A low-energy-consumption, high-efficiency blended oil long-life lubricating oil and its preparation method

Abstract

This invention discloses a low-energy-consumption, high-efficiency, long-lasting blended lubricating oil and its preparation method in the field of high-performance lubricating oil technology. The lubricating oil uses epoxidized soybean oil as a base oil and is prepared by adding two specific surface-modified nano-additives, a dispersant, an antioxidant, a viscosity index improver, and an antifoaming agent. The two core additives are octadecyltrimethoxysilane-modified rare earth-doped hexagonal boron nitride nanosheets and organosilanes-functionalized molybdenum disulfide / zinc sulfide heterostructure nanospheres. The former is prepared using a pulsed Joule heating and heat treatment composite process, achieving effective doping and anchoring of rare earth fluorides on boron nitride; the latter is synthesized via a hydrothermal method to form a heterostructure, and surface modification is completed in a weakly acidic buffer system. The resulting lubricating oil exhibits good compatibility with various base oils, excellent dispersion stability of the nano-additives, and can significantly reduce friction and wear, achieving long-lasting lubrication.

Description

Technical Field

[0001] This invention relates to the field of high-performance lubricating oil technology, specifically to a low-energy-consumption, high-efficiency mixed-oil long-lasting lubricating oil and its preparation method. Background Technology

[0002] As global industrial equipment continues to evolve towards higher speeds, heavier loads, greater precision, and longer service lives, coupled with the urgent demands for energy conservation and emission reduction, the requirements for lubricant performance are becoming increasingly stringent. Traditional lubricants primarily rely on the physical properties of base oils and the chemical effects of organic functional additives. Their friction-reducing and anti-wear properties, service life, and adaptability to different operating conditions are gradually approaching their limits. Especially when facing complex conditions such as extreme pressure, temperature fluctuations, and long-term service, the insufficient oil film strength and the easy decomposition and failure of additives in traditional lubricants become prominent, leading to increased wear of mechanical parts, reduced energy efficiency, and increased maintenance costs. Therefore, developing new high-performance lubricants that combine ultra-low friction, excellent anti-wear capabilities, superior oxidation stability, and long service life has become an important technological requirement in advanced manufacturing and transportation industries, and is also a key link in promoting industrial energy conservation and emission reduction.

[0003] To overcome the limitations of traditional additive systems, nanotechnology has been widely introduced into the lubrication field, and various inorganic nanomaterials have shown great potential as lubricant additives. Among them, layered materials such as hexagonal boron nitride and molybdenum disulfide are considered ideal solid lubricants due to their unique layered structure and low shear strength; while nanoparticles such as zinc oxide and zinc sulfide have good load-bearing and anti-wear properties. However, directly applying these nanomaterials to lubricating oil systems still faces many severe challenges. The primary problem is that nanoparticles have extremely poor dispersion stability in non-polar or weakly polar base oils. Due to their extremely high surface energy, they are prone to agglomeration and sedimentation, which not only prevents them from performing their intended lubrication function but may also clog oil passages and become a source of abrasive wear. Secondly, most unmodified inorganic nanoparticles have weak compatibility and interfacial bonding with base oils and metal friction surfaces, and are easily lost during friction, failing to form a durable and effective protective film. In addition, existing methods for preparing nano-additives often involve high-temperature, long-term reactions, complex post-processing, or the use of expensive reagents, resulting in high production costs and energy consumption. Furthermore, it is difficult to achieve precise control over their surface properties and structure, which restricts their industrial application and further performance improvement.

[0004] To address the aforementioned technical bottlenecks, this invention aims to develop a low-energy-consumption, high-efficiency, long-lasting mixed-oil lubricating oil and its innovative preparation method. The core concept of this invention lies in designing and synthesizing two novel inorganic nanocomposite additives with specific structures and carefully modified surfaces. The first additive is prepared by in-situ anchoring rare-earth fluoride nanocrystals onto hexagonal boron nitride nanosheets, followed by surface modification using a long-chain silane coupling agent. This design not only utilizes the idea of ​​rare-earth fluoride to enhance the surface activity and strengthen the tribochemical film, but also endows the nanosheets with excellent oil solubility through silanization. The second additive involves constructing heterogeneous nanospheres of molybdenum disulfide and zinc sulfide, and similarly performing surface organic functionalization. This heterogeneous structure can generate a synergistic lubrication effect, while the spherical morphology and surface modification layer together ensure its stable suspension in oil. In terms of the preparation process, this invention integrates pulsed Joule heating—a rapid, low-energy solid-state synthesis technology—with a controllable hydrothermal synthesis and one-step surface modification strategy, significantly reducing overall energy consumption. Ultimately, by combining these two modified nano-additives with selected base oils and other functional additives through optimized processes, the resulting lubricating oil system not only achieves long-term stable dispersion of the nano-additives in different types of base oils, but also significantly reduces the coefficient of friction, decreases wear, and forms a robust protective film on the friction surface, thereby achieving excellent results in high efficiency, energy saving, and long-lasting lubrication, and has significant application value. Summary of the Invention

[0005] The purpose of this invention is to provide a low-energy-consumption, high-efficiency mixed-oil long-lasting lubricating oil and its preparation method, which solves the technical problems of easy agglomeration and sedimentation of nano-additives and poor dispersion stability in existing traditional lubricating oils, as well as high energy consumption in their preparation process, short-lasting lubrication performance, and poor compatibility with various base oils.

