阅读说明：本技术 一种ctab改性纳米二硫化钼及其制备方法和应用、一种锂基润滑脂及其制备方法 (CTAB modified nano molybdenum disulfide, preparation method and application thereof, lithium-based lubricating grease and preparation method thereof ) 是由 熊胜锋 储修祥 于 2020-04-26 设计创作，主要内容包括：本发明提供了一种CTAB改性纳米二硫化钼及其制备方法和应用、一种锂基润滑脂及其制备方法,属于润滑脂技术领域。本发明以CTAB(十六烷基三甲基溴化铵)为表面改性剂,对纳米二硫化钼进行改性,在纳米二硫化钼表面形成一层CTAB分子层,CTAB分子的极性端与纳米MoS<Sub>2</Sub>结合,同时非极性端能够与油相“相似相容”稳定分散在润滑脂中,使其可以更稳定地在润滑脂中保持分散状态,不仅降低了纳米二硫化钼的表面能,同时其还有效提高了润滑脂的综合性能,如相对于以无CTAB改性的纳米二硫化钼为添加剂的润滑脂,以CTAB改性纳米二硫化钼为添加剂的润滑脂的最大无卡咬负荷、烧结负荷和滴点提高,钢网分油率降低。(The invention provides CTAB modified nano molybdenum disulfide, a preparation method and application thereof, lithium-based lubricating grease and a preparation method thereof, and belongs to the technical field of lubricating grease. The invention takes CTAB (cetyl trimethyl ammonium bromide) as a surface modifier to modify nano molybdenum disulfide, a CTAB molecular layer is formed on the surface of the nano molybdenum disulfide, and the polar end of the CTAB molecular layer and nano MoS 2 Combined while the non-polar end canThe lubricating grease is stably dispersed in the lubricating grease in a similar and compatible manner with the oil phase, so that the lubricating grease can be more stably kept in a dispersed state, the surface energy of the nano molybdenum disulfide is reduced, and the comprehensive performance of the lubricating grease is effectively improved.)

1. A preparation method of CTAB modified nano molybdenum disulfide is characterized by comprising the following steps:

mixing nano molybdenum disulfide, CTAB and ethanol to obtain a raw material mixed solution;

and carrying out reflux reaction on the raw material mixed solution for 22-26 h, and then standing for reaction for 22-26 h to obtain the CTAB modified nano molybdenum disulfide.

2. The preparation method of claim 1, wherein the mass ratio of the nano molybdenum disulfide to CTAB is 1 (3-5).

3. The method according to claim 1, wherein the reflux reaction is carried out at 75 to 85 ℃ and the standing reaction is carried out at room temperature.

4. The preparation method according to any one of claims 1 to 3, wherein after the standing reaction is completed, the method further comprises a post-treatment, and the post-treatment comprises the following steps: carrying out solid-liquid separation on the reaction liquid obtained by the standing reaction to obtain a solid; the solid was hot washed with alternating petroleum ether and ethanol and then dried.

5. The CTAB modified nano molybdenum disulfide obtained by the preparation method of any one of claims 1 to 4.

6. Use of the CTAB modified nano molybdenum disulphide as claimed in claim 5 as a grease additive.

7. The lithium-based lubricating grease comprises the following main raw materials in parts by mass: 90-100 parts of dodecahydroxy stearic acid, 750-900 parts of base oil, 13-17 parts of lithium hydroxide and 15-22 parts of lubricating grease additive, wherein the lubricating grease additive is the CTAB modified nano molybdenum disulfide as claimed in claim 5.

8. The method of preparing a lithium grease according to claim 7 comprising the steps of:

dissolving dodecahydroxy stearic acid in part of base oil to obtain a base oil solution of dodecahydroxy stearic acid;

dissolving lithium hydroxide in water to obtain a lithium hydroxide aqueous solution;

mixing the base oil solution of the dodecahydroxy stearic acid with a lithium hydroxide aqueous solution, and performing saponification reaction to obtain thickened lubricating oil;

sequentially dehydrating and refining the thickened lubricating oil to obtain anhydrous thickened lubricating oil;

and mixing the anhydrous thickened lubricating oil with the rest base oil and the lubricating grease additive, and then grinding to obtain the lithium-based lubricating grease.

