Preparation method of diesel oil anti-wear agent

Abstract

The invention relates to the technical field of oil additives, and particularly discloses a preparation method of a diesel oil anti-wear agent, which comprises the following steps: uniformly mixing 20-40 parts by mass of conjugated unsaturated fatty acid, 60-80 parts by mass of non-conjugated unsaturated fatty acid, 13-19 parts by mass of polyol, 0.3-0.7 part by mass of antioxidant and 30-40 parts by mass of cyclohexane in an inert atmosphere; the preparation method comprises the following steps: adding 4-6 parts by mass of a catalyst, uniformly mixing, heating to 160-180 DEG C, reacting for 2-4 hours, cooling to 100-120 DEG C, adding 1-2 parts by mass of boric acid, continuously reacting for 120-180 minutes, carrying out solid-liquid separation, and distilling to obtain the diesel oil anti-wear agent. The catalyst is a core-shell structure compound formed by sequentially loading a rare earth metal oxide layer and heteropolyacid metal salt on the surface of a porous metal carrier. The diesel oil anti-wear agent prepared by the invention has relatively good wear resistance and low-temperature fluidity.

Description

Technical Field

[0001] This application relates to the technical field of oil additives, and more specifically, to a preparation method of a diesel anti-wear agent. Background Art

[0002] In diesel, polycyclic aromatic hydrocarbons, oxygen-containing impurities, nitrogen-containing impurities, and sulfur compounds mainly affect its anti-wear lubricity. The strength of diesel lubricity depends on the content of anti-wear substances in it. Polycyclic aromatic hydrocarbons and nitrogen-containing compounds have good anti-wear effects, while sulfides not only do not have anti-wear properties but also promote wear.

[0003] However, most of the sulfides in diesel exist in the form of heterocycles in aromatics and polycyclic aromatic hydrocarbons. Therefore, in the early 20th century, while vigorously advocating the removal of diesel sulfides due to their serious environmental pollution, aromatics, polycyclic aromatic hydrocarbons, and other lubricating components with lubricating properties were also removed. As a result, engines using diesel have continuously shown wear and damage phenomena as the sulfur content decreases, thus shortening their service life. Therefore, improving the anti-wear property of low-sulfur diesel has become an important and urgent research topic.

[0004] Currently, adding an anti-wear agent is the fundamental way to solve the decline in the lubricity of low-sulfur diesel. Diesel anti-wear agents are mainly divided into acid-type anti-wear agents and ester-type anti-wear agents. Among them, after the acid-type anti-wear agent is added to diesel, it will cause the acid value of diesel to rise, which has a negative impact on the alkaline additives in diesel. Ester-type anti-wear agents are mainly synthesized by esterification of long-chain unsaturated fatty acids and polyols, and are clean diesel anti-wear components with great development prospects in current research and use at home and abroad.

[0005] The patent application document with the publication number of 105001924 A discloses a preparation method of a low-freezing-point diesel anti-wear agent, using long-chain unsaturated fatty acids and polyols as raw materials, catalyzed by an Al2O3 multi-loaded rare earth catalyst, and the mass ratio of the raw materials is: Using xylene as a solvent, add long-chain unsaturated fatty acids, polyols, and an Al2O3 multi-loaded rare earth catalyst to the solvent in sequence. Under the condition of a temperature of 140 - 160 °C, xylene refluxes to carry water for low-temperature esterification reaction for 2 - 5 hours; then raise the temperature to 220 - 260 °C for high-temperature esterification reaction for 0.5 - 1.5 hours, and at the same time separate the solvent xylene, filter out the Al2O3 multi-loaded rare earth catalyst, and obtain a low-freezing-point diesel anti-wear agent.

[0006] In the above technical solution, the thermal conductivity of Al2O3 itself is relatively low. In this esterification reaction system, as the carrier of the multi-component supported rare earth catalyst, when the reaction is heated from the low-temperature esterification stage at 140-160 °C to the high-temperature esterification stage at 220-260 °C, due to its poor thermal conductivity, it is easy to cause uneven heat distribution in the reaction system, and local overheating will trigger carbonization of some long-chain unsaturated fatty acids to a certain extent. This will produce impurities, change the composition of the reaction system, and lead to poor anti-wear performance of the anti-wear agent. Summary of the Invention

[0007] In order to improve the anti-wear performance of diesel anti-wear agents, the present application provides a preparation method of diesel anti-wear agents.

[0008] The preparation method of the diesel anti-wear agent of the present application adopts the following technical solution: A preparation method of a diesel anti-wear agent, comprising the following steps: Under an inert atmosphere, 20-40 parts by mass of conjugated unsaturated fatty acid, 60-80 parts by mass of non-conjugated unsaturated fatty acid, 13-19 parts by mass of polyol, 0.3-0.7 parts by mass of antioxidant and 30-40 parts by mass of cyclohexane are mixed evenly, then 4-6 parts by mass of catalyst is added and mixed evenly. The temperature is raised to 160-180 °C, and the reaction is carried out for 2-4 h. Then the temperature is lowered to 100-120 °C, 1-2 parts by mass of boric acid is added, and the reaction is continued for 120-180 min. Then solid-liquid separation and distillation are carried out to obtain the diesel anti-wear agent; The catalyst is a core-shell structure composite in which a rare earth metal oxide layer and a heteropolyacid metal salt are sequentially loaded on the surface of a porous metal carrier.

[0009] In the above technical solution, the conjugated unsaturated fatty acid can rapidly form a firm chemical adsorption film on the metal surface by virtue of the double bond conjugation effect, effectively reducing the direct contact between metals and reducing wear. The molecular structure of the non-conjugated unsaturated fatty acid is stable, which helps to improve the flexibility of the adsorption film at low temperatures and the low-temperature fluidity of the anti-wear agent; at the same time, its good antioxidant stability can inhibit the degradation of the film layer and improve the oxidation stability of the anti-wear agent. The two work together to achieve a comprehensive optimization of anti-wear performance, low-temperature fluidity and oxidation stability. After the main reaction is cooled, adding boric acid can partially form a stable borate film, and its synergistic effect with the fatty acid film significantly improves the high-temperature stability, anti-wear performance and oxidation life of the anti-wear agent.

[0010] The catalyst adopts a core-shell structure composite. The three-dimensional pore network of the porous metal carrier provides an efficient mass transfer channel, which is conducive to the adsorption and diffusion of reactants. The rare earth metal oxide layer and the heteropolyacid metal salt form double acid sites, and through synergistic catalysis, the rate and efficiency of the esterification reaction are significantly improved. At the same time, the core-shell structure ensures the stability of the catalyst, enabling it to maintain good catalytic activity even after multiple cycles of use.