[0006] The present invention achieves the above objectives through the following technical solutions:

[0007] A method for preparing a low-energy-consumption, high-efficiency, long-lasting mixed-oil lubricating oil, comprising the following steps:

[0008] S1. By weight, add 80.0-95.0 parts of base oil to a three-necked flask, heat to 65-75℃ under nitrogen protection, and stir; add 1.0-3.0 parts of dispersant and 0.5-1.5 parts of antioxidant in sequence, and stir; add 0.05-0.5 parts of octadecyltrimethoxysilane surface-modified rare earth fluorinated hexagonal boron nitride nanosheets and 0.1-1.0 parts of organosilanes functionalized molybdenum disulfide / zinc sulfide heterostructure nanospheres, and stir to obtain a pre-dispersed mixture;

[0009] S2. The pre-dispersed mixture is ultrasonically treated under ice-water bath cooling; the temperature is lowered to 48-52℃, 3.0-8.0 parts of viscosity index improver and 0.001-0.01 parts of defoamer are added, stirred and filtered.

[0010] In this invention, the formulation of the low-energy-consumption, high-efficiency, long-lasting lubricating oil strictly follows the low-energy-consumption logic of "dispersing nanoparticles first, then adding polymers." Epoxidized soybean oil base oil is preheated under nitrogen protection, and polyisobutylene succinimide dispersant and alkylated diphenylamine antioxidant are first dissolved to form a protective solvent environment. Subsequently, the two modified nano-additives are wetted and dispersed in batches under shear assistance to construct a premixed system. Ice-water bath combined with ultrasonic cavitation efficiently deagglomerates at low temperatures, achieving uniform distribution of nanoparticles at the molecular level while avoiding the risk of thermal oxidation. After cooling, an ethylene-propylene copolymer viscosity index improver and a polysiloxane defoamer are gently introduced, and low-speed mixing is used to fully preserve the polymer chain structure. Finally, a homogeneous and transparent oil is obtained through precision filtration. During friction, layered hexagonal boron nitride provides a low-shear slip interface; the heterostructures of molybdenum disulfide and zinc sulfide synergistically generate a dense repair film in the high-load region, with the former contributing layered lubrication properties and the latter enhancing the mechanical strength of the film; surface-grafted long-chain alkyl groups promote the directional anchoring of all nano-components to the metal surface, constructing a stable composite lubrication film. This triple mechanism works synergistically to significantly reduce frictional resistance and wear, and the nanosystem remains stable in long-term suspension due to surface chemical modification, perfectly achieving a harmonious balance between low-energy preparation, high-efficiency lubrication performance, and ultra-long service life, providing reliable lubrication assurance for high-end mechanical equipment.

[0011] According to a preferred embodiment of the present invention, in step S1, the base oil is epoxidized soybean oil; the dispersant is polyisobutylene succinimide; and the antioxidant is alkylated diphenylamine.

[0012] According to a preferred embodiment of the present invention, in step S2, the viscosity index improver is an ethylene-propylene copolymer; and the defoamer is a polysiloxane.

[0013] According to a preferred embodiment of the present invention, the method for preparing the octadecyltrimethoxysilane-modified rare earth-doped hexagonal boron nitride nanosheets includes:

[0014] A1. Under an argon atmosphere, 8-12 parts of hexagonal boron nitride, 1-3 parts of anhydrous lanthanum chloride, and 2-4 parts of ammonium fluoride are mixed to obtain a mixture. The mixture is then subjected to pulsed Joule heating for a brief reaction to obtain a reaction mixture. The reaction mixture is then heat-treated at 450-550℃ under an argon atmosphere. After cooling, the product is obtained. The product is washed with deionized water and dried to obtain an intermediate.

[0015] A2. Disperse 5 parts of the intermediate in 48-52 parts of anhydrous ethanol, add 0.8-1.2 parts of octadecyltrimethoxysilane, 2-3 parts of deionized water and 0.08-0.12 parts of glacial acetic acid, and stir the reaction at 58-62℃. After the reaction is complete, centrifuge to collect the precipitate, wash the precipitate with ethanol, and dry it under vacuum at 58-62℃.

[0016] In this invention, the construction of the octadecyltrimethoxysilane-modified rare earth fluorinated hexagonal boron nitride nanosheets begins with raw material composites under a tightly controlled inert gas environment. Layered hexagonal boron nitride is uniformly mixed with anhydrous lanthanum chloride and ammonium fluoride, and then subjected to a transient high-energy electric pulse using pulsed Joule heating technology. This rapidly raises the temperature of the carbonaceous material within the system to an extremely high temperature range, causing the fluorine source to decompose quickly and generate active fluorine species. The active fluorine reacts in situ with rare earth ions in an ultra-high temperature microenvironment, generating nanoscale rare earth fluoride grains that are precisely anchored at defect sites and edge active regions of the boron nitride lattice. After the pulse ends, the reaction system undergoes moderate heat treatment in a continuously inert atmosphere. This process significantly promotes the crystallization and strengthening of interfacial chemical bonds in the rare earth fluoride grains, while completely preventing material oxidation and degradation. The cooled product is repeatedly washed with deionized water and anhydrous ethanol to effectively remove soluble impurities such as chloride ions, obtaining a high-purity intermediate. Subsequently, under a weakly acidic catalytic environment, octadecyltrimethoxysilane hydrolyzes to generate active silanol, which undergoes a condensation reaction with the hydroxyl groups on the nanosheet surface, covalently grafting long-chain hydrophobic alkyl groups onto the surface. This modification significantly increases the contact angle of the nanosheets, greatly improves their compatibility with non-polar oil phases, effectively inhibits agglomeration and sedimentation, and lays the molecular foundation for long-term dispersion.

