generates the phenomena of abrasion, smearing, scratching, tearing, gluing, seizure and the like in the micron level. In addition, most lubricating oil additives in the market contain sulfur, phosphorus or chlorine, so that the lubricating oil has corrosivity and selectivity, and after the lubricating oil is used for a long time, the lubricating oil has poor performance effects, and mechanical parts are easily damaged seriously; the lubricating oil has single function, which brings complexity and cost increase in environmental protection, storage, quality and use for the production process of various lubricating oil, and the contribution to the lubricating oil is common and the quality is difficult to guarantee, when the addition of the additive is increased, the cost is increased on one hand, and the use effect of the lubricating oil is easy to reduce.

The Chinese invention patent with the application number of 201710259138.7 discloses a sulfur-phosphorus-nitrogen lubricating oil additive and a preparation method thereof, wherein the additive is prepared from oleylamine, phosphorus pentasulfide, butanol, hydroxyethyl ethylenediamine and ammonia water; wherein the weight ratio of oleic acid amine to phosphorus pentasulfide, butanol, hydroxyethyl ethylenediamine and ammonia water is as follows: 100: 8.5-10: 10-15, and oleic acid amine is prepared by the reaction of oleic acid, monoethanolamine and butylamine. The additive is an oil-soluble sulfur-phosphorus-nitrogen compound, is a friction improver and an antiwear agent for lubricating oil, particularly lubricating oil and gear oil for internal combustion engines, has a remarkable extreme pressure effect, and has the advantages of energy conservation and environmental protection due to low sulfur-phosphorus content. Simple production method, low cost, good oil solubility and high yield. However, the lubricant additive is liable to cause serious corrosion damage to mechanical parts in long-term use, and in the case of serious use, an accident may occur, and the performance improvement effect thereof is yet to be further improved.

Therefore, the lubricating oil additive with better comprehensive performance, smaller mixing amount, more obvious effect, less influence on equipment corrosivity and environment, excellent wear resistance, extreme pressure property and corrosion resistance of the lubricating oil, capability of obviously improving the service performance of the lubricating oil, capability of meeting the market demand, wide market value and application prospect and very important significance for promoting the development of the lubricating oil industry is developed.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides a preparation method of a lubricating oil additive, which is characterized by comprising the following steps:

step S1, preparation of hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer: dispersing an alumina nanotube in an organic solvent at 20-30 ℃, uniformly dispersing in an ultrasonic dispersion instrument, adding an aminosilane coupling agent, continuously and uniformly dispersing by ultrasonic, stirring and reacting at 65-85 ℃ for 6-8 hours, then adding N, N-dihydroxyethyl-3-amino-methyl propionate, continuously reacting for 3-5 hours by heat preservation, and then removing the solvent by rotary evaporation to obtain a hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer;

step S2, benzimidazole ionization modification: adding the hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer prepared in the step S1 and 2- (chloromethyl) benzimidazole into N, N-dimethylformamide, stirring and reacting at 50-60 ℃ for 3-6 hours, then adding sodium tetrakis (1-imidazolyl) borate, continuously stirring and reacting for 1-2 hours, then precipitating in water, and placing the precipitated product in a vacuum drying oven at 80-90 ℃ for drying to constant weight to obtain an intermediate product;

step S3, modifying the boron nitride alkene nano-sheet: adding boron nitride alkene nanosheets and 3-triethoxysilylpropyltrimethylammonium chloride into dimethyl sulfoxide, stirring and reacting for 3-5 hours at the temperature of 60-80 ℃, then adding carboxyl-terminated hyperbranched polyester into the mixture, continuously stirring and reacting for 1-2 hours, and then performing rotary evaporation to remove the dimethyl sulfoxide to obtain modified boron nitride alkene nanosheets;

step S4, mixing: and (4) uniformly mixing the intermediate product prepared in the step S2 and the modified boron nitride alkene nano-sheet prepared in the step S3, and grinding and sieving the mixture through a 1000-fold 1500-mesh sieve to obtain the lubricating oil additive.

Preferably, the mass ratio of the alumina nanotubes, the organic solvent, the aminosilane coupling agent and the N, N-dihydroxyethyl-3-amino-methyl propionate in the step S1 is 1 (5-10) to 0.2: 0.35.

Preferably, the preparation method of the alumina nanotube is described in chinese patent application No. 201110327588.8, example 1.

