Method for solving performance reduction of lubricating oil caused by soot antagonism molybdenum-containing lubricating additive

Abstract

The invention discloses a method for solving lubricating oil performance reduction caused by a soot antagonistic molybdenum-containing lubricating additive, and relates to the technical field of lubricating oil modification. A MoS2 / TiO2 / Cu compound is used as a molybdenum-containing lubricating additive, the MoS2 / TiO2 / Cu compound is added into the lubricating oil polluted by soot, the MoS2 / TiO2 / Cu compound consists of nano-scale MoS2, nano-scale TiO2 and Cu nanoparticles, and the addition amount of the MoS2 / TiO2 / Cu compound in the lubricating oil is 0.01%-3.0%. The problem of antagonism of soot and the molybdenum-containing lubricating additive is solved by utilizing MoS2 / TiO2 / Cu, after the molybdenum-containing lubricating additive is added into soot-polluted lubricating oil, the antagonism between the molybdenum-containing lubricating additive and soot can be effectively relieved under the condition that ZDDP is not added, and the lubricating performance of the lubricating oil is remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of lubricating oil modification, and in particular to a method for solving the problem that carbon soot antagonizes molybdenum-containing lubricating additives to cause lubricating oil performance degradation. Background Art

[0002] Zinc dialkyl dithiophosphate (ZDDP) and molybdenum-containing lubricant additives are indispensable lubricant additives in lubricating oils, but their application in lubricating oils still has some urgent problems to be solved. ZDDP has excellent performance, but the environmental pollution problems of sulfur and phosphorus in it and the obvious disadvantages to the catalyst activity of engine exhaust treatment systems are one of the problems that have been plaguing the field of lubricating oil additives.

[0003] Molybdenum-containing lubricating additives include MoS2 and other substances that can generate MoS2 through tribochemical reactions during the friction process. The main problem they face in their use in lubricating oils is the antagonistic effect they have on the carbon soot particles in the exhaust gas (after contamination lubrication). This needs to be solved by adding ZDDP, that is, ZDDP and molybdenum-containing lubricating additives need to be used together (ZL201510416795.9).

[0004] MoS2 is a typical transition metal layered compound with excellent lubrication properties. It has excellent performance in lubricating greases, but it is difficult to use in engine lubricating oils because of its large particles and poor dispersibility in lubricating oils. In recent years, with the development of nanotechnology, many nano-MoS2 lubricants have been prepared, and related dispersion technologies have gradually been improved (ZL201610719321.6, ZL201910224141.4, ZL201910224142.9).

[0005] However, studies have found that nano-MoS2, like other molybdenum-based lubricants, also has a significant antagonistic effect with carbon soot, and still needs to be solved by adding ZDDP (Friction, 2024, 12 (12): 2692–2706). To this end, the present invention uses MoS2 / TiO2 / Cu composites to replace traditional nano-MoS2 and organic molybdenum-containing lubricating additives, which not only improves the lubrication performance, but also suppresses the antagonistic effect between molybdenum-containing lubricating additives and carbon soot. Summary of the invention

[0006] The purpose of the present invention is to propose a method for solving the problem of carbon soot antagonizing molybdenum-containing lubricating additives causing the performance of lubricating oil to deteriorate. No ZDDP is added. MoS2 / TiO2 / Cu is used to replace traditional molybdenum-containing lubricating additives to solve the problem of carbon soot antagonizing molybdenum-containing lubricating additives causing the performance of lubricating oil to deteriorate.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A method for solving the problem of lubricating oil performance degradation caused by carbon soot antagonizing molybdenum-containing lubricating additives. A MoS2 / TiO2 / Cu complex is used as a molybdenum-containing lubricating additive. The complex is added to a lubricating oil contaminated by carbon soot, which can effectively alleviate the antagonism between the complex and the carbon soot and improve the lubricating performance of the lubricating oil.

[0009] As a preferred technical solution of the present invention, the MoS2 / TiO2 / Cu composite is composed of nano-sized MoS2, nano-sized TiO2 and Cu nanoparticles. The addition amount in lubricating oil is 0.01% to 3.0%, which can effectively alleviate the carbon smoke pollution not exceeding 3.0%.

