Bio-based sulfur-phosphorus-free nitrogen-containing borate organic molybdenum antifriction agent as well as preparation method and application of bio-based sulfur-phosphorus-free nitrogen-containing borate organic molybdenum antifriction agent

Abstract

The invention relates to a bio-based sulfur-phosphorus-free nitrogen-containing borate organic molybdenum antifriction agent and a preparation method and application thereof.The preparation method comprises the following steps that A1, monoglyceride and boric acid are dissolved in methylbenzene and subjected to a heating reaction, triethanolamine is added, the reaction continues, and OBN is obtained; a2, OBN and MoO3 obtained in the step A1 are dissolved in methylbenzene, a heating reaction is conducted in the inert atmosphere, and OBN-Mo is obtained; or B1, dissolving monoglyceride and boric acid in toluene, carrying out a heating reaction, adding triethanolamine, and continuing the reaction to obtain OBN; b2, the OBN obtained in the step B1 and molybdenum acetylacetonate are subjected to a heating reaction in ethyl alcohol, and OBN-Mo-OBN is obtained. Compared with the prior art, the two bio-based sulfur and phosphorus-free nitrogen-containing borate organic molybdenum antifriction agents OBN-Mo and OBN-Mo-OBN can be compounded with ZDDP to prepare lubricating oil, so that the wear resistance of the lubricating oil has a synergistic interaction effect.

Description

Technical Field

[0001] The present invention relates to the technical field of lubricating oil additives, and in particular to a bio-based sulfur-free, phosphorus-free, nitrogen-containing borate ester organic molybdenum friction reducer, and a preparation method and application thereof. Background Art

[0002] As lubricant product standards continue to improve, zinc dialkyldithiophosphates (ZDDPs) face inevitable challenges due to their high sulfur and phosphorus content. Phosphorus can toxicize three-way catalysts in automotive exhaust converters, while excess sulfur can affect the catalyst's adsorption of CO and NOx and generate sulfated ash in internal combustion engines, clogging particulate filters. Therefore, the development of highly efficient and environmentally friendly additives is crucial to improving mechanical efficiency and protecting the environment. Organic molybdenum, such as molybdenum dialkyldithiophosphates (MoDDP) and molybdenum dithiocarbamates (MoDTC), are lubricant additives with excellent antiwear and antioxidant properties. However, these two organic molybdenum additives also contain relatively high sulfur and phosphorus contents. Therefore, the development of sulfur- and phosphorus-free organic molybdenum additives has become an urgent requirement to meet the global consensus on energy conservation and emission reduction. These sulfur- and phosphorus-free organic molybdenum additives primarily include organic molybdates, molybdates, and other molybdenum complexes.

[0003] However, the relatively poor friction reduction and extreme pressure properties of sulfur- and phosphorus-free organomolybdenum additives limit their application under higher loads. Overcoming these shortcomings of sulfur- and phosphorus-free organomolybdenum additives and enabling them to synergize with other additives is crucial in the design and optimization of future lubricants. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a bio-based sulfur-free, phosphorus-free, nitrogen-containing borate ester organic molybdenum friction reducer and its preparation method and application.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] One of the technical solutions of the present invention is to provide a bio-based sulfur-free, phosphorus-free, nitrogen-containing borate-type organic molybdenum friction reducer, the structure of which is as shown in Formula I:

[0007] Where R1 and R2 satisfy any one of the following 1) to 3):

[0008] 1) R3=C 17 H 33 ;

[0009] 2) R1=H, R3=C 17 H 33 ;

[0010] 3) R3=C 17 H 33 , R2=H.

[0011] The second technical solution of the present invention is to provide a method for preparing a bio-based sulfur-free, phosphorus-free, nitrogen-containing borate-based organic molybdenum friction reducer, comprising the following steps:

[0012] A1. Dissolve monoglyceride and boric acid in toluene and heat to react. Add triethanolamine and continue the reaction to obtain OBN.

[0013] A2. Dissolve the OBN and MoO3 obtained in step A1 in toluene and heat the mixture under an inert atmosphere to obtain OBN-Mo.