[0011] Preferably, the conjugated unsaturated fatty acid is at least one of conjugated linoleic acid and conjugated linolenic acid.

[0012] Preferably, the non-conjugated unsaturated fatty acid is at least one of oleic acid and palmitoleic acid.

[0013] Preferably, the polyol is any one of pentaerythritol and trimethylolpropane.

[0014] Preferably, before use, the catalyst undergoes the following pretreatment steps: The catalyst is impregnated in a silane coupling agent solution with a pH of 3 - 4 and a volume concentration of 1% - 3%, reacted at 40 - 60 °C for 1 - 3 h, subjected to solid-liquid separation, and dried to obtain the product; The silane coupling agent solution includes a silane coupling agent, ethanol, and water.

[0015] Preferably, in the silane coupling agent, the volume ratio of ethanol to water is (5 - 7):(3 - 5).

[0016] In the above technical solution, the silane coupling agent constructs an amphiphilic interfacial layer on the surface of the catalyst. Its hydrophobic group binds to the fatty acid alkyl chain, and the hydrophilic group forms a hydrogen bond network with the polyol, significantly enhancing the repulsion force between particles and inhibiting agglomeration. The pretreated catalyst forms stably dispersed particles in the reaction system, effectively improving the contact efficiency between reactants and active sites and promoting the esterification reaction process.

[0017] Preferably, the antioxidant is antioxidant 1010.

[0018] Preferably, the preparation method of the catalyst includes the following steps: (1) The porous metal support is acid-etched, washed, and dried to obtain a pretreated support; (2) The pretreated support is impregnated in a precursor solution, the pH is adjusted to 9 - 10, then the temperature is raised to 160 - 180 °C, reacted for 6 - 10 h, washed, and dried to obtain a pre-loaded catalyst; (3) The pre-loaded catalyst is impregnated in a heteropolyacid metal salt solution for 30 - 60 min, subjected to solid-liquid separation, dried, and then calcined in an inert atmosphere and cooled to obtain the product; The precursor solution includes a rare earth metal salt, and the molar concentration of the rare earth metal salt is 0.15 - 0.25 mol / L; the molar concentration of the heteropolyacid metal salt solution is 0.05 - 0.2 mol / L.

[0019] Preferably, the mass-volume ratio of the porous metal support, the precursor solution, and the heteropolyacid metal salt solution is 1 g:(15 - 25) mL:(15 - 25) mL.

[0020] In the above technical solution, the porous metal support is pretreated by acid etching to make the surface of the support rough, forming more micropores and grooves, providing more highly active sites for the subsequent loading of active components, and promoting the uniform distribution of active components on the surface of the support. The heteropolyacid metal salt has strong acidity and unique catalytic properties. After being loaded on the surface of the rare earth metal oxide layer, it forms a synergistic effect with the rare earth metal oxide. This synergistic effect can significantly improve the catalytic activity and selectivity of the catalyst for the esterification reaction, accelerate the reaction rate, and increase the yield of the diesel antiwear agent. At the same time, the synergistic effect of the dual acid sites can also inhibit the occurrence of side reactions to a certain extent and improve the purity and quality of the product.

[0021] Preferably, the rare earth metal salt is any one of cerium nitrate and lanthanum nitrate.

[0022] Preferably, the precursor solution further includes polyethylene glycol with a volume concentration of 0.8% - 1.2%.

[0023] Preferably, in the precursor solution and the heteropolyacid metal salt solution, the solvent used is prepared from ethanol and water with a volume ratio of 1:(1 - 2).

[0024] Preferably, the porous metal support is any one of nickel foam and titanium foam.

[0025] Preferably, the heteropolyacid metal salt solution is any one of cesium phosphotungstate and potassium phosphotungstate.

[0026] Preferably, the acidic solution used for acid etching includes nitric acid and water, and the volume concentration of nitric acid is 20% - 25%.

[0027] Preferably, the acidic solution used for acid etching further includes hydrofluoric acid, and the volume concentration of hydrofluoric acid is 3% - 5%.

[0028] Preferably, the acid etching conditions are: temperature 30 - 60 °C, time 15 - 35 min.

[0029] Preferably, the calcination conditions are: first heat up to 200 - 240 °C, sinter for 50 - 70 min, then continue to heat up to 300 - 350 °C, and sinter for 60 - 120 min.

[0030] Preferably, when adding polyol, it further includes the step of adding 0.5 - 2 parts by mass of graphene oxide.

[0031] Preferably, the graphene oxide undergoes the following pretreatment steps before use: Mix graphene oxide and polyethylene glycol evenly, then add oleic acid and mix evenly, and perform ultrasonic treatment for 30 - 40 min to obtain it. The mass ratio of the graphene oxide, polyethylene glycol and oleic acid is 1:(1 - 2):(0.05 - 0.1).

[0032] Preferably, the frequency of the ultrasonic treatment is 20 - 40 kHz and the power is 300 - 500 W.

[0033] In the above technical solution, after mixing the graphene oxide and polyethylene glycol, the hydroxyl groups of polyethylene glycol can form hydrogen bonds with the hydroxyl groups on the surface of graphene oxide, playing a preliminary role in wrapping and dispersing. After adding oleic acid, the long-chain alkyl groups of oleic acid are hydrophobic and can interact with the molecular chains of polyethylene glycol. At the same time, its carboxyl group can also have a certain interaction with the groups on the surface of graphene oxide, further improving the dispersibility and compatibility of graphene oxide in the oil phase.

[0034] The pretreated graphene oxide can form a relatively stable adsorption film with the metal surface through the residual hydroxyl groups on its surface and the polyethylene glycol and oleic acid on its surface. The three work together to effectively reduce the friction coefficient and wear scar diameter, improving the anti-wear performance of the diesel anti-wear agent. In addition, the synergistic effect of polyethylene glycol and oleic acid not only enables graphene oxide to have good dispersion stability in the diesel anti-wear agent system, but also can maintain stable viscosity at high temperatures and improve low-temperature fluidity, providing multi-dimensional protection for long-term lubrication under extreme working conditions.

[0035] Preferably, when adding polyol, it also includes the step of adding 2 - 4 parts by mass of glycerol triglycidyl ether.

[0036] In the above technical solution, in the esterification reaction system, the epoxy groups of glycerol triglycidyl ether can undergo ring-opening reactions with the carboxyl groups of fatty acids, and the generated products have multiple branched chains and polar groups, which can form a denser and more solid adsorption film on the metal surface. During the friction process, this adsorption film can effectively isolate the metal surface, reduce the direct contact and wear between metals, thereby significantly reducing the wear scar diameter and improving the anti-wear performance of the diesel anti-wear agent. In addition, during the use of the diesel anti-wear agent, they can capture free radicals and inhibit the progress of oxidation reactions, thereby improving the oxidation stability of the anti-wear agent.

