CN115960655A - A kind of lubricating oil additive for mechanical system and its preparation method and application - Google Patents

Abstract

The present invention relates to a kind of preparation method of lubricating oil additive used in mechanical system, carry out according to following steps: (1) take graphite phase carbon nitride, add solvent, ultrasonic disperse and obtain graphite phase carbon nitride solution; (2) ) Add modifier, DMAP and DCC to the graphite phase carbon nitride solution obtained in step (1), stir, and heat to reflux reaction under an inert atmosphere; (3) after the reaction is completed, centrifuge to get the precipitate, and use absolute ethanol Wash with petroleum ether and dry. The invention also provides a lubricating oil additive product prepared by the above method and its application. The lubricating oil additive provided by the invention can promote the uniform dispersion of repairing nanomaterials with similar structures, reduce the existence of agglomerated structures, and at the same time, it can effectively fill surface scratches and reduce mechanical damage. The two work together to achieve friction reduction and anti-wear Effect.

Description

A kind of lubricating oil additive for mechanical system and its preparation method and application

technical field

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

Background technique

From the perspective of tribology, friction and wear will directly cause energy loss of mechanical equipment, leading to component failure and serious mechanical accidents, and lubrication is considered to be one of the most effective methods to reduce friction and control wear. With the extreme and harsh development of mechanical system working conditions and environments, lubricating oil additives have been widely used in many types of machinery, and graphene, hexagonal boron nitride, metals (such as Cu, Co and Ni) and metal oxides Nanomaterials (such as Al ₂ O ₃ , ZnO and TiO ₂ ) are added to lubricating oil to reduce friction and wear by forming a tribochemical reaction oil film on the friction contact surface, which can significantly improve the anti-wear, anti-friction, and lubricating properties. In this context, in order to minimize the negative effects of friction and wear in mechanical systems, lubricants are still being extensively researched to develop a high-performance industrial lubricant that satisfies its anti-friction, anti- Grinding needs has always been a core task in both academia and industry. Appropriate amount of additives can significantly improve the friction characteristics of the base oil and play a key role in making up for the shortcomings of traditional lubricating oils. It is especially important to ensure the longest service life of mechanical systems, reduce operating costs, and achieve the "double carbon" strategic goal.

At present, graphitic carbon nitride, as a new type of material composed of carbon and nitrogen, is mainly used in the fields of visible light photocatalysis, solar energy conversion and adsorption, etc. It has the advantages of low cost, easy preparation, reliable thermal stability and environmental friendliness. , theoretically can replace traditional additives. In particular, the van der Waals force between graphite-phase carbon nitride sheets is weak and easy to shear, so in the field of friction, it can be used as a lubricating oil additive to improve tribological properties, and has a good development prospect. However, unfortunately, the extremely high activity and surface energy of graphitic carbon nitrides means that they are not well dispersed in base oils, resulting in the existence of multilayer agglomerated structures, so the current research on graphitic carbon nitrides Very little research has been done on its use as a base oil additive.

Because of this, propose this invention especially.

Contents of the invention

In order to solve the existing technical problems, the present invention provides a lubricating oil additive for mechanical systems and its preparation method, which uses long-chain alkyl acid to modify graphite phase carbon nitride by condensation reflux method to make graphite phase nitrogen Carbon does not agglomerate after being added to the base oil as an additive, and it still has good anti-friction and anti-wear effects in extremely harsh environments.

To achieve the above object, the technical scheme adopted in the present invention is as follows:

In the first aspect, the present invention provides a kind of preparation method for the lubricating oil additive of mechanical system, carries out according to the following steps:

(1) Take graphite phase carbon nitride, add solvent, ultrasonic dispersion makes graphite phase carbon nitride solution;

(2) Add modifier, DMAP and DCC to the graphite phase carbon nitride solution obtained in step (1), stir, and heat to reflux reaction under an inert atmosphere;

(3) After the reaction is completed, the precipitate is collected by centrifugation, washed with absolute ethanol and petroleum ether, and dried.

Preferably or alternatively, the concentration of graphitic carbon nitride in the graphitic carbon nitride solution is 0.005-0.05 g/mL.

Preferably or alternatively, the solvent is any one of deionized water, ethyl acetate, absolute ethanol, toluene, and isopropanol.