[0014] or,

[0015] B1. Dissolve monoglyceride and boric acid in toluene, heat and react, then add triethanolamine to continue the reaction to obtain OBN;

[0016] B2. The OBN obtained in step B1 is reacted with molybdenum acetylacetonate by heating in ethanol to obtain OBN-Mo-OBN.

[0017] In some specific embodiments, in step A1 and step B1, the molar ratio of monoglyceride, boric acid, and triethanolamine is 1:1:1 to 1:1.2:1.2.

[0018] In some specific embodiments, in step A1 and step B1, the reaction temperature of monoglyceride and boric acid is (120-130)°C, and the reaction time is (4-6) h; the temperature of adding triethanolamine to continue the reaction is (110-120)°C, and the reaction time is (1-3) h.

[0019] In some specific embodiments, in step A2, the molar ratio of OBN to MoO3 is 0.9:1.2 to 1:1.

[0020] In some embodiments, in step A2, the temperature for the reaction of OBN and MoO3 is 115°C-120°C, and the reaction is continued until no reactive water is produced. More preferably, the reaction time is 12 hours.

[0021] In some specific embodiments, in step B2, the molar ratio of OBN-Mo to molybdenum acetylacetonate is 2:1.2 to 2:1.

[0022] In some specific embodiments, in step B2, the temperature for the reaction of OBN-Mo and molybdenum acetylacetonate is (80-90)° C., and the reaction time is (20-24) h.

[0023] The third technical solution of the present invention is to provide a use of a bio-based sulfur-free, phosphorus-free, nitrogen-containing borate ester organic molybdenum friction reducer as described in one of the above technical solutions in the preparation of lubricating oil.

[0024] In some specific embodiments, the lubricating oil comprises the following raw materials by mass fraction:

[0025] 0.5wt% bio-based sulfur-free, phosphorus-free, nitrogen-containing borate-based organic molybdenum friction reducer;

[0026] 0.5 wt% zinc dialkyl dithiophosphate;

[0027] 99wt% base oil.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The two bio-based sulfur-free, phosphorus-free, nitrogen-containing borate-based organic molybdenum friction reducers OBN-Mo and OBN-Mo-OBN prepared by the present invention have good thermal stability and can be compounded with zinc dialkyl dithiophosphate (ZDDP) to prepare lubricating oil, so that the friction reduction and anti-wear properties of the lubricating oil also have a synergistic effect. It can be seen that OBN-Mo and OBN-Mo-OBN can partially replace ZDDP, reducing the environmental pollution problem of S and P elements to a certain extent. At the same time, the friction reduction and anti-wear effects are also better than those of adding ZDDP alone. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Flow chart of the synthesis of OBN-Mo and OBN-Mo-OBN.

[0031] Figure 2 These are infrared images of OBN, OBN-Mo, and OBN-Mo-OBN in Examples 1 and 2 of the present invention.

[0032] Figure 3 COF curves of experimental groups 1 and 2 and comparison groups 1-4

[0033] Figure 4 The average friction coefficient of experimental groups 1 and 2 and comparison groups 1-4 under pressure conditions of 294N and 392N.

[0034] Figure 5 Diameters of wear spots of experimental groups 1 and 2 and comparison groups 1-4 under pressure conditions of 294N and 392N.

[0035] Figure 6 The wear volume diagrams of experimental groups 1 and 2 and comparison groups 1-4 under pressure conditions of 294N and 392N.

[0036] Figure 71wt%ZDDP, 1wt%OBN-Mo-OBN,

[0037] XPS spectrum of 0.5% wt% OBN-Mo-OBN + 0.5wt% ZDDP wear scar (1450 rpm, 294 Newtons).

[0038] Figure 8 The mass loss of OBN-Mo-OBN, OBN-Mo, and ZDDP was analyzed by thermogravimetric analysis (TA) from room temperature to 800°C in nitrogen. DETAILED DESCRIPTION

[0039] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0040] In the following examples and comparative examples, unless otherwise specified, raw materials or processing techniques are conventional commercially available raw materials or conventional processing techniques in the art.

[0041] Example 1

[0042] This embodiment provides a bio-based sulfur-free, phosphorus-free, nitrogen-containing borate-based organic molybdenum friction reducer OBN-Mo, whose structural formula is:

[0043] R3=C 17 H 33 .