Preferably, the organic solvent is any one of acetone, acetonitrile, tetrahydrofuran and N, N-dimethylformamide; the amino silane coupling agent is at least one of 3-aminopropyl triethoxysilane, 3-aminopropyl tri (methoxyethoxyethoxy) silane and 4-aminobutyl triethoxysilane; the preparation method of the N, N-dihydroxyethyl-3-amino-methyl propionate is shown in the Chinese patent application No. 201510958560.2, namely the example 1.

Preferably, the mass ratio of the hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer, 2- (chloromethyl) benzimidazole, N-dimethylformamide and sodium tetrakis (1-imidazolyl) borate in the step S2 is 1 (0.2-0.4) to 0.3 (5-10).

Preferably, the mass ratio of the boron nitride alkene nano-sheet, the 3-triethoxysilylpropyltrimethylammonium chloride, the dimethyl sulfoxide and the carboxyl-terminated hyperbranched polyester in the step S3 is 1 (0.1-0.3): 5-8): 0.5-0.8.

Preferably, the preparation method of the boron nitride alkene nano-sheet is described in chinese patent application No. 201410029564.8, example 1; the carboxyl-terminated hyperbranched polyester is any one of Hyper C202, Hyper C203 and Hyper C204, and is purchased from Wuhan hyperbranched resin technology, Inc.

Preferably, the mass ratio (2-4) of the intermediate product and the modified boron nitride alkene nano-sheets in the step S4 is 3.

Another object of the present invention is to provide a lubricating oil additive prepared according to the method for preparing the lubricating oil additive.

Adopt the produced beneficial effect of above-mentioned technical scheme to lie in:

(1) the preparation method of the lubricating oil additive provided by the invention is simple and easy to implement, convenient to operate and control, high in preparation efficiency and finished product qualification rate, suitable for continuous large-scale production, low in equipment requirement, free of substances harmful to the environment and more environment-friendly.

(2) The lubricating oil additive provided by the invention overcomes the defects that the existing lubricating oil additive has limited wear resistance, corrosivity and selectivity, and is not only poor in performance effect of various lubricating oils, but also easy to cause serious damage to mechanical parts after being used for a long time; the lubricating oil has single function, which brings complexity and cost increase in environmental protection, storage, quality and use for the production process of various lubricating oil, and the contribution of the lubricating oil is common and the quality is difficult to guarantee; through the synergistic effect of the components, the prepared lubricating oil additive has better comprehensive performance, smaller mixing amount, more obvious effect and less influence on equipment corrosivity and environment, can endow lubricating oil with excellent wear resistance, extreme pressure property and corrosion resistance, and can obviously improve the service performance of the lubricating oil.

(3) According to the lubricating oil additive provided by the invention, the benzimidazole-ionized modified hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer is added, and the excellent extreme pressure performance and wear resistance of the alumina nanotube, the hyperbranched structure and the benzimidazole structure are combined, so that the synergistic effect is achieved, the comprehensive performance improvement effect of the lubricating oil additive is effectively improved, the addition amount can be effectively reduced, the cost is reduced, and the influence of the addition of a large amount of additives on the performance of the base oil is reduced.

(4) According to the lubricating oil additive provided by the invention, the benzimidazole-ionized modified hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer is added, and the tetrakis (1-imidazolyl) borate is introduced through ion exchange in the preparation process, so that the lubricating property is improved, the compatibility among all components is favorably improved, and the performance is more stable; in addition, the synergistic effect with benzimidazolyl also has the advantage of improving the corrosion resistance.

(5) The lubricating oil additive provided by the invention can effectively improve the wear resistance and friction reduction performance by adding the modified boron nitride alkene structure, can ensure that the lubricating oil added with the lubricating oil additive has better performance stability and viscosity-temperature performance, can bear extreme high pressure, increases the heat dissipation function, bears higher temperature, increases the fuel economy and prolongs the service life of an engine.

Detailed Description

In order to make the technical solutions of the present invention better understood and make the above features, objects, and advantages of the present invention more comprehensible, the present invention is further described with reference to the following examples. The examples are intended to illustrate the invention only and are not intended to limit the scope of the invention; the preparation method of the alumina nanotube related in the embodiment of the invention is disclosed in the embodiment 1 of the Chinese patent with the application number of 201110327588.8; the preparation method of the N, N-dihydroxyethyl-3-amino-methyl propionate is disclosed in the Chinese patent application No. 201510958560.2, namely, the example 1; the preparation method of the boron nitride alkene nano-sheet is disclosed in the embodiment 1 of the Chinese invention patent with the application number of 201410029564.8; other raw materials were all purchased commercially.