9. The method according to claim 8, wherein the part of the base oil accounts for 2/3 of the total amount of the base oil, and the saponification reaction is carried out at 90-125 ℃ for 0.8-1.2 h.

10. The preparation method according to claim 8, wherein the dehydration temperature is 140-160 ℃ and the dehydration time is 15-30 min; the refining temperature is 190-210 ℃, and the refining time is 9-12 min.

Technical Field

The invention relates to the technical field of lubricating grease, and particularly relates to CTAB modified nano molybdenum disulfide, a preparation method and application thereof, lithium-based lubricating grease and a preparation method thereof.

Background

Molybdenum disulfide (MOS)₂) The graphene-like composite material is a typical layered hexagonal metal compound, has a unique sandwich structure and typical graphene-like two-dimensional material characteristics, and has good lubricating, catalytic and electrochemical properties. MoS₂The extreme pressure antiwear additive as lubricating grease is widely applied, and the nano MOS₂Also has been widely studied for anti-wear extreme pressure properties. But nanoscale MOS₂The lubricating grease has small volume, large specific surface area and high specific surface energy, and is easy to agglomerate to form larger particles, thereby influencing the service performance of the lubricating grease.

Disclosure of Invention

The invention aims to provide CTAB modified nano molybdenum disulfide, a preparation method and application thereof, and lithium-based lubricating grease and a preparation method thereof.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a preparation method of CTAB modified nano molybdenum disulfide, which comprises the following steps:

mixing nano molybdenum disulfide, CTAB and ethanol to obtain a raw material mixed solution;

and carrying out reflux reaction on the raw material mixed solution for 22-26 h, and then standing for reaction for 22-26 h to obtain the CTAB modified nano molybdenum disulfide.

Preferably, the mass ratio of the nano molybdenum disulfide to CTAB is 1 (3-5).

Preferably, the temperature of the reflux reaction is 75-85 ℃, and the standing reaction is carried out at room temperature.

Preferably, after the standing reaction is completed, the method further comprises post-treatment, wherein the post-treatment comprises the following steps: carrying out solid-liquid separation on the reaction liquid obtained by the standing reaction to obtain a solid; the solid was hot washed with alternating petroleum ether and ethanol and then dried.

The invention also provides the CTAB modified nano molybdenum disulfide obtained by the preparation method in the technical scheme.

The invention also provides application of the CTAB modified nano molybdenum disulfide as a lubricating grease additive.

The lithium-based lubricating grease comprises the following main raw materials in parts by mass: 90-100 parts of dodecahydroxy stearic acid, 750-900 parts of base oil, 13-17 parts of lithium hydroxide and 15-22 parts of lubricating grease additive, wherein the lubricating grease additive is the CTAB modified nano molybdenum disulfide in the technical scheme.

The invention also provides a preparation method of the lithium-based lubricating grease, which comprises the following steps:

dissolving dodecahydroxy stearic acid in part of base oil to obtain a base oil solution of dodecahydroxy stearic acid;

dissolving lithium hydroxide in water to obtain a lithium hydroxide aqueous solution;

mixing the base oil solution of the dodecahydroxy stearic acid with a lithium hydroxide aqueous solution, and performing saponification reaction to obtain thickened lubricating oil;

sequentially dehydrating and refining the thickened lubricating oil to obtain anhydrous thickened lubricating oil;

and mixing the anhydrous thickened lubricating oil with the rest base oil and the lubricating grease additive, and then grinding to obtain the lithium-based lubricating grease.

Preferably, the part of the base oil accounts for 2/3 of the total amount of the base oil, and the saponification reaction is carried out at the temperature of 90-125 ℃ for 0.8-1.2 h.

Preferably, the dehydration temperature is 140-160 ℃, and the time is 15-30 min; the refining temperature is 190-210 ℃, and the refining time is 9-12 min.