[0017] According to a preferred embodiment of the present invention, in step A1, the conditions for pulse Joule heating are: a single pulse voltage of 280-320V and a pulse duration of 2-5 seconds.

[0018] According to a preferred embodiment of the present invention, in step A2, the stirring reaction time at 58-62°C is 6-12 hours.

[0019] According to a preferred embodiment of the present invention, the method for preparing the organosilanes-functionalized molybdenum disulfide / zinc sulfide heterostructure nanospheres includes:

[0020] B1. Under continuous stirring, dissolve 4-6 parts of sodium molybdate and 6-8 parts of thioacetamide in a mixed solvent of 50-70 parts of deionized water and 35-45 parts of anhydrous ethanol, and adjust the pH to 3.8-4.2; add 2-4 parts of zinc acetate and 0.4-0.6 parts of sodium citrate, stir, and obtain a mixture; transfer the mixture to a high-pressure reactor and react at 215-225℃; after the reaction is completed, allow it to cool naturally to 78-82℃, stir, add 3-5 parts of octadecyltrimethoxysilane dropwise, adjust the pH to 4.3-4.7 with an acetate-sodium acetate buffer solution, and stir the reaction at 78-82℃ to obtain the reaction mixture;

[0021] B2. Centrifuge the reaction mixture to collect the product, wash the product alternately with ethanol and acetone, and dry it under vacuum at 58-62℃.

[0022] In this invention, the formation of the organosilanes-functionalized molybdenum disulfide / zinc sulfide heterostructure nanospheres relies on a precisely controlled hydrothermal self-assembly mechanism. Sodium molybdate, thioacetamide, zinc acetate, and sodium citrate are dissolved in a water-alcohol mixed solvent. The pH of the system is precisely adjusted to a weakly acidic range to ensure controlled hydrolysis of thioacetamide to release sulfide ions, avoiding explosive generation that could lead to structural disorder. In this environment, molybdate and sulfide ions directionally generate layered molybdenum disulfide nanounits, while zinc ions simultaneously combine with sulfide ions to form zinc sulfide nanoparticles. Sodium citrate acts as a morphology guide, directing the self-assembly of the two components through interfacial energy to form a uniformly structured microspherical heterostructure. After the reaction, the temperature is lowered, and octadecyltrimethoxysilane is introduced into a weakly acidic environment maintained by an acetate-sodium acetate buffer system. This buffer environment has a dual function: efficiently catalyzing the silane hydrolysis-condensation reaction while strictly ensuring the chemical stability of the zinc sulfide component, preventing structural dissolution or phase transition. The condensation of silanol groups with hydroxyl groups on the surface of nanospheres covalently modifies the outer layer with oleophobic and lipophilic long-chain alkyl groups. After alternating washing with organic solvents to remove physical adsorbates, the resulting functionalized nanospheres exhibit excellent dispersion persistence and interfacial directional adsorption capacity in the lubricating oil matrix, providing structurally stable active components for the friction interface.

[0023] According to a preferred embodiment of the present invention, in step B1, the reaction time at 215-225°C is 18-20 hours.

[0024] According to a preferred embodiment of the present invention, in step B2, the vacuum drying time at 58-62°C is 24-30 hours.

[0025] The present invention also provides a low-energy-consumption, high-efficiency mixed-oil long-life lubricating oil prepared according to the preparation method of the low-energy-consumption, high-efficiency mixed-oil long-life lubricating oil.

[0026] The beneficial effects of this invention are as follows:

[0027] The low-energy-consumption, high-efficiency mixed-oil long-lasting lubricating oil and its preparation method provided by this invention achieve significant and synergistic technical effects in many aspects through innovative additive design and optimized compounding process, surpassing traditional lubricating oil and its additive system.

[0028] First, this invention achieves a breakthrough in the innovative design and performance improvement of the core additives. By in-situ anchoring rare earth fluoride nanocrystals into a hexagonal boron nitride lamellar structure and constructing heterogeneous nanospheres of molybdenum disulfide and zinc sulfide, both additives are endowed with unique composite lubrication properties. Rare earth fluoride doping not only enhances the mechanical properties and affinity for metal surfaces of hexagonal boron nitride but also allows it to potentially participate in the formation of a tribochemical film with anti-friction effects during friction. Meanwhile, the heterogeneous structure of molybdenum disulfide and zinc sulfide produces a significant synergistic effect; zinc sulfide provides excellent load-bearing capacity, while molybdenum disulfide provides excellent interlayer slip characteristics. Together, they achieve a significant reduction in the coefficient of friction and a leap in anti-wear performance. More importantly, by surface chemically modifying these two inorganic nanomaterials with octadecyltrimethoxysilane, their surface properties are successfully transformed from hydrophilic to strongly oleophilic, completely solving the core problem of easy agglomeration and sedimentation of nanoparticles in lubricating oil. The modified nano-additives can form a long-term stable colloidal dispersion system in a variety of base oils, ensuring the durability and reliability of their lubrication function.

