阅读说明：本技术 一种纳米氮化硼-氧化铜润滑添加剂的制备方法 (Preparation method of nano boron nitride-copper oxide lubricating additive ) 是由 高晓红 王彦明 李萍 于 2021-10-10 设计创作，主要内容包括：本发明公开了一种纳米氮化硼-氧化铜润滑添加剂的制备方法,包括如下步骤：PDA-BNNS的制备、f-CuO的制备以及纳米氮化硼-氧化铜的制备。本发明所制备的纳米氮化硼-氧化铜复合材料,具有良好的减摩抗磨性能,作为润滑油添加剂在液体石蜡等非极性基础油中分散性好,能有效降低摩擦系数和磨损率,具有稳定优良的摩擦学性能；纳米氧化铜和氮化硼纳米颗粒粒度小且分布均匀,能有效的进入摩擦界面,起到减摩抗磨作用；氮化硼发挥其减摩性能的同时,纳米颗粒的介入也能增强润滑油的抗磨和修复性能；本发明的制备方法简单,所需原材料来源广泛,易操作,适合规模化广泛应用。(The invention discloses a preparation method of a nano boron nitride-copper oxide lubricating additive, which comprises the following steps: preparation of PDA-BNNS, preparation of f-CuO and preparation of nano boron nitride-copper oxide. The nano boron nitride-copper oxide composite material prepared by the invention has good antifriction and wear resistance, has good dispersibility in nonpolar base oil such as liquid paraffin and the like as a lubricating oil additive, can effectively reduce friction coefficient and wear rate, and has stable and excellent tribology performance; the nano copper oxide and boron nitride particles have small particle sizes and are uniformly distributed, and can effectively enter a friction interface to play a role in reducing friction and resisting wear; the boron nitride exerts the antifriction performance of the boron nitride, and the intervention of the nano particles can also enhance the antiwear and repair performance of the lubricating oil; the preparation method is simple, the sources of the required raw materials are wide, the operation is easy, and the method is suitable for large-scale wide application.)

1. A preparation method of a nano boron nitride-copper oxide lubricating additive is characterized by comprising the following steps:

preparation of PDA-BNNS: preparing a trihydroxymethylaminomethane solution, adding BNNS into the trihydroxymethylaminomethane solution to uniformly disperse the BNNS, then adding absolute ethyl alcohol and dopamine hydrochloride, stirring, centrifuging, washing, and finally performing vacuum freeze drying to obtain PDA-BNNS; wherein the weight ratio of the trihydroxymethylaminomethane to the BNNS and the dopamine hydrochloride is 1: 5-6: 1-3;

f-CuO preparation: adding CuO and a silane coupling agent KH550 into absolute ethyl alcohol, uniformly dispersing the mixture, adding deionized water, stirring, centrifuging, washing, and finally performing vacuum freeze drying to obtain f-CuO; wherein the weight ratio of CuO to the silane coupling agent KH550 is 1: 15-25;

preparing nanometer boron nitride-copper oxide: adding PDA-BNNS into DMF for ultrasonic treatment to obtain a suspension, adding f-CuO for ultrasonic treatment to form a uniform suspension, stirring, centrifuging, washing, and finally performing vacuum freeze drying to obtain the nano boron nitride-copper oxide lubricating additive; wherein the mass ratio of the PDA-BNNS to the f-CuO is (1-10): 1.

2. the method according to claim 1, wherein said BNNS is a monolayer or few-layer prepared by exfoliation of said h-BN in an ultrasonic cell disruptor.

3. The method according to claim 1, wherein the stirring in the step (1) is high-speed stirring at room temperature for 5-8 h; stirring in the step (2) is carried out at 70-90 ℃, and the stirring time is 3-5 h; and (4) stirring in the step (3) is carried out at 100-110 ℃, and the stirring time is 5-8 h.

4. The method according to claim 1, wherein in the step (2), the CuO and the silane coupling agent KH550 are uniformly dispersed in the absolute ethyl alcohol after being subjected to ultrasonic treatment for 2-3 hours by using a constant-temperature ultrasonic cleaning machine.