[0010] As a preferred technical solution of the present invention, the preparation method of the MoS2 / TiO2 / Cu composite is:

[0011] (1) Weigh a certain amount of sodium molybdate, thioacetamide and nano-TiO2 in a three-necked flask, add deionized water, stir magnetically and heat in a water bath to a temperature higher than 70°C, for example, 70-90°C; add anhydrous ethanol, adjust the pH to a strong acidity (pH<2) with concentrated hydrochloric acid, the reaction starts and a precipitate is produced, and after the reaction, the precipitate is filtered, washed, dried and calcined in a protective atmosphere at a temperature not lower than 420°C, for example, 420-500°C, to obtain a calcined product MoS2 / TiO2;

[0012] (2) After the calcined product is cooled, water, copper chloride, polyvinyl pyrrolidone, NaOH and ascorbic acid are added, and after being fully stirred, the mixture is placed in a hydrothermal reactor. Finally, the reactor is placed in an oven and heated for a certain period of time. After cooling, the mixture is filtered to obtain a MoS2 / TiO2 / Cu composite.

[0013] It is further preferred that the calcined product MoS2 / TiO2 is prepared in the step (1) according to the following ratio:

[0014] The mass ratio of sodium molybdate to thioacetamide is 1:0.5-10;

[0015] The mass ratio of sodium molybdate to nano-TiO2 is 1:0.1-10;

[0016] The mass ratio of sodium molybdate to ethanol is 1:1-100;

[0017] The mass ratio of sodium molybdate to concentrated hydrochloric acid + ethanol is 1:1-100;

[0018] The mass ratio of sodium molybdate to water is 1:10-2000.

[0019] It is further preferred that in the step (2), the MoS2 / TiO2 / Cu composite is prepared according to the following ratio:

[0020] The mass ratio of the calcined product MoS2 / TiO2 to copper chloride is 1:0.01-10;

[0021] The mass ratio of the calcined product MoS2 / TiO2 to polyvinyl pyrrolidone is 1:0.01-100;

[0022] The mass ratio of calcined product MoS2 / TiO2 to NaOH is 1:0.01-10;

[0023] The mass ratio of calcined product MoS2 / TiO2 to ascorbic acid is 1:0.01~50.

[0024] It is further preferred that in step (2), the reaction kettle is placed in an oven for heating, the oven temperature is between 100 and 300° C., and the heating time is between 1 and 24 hours.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] The present invention proposes a method for solving the problem of soot antagonizing molybdenum-containing lubricating additives and causing the performance of lubricating oil to decrease. MoS2 / TiO2 / Cu is used to solve the antagonism problem between soot and molybdenum-containing lubricating additives. After adding it to the lubricating oil contaminated by soot, even without adding ZDDP, the antagonism between the molybdenum-containing lubricating additive and the soot can be effectively alleviated, and the lubricating performance of the lubricating oil is significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 These are the characterization results of MoS2 / TiO2 / Cu prepared by the present invention: (a) powder X-ray diffraction; (b) Cu element photoelectron spectrum; (c) scanning electron microscope photograph; (d) transmission electron microscope photograph.

[0028] according to Figure 1 (a) Powder X-ray diffraction (XRD) characterization results show that all diffraction peaks in the composite can be attributed to MoS2 or TiO2, but Cu is not shown in the XRD spectrum. This is because Cu is deposited on the surface and has poor crystallinity, so no diffraction peak is shown; according to Figure 1 (b) The photoelectron spectrum shows that there is an obvious Cu element signal in the composite, and the two diffraction peaks can be attributed to Cu element, indicating that there is Cu on the surface of the composite and the product is a MoS2 / TiO2 / Cu composite. Figure 1 (c) and Figure 1 (d) It can be seen that the composite is composed of particles with a diameter of tens of nanometers.

[0029] Figure 2The effect of 2.0% soot pollution on the tribological properties of lubricating oils modified with different molybdenum additives (taking corn oil as an example): (a) friction coefficient; (b) wear rate.