The invention provides a preparation method of CTAB modified nano molybdenum disulfide, which comprises the following steps: mixing nano molybdenum disulfide, CTAB and ethanol to obtain a raw material mixed solution; and carrying out reflux reaction on the raw material mixed solution for 22-26 h, and then standing for reaction for 22-26 h to obtain the CTAB modified nano molybdenum disulfide. The invention takes CTAB (cetyl trimethyl ammonium bromide) as a surface modifier to modify nano molybdenum disulfide, a CTAB molecular layer is formed on the surface of the nano molybdenum disulfide, and the polar end of the CTAB molecular layer and nano MoS₂And the nonpolar end can be stably dispersed in the lubricating grease in a similar and compatible manner with the oil phase, so that the nonpolar end can be more stably kept in a dispersed state in the lubricating grease, the surface energy of the nano molybdenum disulfide is reduced, and the comprehensive performance of the lubricating grease is effectively improved.

Drawings

FIG. 1 is an SEM image of CTAB modified nano molybdenum disulfide obtained in example 1;

FIG. 2 is an infrared spectrum of the lithium-based grease obtained in comparative example 2;

FIG. 3 is an infrared spectrum of the lithium-based grease obtained in comparative example 1;

FIG. 4 is an infrared spectrum of the lithium grease obtained in example 1.

Detailed Description

The invention provides a preparation method of CTAB modified nano molybdenum disulfide, which comprises the following steps:

mixing nano molybdenum disulfide, CTAB and ethanol to obtain a raw material mixed solution;

and carrying out reflux reaction on the raw material mixed solution for 22-26 h, and then standing for reaction for 22-26 h to obtain the CTAB modified nano molybdenum disulfide.

The method mixes the nano molybdenum disulfide, CTAB and ethanol to obtain a raw material mixed solution.

The specification of the nano molybdenum disulfide is not particularly limited, commercially available nano molybdenum disulfide can be adopted, and in the embodiment of the invention, the average sheet diameter of the nano molybdenum disulfide is preferably 500nm, and the thickness of the nano molybdenum disulfide is preferably 80 nm.

In the invention, the mass ratio of the nano molybdenum disulfide to CTAB is preferably 1 (3-5), and more preferably 1: 5.

In the invention, the ethanol is preferably absolute ethanol, the dosage of the ethanol is not particularly limited, and the conventional solvent dosage is adopted, and in the embodiment of the invention, the dosage ratio of the molybdenum disulfide to the ethanol is preferably 1g (40-50) m L, and more preferably 1g:45m L.

The invention has no special limitation on the mixing sequence of the nano molybdenum disulfide, CTAB and ethanol, and can obtain the raw material mixed solution which is uniformly mixed. In an embodiment of the present invention, the mixing preferably comprises the steps of:

dispersing nano molybdenum disulfide in partial ethanol to obtain nano molybdenum disulfide dispersion liquid;

dissolving CTAB in the residual ethanol to obtain CTAB solution;

mixing the CTAB solution with the nano molybdenum disulfide dispersion.

The invention has no special limit on the amount of the partial ethanol, can ensure that the nano molybdenum disulfide is uniformly dispersed, and the CTAB can be completely dissolved in the residual ethanol.

In the embodiment of the invention, the mixing process of the CTAB solution and the nano molybdenum disulfide dispersion liquid is preferably carried out by heating the nano molybdenum disulfide dispersion liquid to the temperature of reflux reaction and then adding the CTAB solution, wherein the adding rate of the CTAB solution is preferably 8-12 m L/min, and more preferably 10m L/min.

After the raw material mixed solution is obtained, the raw material mixed solution is subjected to reflux reaction for 22-26 hours, and then is subjected to standing reaction for 22-26 hours to obtain the CTAB modified nano molybdenum disulfide.