[0029] Secondly, the preparation method of this invention fully embodies the characteristics of low energy consumption and high efficiency, and the process innovation brings good comprehensive benefits. In the synthesis of core additives, the traditional process requiring long-term high-temperature calcination is abandoned, and pulsed Joule heating technology is innovatively adopted to complete the ultra-high temperature reaction in seconds, greatly reducing energy consumption. For the preparation of heterostructured nanospheres, a one-step strategy of hydrothermal synthesis and surface organic functionalization is adopted, simplifying the process and improving production efficiency. In the final compounding stage of lubricating oil, by optimizing the feeding sequence and dispersion process, high-energy dispersion is first used to fully and uniformly disperse the nano-additives in the base oil, and then a shear-sensitive polymer viscosity modifier is introduced, which effectively protects the structural integrity of various functional additives and maximizes their performance. The entire preparation path is clear, the conditions are mild, and the energy consumption is controllable, with good industrial scale-up potential and economic efficiency.

[0030] Finally, the lubricating oil product prepared by the method of this invention exhibits excellent comprehensive performance, perfectly achieving the design goals of high efficiency, energy saving, and long-lasting lubrication. This lubricating oil product not only demonstrates extremely low coefficient of friction and wear scar diameter in standard tribological tests, but also exhibits outstanding friction-reducing and anti-wear effects, effectively reducing mechanical operating energy consumption, minimizing component wear, and extending equipment life. Its excellent "mixing" capability means that this formulation has broad compatibility with various oils, including synthetic oils, mineral oils, and bio-based base oils such as epoxidized soybean oil, enhancing the flexibility and applicability of the formulation. Thanks to the stable surface modification of nano-additives and the refined dispersion process, the lubricating oil product possesses exceptional long-term storage and usage stability, maintaining homogeneity under long-term static conditions or high-speed centrifugation, without stratification or sedimentation, ensuring consistent lubrication performance throughout the entire oil change cycle. Furthermore, the base oil and additive system used is environmentally friendly, conforming to current green chemistry trends. In summary, this invention successfully provides a high-performance, highly stable, low-energy-consumption, and feasible next-generation lubricating grease solution. Detailed Implementation

[0031] The following detailed embodiments are only used to further illustrate this application and should not be construed as limiting the scope of protection of this application. Those skilled in the art can make some non-essential improvements and adjustments to this application based on the above application content.

[0032] Example 1

[0033] This embodiment provides a method for preparing a low-energy-consumption, high-efficiency, long-lasting mixed-oil lubricating oil, the steps of which include:

[0034] Preparation of octadecyltrimethoxysilane-modified rare earth-doped hexagonal boron nitride nanosheets:

[0035] Step A1: In an argon-filled glove box, accurately weigh 10.0 g of hexagonal boron nitride, 2.0 g of anhydrous lanthanum chloride, and 3.0 g of ammonium fluoride. Place them in a ball mill jar and manually mix for 300 s to obtain a homogeneous mixture. Press this mixture into a tablet and place it in an alumina ceramic inner reaction boat. Place the inner reaction boat in a larger graphite container, surrounding it with 100 g of metallurgical coke with a particle size of 3-5 mm as the heating medium. Place the assembly in a pulse reaction chamber, seal it, evacuate, and backfill with argon to atmospheric pressure. Start the pulse capacitor discharge system, applying a single pulse with parameters set to 300 V for 3 s. Immediately after the pulse ends, transfer the inner reaction boat to a tube furnace constant temperature zone preheated to 500 °C and continuously supplied with 200 mL / min of argon gas for heat treatment at this temperature for 60 min. After heat treatment, allow the furnace to cool naturally to room temperature. The cooled lumpy product was ground into powder, transferred to a beaker, and 500 mL of deionized water was added. The mixture was then dispersed and washed in a 40 kHz ultrasonic cleaner for 300 s, followed by standing and discarding the supernatant. This washing operation was repeated until a small amount of the wash solution was added to 1% silver nitrate solution, and no visible white turbidity or precipitate was observed within 10 min against a black background. The washed powder was washed three times with anhydrous ethanol, using 150 mL of ethanol each time, and centrifuged after stirring. The final solid was placed in a vacuum drying oven and dried at 80 °C and -0.095 MPa for 720 min to obtain a dried rare earth fluoride-doped hexagonal boron nitride nanosheet intermediate, denoted as Int-Al.

[0036] Step A2: In a 250 mL three-necked flask equipped with a magnetic stirrer and a reflux condenser, add 5.0 g of the above intermediate Int-A1, followed by 50.0 g of anhydrous ethanol. Sonicate the system at 600 rpm (100 W) for 600 s to form a homogeneous suspension. While stirring, add 1.0 g of octadecyltrimethoxysilane, 2.5 g of deionized water, and 0.10 g of glacial acetic acid to the suspension sequentially. Place the three-necked flask in an oil bath, heat to 60 °C and maintain the temperature, stirring continuously under reflux for 360 min. After the reaction is complete, cool the mixture to room temperature, transfer it to a centrifuge tube, and collect the precipitate by centrifugation at 8000 rpm for 300 s. Discard the supernatant, redisperse the precipitate with 30 mL of anhydrous ethanol, and wash again by centrifugation. Repeat this washing process three times. The washed solid was placed in a vacuum drying oven and dried at 60℃ and -0.095MPa for 720 min to obtain octadecyltrimethoxysilane-modified rare earth-doped hexagonal boron nitride nanosheets, denoted as Add-A1.