Preferably or optionally, the modifying agent includes any one of oleic acid, linoleic acid, stearic acid and palmitic acid.

Preferably or alternatively, the mass ratio of modifier, DMAP, DCC and graphitic carbon nitride added in step (2) is 30-40:1-2:2-3:0.5-3.

Preferably or alternatively, the heating and reflux reaction temperature in step (2) is 60-120°C, and the reaction time is 8-15h.

Preferably or optionally, in step (3), the centrifugation speed is 6000-12000rpm, and the centrifugation time is 5-10min.

Preferably or optionally, in step (3), the drying method is any one of vacuum freeze drying, low temperature vacuum drying, blast drying, and spray drying.

In the second aspect, the present invention provides a lubricating oil additive for mechanical systems, which is prepared by the above-mentioned method.

In the third aspect, the present invention also provides an application of the above lubricating oil additive in 150BS base oil.

Beneficial effect

Compared with prior art, the beneficial effect of the present invention is:

The invention adopts the condensation reflux method to prepare graphite phase carbon nitride lubricating oil additive, which is easily adsorbed on the surface of the friction pair of the mechanical system, forms a lubricating oil film that hinders the direct contact between the surfaces, and has a better effect of reducing friction and antiwear . The method and process are simple and efficient, easy to operate, and easy to realize industrial production;

Further through formula design and process adjustment, it can be fully miscible with 150BS recycled base oil, overcome the problem of dispersion into the base oil and agglomerate, can significantly improve the tribological properties of 150BS recycled base oil, and prolong the service life of the mechanical system;

Furthermore, the lubricating oil additive prepared by the present invention does not contain elements such as sulfur, phosphorus, and chlorine, is environmentally friendly, and also conforms to the concept of low-carbon environmental protection, and has great application potential as a high-efficiency lubricating oil additive.

Description of drawings

Fig. 1 is the SEM photograph of the surface of the friction pair of the four-ball friction experiment of the embodiment 1 group in the effect embodiment 1 of the present invention;

Fig. 2 is the SEM photograph of the surface of the friction pair of the four-ball friction experiment of the embodiment 2 group in the effect embodiment 1 of the present invention;

Fig. 3 is the SEM photo of the surface of the friction pair in the embodiment 3 group of four-ball friction experiments in the effect embodiment 1 of the present invention;

Fig. 4 is the SEM photograph of the surface of the friction pair in the four-ball friction experiment of embodiment 4 in the effect embodiment 1 of the present invention;

Fig. 5 is the SEM photo of the surface of the friction pair in the four-ball friction experiment of the blank control group in effect example 1 of the present invention;

Fig. 6 is the SEM photo of the surface of the friction pair in the comparative example 1 group of four-ball friction experiments in the effect embodiment 1 of the present invention;

Fig. 7 is the test result of average coefficient of friction in effect embodiment 2 of the present invention;

Fig. 8 is the test result of the wear spot diameter in the effect example 2 of the present invention.

Detailed ways

In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively and in detail below in conjunction with the accompanying drawings and preferred experimental examples, but the protection scope of the present invention is not limited to the following specific examples.

Unless otherwise defined, all technical terms used hereinafter have the same meanings as commonly understood by those skilled in the art. The terminology used herein is only for the purpose of describing specific embodiments, and is not intended to limit the protection scope of the present invention.

Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

The graphite phase carbon nitride used in each embodiment of the present invention is prepared by the following method:

Weigh 10g of melamine and place it in a 50mL corundum crucible with a cover, put the crucible into a muffle furnace, heat it up to 550°C at a heating rate of 5°C/min, and calcinate it for 4 hours, cool it down to room temperature naturally, and grind it to obtain Yellow blocky powder; spread a certain amount of yellow powder on a combustion boat, then heat it to 550°C at a heating rate of 2°C/min, and calcinate for 2 hours, take it out after cooling, grind it, and use deionized water and anhydrous Alternately washed with water and ethanol for 3 times, and dried at 60°C for 8 hours to obtain lamellar graphitic carbon nitride.

Example 1

The embodiment of the invention provides a lubricating oil additive for a mechanical system.

Take 0.1g of graphitic carbon nitride in a 100mL flask, add 20mL of ethyl acetate, and perform ultrasonic treatment with a frequency of 20-30kHz for 5-30min to uniformly disperse the graphitic carbon nitride.