In the invention, the temperature of the reflux reaction is preferably 75-85 ℃, more preferably 80 ℃, and the time is preferably 24 h; in the reflux reaction process, stirring is preferably maintained, and the rotating speed of the stirring is preferably 60-75 rpm, more preferably 70 rpm; the standing reaction is preferably carried out at room temperature (i.e., without additional heating or cooling), and the time for the standing reaction is preferably 24 hours.

In the present invention, after the standing reaction is completed, the method preferably further comprises a post-treatment, and the post-treatment preferably comprises the following steps: carrying out solid-liquid separation on the reaction liquid obtained by the standing reaction to obtain a solid; the solid was hot washed with alternating petroleum ether and ethanol and then dried. The solid-liquid separation mode is not particularly limited, and a conventional solid-liquid separation mode, such as filtration, is adopted; the temperature of the petroleum ether used for hot washing is preferably 40-50 ℃, more preferably 45 ℃, and the temperature of the ethanol used for hot washing is preferably 65-70 ℃, more preferably 70 ℃; the number of times of hot washing is not particularly limited, and CTAB can be removed, and in the embodiment of the invention, the number of times of alternately hot washing by petroleum ether and ethanol is preferably 3-5 times. The drying mode and parameters are not particularly limited in the invention, and a constant weight product can be obtained, in the embodiment of the invention, the drying is preferably vacuum drying, and the drying temperature is preferably 80 ℃.

The invention also provides the CTAB modified nano molybdenum disulfide obtained by the preparation method in the technical scheme.

The invention also provides the application of the CTAB modified nano molybdenum disulfide as a lubricating grease additive in the technical scheme; the grease additive is preferably a lithium-based grease additive.

The invention provides lithium-based lubricating grease which comprises the following main raw materials in parts by mass: 90-100 parts of dodecahydroxy stearic acid, 750-900 parts of base oil, 13-17 parts of lithium hydroxide and 15-22 parts of lubricating grease additive, wherein the lubricating grease additive is the CTAB modified nano molybdenum disulfide in the technical scheme. The raw material of the lithium-based lubricating grease provided by the invention also comprises water for dissolving lithium hydroxide, and the amount of the water is not particularly limited in the invention and can be removed in the preparation process.

In the present invention, the lithium-based grease preferably comprises the following main raw materials in parts by mass: 100 parts of dodecahydroxy stearic acid, 865 parts of base oil, 15 parts of lithium hydroxide and 20 parts of a lubricating grease additive.

The type of the base oil is not particularly limited, in the embodiment of the invention, the base is preferably 500N base oil, and the kinematic viscosity of the 500N base oil at 40 ℃ is preferably 95-100 mm²S, more preferably 98.0mm²/s。

The invention also provides a preparation method of the lithium-based lubricating grease, which comprises the following steps:

dissolving dodecahydroxy stearic acid in part of base oil to obtain a base oil solution of dodecahydroxy stearic acid;

dissolving lithium hydroxide in water to obtain a lithium hydroxide aqueous solution;

mixing the base oil solution of the dodecahydroxy stearic acid with a lithium hydroxide aqueous solution, and performing saponification reaction to obtain thickened lubricating oil;

sequentially dehydrating and refining the thickened lubricating oil to obtain anhydrous thickened lubricating oil;

and mixing the anhydrous thickened lubricating oil with the rest base oil and the lubricating grease additive, and then grinding to obtain the lithium-based lubricating grease.

The invention dissolves the dodecahydroxy stearic acid in part of base oil to obtain the base oil solution of the dodecahydroxy stearic acid.

In the present invention, the portion of the base oil is preferably 2/3 based on the total amount of base oil.

In the present invention, the above-mentioned dissolving method is not particularly limited, and it is sufficient if the dodecahydroxystearic acid is completely dissolved, and in the present embodiment, it is preferable to mix the dodecahydroxystearic acid and a part of the base oil and heat the mixture to a saponification reaction temperature so that the dodecahydroxystearic acid is completely dissolved and prepare for the saponification reaction.

The invention dissolves lithium hydroxide in water to obtain the lithium hydroxide aqueous solution.