[0037] In summary, the present application has the following beneficial effects: 1. The present application adopts a gradient ratio of conjugated / non-conjugated unsaturated fatty acids to construct a dynamic-stable double film layer system: the conjugated fatty acids form a chemical adsorption layer with the metal surface through conjugated double bonds, providing a long-term anti-wear basis; the non-conjugated fatty acids continuously supplement the film layer defects by virtue of molecular flexibility, and the boric acid added in the later stage of the reaction and the fatty acid ester generate a boron-containing glassy film layer through a condensation reaction, forming a double-layer anti-wear structure with the physical adsorption layer, improving the anti-wear performance.

[0038] 2. The core-shell catalyst used in this application uses rare earth metal oxide as the core and loaded heteropolyacid metal salt as the shell to construct a double acid site synergistic catalytic system, which realizes efficient synergistic catalysis of the esterification reaction of conjugated / non-conjugated unsaturated fatty acids and polyols, which can not only reduce the activation energy of the reaction, but also increase the yield of the target product.

[0039] 3. This application preferably uses pretreated graphene oxide, which improves its dispersibility, stability, and lubrication properties in diesel antiwear systems. Leveraging its ultra-low friction coefficient and ultra-high hardness, the pretreated graphene oxide forms a layered physical adsorption layer at the friction interface, significantly reducing direct contact. Furthermore, its surface oxygen-containing functional groups hydrogen-bond with polar molecules in diesel (such as fatty acid esters), forming a boundary lubrication synergistic network and enhancing lubricating film stability. DETAILED DESCRIPTION

[0040] The present application is further described in detail below with reference to the embodiments.

[0041] Unless otherwise specified, the raw materials used in the examples and comparative examples of the present application are all commercially available.

[0042] In the preparation example, the nickel foam has a pore size of 100-500 μm and a porosity of ≥90%; the titanium foam has a pore size of 50-200 μm and a porosity of ≥85%. Before use, the nickel foam or titanium foam is cut into 0.5 cm × 0.5 cm sheets, immersed in a container filled with acetone, and ultrasonically cleaned for 10 minutes at an ultrasonic frequency of 30 kHz and a power of 120 W. After cleaning, the sheets are naturally dried and set aside. The thickness of the nickel foam or titanium foam is about 0.5-1 mm. The polyethylene glycol was polyethylene glycol 2000.

[0043] Synthesis of Catalysts in Preparation Examples 1 to 6 Preparation Example 1 The preparation method of the catalyst of this preparation example comprises the following steps: (1) Immerse 10 g of nickel foam in 100 mL of 22% nitric acid solution, heat to 55 °C, etch for 30 min, wash with deionized water until neutral, transfer to a vacuum drying oven and adjust the temperature to 60 °C, and dry to constant weight to obtain pretreated nickel foam; (2) Immerse the pretreated nickel foam in 200 mL of the precursor solution, slowly add ammonia water with a molar concentration of 0.6 mol / L at a stirring speed of 200 r / min, adjust the pH to between 9 and 9.5, heat to 170 ° C, react for 8 h, cool naturally, wash with ethanol three times, transfer to a vacuum drying oven and adjust the temperature to 60 ° C, dry to constant weight, and obtain a preloaded catalyst; (3) Immerse the pre-loaded catalyst in 200 mL of a cesium phosphotungstate solution with a molar concentration of 1 mol / L, perform vacuum treatment at -0.1 MPa for 45 min, filter, transfer it to a vacuum drying oven and adjust the temperature to 60 °C, dry to constant weight, then transfer it to a sintering furnace. After purging with nitrogen 3 times, continuously introduce nitrogen at a rate of 50 mL / min. First, heat it to 220 °C at a rate of 5 °C / min and hold for 60 min, then heat it to 320 °C at a rate of 3 °C / min and hold for 90 min. After that, stop introducing nitrogen and cool it with the furnace to obtain the catalyst.

[0044] The precursor solution includes cerium nitrate, polyethylene glycol and a solvent. The molar concentration of cerium nitrate is 0.2 mol / L, the volume concentration of polyethylene glycol is 1%, and the solvent is a mixture of ethanol and water with a volume ratio of 1:1.5. The solvent of the cesium phosphotungstate solution is a mixture of ethanol and water with a volume ratio of 1:1.5.

[0045] Preparation Example 2 The preparation method of the catalyst in this preparation example includes the following steps: (1) Immerse 10 g of nickel foam in 100 mL of a nitric acid solution with a volume concentration of 20%, heat it to 60 °C, etch for 35 min, wash it with deionized water until neutral, transfer it to a vacuum drying oven and adjust the temperature to 60 °C, dry to constant weight to obtain pretreated nickel foam. (2) Immerse the pretreated nickel foam in 150 mL of the precursor solution, slowly add ammonia water with a molar concentration of 0.6 mol / L at a stirring speed of 200 r / min, adjust the pH to between 9.5 and 10, heat it to 180 °C, react for 10 h, cool it naturally, wash it 3 times with ethanol, transfer it to a vacuum drying oven and adjust the temperature to 60 °C, dry to constant weight to obtain the pre-loaded catalyst. (3) Immerse the pre-loaded catalyst in 150 mL of a cesium phosphotungstate solution with a molar concentration of 0.05 mol / L, perform vacuum treatment at -0.12 MPa for 60 min, filter, transfer it to a vacuum drying oven and adjust the temperature to 60 °C, dry to constant weight, then transfer it to a sintering furnace. After purging with nitrogen 3 times, continuously introduce nitrogen at a rate of 40 mL / min. First, heat it to 200 °C at a rate of 5 °C / min and hold for 70 min, then heat it to 350 °C at a rate of 3 °C / min and hold for 120 min. After that, stop introducing nitrogen and cool it with the furnace to obtain the catalyst.

[0046] The precursor solution includes cerium nitrate, polyethylene glycol and a solvent. The molar concentration of cerium nitrate is 0.15 mol / L, the volume concentration of polyethylene glycol is 0.8%, and the solvent is a mixture of ethanol and water with a volume ratio of 1:1. The solvent of the cesium phosphotungstate solution is a mixture of ethanol and water with a volume ratio of 1:1.