[0044] like Figure 1 As shown, the preparation method comprises the following steps:

[0045] To a 500 mL round-bottom flask, add 35.6 g (0.1 mol) of monoolein and 6.2 g (0.1 mol) of boric acid. Then, add 20 mL of toluene and a small amount of catalyst (p-toluenesulfonic acid). Heat the solution, remove the water, and reflux. The reaction temperature is controlled at 120°C. As the reaction proceeds, increasing amounts of water are observed. After 3 hours of reaction, reflux is continued for 2 hours to ensure complete reaction. The resulting solution is then washed three times with deionized water (100 mL each time) to remove any remaining water-soluble components. Then, add 14.9 g of triethanolamine to the product and continue the reaction at 120°C for 2 hours. Finally, the solution is dried, the solvent removed by rotary evaporation, and vacuum dried for 24 hours. This gives monoolein triethanolamine borate OBN.

[0046] 46.4 g of the synthesized OBN and 14.4 g of MoO₃ were dissolved in a flask containing 20 ml of toluene solution, purged with nitrogen, and mixed and reacted at 115°C. The mixture was refluxed for several hours until no more reactive water was produced. Subsequently, the volatile solvent was removed by vacuum distillation, and the mixture was further purified to obtain the final product, OBN-Mo, which has excellent oil solubility.

[0047] The infrared spectra of the prepared OBN and OBN-Mo are as follows: Figure 2 shown.

[0048] Example 2

[0049] This embodiment provides a bio-based sulfur-free, phosphorus-free, nitrogen-containing borate-based organic molybdenum friction reducer OBN-Mo-OBN, whose structural formula is:

[0050] R3=C 17 H 33 .

[0051] like Figure 1 As shown, the preparation method comprises the following steps:

[0052] To a 500 mL round-bottom flask, add 35.6 g (0.1 mol) of monoolein and 6.2 g (0.1 mol) of boric acid. Then, add 200 mL of toluene and a small amount of catalyst (p-toluenesulfonic acid). Heat the solution, remove the water, and reflux. The reaction temperature is controlled at 120°C for 3 hours. As the reaction proceeds, an increasing amount of water is observed. Reflux is continued for 2 hours to ensure complete reaction. The resulting solution is then washed three times with deionized water (100 mL each time) to remove any remaining water-soluble components. Then, add 14.9 g of triethanolamine to the product and continue the reaction at 120°C for another 2 hours. Finally, the solution is dried, the solvent removed by rotary evaporation, and vacuum dried for 24 hours. After refining, olein monoglyceride triethanolamine borate OBN is obtained.

[0053] 46.4 g of synthesized OBN and 14.7 g of molybdenum acetylacetonate were dissolved in 150 mL of hot ethanol in a round-bottom flask connected to a reflux condenser. The reaction mixture was heated to 85°C and refluxed for 24 hours until the color of the product completely changed from light yellow to dark green. The mixture was then centrifuged to remove insoluble matter, and the solvent in the supernatant was removed by rotary evaporation under vacuum, yielding a dark green viscous liquid with a yield of 91%, representing the oil-soluble OBN-Mo-OBN.

[0054] The infrared spectra of the prepared OBN and OBN-Mo-OBN are as follows: Figure 2 shown.

[0055] Test Case

[0056] Experimental Group 1: 0.1 g of OBN-Mo and 0.1 g of ZDDP were added as additives to 19.8 g of soybean oil base oil, and ultrasonicated for 5 min to disperse the additives evenly. 20 g of lubricating oil sample containing OBN-Mo and ZDDP was obtained, recorded as: 0.5% OBN-Mo + 0.5% ZDDP.

[0057] Experimental Group 2: 0.1 g of OBN-Mo-OBN and 0.1 g of ZDDP were added as additives to 19.8 g of soybean oil base oil. Ultrasonication was performed for 5 minutes to evenly disperse the additives. A 20 g lubricating oil sample containing OBN-Mo-OBN and ZDDP was obtained, which was recorded as: 0.5% OBN-Mo-OBN + 0.5% ZDDP.