5. The method according to claim 1, wherein the washing in the step (1), the step (2) and the step (3) is performed 3 times by using deionized water and then 3 times by using absolute ethyl alcohol, or is performed 3 to 5 times by using only deionized water.

6. The method according to claim 1, wherein the vacuum freeze-drying in the steps (1), (2) and (3) is performed by using a freeze-dryer at-60 to-90 ℃ for 20 to 24 hours.

7. The method according to claim 1, wherein the tris solution has a PH of 8 to 9.

8. The method of claim 1, wherein the nano boron nitride-copper oxide lubricant additive is used in a lubricant as a lubricant additive, and the weight ratio of the nano boron nitride-copper oxide lubricant additive in the lubricant is 0.02-5%.

9. The method of claim 8, wherein the nano boron nitride-copper oxide lubricant additive is uniformly dispersed in the lubricant oil by ultrasonic and shear agitation.

10. The method according to claim 8, wherein the lubricating oil is a non-polar liquid paraffin or silicone oil.

Technical Field

The invention relates to the technical field of functional composite materials, in particular to a preparation method of a nano boron nitride-copper oxide lubricating additive.

Background

In recent years, with the wide application of lubricating oils in equipment manufacturing, great attention has been paid to the anti-friction and anti-wear properties of lubricating oils. The performance of the lubricating additive as a core component in the lubricating oil directly determines the exertion of the performance of the lubricating oil under severe conditions.

With the deepening of people's understanding of tribology, how to improve the antifriction and antiwear properties of lubricating oil and reduce the energy or material loss caused by friction has important economic significance and social value. The nanometer copper oxide particle is one of the most common antiwear additives in composite material and has reinforcing effect on the strength of transfer film. The nano particles have the special properties of large specific surface area, small particle size, low aggregation density and the like, so that the nano particles can generate a friction chemical reaction in a friction process to further enhance the friction-reducing and wear-resisting effects of the nano particles. Hexagonal boron nitride (h-BN) has a graphite-like layered structure, is called white graphite, has excellent friction-reducing and wear-resisting properties, and is one of the commonly used solid lubricants. However, with the improvement of the requirements of the friction working condition, the single lubricating additive can not meet the requirements of the current technical progress, and the development of the composite lubricating additive is an effective way for improving the antifriction and antiwear performance of the lubricating oil.

Disclosure of Invention

The invention aims to solve the problems and designs a preparation method of a nano boron nitride-copper oxide lubricating additive.

The technical scheme of the invention is that the preparation method of the nano boron nitride-copper oxide lubricating additive comprises the following steps:

(1) preparation of PDA-BNNS: preparing a trihydroxymethyl aminomethane solution, putting the trihydroxymethyl aminomethane solution into a three-neck flask, adding BNNS into the trihydroxymethyl aminomethane solution, uniformly dispersing the solution by adopting an ultrasonic cleaning machine with the power of 300-500W for 30-60 min, then adding absolute ethyl alcohol and dopamine hydrochloride, stirring, centrifuging, washing, and finally carrying out vacuum freeze drying to obtain PDA-BNNS; wherein the weight ratio of the trihydroxymethylaminomethane to the BNNS to the dopamine hydrochloride is 1: 5-6: 1-3;

(2) f-CuO preparation: adding CuO and a silane coupling agent KH550 into absolute ethyl alcohol, uniformly dispersing the CuO and the silane coupling agent KH550 by using an ultrasonic cleaning machine, adding deionized water, stirring, centrifuging, washing, and finally performing vacuum freeze drying to obtain f-CuO, wherein the power is 300-500W and the time is 120-180 min; wherein the weight ratio of CuO to the silane coupling agent KH550 is 1: 15-25;

(3) preparing nanometer boron nitride-copper oxide: adding DMF into a three-neck flask, adding PDA-BNNS into the DMF for ultrasonic treatment, wherein the ultrasonic treatment adopts an ultrasonic cleaning machine, the power of the ultrasonic cleaning machine is 300-500W, the time is 40-60 min, obtaining suspension, adding 0.1gf-CuO for ultrasonic treatment, forming uniform suspension, stirring, centrifuging, washing, and finally performing vacuum freeze drying to obtain the nano boron nitride-copper oxide lubricating additive; wherein the mass ratio of the PDA-BNNS to the f-CuO is (1-10): 1.

the BNNS is a single layer or a few layers and is prepared by peeling the h-BN in an ultrasonic cell crusher. The few layers are 2-5 layers. The power of the ultrasonic cell crusher is 300-500W, the ultrasonic cell crusher works for 2-8 h, and the h-BN is stripped to prepare single-layer or few-layer BNNS.