[0047] Preparation Example 3 The preparation method of the catalyst in this preparation example includes the following steps: (1) Immerse 10 g of nickel foam in 100 mL of nitric acid solution with a volume concentration of 25%, heat up to 50 °C, etch for 25 min, wash with deionized water until neutral, transfer to a vacuum drying oven and adjust the temperature to 60 °C, dry to constant weight to obtain pretreated nickel foam; (2) Immerse the pretreated nickel foam in 250 mL of the precursor solution, slowly add ammonia water with a molar concentration of 0.6 mol / L at a stirring speed of 200 r / min, adjust the pH to between 9 and 9.5, heat up to 160 °C, react for 6 h, after natural cooling, wash 3 times with ethanol, transfer to a vacuum drying oven and adjust the temperature to 60 °C, dry to constant weight to obtain a pre-loaded catalyst; (3) Immerse the pre-loaded catalyst in 250 mL of cesium phosphotungstate solution with a molar concentration of 0.2 mol / L, perform vacuum treatment at -0.08 MPa for 30 min, filter, transfer to a vacuum drying oven and adjust the temperature to 60 °C, dry to constant weight, then transfer to a sintering furnace, replace with nitrogen 3 times, continuously introduce nitrogen at a rate of 60 mL / min, first heat up to 240 °C at a rate of 5 °C / min, keep the temperature for 50 min, then heat up to 300 °C at a rate of 3 °C / min, keep the temperature for 60 min, stop introducing nitrogen, and cool with the furnace to obtain the catalyst.

[0048] The precursor solution includes cerium nitrate, polyethylene glycol and a solvent. The molar concentration of cerium nitrate is 0.25 mol / L, the volume concentration of polyethylene glycol is 1.2%, and the solvent is a mixture of ethanol and water with a volume ratio of 1:2; The solvent of the cesium phosphotungstate solution is a mixture of ethanol and water with a volume ratio of 1:2.

[0049] Preparation Example 4 The difference between this preparation example and Preparation Example 1 is that: Potassium phosphotungstate with the same molar concentration and volume is used to replace cesium phosphotungstate.

[0050] Others are the same as Preparation Example 1.

[0051] Preparation Example 5 The difference between this preparation example and Preparation Example 1 is that: In step (1), immerse 10 g of titanium foam in 100 mL of acid solution, heat up to 30 °C, etch for 20 min, wash with deionized water until neutral, transfer to a vacuum drying oven and adjust the temperature to 60 °C, dry to constant weight to obtain pretreated nickel foam; Among them, the acid solution includes nitric acid, hydrofluoric acid and water. The volume concentration of nitric acid is 20%, and the volume concentration of hydrofluoric acid is 3%.

[0052] The others are the same as Preparation Example 1.

[0053] Preparation Example 6 The difference between this preparation example and Preparation Example 1 lies in: In step (1), 10 g of titanium foam is impregnated in 100 mL of acid solution, heated to 40 °C, etched for 15 min, washed with deionized water until neutral, transferred to a vacuum drying oven and the temperature is adjusted to 60 °C, dried to constant weight to obtain pretreated nickel foam. Among them, the acid solution includes nitric acid, hydrofluoric acid and water, the volume concentration of nitric acid is 25%, and the volume concentration of hydrofluoric acid is 5%.

[0054] The others are the same as Preparation Example 1.

[0055] Example 1 The preparation method of the diesel antiwear agent in this example includes the following steps: In a reaction kettle equipped with a stirring device, a thermometer, a reflux condenser and a water separator, after purging with nitrogen 3 times, 30 g of conjugated linoleic acid, 70 g of oleic acid, 13 g of pentaerythritol and 30 g of cyclohexane are added in sequence, then the stirrer is started, and after stirring and mixing evenly at a speed of 200 r / min, 4 g of catalyst is added, and stirring and mixing continue for 10 min, then the temperature is raised to 170 °C at a rate of 3 °C / min, after reacting for 3 h, during which the water in the water separator is discharged every 30 min, the temperature is lowered to 110 °C, boric acid is added in three portions, 0.5 g each time, with an interval of 10 min each time, after continuing to stir and react for 150 min, a small amount of sample is taken out from the reaction kettle for acid value detection. If the acid value > 1 mg KOH / g, additional catalyst is added and the reaction continues until the acid value ≤ 1 mg KOH / g, and the total additional amount of catalyst does not exceed 10% of the mass of the catalyst already added. Filter to separate the catalyst, wash the filtered catalyst with 15 mL of cyclohexane, combine the washing liquid and the filtrate, transfer the combined liquid product to a distillation device, raise the temperature to 85 °C, carry out atmospheric distillation to remove cyclohexane, then adjust the pressure to 8 kPa, raise the temperature to 130 °C, carry out vacuum distillation, cool to 80 °C, add 0.4 g of antioxidant 1010, and stir and mix evenly to obtain the diesel antiwear agent.

[0056] The catalyst is from Preparation Example 1.

[0057] [[ID=??]]Among them, before use, the catalyst undergoes the following pretreatment steps: The above catalyst is impregnated in a silane coupling agent solution, heated to 50 °C, reacted for 2 h, filtered, washed 3 times with deionized water, transferred to a vacuum drying oven and the temperature is adjusted to 60 °C, dried to constant weight to obtain it.

[0058] It should be noted that there seems to be a tag error in the original text where "[[ID=??]]" is used instead of a proper ID. This has been translated as best as possible while maintaining the integrity of the text.The silane coupling agent solution includes silane coupling agent KH550 and a solvent. The dosage of the silane coupling agent solution is 100 mL, the volume concentration of silane coupling agent KH550 is 2%, and the solvent is composed of ethanol and water mixed at a volume ratio of 3:2.

[0059] Example 2 The preparation method of the diesel antiwear agent in this example includes the following steps: In a reaction kettle equipped with a stirring device, a thermometer and a reflux condenser, after purging with nitrogen 3 times, 20 g of conjugated linoleic acid, 80 g of oleic acid, 13.5 g of pentaerythritol and 40 g of cyclohexane are added in sequence. Then, the stirrer is started and stirred at a speed of 200 r / min until evenly mixed. Then, 5 g of a catalyst is added and stirring is continued for 10 min. Then, the temperature is raised to 160 °C at a rate of 3 °C / min and reacted for 4 h. After that, the temperature is lowered to 100 °C, and boric acid is added in two portions, 0.5 g each time, with an interval of 15 min between each addition. After continuing to stir and react for 180 min, a small amount of sample is taken out from the reaction kettle for acid value detection. If the acid value > 1 mg KOH / g, additional catalyst is added and the reaction is continued until the acid value ≤ 1 mg KOH / g. The total additional amount of the catalyst does not exceed 10% of the mass of the catalyst already added. Then, filtration is carried out to separate the catalyst, and 15 mL of cyclohexane is used to wash the filtered catalyst. The washing liquid is combined with the filtrate. The combined liquid product is transferred to a distillation device, the temperature is raised to 105 °C, and cyclohexane is removed by atmospheric distillation. Then, the pressure is adjusted to 8 kPa, the temperature is raised to 130 °C, and vacuum distillation is carried out. After cooling to 80 °C, 0.3 g of antioxidant 1010 is added and stirred until evenly mixed to obtain the diesel antiwear agent.