Example 1

A preparation method of a lubricating oil additive is characterized by comprising the following steps:

step S1, preparation of hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer: dispersing an alumina nanotube in an organic solvent at 20 ℃, uniformly dispersing in an ultrasonic dispersion instrument, adding an aminosilane coupling agent, continuously and uniformly dispersing by ultrasonic, stirring and reacting for 6 hours at 65 ℃, then adding N, N-dihydroxyethyl-3-amino-methyl propionate, continuously reacting for 3 hours at a heat preservation temperature, and then removing the solvent by rotary evaporation to obtain a hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer;

step S2, benzimidazole ionization modification: adding the hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer prepared in the step S1 and 2- (chloromethyl) benzimidazole into N, N-dimethylformamide, stirring and reacting for 3 hours at 50 ℃, then adding sodium tetrakis (1-imidazolyl) borate, continuously stirring and reacting for 1 hour, then precipitating in water, and placing the precipitated product in a vacuum drying oven for drying at 80 ℃ to constant weight to obtain an intermediate product;

step S3, modifying the boron nitride alkene nano-sheet: adding boron nitride alkene nanosheets and 3-triethoxysilylpropyltrimethylammonium chloride into dimethyl sulfoxide, stirring and reacting for 3 hours at 60 ℃, then adding carboxyl-terminated hyperbranched polyester into the mixture, continuing stirring and reacting for 1 hour, and then performing rotary evaporation to remove the dimethyl sulfoxide to obtain modified boron nitride alkene nanosheets;

step S4, mixing: and (4) uniformly mixing the intermediate product prepared in the step S2 and the modified boron nitride alkene nanosheet prepared in the step S3, and then grinding and sieving the mixture through a 1000-mesh sieve to obtain the lubricating oil additive.

In the step S1, the mass ratio of the alumina nano tube, the organic solvent, the aminosilane coupling agent and the N, N-dihydroxyethyl-3-amino-methyl propionate is 1:5:0.2: 0.35; the organic solvent is acetone; the amino silane coupling agent is 3-aminopropyl triethoxysilane.

The mass ratio of the hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer, 2- (chloromethyl) benzimidazole, N-dimethylformamide and sodium tetrakis (1-imidazolyl) borate in the step S2 is 1:0.2:5: 0.3.

In the step S3, the mass ratio of the boron nitride alkene nano-sheet to the 3-triethoxysilylpropyltrimethylammonium chloride to the dimethyl sulfoxide to the carboxyl-terminated hyperbranched polyester is 1:0.1:5: 0.5; the carboxyl-terminated hyperbranched polyester is of the trademark of Hyper C202.

And the mass ratio of the intermediate product to the modified boron nitride alkene nano sheet in the step S4 is 2: 3.

A lubricating oil additive prepared according to the preparation method of the lubricating oil additive.

Example 2

A preparation method of a lubricating oil additive is characterized by comprising the following steps:

step S1, preparation of hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer: dispersing the aluminum oxide nano-tube in an organic solvent at 23 ℃, uniformly dispersing in an ultrasonic dispersion instrument, adding an aminosilane coupling agent, continuously and uniformly dispersing by ultrasonic, stirring and reacting at 70 ℃ for 6.5 hours, then adding N, N-dihydroxyethyl-3-amino-methyl propionate, continuously reacting for 3.5 hours under heat preservation, and then removing the solvent by rotary evaporation to obtain a hydroxyl-terminated hyperbranched aluminum oxide nano-tube hybrid polymer;

step S2, benzimidazole ionization modification: adding the hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer prepared in the step S1 and 2- (chloromethyl) benzimidazole into N, N-dimethylformamide, stirring and reacting for 4 hours at 52 ℃, then adding sodium tetrakis (1-imidazolyl) borate, continuously stirring and reacting for 1.2 hours, then precipitating in water, and placing the precipitated product in a vacuum drying oven for drying at 83 ℃ to constant weight to obtain an intermediate product;

step S3, modifying the boron nitride alkene nano-sheet: adding boron nitride alkene nanosheets and 3-triethoxysilylpropyltrimethylammonium chloride into dimethyl sulfoxide, stirring and reacting for 3.5 hours at 65 ℃, then adding carboxyl-terminated hyperbranched polyester into the mixture, continuously stirring and reacting for 1.2 hours, and then performing rotary evaporation to remove the dimethyl sulfoxide to obtain modified boron nitride alkene nanosheets;

step S4, mixing: and (4) uniformly mixing the intermediate product prepared in the step S2 and the modified boron nitride alkene nanosheet prepared in the step S3, and then grinding and sieving the mixture through a 1100-mesh sieve to obtain the lubricating oil additive.