Add 4mL palmitic acid, 0.16g DMAP (4-dimethylaminopyridine) and 0.27g DCC (N,N'-dicyclohexylcarboimide), stir continuously, and reflux the system at 90°C under nitrogen atmosphere 10h.

After the reaction was completed, it was centrifuged at 6000 rpm for 10 min, and the precipitate was collected, washed three times with absolute ethanol and petroleum ether, and dried overnight in an oven at 100°C.

Example 2

The embodiment of the invention provides a lubricating oil additive for a mechanical system.

Take 0.2g of graphite-phase carbon nitride in a 100mL flask, add 20mL of deionized water, and perform ultrasonic treatment with a frequency of 20-30kHz for 5-30min to uniformly disperse the graphite-phase carbon nitride.

Add 4mL linoleic acid, 0.16g DMAP and 0.27g DCC, stir continuously, and reflux the system at 80°C for 8h under nitrogen atmosphere.

After the reaction was completed, it was centrifuged at 6000 rpm for 10 min, and the precipitate was collected, washed three times with absolute ethanol and petroleum ether, and dried overnight in an oven at 60°C.

Example 3

The embodiment of the invention provides a lubricating oil additive for a mechanical system.

Take 0.2g of graphitic carbon nitride in a 100mL flask, add 20mL of toluene, and perform ultrasonic treatment with a frequency of 20-30kHz for 5-30min to uniformly disperse the graphitic carbon nitride.

Add 4mL oleic acid, 0.16g DMAP and 0.27g DCC, stir continuously, and reflux the system at 110°C for 12h under nitrogen atmosphere.

After the reaction was completed, it was centrifuged at 6000 rpm for 10 min, and the precipitate was collected, washed three times with absolute ethanol and petroleum ether, and dried overnight in an oven at 80°C.

Example 4

The embodiment of the invention provides a lubricating oil additive for a mechanical system.

Take 0.2g of graphite-phase carbon nitride in a 100mL flask, add 20mL of absolute ethanol, and perform ultrasonic treatment with a frequency of 20-30kHz for 5-30min to uniformly disperse the graphite-phase carbon nitride.

Add 4mL stearic acid, 0.16g DMAP and 0.27g DCC, stir continuously, and reflux the system at 80°C for 15h under nitrogen atmosphere.

After the reaction was completed, it was centrifuged at 6000 rpm for 6 min, and the precipitate was collected, washed three times with absolute ethanol and petroleum ether, and placed at -20° C. for vacuum freeze-drying overnight.

Comparative example 1

This comparative example provides a lubricating oil additive for a mechanical system.

Take 0.1g of graphite-phase carbon nitride in a 100mL flask, add 20mL of isopropanol, and perform ultrasonic treatment with a frequency of 20-30kHz for 5-30min to uniformly disperse the graphite-phase carbon nitride.

Add 4mL myristic acid, 0.16g DMAP and 0.27g DCC, stir continuously, and reflux the system at 80°C for 10h under nitrogen atmosphere.

After the reaction was completed, it was centrifuged at 6000 rpm for 5 min, and the precipitate was collected, washed three times with absolute ethanol and petroleum ether, and dried overnight in an oven at 80°C.

Effect Example 1

Take the additive products prepared in Examples 1-4 and Comparative Example 1 respectively, add them to 150BS base oil according to 0.03wt%, and magnetically stir for 0.5h, and ultrasonically disperse for 0.5h to disperse the additives in the base oil evenly, and The 150BS base oil with additives was used as the blank control, and the four-ball friction test was carried out for each group of products.

Wherein the friction test adopts a four-ball friction testing machine model, and the four-ball friction testing machine is a four-ball friction testing machine of the model MRS-10W produced by Jinan Chenda Testing Machine Manufacturing Co., Ltd.

The test parameters are: load 392N, oil temperature 75°C, test time 30min, speed 1200r/min.

The steel balls used in the test are GCr15 steel balls (Ф=12.7mm, 60-65HRC) produced by Shanghai Steel Ball Factory Co., Ltd., and the steel balls need to be ultrasonically cleaned in petroleum ether and absolute ethanol before and after the friction test .