Stirring in the step (1) is high-speed stirring at room temperature for 5-8 h; stirring in the step (2) is carried out at 70-90 ℃, and the stirring time is 3-5 h; and (4) stirring in the step (3) is carried out at 100-110 ℃, and the stirring time is 5-8 h.

And (3) in the step (2), the CuO and the silane coupling agent KH550 are subjected to ultrasonic treatment for 2-3 hours by using a constant-temperature ultrasonic cleaning machine, and then are uniformly dispersed in the absolute ethyl alcohol.

The washing in the step (1), the step (2) and the step (3) is carried out for 3 times by using deionized water, and then for 3 times by using absolute ethyl alcohol; or washing with deionized water for 3-5 times.

The vacuum freeze drying in the step (1), the step (2) and the step (3) is to freeze and dry for 20-24 hours at the temperature of minus 60-90 ℃ by using a freeze dryer.

The pH value of the tris solution is 8-9.

The invention also provides an application of the nano boron nitride-copper oxide lubricating additive prepared by the method in lubricating oil as a lubricating oil additive, wherein the weight ratio of the nano boron nitride-copper oxide lubricating additive in the lubricating oil is 0.02-5%.

The nano boron nitride-copper oxide lubricating additive is uniformly dispersed in the lubricating oil by adopting an ultrasonic and shearing stirring mode.

The lubricating oil is base oil such as nonpolar liquid paraffin or silicone oil.

The invention has the beneficial effects that:

(1) the nano boron nitride-copper oxide composite material prepared by the invention has good antifriction and wear resistance, has good dispersibility in nonpolar base oil such as liquid paraffin and the like as a lubricating oil additive, can effectively reduce friction coefficient and wear rate, and has stable and excellent tribology performance;

(2) the product obtained by the preparation method has small and even distribution of the nanometer particles of the nanometer copper oxide and the boron nitride, can effectively enter a friction interface, and has the functions of friction reduction and wear resistance; the boron nitride exerts the antifriction performance of the boron nitride, and the intervention of the nano particles can also enhance the antiwear and repair performance of the lubricating oil;

(3) the preparation method is simple, the sources of the required raw materials are wide, the operation is easy, and the method is suitable for large-scale wide application.

Drawings

Fig. 1 is an XRD pattern of the nano boron nitride-copper oxide composite material prepared in example 1 of the present application;

FIG. 2 is an infrared spectrum of a nano boron nitride-copper oxide composite material prepared in example 1 of the present application;

FIG. 3 is a pictorial representation of BNNS and its composite material prepared in example 1 of the present application;

FIG. 4 is a scanning electron microscope image of the nano boron nitride-copper oxide composite material prepared in example 1 of the present application;

FIG. 5 is a surface topography of a steel ball after being rubbed by a sample in an experimental example;

FIG. 6 is a graph showing the results of friction coefficient and wear rate in the friction test of each sample in the experimental examples.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the detailed description and specific examples, while indicating the scope of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. The nano boron nitride-copper oxide composite material described in the examples, also referred to as nano boron nitride-copper oxide lubricant additive or nano PDA-BNNS @ f-CuO composite, was boron nitride for PDA-BNNS, nano copper oxide for f-CuO, and exfoliated boron nitride nanosheet for BN.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Example 1