In the step S1, the mass ratio of the alumina nano tube, the organic solvent, the aminosilane coupling agent and the N, N-dihydroxyethyl-3-amino-methyl propionate is 1:6:0.2: 0.35; the organic solvent is acetonitrile; the amino silane coupling agent is 3-aminopropyl tri (methoxy ethoxy) silane.

The mass ratio of the hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer, 2- (chloromethyl) benzimidazole, N-dimethylformamide and sodium tetrakis (1-imidazolyl) borate in the step S2 is 1:0.25:6: 0.3.

In the step S3, the mass ratio of the boron nitride alkene nano-sheet to the 3-triethoxysilylpropyltrimethylammonium chloride to the dimethyl sulfoxide to the carboxyl-terminated hyperbranched polyester is 1:0.15:6: 0.6; the carboxyl-terminated hyperbranched polyester is of the trademark Hyper C203.

And the mass ratio of the intermediate product to the modified boron nitride alkene nano sheet in the step S4 is 2.5: 3.

A lubricating oil additive prepared according to the preparation method of the lubricating oil additive.

Example 3

A preparation method of a lubricating oil additive is characterized by comprising the following steps:

step S1, preparation of hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer: dispersing an alumina nanotube in an organic solvent at 25 ℃, uniformly dispersing in an ultrasonic dispersion instrument, adding an aminosilane coupling agent, continuously and uniformly dispersing by ultrasonic, stirring and reacting for 7 hours at 75 ℃, then adding N, N-dihydroxyethyl-3-amino-methyl propionate, continuously reacting for 4 hours under heat preservation, and then removing the solvent by rotary evaporation to obtain a hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer;

step S2, benzimidazole ionization modification: adding the hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer prepared in the step S1 and 2- (chloromethyl) benzimidazole into N, N-dimethylformamide, stirring and reacting for 4.5 hours at 55 ℃, then adding sodium tetrakis (1-imidazolyl) borate, continuously stirring and reacting for 1.5 hours, then precipitating in water, and placing the precipitated product in a vacuum drying oven at 85 ℃ for drying to constant weight to obtain an intermediate product;

step S3, modifying the boron nitride alkene nano-sheet: adding boron nitride alkene nanosheets and 3-triethoxysilylpropyltrimethylammonium chloride into dimethyl sulfoxide, stirring and reacting for 4 hours at 70 ℃, then adding carboxyl-terminated hyperbranched polyester into the mixture, continuing stirring and reacting for 1.5 hours, and then performing rotary evaporation to remove the dimethyl sulfoxide to obtain modified boron nitride alkene nanosheets;

step S4, mixing: and (4) uniformly mixing the intermediate product prepared in the step S2 and the modified boron nitride alkene nanosheet prepared in the step S3, and then grinding and sieving the mixture through a 1200-mesh sieve to obtain the lubricating oil additive.

In the step S1, the mass ratio of the alumina nano tube, the organic solvent, the aminosilane coupling agent and the N, N-dihydroxyethyl-3-amino-methyl propionate is 1:8:0.2: 0.35; the organic solvent is tetrahydrofuran; the amino silane coupling agent is 4-amino butyl triethoxy silane.

The mass ratio of the hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer, 2- (chloromethyl) benzimidazole, N-dimethylformamide and sodium tetrakis (1-imidazolyl) borate in the step S2 is 1:0.3:7.5: 0.3.

In the step S3, the mass ratio of the boron nitride alkene nano-sheet to the 3-triethoxysilylpropyltrimethylammonium chloride to the dimethyl sulfoxide to the carboxyl-terminated hyperbranched polyester is 1:0.2:6.5: 0.65; the carboxyl-terminated hyperbranched polyester is of the trademark of Hyper C204.

And in the step S4, the mass ratio of the intermediate product to the modified boron nitride alkene nano-sheet is 3: 3.