[0060] The catalyst is from Preparation Example 2.

[0061] Among them, before use, the catalyst undergoes the following pretreatment steps: The above catalyst is impregnated in the silane coupling agent solution, the temperature is raised to 40 °C, reacted for 3 h, filtered, washed 3 times with deionized water, transferred to a vacuum drying oven and the temperature is adjusted to 60 °C, and dried to constant weight to obtain the product.

[0062] The silane coupling agent solution includes silane coupling agent KH550 and a solvent. The dosage of the silane coupling agent solution is 100 mL, the volume concentration of silane coupling agent KH550 is 1%, and the solvent is composed of ethanol and water mixed at a volume ratio of 7:3.

[0063] Example 3 The preparation method of the diesel antiwear agent in this example includes the following steps: In a reaction kettle equipped with a stirring device, a thermometer and a reflux condenser, after purging with nitrogen three times, 40 g of conjugated linoleic acid, 60 g of oleic acid, 14 g of pentaerythritol and 35 g of cyclohexane are added in sequence. Then, the stirrer is started and stirred at a speed of 200 r / min until evenly mixed. After that, 6 g of catalyst is added and stirring is continued for 10 min. Then, the temperature is raised to 180 °C at a rate of 3 °C / min and reacted for 4 h. After that, the temperature is lowered to 120 °C, and boric acid is added in four portions, 0.5 g each time, with an interval of 10 min each time. After continuing to stir and react for 90 min, a small amount of sample is taken out from the reaction kettle for acid value detection. If the acid value > 1 mg KOH / g, additional catalyst is added and the reaction is continued until the acid value ≤ 1 mg KOH / g. The total additional amount of catalyst does not exceed 10% of the mass of the catalyst already added. Then, filtration is carried out to separate the catalyst, and the filtered catalyst is washed with 15 mL of cyclohexane. The washing liquid is combined with the filtrate, and the combined liquid product is transferred to a distillation device. The temperature is raised to 105 °C, and cyclohexane is removed by atmospheric distillation. Then, the pressure is adjusted to 8 kPa, the temperature is raised to 130 °C, and vacuum distillation is carried out. After cooling to 80 °C, 0.5 g of antioxidant 1010 is added and stirred until evenly mixed to obtain a diesel antiwear agent.

[0064] The catalyst is from Preparation Example 3.

[0065] Among them, before use, the catalyst undergoes the following pretreatment steps: The above catalyst is impregnated in a silane coupling agent solution, the temperature is raised to 60 °C, reacted for 1 h, filtered, washed 3 times with deionized water, transferred to a vacuum drying oven and the temperature is adjusted to 60 °C, and dried to constant weight to obtain.

[0066] The silane coupling agent solution includes silane coupling agent KH550 and a solvent. The amount of the silane coupling agent solution is 100 mL, the volume concentration of silane coupling agent KH550 is 3%, and the solvent is composed of ethanol and water mixed in a volume ratio of 1:1.

[0067] Example 4 The preparation method of the diesel antiwear agent in this example includes the following steps: In a reaction kettle equipped with a stirring device, a thermometer, a reflux condenser, and a water separator, after purging with nitrogen three times, 30 g of conjugated linolenic acid, 70 g of palmitoleic acid, 14.5 g of pentaerythritol, and 35 g of cyclohexane were added in sequence. Then, the stirrer was started, and after stirring and mixing evenly at a speed of 200 r / min, 6 g of a catalyst was added, and stirring and mixing continued for 10 min. Then, the temperature was raised to 170 °C at a rate of 3 °C / min. After reacting for 3 h, the water in the water separator was drained every 30 min during this period. The temperature was lowered to 110 °C, and boric acid was added in three portions, 0.5 g each time, with an interval of 10 min each time. After continuing to stir and react for 150 min, a small amount of sample was taken out from the reaction kettle for acid value detection. If the acid value > 1 mg KOH / g, the catalyst was replenished and the reaction continued until the acid value ≤ 1 mg KOH / g. The total amount of catalyst replenished was not higher than 10% of the mass of the catalyst already added. The catalyst was filtered out, and the filtered catalyst was washed with 15 mL of cyclohexane. The washing liquid was combined with the filtrate, and the combined liquid product was transferred to a distillation device. The temperature was raised to 85 °C, and cyclohexane was removed by atmospheric distillation. Then, the pressure was adjusted to 8 kPa, the temperature was raised to 130 °C, and vacuum distillation was carried out. After cooling to 80 °C, 0.7 g of antioxidant 1010 was added and stirred and mixed evenly to obtain a diesel antiwear agent.

[0068] The catalyst was from Preparation Example 4.

[0069] Among them, before use, the catalyst was pretreated through the following steps: The above catalyst was impregnated in a silane coupling agent solution, the temperature was raised to 50 °C, and the reaction was carried out for 2 h. After filtration, it was washed 3 times with deionized water, transferred to a vacuum drying oven, and the temperature was adjusted to 60 °C and dried to constant weight to obtain the product.

[0070] The silane coupling agent solution included silane coupling agent KH550 and a solvent. The amount of the silane coupling agent solution was 100 mL, the volume concentration of silane coupling agent KH550 was 2%, and the solvent was composed of ethanol and water mixed in a volume ratio of 3:2.

[0071] Example 5 The preparation method of the diesel antiwear agent in this example includes the following steps: In a reactor equipped with a stirring device, a thermometer, a reflux condenser and a water separator, after purging with nitrogen three times, 20 g of conjugated linoleic acid, 10 g of conjugated linolenic acid, 70 g of palmitoleic acid, 15 g of pentaerythritol and 35 g of cyclohexane were added in sequence. Then, the stirrer was started and stirred at a speed of 200 r / min until evenly mixed. After that, 6 g of catalyst was added and stirring was continued for 10 min. Then, the temperature was raised to 170 °C at a rate of 3 °C / min and reacted for 3 h. During this period, the water in the water separator was discharged every 30 min. After cooling to 110 °C, boric acid was added in three portions, 0.5 g each time, with an interval of 10 min each time. After continuing to stir and react for 150 min, a small amount of sample was taken out from the reactor for acid value detection. If the acid value > 1 mg KOH / g, additional catalyst was added and the reaction was continued until the acid value ≤ 1 mg KOH / g. The total additional amount of catalyst was not higher than 10% of the mass of the catalyst already added. Then, filtration was carried out to separate the catalyst, and the filtered catalyst was washed with 15 mL of cyclohexane. The washing liquid was combined with the filtrate, and the combined liquid product was transferred to a distillation device. The temperature was raised to 85 °C, and cyclohexane was removed by atmospheric distillation. Then, the pressure was adjusted to 8 kPa, the temperature was raised to 130 °C, and vacuum distillation was carried out. After cooling to 80 °C, 0.7 g of antioxidant 1010 was added and stirred until evenly mixed to obtain a diesel antiwear agent.