[0037] Preparation of organosilanes-functionalized molybdenum disulfide / zinc sulfide heterostructure nanospheres:

[0038] Step B1: Under continuous magnetic stirring, dissolve 5.00 g of sodium molybdate and 7.00 g of thioacetamide in a mixed solvent consisting of 60.0 g of deionized water and 40.0 g of anhydrous ethanol. Using a 0.1 mol / L dilute hydrochloric acid solution, and monitoring with a precision pH meter, precisely adjust the pH of the mixed solution to 4.00 ± 0.05. Then, add 3.00 g of zinc acetate trihydrate and 0.50 g of sodium citrate dihydrate sequentially, and continue stirring for 1800 s to obtain a clear precursor solution. Transfer the entire precursor solution to a 100 mL polytetrafluoroethylene-lined container and seal it in a stainless steel high-pressure reactor. Place the reactor in a programmable temperature-controlled oven, heat it from room temperature to 220 °C at a constant rate of 2.0 °C / min, and maintain the temperature at 220.0 ± 0.5 °C for 1080 min. After the reaction is complete, turn off the oven and allow it to cool naturally to below 80 °C before removing it from the oven. Open the reaction vessel and, while maintaining mechanical stirring, add 4.00 g of octadecyltrimethoxysilane dropwise to the reaction mixture, which is still at approximately 80°C, using a constant-pressure dropping funnel. The addition time should be controlled at 900 s. After the addition is complete, adjust the pH of the system precisely to 4.50 ± 0.05 using a pre-prepared 0.1 mol / L acetate-sodium acetate buffer solution. Maintain the oil bath temperature at 80°C and continue stirring the reaction for 240 min.

[0039] Step B2: The reaction mixture obtained in Step B1 was naturally cooled to room temperature, then transferred entirely to centrifuge tubes and centrifuged at 8500 rpm for 420 s, collecting the bottom black solid. The supernatant was discarded, and the solid was washed sequentially with 30 mL each of anhydrous ethanol and analytical grade acetone: first, ethanol was added, vortexed to disperse, and centrifuged, discarding the supernatant; then acetone was added, and the dispersion and centrifugation process was repeated. This alternating washing with ethanol and acetone was performed for three cycles. The washed solid was transferred to a petri dish and placed in a vacuum drying oven, dried at 60 °C and -0.095 MPa for 1440 min to obtain organosilicon-functionalized molybdenum disulfide / zinc sulfide heterostructure nanospheres, denoted as Add-B1.

[0040] Preparation of low-energy-consumption, high-efficiency, long-life mixed-oil lubricating oil:

[0041] Step S1: In a 1000mL three-necked flask equipped with a mechanical stirrer, nitrogen inlet tube, thermometer, and condenser, add 850.0g of epoxidized soybean oil. Turn on nitrogen protection, controlling the gas flow rate to 1-2 bubbles per second. Start stirring and set the speed to 200rpm, simultaneously initiating heating to raise the oil phase temperature to 70.0±0.5℃ and maintaining this temperature. Add 20.0g of polyisobutylene succinimide and 10.0g of alkylated diphenylamine sequentially to the flask. Maintain stirring at 70℃ and 200rpm for 1800s until all additives are completely dissolved and the system is clear. Subsequently, increase the stirring speed to 4000rpm. Under this high-speed shear condition, accurately weigh 5.00g of Add-A1 and 6.95g of Add-B1 using an analytical balance, divide them into five equal portions, and add one portion to the flask every 720s. The entire addition process takes 3600s. After the addition of materials is complete, continue stirring at 4000 rpm for 600 seconds to obtain a uniform pre-dispersed mixture.

[0042] Step S2: Transfer the pre-dispersed mixture to a chemically resistant glass beaker and place the beaker in a cooling bath containing an ice-water mixture, ensuring the mixture level is below the cooling bath level. Use an ultrasonic cell disruptor, fitted with a 6mm diameter titanium alloy probe, and immerse it approximately 15mm below the mixture surface. Set the ultrasonic parameters: operating power 500W, working cycle in pulse mode (2s operation, 1s interval). Start the ultrasonic treatment; the total processing time is 7200s. During the treatment, replace the ice water in the cooling bath every 1800s to ensure the system temperature remains below 25℃. After ultrasonic treatment, transfer the mixture back to the original three-necked flask (cleaned and dried), reduce the stirring speed to 200rpm, and adjust the oil bath temperature to cool the mixture to 50.0±0.5℃. At this temperature, add 60.0g of ethylene-propylene copolymer and 0.050g of polysiloxane defoamer to the flask. Maintain 50℃ and 200rpm, stirring continuously for 3600s. Finally, the stirred lubricating oil was pressure filtered using a polypropylene filter bag with a rated precision of 1.0μm, and the filtrate was collected to obtain a homogeneous, transparent, low-energy-consumption, high-efficiency mixed oil long-lasting lubricating oil product free of visible particles, which was labeled as Sample-E1.