[0030] The figure shows that after 2.0% carbon soot contamination, adding 0.5% nano-MoS2 not only has no effect, but the friction coefficient and wear rate will increase significantly, indicating that there is a significant lubrication antagonism between nano-MoS2 and carbon soot; after replacing nano-MoS2 with MoS2 / TiO2, the antagonistic effect is significantly weakened, but the effect is still not ideal; after replacing nano-MoS2 with MoS2 / TiO2 / Cu, the antagonistic effect between nano-MoS2 and carbon soot not only disappears, but the two also show a synergistic effect, the friction coefficient and wear rate are significantly reduced, and the lubrication performance is significantly improved. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below in conjunction with embodiments and drawings.

[0032] Example 1

[0033] Weigh 2.4g sodium molybdate, 4.5g thioacetamide and 3.2g nano-TiO2 into a three-necked flask, add 200mL water, stir magnetically and heat in a water bath to 80°C, add 36mL anhydrous ethanol, add 44mL concentrated hydrochloric acid at 82°C to make it strongly acidic, the reaction starts and precipitates, after which the precipitate is filtered, washed, dried and calcined at 480°C in a N2 protective atmosphere.

[0034] 0.55 g of the calcined product, 0.072 g of copper chloride, 4.0 g of polyvinyl pyrrolidone, 1.2 g of NaOH, 2.4 g of ascorbic acid solution and 65 mL of water were added. The mixed system was fully stirred, and the obtained suspension was placed in a hydrothermal reactor, reacted in a drying oven at 160°C for 6 h, and filtered after cooling to obtain a MoS2 / TiO2 / Cu composite ( Figure 1 Finally, MoS2 / TiO2 / Cu was added to the lubricating oil contaminated by soot at an addition amount of 0.5%. No antagonism between the molybdenum-containing lubricating additive MoS2 / TiO2 / Cu and the soot was observed, and the lubricating performance of the lubricating oil was significantly improved ( Figure 2 shown).

[0035] Example 2

[0036] Weigh 1.4g sodium molybdate, 4.5g thioacetamide and 3.2g nano-TiO2 into a three-necked flask, add 200mL water, stir magnetically and heat in a water bath to 80°C, add 18mL anhydrous ethanol, add 20mL concentrated hydrochloric acid at 82°C to make it strongly acidic, the reaction starts and precipitates, after which the precipitate is filtered, washed, dried and calcined at 480°C in a N2 protective atmosphere.

[0037] 0.25g of calcined product, 0.072g of copper chloride, 4.0g of polyvinyl pyrrolidone, 1.2g of NaOH, 2.4g of ascorbic acid solution and 65mL of water were added. The mixed system was fully stirred, and the obtained suspension was placed in a hydrothermal reactor, reacted in a drying oven at 160°C for 6h, and filtered after cooling to obtain a MoS2 / TiO2 / Cu complex. Finally, MoS2 / TiO2 / Cu was added to the lubricating oil contaminated by carbon soot at an addition amount of 0.5%. No antagonism between the molybdenum-containing lubricating additive MoS2 / TiO2 / Cu and carbon soot was observed, and the lubricating performance of the lubricating oil was significantly improved.

[0038] Example 3

[0039] Weigh 2.4g sodium molybdate, 4.5g thioacetamide and 1.2g nano-TiO2 into a three-necked flask, add 200mL water, stir magnetically and heat in a water bath to 75°C, add 18mL anhydrous ethanol, add 20mL concentrated hydrochloric acid at 78°C to make it strongly acidic, the reaction starts and precipitates, after which the precipitate is filtered, washed, dried and calcined at 480°C in a N2 protective atmosphere.

[0040] 0.25g of calcined product, 0.072g of copper chloride, 4.0g of polyvinyl pyrrolidone, 1.2g of NaOH, 2.4g of ascorbic acid and 65mL of water were added. The mixed system was fully stirred, and the obtained suspension was placed in a hydrothermal reactor, reacted in a drying oven at 180°C for 5h, and filtered after cooling to obtain a MoS2 / TiO2 / Cu complex. Finally, MoS2 / TiO2 / Cu was added to the lubricating oil contaminated by carbon soot at an addition amount of 1.0%. No antagonism between the molybdenum-containing lubricating additive MoS2 / TiO2 / Cu and carbon soot was observed, and the lubricating performance of the lubricating oil was significantly improved.