(1) Preparation of PDA-BNNS: h-BN is stripped in an ultrasonic cell crusher to prepare BNNS, 0.1211g of Tris is weighed to prepare 100mL of solution, the pH value of the Tris solution is 8.5, 0.666g of BNNS is put into a three-mouth flask filled with 100mL of Tris solution, an ultrasonic cleaner is adopted to uniformly disperse the BNNS with the power of 500W and the time of 50min, then 33.4mL of absolute ethyl alcohol and 0.266g of dopamine hydrochloride are added, the mixture is stirred at high speed for 6h at room temperature, then the centrifugal separation and the washing are carried out, and finally the PDA-BNNS is obtained by vacuum freeze drying;

(2) f-CuO preparation: adding 0.2g of CuO and 4g of KH550 silane coupling agent into 100g of absolute ethyl alcohol, uniformly dispersing the mixture by using an ultrasonic cleaner with the power of 500W for 150min, adding 8g of deionized water, stirring for 4h at 80 ℃, centrifuging, washing, and finally performing vacuum freeze drying to obtain f-CuO;

(3) preparing nanometer boron nitride-copper oxide: adding 0.1g of PDA-BNNS into a three-neck flask containing 50mLDMF, carrying out ultrasonic treatment to obtain a suspension, carrying out ultrasonic treatment by using an ultrasonic cleaner with the power of 400W for 50min to obtain the suspension, adding 0.03gf-CuO, carrying out ultrasonic treatment, stirring the formed uniform suspension at 105 ℃ for reaction for 6h, centrifuging, washing, and finally carrying out vacuum freeze drying to obtain the nano boron nitride-copper oxide lubricating additive; wherein the mass ratio of the PDA-BNNS to the f-CuO is 1: 1.

wherein the BNNS is a single layer or a few layers and is prepared by peeling the h-BN in an ultrasonic cell crusher. The few layers are 2-5 layers. The power of the ultrasonic cell crusher is 400W, and the ultrasonic cell crusher works for 4 hours.

And (3) in the step (2), the CuO and the silane coupling agent KH550 are subjected to ultrasonic treatment for 2-3 hours by using a constant-temperature ultrasonic cleaning machine, and then are uniformly dispersed in the absolute ethyl alcohol.

And (3) washing in the steps (1), (2) and (3) by firstly washing with deionized water for 3 times and then washing with absolute ethyl alcohol for 3 times.

The vacuum freeze drying in the step (1), the step (2) and the step (3) is to freeze and dry for 20-24 hours at the temperature of minus 60-90 ℃ by using a freeze dryer.

5g of the nano boron nitride-copper oxide composite material prepared by the method and 95g of liquid paraffin are weighed and uniformly mixed by adopting an ultrasonic and shearing stirring mode to obtain the modified liquid paraffin lubricating oil.

The product of example 1 was characterized in relation to FIGS. 1-4.

Example 2

This embodiment is substantially the same as embodiment 1, except that,

(1) preparation of PDA-BNNS: h-BN is peeled off in an ultrasonic cell crusher to prepare BNNS, 0.0605g of Tris is weighed to prepare 100mL of solution, 0.333g of BNNS is put into a three-neck flask filled with 50mL of Tris solution, an ultrasonic cleaner is adopted to uniformly disperse the BNNS with the power of 400W and the time of 50min, then 16.7mL of absolute ethyl alcohol and 0.133g of dopamine hydrochloride are added, the mixture is stirred at high speed for 6h at room temperature, then the centrifugal separation and the washing are carried out, and finally the PDA-BNNS is obtained by vacuum freeze drying;

(2) f-CuO preparation: adding 0.1g of CuO and 2g of a silane coupling agent KH550 into 50g of absolute ethyl alcohol, uniformly dispersing the mixture by using an ultrasonic cleaner with the power of 500W for 150min, adding 4g of deionized water, stirring for 4h at 80 ℃, centrifuging, washing, and finally performing vacuum freeze drying to obtain f-CuO;

(3) preparing nanometer boron nitride-copper oxide: adding 0.06g of PDA-BNNS into a three-neck flask containing 50mLDMF, carrying out ultrasonic treatment to obtain a suspension, carrying out ultrasonic treatment by adopting an ultrasonic cleaner with the power of 400W for 50min to obtain the suspension, adding 0.03gf-CuO, carrying out ultrasonic treatment, stirring the formed uniform suspension at 105 ℃ for reaction for 6h, centrifuging, washing, and finally carrying out vacuum freeze drying to obtain the nano boron nitride-copper oxide lubricating additive; wherein the mass ratio of the PDA-BNNS to the f-CuO is 2: 1.