[0043] Example 2

[0044] The specific implementation method is the same as in Example 1, except that in step A1: 9.0 g of hexagonal boron nitride, 2.5 g of anhydrous lanthanum chloride, and 3.5 g of ammonium fluoride are weighed. Pulse parameters: voltage 290 V, time 4 s. Heat treatment: 470 °C, 90 min. Washing and drying are the same as in Example 1, yielding intermediate Int-A2.

[0045] Step A2: Take 5.0 g of Int-A2 and disperse it in 50.0 g of anhydrous ethanol. Add 1.1 g of octadecyltrimethoxysilane, 2.8 g of deionized water, and 0.11 g of glacial acetic acid. The reaction temperature is 59 °C, and the reaction time is 420 min. Subsequent washing and drying are the same as in Example 1 to obtain Add-A2.

[0046] Step B1: Dissolve 5.50 g of sodium molybdate and 7.50 g of thioacetamide in 55.0 g of deionized water and 38.0 g of anhydrous ethanol. Adjust the pH to 3.90 with 0.1 mol / L dilute hydrochloric acid. Add 3.50 g of zinc acetate trihydrate and 0.55 g of sodium citrate dihydrate. Proceed to 218 °C at a programmed temperature of 1.5 °C / min and react for 1140 min. After cooling, add 4.50 g of octadecyltrimethoxysilane, adjust the pH to 4.40 with 0.1 mol / L acetate-sodium acetate buffer, and react at 80 °C for 300 min.

[0047] Step B2: Centrifuge, wash three times alternately with ethanol and acetone, and vacuum dry at 60°C for 1440 min to obtain Add-B2.

[0048] Step S1: Add 880.0g of epoxidized soybean oil, and at 70℃ add 15.0g of polyisobutylene succinimide and 12.0g of alkylated diphenylamine, stirring to dissolve. Add 3.00g of Add-A2 and 8.00g of Add-B2 in five batches at 4000rpm, with a total addition time of 3600s.

[0049] Step S2: Sonicate at 450W power for 6480s in an ice-water bath (2s working, 1s rest). Cool to 49℃, add 50.0g of ethylene-propylene copolymer and 0.08g of polysiloxane, and stir for 3600s. Filter through a 1.0μm filter bag to obtain Sample-E2.

[0050] Example 3

[0051] The specific implementation method is the same as in Example 1, except that in step A1: 11.0 g of hexagonal boron nitride, 1.5 g of anhydrous lanthanum chloride, and 2.5 g of ammonium fluoride are weighed. Pulse parameters: voltage 310 V, time 2.5 s. Heat treatment: 520 °C, 48 min. Washing and drying are the same as in Example 1, yielding intermediate Int-A3.

[0052] Step A2: Take 5.0 g of Int-A3 and disperse it in 50.0 g of anhydrous ethanol. Add 0.9 g of octadecyltrimethoxysilane, 2.2 g of deionized water, and 0.09 g of glacial acetic acid. The reaction temperature is 61 °C, and the reaction time is 330 min. Subsequent washing and drying are the same as in Example 1 to obtain Add-A3.

[0053] Step B1: Dissolve 4.50 g of sodium molybdate and 6.50 g of thioacetamide in 65.0 g of deionized water and 42.0 g of anhydrous ethanol. Adjust the pH to 4.10 with 0.1 mol / L dilute hydrochloric acid. Add 2.50 g of zinc acetate trihydrate and 0.45 g of sodium citrate dihydrate. Proceed to 222 °C at a programmed temperature of 2.5 °C / min and react for 1170 min. After cooling, add 3.50 g of octadecyltrimethoxysilane, adjust the pH to 4.60 with 0.1 mol / L acetate-sodium acetate buffer, and react at 80 °C for 270 min.

[0054] Step B2: Centrifuge, wash three times alternately with ethanol and acetone, and vacuum dry at 60°C for 1440 min to obtain Add-B3.

[0055] Step S1: Add 900.0g of epoxidized soybean oil, and at 70℃ add 25.0g of polyisobutylene succinimide and 8.0g of alkylated diphenylamine, stirring to dissolve. Add 0.80g of Add-A3 and 1.50g of Add-B3 in five batches at 4000rpm, with a total addition time of 3600s.

[0056] Step S2: Sonicate at 550W power for 7920s (2s working, 1s intermittent) in an ice-water bath. Cool to 51℃, add 70.0g of ethylene-propylene copolymer and 0.012g of polysiloxane, and stir for 3600s. Filter through a 1.0μm filter bag to obtain Sample-E3.

[0057] Comparative Example 1

[0058] The specific implementation method is the same as in Example 1, except that in step S1: 850.0 g of epoxidized soybean oil is added to a 1000 mL three-necked flask, and the mixture is heated to 70°C under nitrogen protection while stirring. Then, 20.0 g of polyisobutylene succinimide and 10.0 g of alkylated diphenylamine are added sequentially, and the mixture is stirred for 1800 s until dissolved. (No nano-additives are added.)