In the present invention, the lithium hydroxide is dissolved in water without any particular limitation, and the lithium hydroxide may be dissolved, and in the embodiment of the present invention, the lithium hydroxide is preferably dissolved by heating at a temperature of preferably 75 to 85 ℃, more preferably 80 ℃, and the concentration of the lithium hydroxide aqueous solution is preferably 12 to 13g/100m L, more preferably 12.8g/100m L.

The order of preparation of the base oil solution of dodecahydroxystearic acid and the aqueous solution of lithium hydroxide is not particularly limited.

After the base oil solution of the dodecahydroxystearic acid and the lithium hydroxide aqueous solution are obtained, the base oil solution of the dodecahydroxystearic acid and the lithium hydroxide aqueous solution are mixed for saponification reaction to obtain the thickened lubricating oil.

In the present invention, after the base oil solution of dodecahydroxystearic acid and the aqueous solution of lithium hydroxide are mixed, the dodecahydroxystearic acid and the lithium hydroxide are saponified to generate lithium dodecahydroxystearate, a large amount of heat is generated, and water is boiled to generate a large amount of foam, so that it is preferable to maintain stirring at a rotation speed of 80 to 110rpm, more preferably 110rpm, during the saponification reaction to reduce the foam.

In the present invention, the order of mixing the base oil solution of dodecahydroxystearic acid and the aqueous solution of lithium hydroxide is preferably such that the aqueous solution of lithium hydroxide is slowly added to the base oil solution of dodecahydroxystearic acid, to the extent that no boiling phenomenon occurs.

In the invention, the temperature of the saponification reaction is preferably 90-125 ℃, more preferably 115 ℃, and the time of the saponification reaction is preferably based on the alkali of the reaction liquid of the saponification reaction; in the embodiment of the invention, preferably, when the time of the saponification reaction is 1h, the acid-base degree of the reaction solution is detected, the saponification reaction is completed when the reaction solution is detected to be alkalescent, namely, the pH value is 8-10, the next step is carried out, if the reaction solution is detected to be acidic, the saponification reaction is continued, and a proper amount of sodium hydroxide solution can be added dropwise.

The temperature and time for dehydration are not particularly limited, and water can be removed, in the embodiment of the invention, the temperature for dehydration is preferably 140-160 ℃, more preferably 150 ℃, and the time is preferably 15-30 min, more preferably 30 min.

In the invention, the refining temperature is preferably 190-210 ℃, more preferably 200 ℃, and the time is preferably 9-12 min, more preferably 10 min. In the present invention, the refining enables better blending of the base oil with lithium dodecahydroxystearate, resulting in the formation of stable soap fibers.

After the anhydrous thickened lubricating oil is obtained, the anhydrous thickened lubricating oil is mixed with the rest base oil and the lubricating grease additive, and then the mixture is ground to obtain the lithium-based lubricating grease.

In the invention, after the anhydrous thickened lubricating oil is mixed with the rest base oil and the lubricating grease additive, the temperature is preferably reduced to 57-63 ℃, more preferably to 60 ℃, and then grinding is carried out, wherein the grinding at the preferred temperature can better fuse the rest base oil and the lubricating grease additive in a soap fiber framework; the cooling rate is not particularly limited, and a person skilled in the art can control the cooling rate according to needs, for example, when short soap fibers and lubricating grease with a large cone penetration are required to be obtained, rapid cooling is preferably adopted, and the cooling rate is preferably 10-15 ℃/min, and more preferably 10 ℃/min; the grinding equipment is preferably a three-roll mill, and the grinding parameters comprise: the rough roll milling gap is preferably 0.09-0.39 mm, more preferably 0.09mm, and the fine roll milling gap is preferably 0.05-0.09 mm, more preferably 0.05mm, and the milling can obtain uniform and smooth grease.

The CTAB modified nano molybdenum disulfide, the preparation method and the application thereof, the lithium grease and the preparation method thereof provided by the present invention are described in detail below with reference to the examples, but they should not be construed as limiting the scope of the present invention.