A lubricating oil additive prepared according to the preparation method of the lubricating oil additive.

Example 4

A preparation method of a lubricating oil additive is characterized by comprising the following steps:

step S1, preparation of hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer: dispersing the aluminum oxide nano-tube in an organic solvent at 28 ℃, uniformly dispersing in an ultrasonic dispersion instrument, adding an aminosilane coupling agent, continuously and uniformly dispersing by ultrasonic, stirring and reacting at 83 ℃ for 7.8 hours, then adding N, N-dihydroxyethyl-3-amino-methyl propionate, continuously reacting for 4.5 hours under heat preservation, and then performing rotary evaporation to remove the solvent to obtain a hydroxyl-terminated hyperbranched aluminum oxide nano-tube hybrid polymer;

step S2, benzimidazole ionization modification: adding the hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer prepared in the step S1 and 2- (chloromethyl) benzimidazole into N, N-dimethylformamide, stirring and reacting for 5.5 hours at 58 ℃, then adding sodium tetrakis (1-imidazolyl) borate, continuously stirring and reacting for 1.8 hours, then precipitating in water, and placing the precipitated product in a vacuum drying oven at 87 ℃ for drying to constant weight to obtain an intermediate product;

step S3, modifying the boron nitride alkene nano-sheet: adding boron nitride alkene nanosheets and 3-triethoxysilylpropyltrimethylammonium chloride into dimethyl sulfoxide, stirring and reacting for 4.5 hours at 78 ℃, then adding carboxyl-terminated hyperbranched polyester into the mixture, continuously stirring and reacting for 1.8 hours, and then performing rotary evaporation to remove the dimethyl sulfoxide to obtain modified boron nitride alkene nanosheets;

step S4, mixing: and (4) uniformly mixing the intermediate product prepared in the step S2 and the modified boron nitride alkene nanosheet prepared in the step S3, and grinding and sieving the mixture through a 1400-mesh sieve to obtain the lubricating oil additive.

In the step S1, the mass ratio of the alumina nano tube, the organic solvent, the aminosilane coupling agent and the N, N-dihydroxyethyl-3-amino-methyl propionate is 1:9.5:0.2: 0.35; the organic solvent is N, N-dimethylformamide; the amino silane coupling agent is formed by mixing 3-aminopropyl triethoxysilane, 3-aminopropyl tri (methoxyethoxy ethoxy) silane and 4-aminobutyl triethoxysilane according to the mass ratio of 1:3: 4.

The mass ratio of the hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer, 2- (chloromethyl) benzimidazole, N-dimethylformamide and sodium tetrakis (1-imidazolyl) borate in the step S2 is 1:0.35:9: 0.3.

In the step S3, the mass ratio of the boron nitride alkene nano-sheet to the 3-triethoxysilylpropyltrimethylammonium chloride to the dimethyl sulfoxide to the carboxyl-terminated hyperbranched polyester is 1:0.27:7.5: 0.75; the carboxyl-terminated hyperbranched polyester is of the trademark of Hyper C202.

And the mass ratio of the intermediate product to the modified boron nitride alkene nano sheet in the step S4 is 3.5: 3.

A lubricating oil additive prepared according to the preparation method of the lubricating oil additive.

Example 5

A preparation method of a lubricating oil additive is characterized by comprising the following steps:

step S1, preparation of hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer: dispersing an alumina nanotube in an organic solvent at 30 ℃, uniformly dispersing in an ultrasonic dispersion instrument, adding an aminosilane coupling agent, continuously and uniformly dispersing by ultrasonic, stirring and reacting for 8 hours at 85 ℃, then adding N, N-dihydroxyethyl-3-amino-methyl propionate, continuously reacting for 5 hours at a constant temperature, and then removing the solvent by rotary evaporation to obtain a hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer;

step S2, benzimidazole ionization modification: adding the hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer prepared in the step S1 and 2- (chloromethyl) benzimidazole into N, N-dimethylformamide, stirring and reacting for 6 hours at 60 ℃, then adding sodium tetrakis (1-imidazolyl) borate, continuously stirring and reacting for 2 hours, then precipitating in water, and drying the precipitated product in a vacuum drying oven at 90 ℃ to constant weight to obtain an intermediate product;

step S3, modifying the boron nitride alkene nano-sheet: adding boron nitride alkene nanosheets and 3-triethoxysilylpropyltrimethylammonium chloride into dimethyl sulfoxide, stirring and reacting for 5 hours at 80 ℃, then adding carboxyl-terminated hyperbranched polyester into the mixture, continuing stirring and reacting for 2 hours, and then performing rotary evaporation to remove the dimethyl sulfoxide to obtain modified boron nitride alkene nanosheets;

step S4, mixing: and (4) uniformly mixing the intermediate product prepared in the step S2 and the modified boron nitride alkene nanosheet prepared in the step S3, and grinding and sieving with a 1500-mesh sieve to obtain the lubricating oil additive.