[0041] Example 4

[0042] Weigh 2.4g sodium molybdate, 4.5g thioacetamide and 3.2g nano-TiO2 into a three-necked flask, add 300mL water, stir magnetically and heat in a water bath to 85°C, add 36mL anhydrous ethanol, add 20mL concentrated hydrochloric acid at 80°C to make it strongly acidic, the reaction starts and precipitates, after which the precipitate is filtered, washed, dried and calcined at 480°C in a N2 protective atmosphere.

[0043] 0.25g of calcined product, 0.072g of copper chloride, 4.0g of polyvinyl pyrrolidone, 1.2g of NaOH, 2.4g of ascorbic acid and 65mL of water were added. The mixed system was fully stirred, and the obtained suspension was placed in a hydrothermal reactor, reacted in a drying oven at 150°C for 12h, and filtered after cooling to obtain a MoS2 / TiO2 / Cu complex. Finally, MoS2 / TiO2 / Cu was added to the lubricating oil contaminated by carbon soot at an addition amount of 0.5%. No antagonism between the molybdenum-containing lubricating additive MoS2 / TiO2 / Cu and carbon soot was observed, and the lubricating performance of the lubricating oil was significantly improved.

[0044] The above contents are merely examples and explanations of the concept of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A method for solving the problem of carbon soot antagonizing molybdenum-containing lubricating additives and causing lubricating oil performance degradation, characterized in that: Using MoS2 / TiO2 / Cu composite as a molybdenum-containing lubricating additive and adding it to soot-contaminated lubricating oil can effectively alleviate the antagonism between it and soot and improve the lubricating performance of the lubricating oil.

2. The method according to claim 1, characterized in that The MoS2 / TiO2 / Cu composite is added to the lubricating oil in an amount of 0.01% to 3.0%, which can effectively alleviate carbon smoke pollution not exceeding 3.0%.

3. The method according to claim 1, characterized in that The preparation method of the MoS2 / TiO2 / Cu composite is as follows: (1) Weigh a certain amount of sodium molybdate, thioacetamide and nano-TiO2 in a three-necked flask, add deionized water, stir magnetically and heat in a water bath to a temperature higher than 70°C, add anhydrous ethanol, adjust the pH to strong acidity with concentrated hydrochloric acid, react and produce precipitation, filter, wash, dry and calcine the precipitate at not less than 420°C in a protective atmosphere to obtain a calcined product MoS2 / TiO2; (2) After the calcined product is cooled, water, copper chloride, polyvinyl pyrrolidone, NaOH and ascorbic acid are added, and after being fully stirred, the mixture is placed in a hydrothermal reactor. Finally, the reactor is placed in an oven and heated for a certain period of time. After cooling, the mixture is filtered to obtain a MoS2 / TiO2 / Cu composite.

4. The method according to claim 3, characterized in that In the step (1), the calcined product MoS2 / TiO2 is prepared according to the following ratio: The mass ratio of sodium molybdate to thioacetamide is 1:0.5-10; The mass ratio of sodium molybdate to nano-TiO2 is 1:0.1-10; The mass ratio of sodium molybdate to ethanol is 1:1-100; The mass ratio of sodium molybdate to concentrated hydrochloric acid + ethanol is 1:1-100; The mass ratio of sodium molybdate to water is 1:10-2000.

5. The method according to claim 3, characterized in that In the step (2), the MoS2 / TiO2 / Cu composite is prepared according to the following ratio: The mass ratio of the calcined product MoS2 / TiO2 to copper chloride is 1:0.01-10; The mass ratio of the calcined product MoS2 / TiO2 to polyvinyl pyrrolidone is 1:0.01-100; The mass ratio of calcined product MoS2 / TiO2 to NaOH is 1:0.01-10; The mass ratio of the calcined product MoS2 / TiO2 to ascorbic acid is 1:0.01-50.

6. The method according to claim 3, characterized in that In the step (2), the reaction kettle is placed in an oven for heating, the oven temperature is between 100 and 300° C., and the heating time is between 1 and 24 hours.

7. The method according to any one of claims 3 to 6, characterized in that: The prepared MoS2 / TiO2 / Cu composite is composed of nano-sized MoS2, nano-sized TiO2 and Cu nanoparticles.

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