5g of the nano boron nitride-copper oxide composite material prepared by the method and 95g of liquid paraffin are weighed and uniformly mixed by adopting an ultrasonic and shearing stirring mode to obtain the modified liquid paraffin lubricating oil.

Example 3

(1) Preparation of PDA-BNNS: h-BN is stripped in an ultrasonic cell crusher to prepare BNNS, 0.1211g of Tris is weighed to prepare 100mL of solution, 0.666g of BNNS is put into a three-neck flask filled with 100mL of Tris solution, an ultrasonic cleaner is adopted to uniformly disperse the BNNS with the power of 400W for 50min, then 33.4mL of absolute ethyl alcohol and 0.266g of dopamine hydrochloride are added, high-speed stirring is carried out for 6h at room temperature, centrifugal separation and washing are carried out, and finally, vacuum freeze drying is carried out to obtain PDA-BNNS;

(2) f-CuO preparation: adding 0.2g of CuO and 4g of KH550 silane coupling agent into 50g of absolute ethyl alcohol, uniformly dispersing the mixture by using an ultrasonic cleaner with the power of 500W for 150min, adding 8g of deionized water, stirring for 4h at 80 ℃, centrifuging, washing, and finally performing vacuum freeze drying to obtain f-CuO;

(3) preparing nanometer boron nitride-copper oxide: adding 0.4g of PDA-BNNS into a three-neck flask containing 50mLDMF, carrying out ultrasonic treatment to obtain a suspension, carrying out ultrasonic treatment by using an ultrasonic cleaner with the power of 400W for 50min to obtain the suspension, adding 0.1gf-CuO, carrying out ultrasonic treatment, stirring the formed uniform suspension at 105 ℃ for reaction for 6h, centrifuging, washing, and finally carrying out vacuum freeze drying to obtain the nano boron nitride-copper oxide lubricating additive; wherein the mass ratio of the PDA-BNNS to the f-CuO is 4: 1.

5g of the nano boron nitride-copper oxide composite material prepared by the method and 95g of liquid paraffin are weighed and uniformly mixed by adopting an ultrasonic and shearing stirring mode to obtain the modified liquid paraffin lubricating oil.

Example 4

(1) Preparation of PDA-BNNS: h-BN is peeled off in an ultrasonic cell crusher to prepare BNNS, 0.0605g of Tris is weighed to prepare 50mL of solution, 0.333g of BNNS is put into a three-neck flask filled with 50mL of Tris solution, an ultrasonic cleaner is adopted to uniformly disperse the BNNS with the power of 400W and the time of 50min, then 16.7mL of absolute ethyl alcohol and 0.133g of dopamine hydrochloride are added, the mixture is stirred at high speed for 6h at room temperature, then the centrifugal separation and the washing are carried out, and finally the PDA-BNNS is obtained by vacuum freeze drying;

(2) f-CuO preparation: adding 0.1g of CuO and 2g of a silane coupling agent KH550 into 50g of absolute ethyl alcohol, uniformly dispersing the mixture by using an ultrasonic cleaner with the power of 500W for 150min, adding 4g of deionized water, stirring for 4h at 80 ℃, centrifuging, washing, and finally performing vacuum freeze drying to obtain f-CuO;

(3) preparing nanometer boron nitride-copper oxide: adding 0.24g of PDA-BNNS into a three-neck flask containing 50mLDMF, carrying out ultrasonic treatment to obtain a suspension, carrying out ultrasonic treatment by using an ultrasonic cleaner with the power of 400W for 50min to obtain the suspension, adding 0.03gf-CuO, carrying out ultrasonic treatment, stirring the formed uniform suspension at 105 ℃ for reaction for 6h, centrifuging, washing, and finally carrying out vacuum freeze drying to obtain the nano boron nitride-copper oxide lubricating additive; wherein the mass ratio of the PDA-BNNS to the f-CuO is 8: 1.