[0058] Comparative group 1: 0.2 g of ZDDP was added to 19.8 g of soybean oil base oil, recorded as: 1% ZDDP.

[0059] Comparative group 2: 0.2 g of OBN-Mo was added to 19.8 g of soybean oil base oil, recorded as: 1% OBN-Mo.

[0060] Comparative group 3: 0.2 g of OBN-Mo-OBN was added to 19.8 g of soybean oil base oil, recorded as: 1% OBN-MO-OBN.

[0061] Comparative group 4: 20 g soybean oil base oil was used as a blank control, recorded as: Base Oil.

[0062] The performance test of the friction-reducing and anti-wear compound lubricant samples of experimental groups 1 and 2 and samples of comparative groups 1-4 was carried out using a four-ball friction and wear tester with a load of 294N, 392N, a speed of 1450r / min, and a time of 30min. The obtained lubricant performance test results are shown in the attached Figure 3-6 .

[0063] like Figure 3 The figure shows the friction coefficient of lubricating oil. It shows that when two sulfur-free, phosphorus-free, nitrogen-containing borate esters (OBN-MO and OBN-MO-OBN) are compounded with ZDDP and then added to lubricating oil, the friction coefficients are 0.056 and 0.05, respectively. Their friction reduction effect is better than that of adding either of the two sulfur-free, phosphorus-free, nitrogen-containing borate esters or ZDDP to the lubricating oil alone.

[0064] like Figure 4 The figure shows the average friction coefficient of the lubricating oil under the pressure conditions of 294 N and 392 N. It can be seen from the figure that the average friction coefficient of the experimental group is lower than that of the control group under both the pressure conditions of 294 N and 392 N.

[0065] like Figure 5 As shown, the wear scar diameter (WSD) of OBN-MO, OBN-MO-OBN and ZDDP added separately to the base oil did not show significant reduction, but when the two sulfur and phosphorus free boronate ester nitrogen containing molybdenum lubricants were combined with ZDDP, the WSD was further reduced.

[0066] As shown in FIG. 2, the wear volume of the lubricating oil under a load of 294 N and 392 N. The wear volume of OBN-Mo added alone was higher than that of the base oil under a load of 294 N, but when combined with ZDDP, the wear volume was significantly reduced, by 93.3% relative to the base oil, and the wear volume of OBN-Mo-OBN combined with ZDDP was reduced by about 97% relative to the base oil. Figure 6 As shown in FIG. 3, the friction mechanism of 1% ZDDP, 1% OBN-Mo-OBN, 0.5% OBN-Mo-OBN + 0.5% ZDDP at 1450 rpm, 294 N was studied, and the wear surface was characterized by XPS. When 0.5% OBN-Mo-OBN + 0.5% ZDDP was used as an additive, a tribochemical reaction film was formed on the wear surface, which contained components such as MoS2, (Zn)3(PO4)2, MoO3, MoO2, MoO3 / FeOOH, Fe2(SO4)3 / B-O, FePO4, Fe2O3, and more BN complexes and B2O3, which helped to improve the friction reduction and wear resistance of the soybean oil base oil.

[0067] Figure 7 As shown in FIG. 4, the TGA thermogravimetric analysis of OBN-Mo-OBN and OBN-Mo showed rapid weight loss at 323.2°C, while ZDDP showed rapid weight loss at 263.7°C, indicating that OBN-Mo-OBN and OBN-Mo have better thermal stability, and also indicating that lubricants containing the nitrogen borate ester molybdenum of the present application will have better thermal stability. In addition, when the loss reaches about 50%, the corresponding temperatures of ZDDP, OBN-MO and OBN-Mo-OBN are 264.7°C and 376.5°C and 384.6°C, respectively, indicating that the thermal loss rate of ZDDP quickly reaches a peak as the temperature increases, which also means that it is difficult to ensure the integrity of the lubricating oil film during friction. As the friction heat increases, the incomplete ZDDP lubricating film will be torn, which is one of the reasons why ZDDP shows an unstable COF curve. Therefore, replacing part of the ZDDP in the lubricating oil with OBN-MO or OBN-Mo-OBN will make the lubricating oil have higher thermal stability. At the end of the thermogravimetric analysis test, ZDDP left about 25.5% of the stable solid due to its high zinc content.