[0072] The catalyst was from Preparation Example 5.

[0073] Among them, before use, the catalyst was pretreated through the following steps: The above catalyst was impregnated in a silane coupling agent solution, the temperature was raised to 50 °C, and the reaction was carried out for 2 h. Then, filtration was carried out, and it was washed 3 times with deionized water, transferred to a vacuum drying oven and the temperature was adjusted to 60 °C, and dried to constant weight to obtain the product.

[0074] The silane coupling agent solution included silane coupling agent KH550 and a solvent. The dosage of the silane coupling agent solution was 100 mL, the volume concentration of silane coupling agent KH550 was 2%, and the solvent was composed of ethanol and water mixed according to a volume ratio of 3:2.

[0075] Example 6 The preparation method of the diesel antiwear agent in this example includes the following steps: In a reaction kettle equipped with a stirring device, a thermometer, a reflux condenser and a water separator, after purging with nitrogen three times, 30 g of conjugated linoleic acid, 40 g of palmitoleic acid, 30 g of oleic acid, 19 g of trimethylolpropane and 35 g of cyclohexane were added in sequence. Then, the stirrer was started and stirred at a speed of 200 r / min until evenly mixed. After that, 6 g of catalyst was added and stirring was continued for 10 min. Then, the temperature was raised to 170 °C at a rate of 3 °C / min and reacted for 3 h. During this period, the water in the water separator was drained every 30 min. After cooling to 110 °C, boric acid was added in three portions, 0.5 g each time, with an interval of 10 min between each addition. After continuing to stir and react for 150 min, a small amount of sample was taken out from the reaction kettle for acid value detection. If the acid value > 1 mg KOH / g, additional catalyst was added and the reaction was continued until the acid value ≤ 1 mg KOH / g. The total additional amount of catalyst was not higher than 10% of the mass of the catalyst already added. Then, filtration was carried out to separate the catalyst, and the catalyst obtained by filtration was washed with 15 mL of cyclohexane. The washing liquid was combined with the filtrate, and the combined liquid product was transferred to a distillation device. The temperature was raised to 85 °C, and cyclohexane was removed by atmospheric distillation. Then, the pressure was adjusted to 8 kPa, and the temperature was raised to 130 °C for vacuum distillation. After cooling to 80 °C, 0.7 g of antioxidant 1010 was added and stirred until evenly mixed to obtain a diesel antiwear agent.

[0076] The catalyst was from Preparation Example 6.

[0077] Among them, before use, the catalyst was subjected to the following pretreatment steps: The above catalyst was impregnated in a silane coupling agent solution, the temperature was raised to 50 °C, and the reaction was carried out for 2 h. Then, filtration was carried out, and it was washed 3 times with deionized water, transferred to a vacuum drying oven and the temperature was adjusted to 60 °C, and dried to constant weight to obtain.

[0078] The silane coupling agent solution included silane coupling agent KH550 and a solvent. The amount of the silane coupling agent solution was 100 mL, the volume concentration of silane coupling agent KH550 was 2%, and the solvent was composed of ethanol and water mixed in a volume ratio of 3:2.

[0079] Example 7 The difference between this example and Example 1 was that: When adding pentaerythritol, 0.5 g of graphene oxide was also added.

[0080] Before use, graphene oxide was subjected to the following pretreatment steps: 0.5 g of graphene oxide and 0.5 g of polyethylene glycol were stirred and mixed evenly, then 0.025 g of oleic acid was added, and after stirring and mixing evenly, it was ultrasonically treated for 20 min, with an ultrasonic frequency of 20 kHz and a power of 300 W.

[0081] Other conditions were the same as in Example 1.

[0082] Example 8 The difference between this example and Example 7 is as follows: When adding pentaerythritol, 1.5 g of graphene oxide was also added.

[0083] Before using graphene oxide, it was subjected to the following pretreatment steps: After stirring and mixing 1.5 g of graphene oxide and 3 g of polyethylene glycol evenly, 0.15 g of oleic acid was added. After stirring and mixing evenly, it was ultrasonically treated for 30 min, with an ultrasonic frequency of 30 kHz and a power of 400 W.

[0084] Others are the same as in Example 7.

[0085] Example 9 The difference between this example and Example 8 is as follows: When adding pentaerythritol, 2 g of graphene oxide and 2 g of glycerol triglycidyl ether were also added.

[0086] Before using graphene oxide, it was subjected to the following pretreatment steps: After stirring and mixing 2 g of graphene oxide and 4 g of polyethylene glycol evenly, 0.2 g of oleic acid was added. After stirring and mixing evenly, it was ultrasonically treated for 40 min, with an ultrasonic frequency of 40 kHz and a power of 500 W.

[0087] Others are the same as in Example 8.

[0088] Example 10 The difference between this example and Example 9 is as follows: The dosage of glycerol triglycidyl ether is 4 g.

[0089] Others are the same as in Example 9.

[0090] Comparative Example 1 The preparation method of the diesel anti-wear agent in this comparative example includes the following steps: In a reaction kettle equipped with a stirring device, a thermometer, a reflux condenser, and a water separator, after purging with nitrogen three times, 100 g of oleic acid, 13 g of pentaerythritol, and 30 g of cyclohexane were successively added. Then, the stirrer was started, and after stirring and mixing evenly at a speed of 200 r / min, 4 g of catalyst was added, and stirring and mixing continued for 10 min. Then, the temperature was raised to 170 °C at a rate of 3 °C / min. After reacting for 3 h, the water in the water separator was drained every 30 min during this period. The temperature was lowered to 110 °C, and boric acid was added in three portions, 0.5 g each time, with an interval of 10 min each time. After continuing to stir and react for 150 min, a small amount of sample was taken out from the reaction kettle for acid value detection. If the acid value > 1 mg KOH / g, additional catalyst was added, and the reaction continued until the acid value ≤ 1 mg KOH / g. The total additional amount of catalyst did not exceed 10% of the mass of the catalyst already added. Filtration was carried out to separate the catalyst, and the catalyst obtained by filtration was washed with 15 mL of cyclohexane. The washing liquid was combined with the filtrate, and the combined liquid product was transferred to a distillation device. The temperature was raised to 85 °C, and cyclohexane was removed by atmospheric distillation. Then, the pressure was adjusted to 8 kPa, the temperature was raised to 130 °C, and vacuum distillation was carried out. After cooling to 80 °C, 0.4 g of antioxidant 1010 was added, and stirring and mixing were carried out evenly to obtain a diesel antiwear agent.