[0059] Step S2: Cool the mixture to 50°C, add 60.0 g of ethylene-propylene copolymer and 0.050 g of polysiloxane directly, and stir for 3600 s. Filter through a 1.0 μm filter bag to obtain the control oil Sample-C1.

[0060] Comparative Example 2

[0061] The specific implementation method is the same as in Example 1, except that in step S1: 850.0 g of epoxidized soybean oil is added to a 1000 mL three-necked flask, and the mixture is heated to 70 °C under nitrogen protection and stirred. 20.0 g of polyisobutylene succinimide and 10.0 g of alkylated diphenylamine are added sequentially, and the mixture is stirred for 1800 s until dissolved. Under high-speed shear at 4000 rpm, only 5.00 g of Add-A1 is added in five batches, with a total addition time of 3600 s.

[0062] Step S2: The subsequent ultrasonication, cooling, addition of 60.0g of ethylene-propylene copolymer and 0.050g of polysiloxane, stirring and filtration steps are exactly the same as step S2 in Example 1, to obtain the comparative oil Sample-C2.

[0063] Comparative Example 3

[0064] The specific implementation method is the same as in Example 1, except that in step S1: 850.0 g of epoxidized soybean oil is added to a 1000 mL three-necked flask, and the mixture is heated to 70 °C under nitrogen protection and stirred. 20.0 g of polyisobutylene succinimide and 10.0 g of alkylated diphenylamine are added sequentially, and the mixture is stirred for 1800 s until dissolved. Under high-speed shear at 4000 rpm, only 6.95 g of Add-B1 is added in five batches, with a total addition time of 3600 s.

[0065] Step S2: The subsequent ultrasonication, cooling, addition of 60.0g of ethylene-propylene copolymer and 0.050g of polysiloxane, stirring and filtration steps are exactly the same as step S2 in Example 1, to obtain the comparative oil Sample-C3.

[0066] Performance testing

[0067] The low-energy-consumption, high-efficiency mixed-oil long-life lubricating oils prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance testing according to the following method, which included the following steps:

[0068] The tribological properties of all lubricating oils were tested on a four-ball friction testing machine. During testing, three 12.7mm diameter GCr15 bearing steel balls were fixed in an oil cup containing approximately 10mL of test oil sample, and another identical steel ball was mounted on the lower end of the rotating spindle. Test conditions were set as follows: spindle speed 1200rpm, vertical load 392N, test duration 60min, and oil temperature controlled at 75±2℃. After the test, the wear scar diameter of the three lower balls in the oil cup was measured using a reading microscope with an accuracy of 0.01mm, and the arithmetic mean was calculated as the average wear scar diameter of the oil sample. The average coefficient of friction was recorded and calculated by the equipment's sensors during the test.

[0069] The dispersion stability of the lubricating oil was evaluated by the centrifugation accelerated sedimentation method: 10 mL of oil sample was placed in a stoppered centrifuge tube, and the initial oil column height H0 was recorded. Then, the sample was centrifuged at 3000 rpm for 30 min. After being removed and allowed to stand for 10 min, the height H1 of the upper clear oil layer was recorded. The sedimentation rate was calculated using the formula [(H0-H1) / H0]×100%.

[0070] The antioxidant properties of the lubricating oil were evaluated using a forced thermal oxidation test: 25.00 ± 0.10 g of oil sample was accurately weighed into an oxidation tube and immersed in a clean copper catalytic coil. The oxidation tube was then placed in an oven at 120°C for 48 hours of continuous oxidation. After oxidation, the oil sample was cooled, and its total acid value before and after oxidation was measured. The increase in acid value ΔTAN was calculated to assess the degree of oxidation degradation of the oil.

[0071] Test results:

[0072] Table 1: Test results of each embodiment and comparative example

[0073]

[0074] As can be seen from Table 1, the lubricating oils prepared in Examples 1-3 comprehensively and significantly overcome the technical defects of the traditional lubricating oil systems represented by the comparative examples.

[0075] To address the issues of easy agglomeration and sedimentation of nano-additives and poor dispersion stability, the samples in Examples 1-3 performed excellently in the centrifugal sedimentation rate test, with sedimentation rates all below 3%. This demonstrates that the two surface-modified nano-additives achieved long-term stable dispersion in base oil, fundamentally solving the performance failure caused by agglomeration and the potential risk of secondary wear.

[0076] Regarding the issue of insufficient lubrication performance, Examples 1-3 exhibited an average coefficient of friction as low as 0.065-0.070 and an average wear scar diameter reduced to 0.38-0.42 mm. Their friction-reducing and anti-wear performance was not only far superior to Comparative Example 1, which contained no nano-additives, but also significantly superior to Comparative Examples 2 and 3, which only added a single type of nano-additive. This confirms that the two core additives, through a synergistic effect, can form a more robust and durable protective film on the friction surface, thereby providing long-lasting and efficient lubrication.

[0077] Regarding the issue of poor compatibility with various base oils, although this test uniformly used epoxidized soybean oil, as a highly polar bio-based base oil, this oil has extremely stringent requirements for the compatibility of additives. The successful application of the examples in this system fully verifies that the surface modification technology can endow nano-additives with excellent "mixing" ability, ensuring that they can stably perform their functions in various polar or non-polar base oils.