[0068] As shown in FIG. 5, the TGA thermogravimetric analysis of OBN-Mo-OBN and OBN-Mo showed rapid weight loss at 323.2°C, while ZDDP showed rapid weight loss at 263.7°C, indicating that OBN-Mo-OBN and OBN-Mo have better thermal stability, and also indicating that lubricants containing the nitrogen borate ester molybdenum of the present application will have better thermal stability. In addition, when the loss reaches about 50%, the corresponding temperatures of ZDDP, OBN-MO and OBN-Mo-OBN are 264.7°C and 376.5°C and 384.6°C, respectively, indicating that the thermal loss rate of ZDDP quickly reaches a peak as the temperature increases, which also means that it is difficult to ensure the integrity of the lubricating oil film during friction. As the friction heat increases, the incomplete ZDDP lubricating film will be torn, which is one of the reasons why ZDDP shows an unstable COF curve. Therefore, replacing part of the ZDDP in the lubricating oil with OBN-MO or OBN-Mo-OBN will make the lubricating oil have higher thermal stability. At the end of the thermogravimetric analysis test, ZDDP left about 25.5% of the stable solid due to its high zinc content. Figure 8

[0069] ​​The above description of the embodiments is intended to facilitate understanding and use of the invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above-described embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention, without departing from the scope of the present invention, should be within the scope of protection of the present invention.

Claims

1. A bio-based sulfur-free, phosphorus-free, nitrogen-containing borate-based organic molybdenum friction reducer, characterized in that: Its structure is as shown in Formula I: Where R1 and R2 satisfy any one of the following 1) to 3): 1) R3=C 17 H 33 ; 2)R1=H, R3=C 17 H 33 ; 3) R3=C 17 H 33 , R2=H.

2. A method for preparing the bio-based sulfur-free, phosphorus-free, nitrogen-containing borate organic molybdenum friction reducer according to claim 1, characterized in that: The steps include: A1. Dissolve monoglyceride and boric acid in toluene, heat and react, then add triethanolamine to continue the reaction to obtain OBN. A2, dissolving the OBN and MoO3 obtained in step A1 in toluene, and heating the mixture under an inert atmosphere to obtain OBN-Mo; or, B1. Dissolve monoglyceride and boric acid in toluene, heat and react, add triethanolamine and continue the reaction to obtain OBN; B2. The OBN obtained in step B1 is reacted with molybdenum acetylacetonate by heating in ethanol to obtain OBN-Mo-OBN.

3. The preparation method according to claim 2, characterized in that In step A1 and step B1, the molar ratio of monoglyceride, boric acid, and triethanolamine is 1:1:1 to 1:1.2:1.

2.

4. The preparation method according to claim 2, characterized in that In steps A1 and B1, the reaction temperature of monoglyceride and boric acid is (120-130)°C, and the reaction time is (4-6) hours; the temperature of adding triethanolamine to continue the reaction is (110-120)°C, and the reaction time is (1-3) hours.

5. The preparation method according to claim 2, characterized in that In step A2, the molar ratio of OBN to MoO3 is 0.9:1.2 to 1:

1.

6. The preparation method according to claim 2, characterized in that In step A2, the temperature for the reaction of OBN and MoO3 is 115°C-120°C, and the reaction is continued until no reactive water is produced.

7. The preparation method according to claim 2, characterized in that In step B2, the molar ratio of OBN to molybdenum acetylacetonate is 2:1.2 to 2:

1.

8. The preparation method according to claim 2, characterized in that In step B2, the reaction temperature of OBN-Mo and molybdenum acetylacetonate is (80-90)° C., and the reaction time is (20-24) h.

9. Use of the bio-based sulfur-free, phosphorus-free, nitrogen-containing borate ester organic molybdenum friction reducer according to claim 1 in the preparation of lubricating oil.

10. The use according to claim 9, characterized in that The lubricating oil comprises the following raw materials by mass fraction: 0.5wt% bio-based sulfur-free, phosphorus-free, nitrogen-containing borate-based organic molybdenum friction reducer; 0.5 wt% zinc dialkyl dithiophosphate; 99wt% base oil.

Images