[0091] The catalyst was from Preparation Example 1.

[0092] Among them, before use, the catalyst was subjected to the following pretreatment steps: The above catalyst was impregnated in a silane coupling agent solution, the temperature was raised to 50 °C, and the reaction was carried out for 2 h. Filtration was carried out, and it was washed 3 times with deionized water, transferred to a vacuum drying oven, and the temperature was adjusted to 60 °C, and dried to constant weight to obtain.

[0093] The silane coupling agent solution included silane coupling agent KH550 and a solvent. The amount of the silane coupling agent solution was 100 mL, the volume concentration of silane coupling agent KH550 was 2%, and the solvent was composed of ethanol and water mixed in a volume ratio of 3:2.

[0094] Comparative Example 2 The preparation method of the diesel antiwear agent in this comparative example included the following steps: In a reaction kettle equipped with a stirring device, a thermometer, a reflux condenser and a water separator, after purging with nitrogen three times, 100 g of conjugated linoleic acid, 13 g of pentaerythritol and 30 g of cyclohexane are added in sequence. Then, the stirrer is started and stirred at a speed of 200 r / min until evenly mixed. After that, 4 g of catalyst is added and stirring is continued for 10 min. Then, the temperature is raised to 170 °C at a rate of 3 °C / min. After reacting for 3 h, the water in the water separator is discharged every 30 min during this period. The temperature is lowered to 110 °C, and boric acid is added in three portions, 0.5 g each time, with an interval of 10 min each time. After continuing to stir and react for 150 min, a small amount of sample is taken out from the reaction kettle for acid value detection. If the acid value > 1 mg KOH / g, additional catalyst is added and the reaction is continued until the acid value ≤ 1 mg KOH / g. The total additional amount of catalyst does not exceed 10% of the mass of the catalyst already added. Then, filtration is carried out to separate the catalyst. The filtered catalyst is washed with 15 mL of cyclohexane. The washing liquid is combined with the filtrate. The combined liquid product is transferred to a distillation device, the temperature is raised to 85 °C, and cyclohexane is removed by atmospheric distillation. Then, the pressure is adjusted to 8 kPa, the temperature is raised to 130 °C, and vacuum distillation is carried out. After cooling to 80 °C, 0.4 g of antioxidant 1010 is added and stirred until evenly mixed to obtain a diesel antiwear agent.

[0095] The catalyst is from Preparation Example 1.

[0096] Among them, before use, the catalyst undergoes the following pretreatment steps: The above catalyst is impregnated in a silane coupling agent solution, the temperature is raised to 50 °C, and the reaction is carried out for 2 h. Then, filtration is carried out and washed 3 times with deionized water. It is transferred to a vacuum drying oven and the temperature is adjusted to 60 °C and dried to constant weight to obtain the product.

[0097] The silane coupling agent solution includes silane coupling agent KH550 and a solvent. The amount of the silane coupling agent solution is 100 mL, the volume concentration of silane coupling agent KH550 is 2%, and the solvent is composed of ethanol and water mixed in a volume ratio of 3:2.

[0098] Comparative Example 3 The preparation method of the diesel antiwear agent in this comparative example includes the following steps: In a reaction kettle equipped with a stirring device, a thermometer, a reflux condenser, and a water separator, after purging with nitrogen three times, 100 g of conjugated linoleic acid, 13 g of pentaerythritol, and 30 g of cyclohexane were added in sequence. Then, the stirrer was started, and after stirring and mixing evenly at a speed of 200 r / min, 4 g of catalyst was added, and stirring and mixing continued for 10 min. Then, the temperature was raised to 170 °C at a rate of 3 °C / min. After reacting for 3 h, during which the water in the water separator was drained every 30 min. After the reaction ended, a small amount of sample was taken out from the reaction kettle for acid value detection. If the acid value > 1 mg KOH / g, additional catalyst was added and the reaction continued until the acid value ≤ 1 mg KOH / g. The total additional amount of catalyst was not higher than 10% of the mass of the catalyst already added. The temperature was lowered to 80 °C, filtered to separate the catalyst, and the filtered catalyst was washed with 15 mL of cyclohexane. The washing liquid was combined with the filtrate, and the combined liquid product was transferred to a distillation device. The temperature was raised to 85 °C for atmospheric distillation to remove cyclohexane. Then, the pressure was adjusted to 8 kPa, the temperature was raised to 130 °C for vacuum distillation, and after cooling to 80 °C, 0.4 g of antioxidant 1010 was added and stirred and mixed evenly to obtain a diesel antiwear agent.

[0099] Among them, before use, the catalyst was pretreated through the following steps: The above catalyst was impregnated in a silane coupling agent solution, the temperature was raised to 50 °C, reacted for 2 h, filtered, washed 3 times with deionized water, transferred to a vacuum drying oven and the temperature was adjusted to 60 °C, and dried to constant weight to obtain it.

[0100] The silane coupling agent solution included silane coupling agent KH550 and a solvent. The amount of the silane coupling agent solution was 100 mL, the volume concentration of silane coupling agent KH550 was 2%, and the solvent was composed of ethanol and water mixed according to a volume ratio of 3:2.

[0101] Comparative Example 4 The difference between this comparative example and Example 1 was that: The amount of the catalyst used was the same.

[0102] Among them, the preparation method of the catalyst included the following steps: The preparation method of the catalyst in this preparation example included the following steps: (1) 10 g of nickel foam was impregnated in 100 mL of a nitric acid solution with a volume concentration of 22%, the temperature was raised to 55 °C, etched for 30 min, washed with deionized water until neutral, transferred to a vacuum drying oven and the temperature was adjusted to 60 °C, and dried to constant weight to obtain pretreated nickel foam; (2) Immerse the pretreated nickel foam in 200 mL of the precursor solution. While stirring at a speed of 200 r / min, slowly add ammonia water with a molar concentration of 0.6 mol / L to adjust the pH to between 9 and 9.5. Then heat up to 170 °C and react for 8 h. After natural cooling, wash it three times with ethanol, transfer it to a vacuum drying oven, adjust the temperature to 60 °C, and dry it to constant weight. Then transfer it to a sintering furnace. After purging with nitrogen three times, continuously introduce nitrogen at a rate of 50 mL / min. First, heat up to 220 °C at a rate of 5 °C / min and hold for 60 min. Then heat up to 320 °C at a rate of 3 °C / min and hold for 90 min. After that, stop introducing nitrogen and cool it with the furnace to obtain the catalyst.

[0103] Others are the same as in Example 1.