After the test was completed, the diameter of the wear spot was measured with a 19JPC-V microcomputer universal tool microscope produced by Shanghai No. 1 Optical Instrument Factory, and the surface of the friction pair was observed with a field emission scanning electron microscope.

After the four-ball test, the SEM photos of the friction pair surfaces of each group are shown in Figure 1-6.

As can be seen from Figures 1-6, compared with the blank group and Comparative Example 1, the additive products in Examples 1-4 have better wear conditions of friction pairs, especially Example 3, whose friction-reducing and anti-wear effects best.

Effect Example 2

The same equipment as in Effect Example 1 was used to measure the tribological properties of each sample oil prepared in Effect Example 1. The test parameters were: load 392N, oil temperature 75°C, test duration 30min, rotation speed 1200r/min. The result is shown in Figure 7-8.

It can be seen from Figures 7-8 that compared with the blank group and Comparative Example 1, the additive products in Examples 1-4 have better tribological properties, especially Example 3, which has the best tribological properties, and its phase Compared with the blank control group, the average friction coefficient and wear spot diameter were reduced by 27.7% and 9.2%, respectively.

The present invention uses graphite phase carbon nitride as the main raw material to prepare lubricating oil additives. The graphite phase carbon nitride has a sheet structure similar to graphene. During the friction process, the graphite phase carbon nitride can better generate electrostatic adsorption, thereby It is easier to form a thin protective oil film and make the contact surface of the friction pair smoother. And through formula design and process adjustment further, the present invention adopts long-chain alkyl acid modified graphite phase carbon nitride, and cooperates the selection and use of activator DMAP and DCC, the graphite phase carbon nitride of modification is expanded Interlamellar spacing hinders the interaction of Van der Waals force, which can promote the uniform dispersion of repairing nanomaterials with similar structures and reduce the existence of agglomerated structures. At the same time, it can effectively fill surface scratches and reduce mechanical damage. The two work together to achieve reduction Anti-wear effect.

It should be noted that, in the actual operation process, the choice of solvent needs to correspond to the subsequent reaction temperature, so that the boiling point of the solvent is as close as possible to the reaction temperature.

As a possible adjustment scheme, the solvent and reaction temperature can be selected according to the table below.

solvent boiling point temperature reflex ethyl acetate 77°C 90°C Deionized water 100°C 80°C toluene 110.6°C 110°C Absolute ethanol 78.4°C 80°C Isopropanol 82.5°C 80°C

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent replacements are made to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims (10)

1. a preparation method for a lubricating oil additive of mechanical system, is characterized in that, carries out according to the following steps: (1) Take graphite phase carbon nitride, add solvent, ultrasonic dispersion makes graphite phase carbon nitride solution; (2) Add modifier, DMAP and DCC to the graphite phase carbon nitride solution obtained in step (1), stir, and heat to reflux reaction under an inert atmosphere; (3) After the reaction is completed, the precipitate is collected by centrifugation, washed with absolute ethanol and petroleum ether, and dried. 2. The preparation method according to claim 1, wherein the concentration of the graphite phase carbon nitride in the graphite phase carbon nitride solution is 0.005-0.05g/mL. 3. preparation method according to claim 1, is characterized in that, described solvent is any one in deionized water, ethyl acetate, dehydrated alcohol, toluene, Virahol. 4. preparation method according to claim 1, is characterized in that, described modifying agent comprises any one in oleic acid, linoleic acid, stearic acid, palmitic acid. 5. preparation method according to claim 4, is characterized in that, the mass ratio of modifier, DMAP, DCC and graphite phase carbon nitride added in step (2) is 30-40:1-2:2- 3:0.5-3. 6. The preparation method according to claim 1, characterized in that, the temperature of the heating-reflux reaction in step (2) is 60-120°C, and the reaction time is 8-15h. 7. The preparation method according to claim 1, characterized in that, in step (3), the centrifugal speed is 6000-12000rpm, and the centrifugation time is 5-10min. 8. The preparation method according to claim 1, characterized in that, in step (3), the drying method is any one of vacuum freeze drying, low temperature vacuum drying, blast drying, and spray drying. 9. A lubricating oil additive for mechanical systems, characterized in that it is prepared by the method according to any one of claims 1-8. 10. The application of the lubricating oil additive described in claim 9 in 150BS base oil.

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