5g of the nano boron nitride-copper oxide composite material prepared by the method and 95g of liquid paraffin are weighed and uniformly mixed by adopting an ultrasonic and shearing stirring mode to obtain the modified liquid paraffin lubricating oil.

Example 5

(1) Preparation of PDA-BNNS: h-BN is peeled off in an ultrasonic cell crusher to prepare BNNS, 0.0605g of Tris is weighed to prepare 50mL of solution, 0.333g of BNNS is put into a three-neck flask filled with 50mL of Tris solution, an ultrasonic cleaner is adopted to uniformly disperse the BNNS with the power of 400W and the time of 50min, then 16.7mL of absolute ethyl alcohol and 0.133g of dopamine hydrochloride are added, the mixture is stirred at high speed for 6h at room temperature, then the centrifugal separation and the washing are carried out, and finally the PDA-BNNS is obtained by vacuum freeze drying;

(2) f-CuO preparation: adding 0.1g of CuO and 2g of a silane coupling agent KH550 into 50g of absolute ethyl alcohol, uniformly dispersing the mixture by using an ultrasonic cleaner with the power of 500W for 150min, adding 4g of deionized water, stirring for 4h at 80 ℃, centrifuging, washing, and finally performing vacuum freeze drying to obtain f-CuO;

(3) preparing nanometer boron nitride-copper oxide: adding 0.3g of PDA-BNNS into a three-neck flask containing 50mLDMF, carrying out ultrasonic treatment to obtain a suspension, carrying out ultrasonic treatment by using an ultrasonic cleaner with the power of 400W for 50min to obtain the suspension, adding 0.03gf-CuO, carrying out ultrasonic treatment, stirring the formed uniform suspension at 105 ℃ for reaction for 6h, centrifuging, washing, and finally carrying out vacuum freeze drying to obtain the nano boron nitride-copper oxide lubricating additive; wherein the mass ratio of the PDA-BNNS to the f-CuO is 10: 1.

5g of the nano boron nitride-copper oxide composite material prepared by the method and 95g of liquid paraffin are weighed and uniformly mixed by adopting an ultrasonic and shearing stirring mode to obtain the modified liquid paraffin lubricating oil.

Examples of the experiments

The liquid paraffin lubricating oil prepared in the examples 1 to 5 was subjected to a friction test in a four-ball friction tester, and the friction coefficient and the wear rate were analyzed. In addition, a friction experiment was also performed on a four-ball friction tester by combining liquid paraffin and the PDA-BNNS prepared in example 1 with liquid paraffin, and combining the f-CuO prepared in example 1 with liquid paraffin, and the surface morphology of the steel ball after the experiment was shown in fig. 5, in which a represents a photograph of 200 times the wear scar diameter on the steel ball surface after the friction experiment was performed using liquid paraffin, B represents a photograph of 200 times the wear scar diameter on the steel ball surface after the friction experiment was performed using liquid paraffin + PDA-BNN, C represents a photograph of 200 times the wear scar diameter on the steel ball surface after the friction experiment was performed using liquid paraffin + f-CuO, and D represents a photograph of 200 times the wear scar diameter on the steel ball surface after the friction experiment was performed using the liquid paraffin lubricating oil prepared in example 1.

As shown in fig. 6, it can be seen from the experimental results that the liquid paraffin lubricating oils prepared in examples 1 to 5 have more stable and excellent tribological properties than the liquid paraffin, the combination of nano boron nitride and liquid paraffin, and the combination of copper oxide and liquid paraffin, and can effectively reduce the friction coefficient, and particularly, the liquid paraffin lubricating oil prepared in example 1 has the smallest friction coefficient, and the smallest diameter of the wear scar obtained by performing the friction experiment on a four-ball friction tester.

The preparation method of the nano boron nitride-copper oxide composite lubricating additive provided by the invention is described in detail, specific examples are applied in the description to explain the implementation of the invention, and the description of the examples is only used for helping to understand the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.