[0104] Performance detection test Add the diesel anti-wear agents in Examples 1 - 10 and Comparative Examples 1 - 4 to low-sulfur diesel (sulfur content 10.0 mg / kg, kinematic viscosity at 40 °C is 3.2 mm 2 / s) for the wear test of diesel. The wear test conditions are as follows: Use a high-frequency reciprocating testing machine, the temperature is 60 ± 0.5 °C, the normal load is 200 ± 0.5 N, the reciprocating frequency is 50 Hz (corresponding to a stroke of 1 mm), and the single test duration is 75 min; Each group of tests is repeated 3 times, and the average value is taken. A blank control group is set, and the specific test results are shown in Table 1.

[0105] Add the diesel anti-wear agents in Examples 1 - 10 and Comparative Examples 1 - 4 to low-sulfur diesel (sulfur content 10.0 mg / kg, kinematic viscosity at 40 °C is 3.2 mm 2 / s) for the pour point detection of diesel. The detection conditions are as follows: Use an automatic pour point tester to test the pour point at a cooling rate of 3 °C / min. Each group of tests is repeated 3 times, and the average value is taken. The specific test results are shown in Table 1.

[0106] The mixing ratio of the diesel anti-wear agent and low-sulfur diesel is 40 - 100 μg / g. Add the diesel anti-wear agent to low-sulfur diesel according to the ratio, heat up to 60 °C, and stir and mix for 60 min at a stirring speed of 600 r / min to ensure uniform dispersion.

[0107] Table 1 Wear test data of diesel anti-wear agents in Examples 1 - 10 and Comparative Examples 1 - 4

[0108] Analyze the performance test data in Table 1: It can be seen from Examples 1 to 3 and Comparative Examples 1 to 4 that within a certain range, the higher the proportion of conjugated linoleic acid in the fatty acid combination, the better the anti-wear performance. However, the pour point will increase slightly because the regular molecular structure of conjugated linoleic acid promotes crystallization. Although the anti-wear performance is good when conjugated linoleic acid is used alone, the low-temperature fluidity is poor. On the contrary, when oleic acid is used alone, the low-temperature fluidity is good, but the anti-wear performance is insufficient. In addition, the boron-containing lubricating film synergistic adsorption film formed by the reaction of boric acid and fatty acids reduces the wear scar diameter by enhancing the boundary lubrication effect.

[0109] It can be seen from Examples 4 to 10 that: First, due to the adaptability of the conjugated double bond of conjugated linoleic acid to the metal surface, its anti-wear activity is significantly better than that of conjugated linolenic acid; Second, the two-dimensional sheets of graphene oxide form a continuous reinforced film layer through physical filling and chemical cross-linking of glycerol triglycidyl ether, and the performance shows a stepwise improvement with the increase of the addition amount; Third, the symmetric structure of pentaerythritol can form a three-dimensional network film layer, and its hardness and load-carrying capacity are better than those of trimethylolpropane.

[0110] This specific embodiment is only an explanation of the present application, and it does not limit the present application. Those skilled in the art can make modifications to this embodiment without creative contributions according to needs after reading this specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A preparation method of a diesel antiwear agent, characterized in that, It includes the following steps: Under an inert atmosphere, 20 - 40 parts by mass of conjugated unsaturated fatty acid, 60 - 80 parts by mass of non - conjugated unsaturated fatty acid, 13 - 19 parts by mass of polyol, 0.3 - 0.7 parts by mass of antioxidant and 30 - 40 parts by mass of cyclohexane are mixed evenly, then 4 - 6 parts by mass of catalyst is added and mixed evenly. The temperature is raised to 160 - 180 °C, and the reaction is carried out for 2 - 4 h. Then the temperature is lowered to 100 - 120 °C, 1 - 2 parts by mass of boric acid is added, and the reaction continues for 120 - 180 min. After solid - liquid separation and distillation, a diesel anti - wear agent is obtained; The catalyst is a core - shell structure composite in which a rare - earth metal oxide layer and a heteropolyacid metal salt are successively loaded on the surface of a porous metal support.

2. The preparation method of the diesel anti-wear agent according to claim 1, characterized in that, The conjugated unsaturated fatty acid is at least one of conjugated linoleic acid and conjugated linolenic acid.

3. The preparation method of the diesel anti-wear agent according to claim 1, wherein, The non - conjugated unsaturated fatty acid is at least one of oleic acid and palmitoleic acid.

4. The preparation method of the diesel anti-wear agent according to claim 1, characterized in that, The polyol is any one of pentaerythritol and trimethylolpropane.

5. The preparation method of the diesel anti-wear agent according to claim 1, wherein, The preparation method of the catalyst includes the following steps: (1) The porous metal support is acid - etched, washed and dried to obtain a pretreated support; (2) The pretreated support is immersed in a precursor solution, the pH is adjusted to 9 - 10, then the temperature is raised to 160 - 180 °C, and the reaction is carried out for 6 - 10 h. After washing and drying, a pre - loaded catalyst is obtained; (3) The pre - loaded catalyst is immersed in a heteropolyacid metal salt solution for 30 - 60 min, followed by solid - liquid separation and drying. Then it is calcined under an inert atmosphere and cooled to obtain the catalyst; The precursor solution includes a rare - earth metal salt, and the molar concentration of the rare - earth metal salt is 0.15 - 0.25 mol / L; the molar concentration of the heteropolyacid metal salt solution is 0.05 - 0.2 mol / L.

6. The preparation method of the diesel antiwear agent according to claim 5, characterized in that, Before use, the catalyst undergoes the following pretreatment steps: The catalyst is immersed in a silane coupling agent solution with a pH of 3 - 4 and a volume concentration of 1% - 3%, and the reaction is carried out at 40 - 60 °C for 1 - 3 h. After solid - liquid separation and drying, the catalyst is obtained; The silane coupling agent solution includes a silane coupling agent, ethanol and water.

7. The preparation method of the diesel anti-wear agent according to claim 1, characterized in that, The rare - earth metal salt is any one of cerium nitrate and lanthanum nitrate; the heteropolyacid metal salt solution is any one of cesium phosphotungstate and potassium phosphotungstate.

8. The preparation method of the diesel anti-wear agent according to claim 1, characterized in that, The porous metal support is any one of nickel foam and titanium foam.

9. The preparation method of the diesel anti-wear agent according to claim 1, characterized in that, When adding the polyol, it also includes the step of adding 0.5 - 2 parts by mass of graphene oxide.

10. The preparation method of the diesel anti-wear agent according to claim 9, wherein, Before use, the graphene oxide undergoes the following pretreatment steps: The graphene oxide and polyethylene glycol are mixed evenly, then oleic acid is added and mixed evenly, and ultrasonic treatment is carried out for 30 - 40 min to obtain the product; The mass ratio of the graphene oxide, polyethylene glycol and oleic acid is 1:(1 - 2):(0.05 - 0.1).

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