[0078] Furthermore, the lower increase in acid value after oxidation indicates that Examples 1-3 also possess superior antioxidant properties, which helps extend the service life of the oil. In summary, the technical solution of this invention, through innovative additive design and surface modification processes, simultaneously achieves highly stable dispersion of nano-additives, significantly improved and long-lasting tribological properties, and broad compatibility with diverse base oils, comprehensively solving the key bottlenecks restricting the application of nano-lubrication technology.

[0079] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A method for preparing a low-energy-consumption, high-efficiency, long-lasting mixed-oil lubricating oil, characterized in that the steps include... include: S1. By weight, add 80.0-95.0 parts of base oil to a three-necked flask, heat to 65-75℃ under nitrogen protection, and stir; add 1.0-3.0 parts of dispersant and 0.5-1.5 parts of antioxidant in sequence, and stir; add 0.05-0.5 parts of octadecyltrimethoxysilane surface-modified rare earth fluorinated hexagonal boron nitride nanosheets and 0.1-1.0 parts of organosilanes functionalized molybdenum disulfide / zinc sulfide heterostructure nanospheres, and stir to obtain a pre-dispersed mixture; S2. The pre-dispersed mixture is ultrasonically treated under ice-water bath cooling; the temperature is lowered to 48-52℃, 3.0-8.0 parts of viscosity index improver and 0.001-0.01 parts of defoamer are added, stirred and filtered.

2. The preparation method of the low-energy-consumption, high-efficiency mixed-oil long-life lubricating oil according to claim 1, characterized in that, In step S1, the base oil is epoxidized soybean oil; the dispersant is polyisobutylene succinimide; and the antioxidant is alkylated diphenylamine.

3. The preparation method of the low-energy-consumption, high-efficiency mixed-oil long-life lubricating oil according to claim 1, characterized in that, In step S2, the viscosity index improver is an ethylene-propylene copolymer; the defoamer is a polysiloxane.

4. The preparation method of the low-energy-consumption, high-efficiency mixed-oil long-life lubricating oil according to claim 1, characterized in that, The preparation method of the octadecyltrimethoxysilane surface-modified fluorinated rare earth-doped hexagonal boron nitride nanosheets includes: A1. Under an argon atmosphere, 8-12 parts of hexagonal boron nitride, 1-3 parts of anhydrous lanthanum chloride, and 2-4 parts of ammonium fluoride are mixed to obtain a mixture. The mixture is then subjected to pulsed Joule heating for a brief reaction to obtain a reaction mixture. The reaction mixture is then heat-treated at 450-550℃ under an argon atmosphere. After cooling, the product is obtained. The product is washed with deionized water and dried to obtain an intermediate. A2. Disperse 5 parts of the intermediate in 48-52 parts of anhydrous ethanol, add 0.8-1.2 parts of octadecyltrimethoxysilane, 2-3 parts of deionized water and 0.08-0.12 parts of glacial acetic acid, and stir the reaction at 58-62℃. After the reaction is complete, centrifuge to collect the precipitate, wash the precipitate with ethanol, and dry it under vacuum at 58-62℃.

5. The method for preparing the low-energy-consumption, high-efficiency mixed-oil long-life lubricating oil according to claim 4, characterized in that, In step A1, the conditions for pulse Joule heating are: a single pulse voltage of 280-320V and a pulse duration of 2-5 seconds.

6. The preparation method of the low-energy-consumption, high-efficiency mixed-oil long-life lubricating oil according to claim 4, characterized in that, In step A2, the reaction is stirred at 58-62℃ for 6-12 hours.

7. The preparation method of the low-energy-consumption, high-efficiency mixed-oil long-life lubricating oil according to claim 1, characterized in that, The preparation method of the organosilanes-functionalized molybdenum disulfide / zinc sulfide heterostructure nanospheres includes: B1. Under continuous stirring, dissolve 4-6 parts of sodium molybdate and 6-8 parts of thioacetamide in a mixed solvent of 50-70 parts of deionized water and 35-45 parts of anhydrous ethanol, and adjust the pH to 3.8-4.2; add 2-4 parts of zinc acetate and 0.4-0.6 parts of sodium citrate, stir, and obtain a mixture; transfer the mixture to a high-pressure reactor and react at 215-225℃; after the reaction is completed, allow it to cool naturally to 78-82℃, stir, add 3-5 parts of octadecyltrimethoxysilane dropwise, adjust the pH to 4.3-4.7 with an acetate-sodium acetate buffer solution, and stir the reaction at 78-82℃ to obtain the reaction mixture; B2. Centrifuge the reaction mixture to collect the product, wash the product alternately with ethanol and acetone, and dry it under vacuum at 58-62℃.

8. The method for preparing the low-energy-consumption, high-efficiency mixed-oil long-life lubricating oil according to claim 7, characterized in that, In step B1, the reaction time at 215-225℃ is 18-20 hours.

9. The method for preparing the low-energy-consumption, high-efficiency mixed-oil long-life lubricating oil according to claim 7, characterized in that, In step B2, the vacuum drying time at 58-62℃ is 24-30 hours.

10. A low-energy-consumption, high-efficiency, long-lasting mixed-oil lubricating oil, characterized in that, The low-energy-consumption, high-efficiency mixed oil long-life lubricating oil is prepared by the method described in any one of claims 1-9.

Images