In the step S1, the mass ratio of the alumina nano tube, the organic solvent, the aminosilane coupling agent and the N, N-dihydroxyethyl-3-amino-methyl propionate is 1:10:0.2: 0.35; the organic solvent is N, N-dimethylformamide; the amino silane coupling agent is 3-aminopropyl triethoxysilane.

The mass ratio of the hydroxyl-terminated hyperbranched alumina nanotube hybrid polymer, 2- (chloromethyl) benzimidazole, N-dimethylformamide and sodium tetrakis (1-imidazolyl) borate in the step S2 is 1:0.4:10: 0.3.

In the step S3, the mass ratio of the boron nitride alkene nano-sheet to the 3-triethoxysilylpropyltrimethylammonium chloride to the dimethyl sulfoxide to the carboxyl-terminated hyperbranched polyester is 1:0.3:8: 0.8; the carboxyl-terminated hyperbranched polyester is of the trademark Hyper C203.

And in the step S4, the mass ratio of the intermediate product to the modified boron nitride alkene nano-sheet is 4: 3.

A lubricating oil additive prepared according to the preparation method of the lubricating oil additive.

Comparative example 1

This example provides a lubricating oil additive having substantially the same formulation and preparation as in example 1, except that no modified boron nitride nanosheets were added.

Comparative example 2

This example provides a lubricating oil additive having substantially the same formulation and method of preparation as example 1, except that step S2, the benzimidazole ionization modification, was not present.

Comparative example 3

This example provides a lubricant additive, the formulation and preparation method of which are essentially the same as those of example 1, except that a hydroxyl-terminated hyperbranched nano-hybrid polymer HB-SiO is used₂Replace the hybrid polymer of hyperbranched alumina nanotube of terminal hydroxyl; the hydroxyl-terminated hyperbranched nano hybrid polymer HB-SiO₂The preparation method is shown in the first embodiment of Chinese patent application No. 201910425260.6.

Comparative example 4

The present example provides a lubricating oil additive, the formulation and preparation method of which are essentially the same as in example 1, except that boron nitride nanosheets are used in place of modified boron nitride alkene nanosheets.

The lubricating oil additives obtained in the above examples 1 to 5 and comparative examples 1 to 4 were dispersed in a 7% by weight addition amount in a polyalphaolefin base oil having a trademark of Spectrasyn8 to form lubricating oil samples, which were then subjected to respective performance tests, and the test results are shown in table 1. The test method is as follows:

(1) four-ball experiment: testing was performed according to ASTM D-2783; in the test results of the four-ball experiment, the maximum non-seizure load PB value indicates the maximum load of the steel ball without seizure in a lubricating state at a certain temperature and a certain rotating speed, and the higher the PB value is, the better the lubricating performance of the lubricating oil is. The sintering load PD value indicates that the load is increased step by step, the upper steel ball and the lower steel ball are sintered at high temperature due to the overlarge load, the equipment has to stop running, and the higher the PD value is, the better the extreme pressure lubricating performance of the lubricating oil is. The value d of the wear scar diameter represents the size of the wear scar diameter of the bearing steel spherical surface caused by friction, and the smaller the value d is, the better the anti-wear capability and lubricity of the lubricating oil is.

(2) Pour point: the test was performed according to GB/T3535-2006.

(3) Corrosion experiments: the test was carried out according to GB/T5096 for copper sheets at 121 ℃ for 3 hours.

TABLE 1 Properties of samples of examples and comparative examples

As can be seen from Table 1, the lubricating oil formed by adding the lubricating oil additive disclosed in the examples of the present invention to the base oil has better extreme pressure performance and lubricating performance, lower pour point and better corrosion resistance, which are the result of the synergistic effect of the components.

The foregoing shows and describes the general principles and broad features of the present invention and advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.