A diesel anti-wear agent and a method for preparing the same

Abstract

This invention provides a diesel anti-wear agent and its preparation method, belonging to the technical field of diesel additives. The method includes the following steps: mixing and stirring diisooctyl maleate and xylene, adding diethylenetriamine and deionized water, heating and reacting, adding toluene, 4-(aminomethyl)pyridine, and ethylene oxide, mixing and reacting to obtain pyridinium-based polyester hollow capsules; mixing xylene, catechol, ethylenephosphonic acid, ammonium persulfate, and deionized water, heating, dispersing in cyclohexane, adding polyvinyl alcohol, octadecyl methacrylate, and azobisisobutyronitrile, mixing and reacting to obtain catechol phosphonate nanoparticles; mixing and stirring fatty acid ester solution, oleoyl fluorocarbon copolymer, and pyridinium-based polyester hollow capsules, adding catechol phosphonate nanoparticles, continuously stirring, sonicating, and degassing to obtain the diesel anti-wear agent. This invention can improve the anti-wear and deemulsification properties of diesel anti-wear agents.

Description

Technical Field

[0001] This invention relates to the field of diesel additive technology, specifically to a diesel anti-wear agent and its preparation method. Background Technology

[0002] Diesel engines operate under high pressure and high temperature for extended periods, causing wear. To reduce frictional losses, anti-wear agents are typically added to the fuel. Existing anti-wear agents can adsorb onto metal surfaces to form a lubricating film. However, due to uneven molecular distribution on the metal surface, localized accumulation and film vacancies often occur, resulting in discontinuous protective effects and consequently affecting the anti-wear performance of diesel anti-wear agents.

[0003] To enhance the performance of the lubricating film, some studies have attempted to add hard inorganic fillers such as silica, alumina, and molybdenum sulfide. These particles improve the mechanical support of the lubricating film to a certain extent, but due to their high hardness, they are prone to scratching the metal surface during friction and may even cause secondary wear. At the same time, inorganic particles tend to agglomerate and settle in oil, resulting in poor dispersibility, which also limits their application effect.

[0004] Traditional anti-wear agents primarily interact with metal surfaces through physical adsorption, lacking sufficient chemical adhesion. Under high-shear conditions, the lubricating film is easily damaged or peeled off, leading to a decrease in anti-wear effectiveness. This problem is particularly pronounced in ultra-low sulfur diesel systems due to the lack of polar components. Therefore, the key to improving diesel anti-wear agents lies in achieving uniform spreading of fatty acid ester solution molecules on metal surfaces while avoiding damage to hard inorganic fillers and enhancing the adhesion between the lubricating film and the metal surface.

[0005] Diesel anti-wear agents also have the problem of poor demulsification in application. Diesel inevitably comes into contact with water during use. When water droplets enter diesel containing anti-wear agents, if the anti-wear agent molecules exhibit certain surface activity at the oil-water interface, it will reduce the oil-water interfacial tension, causing the water droplets to be stably dispersed in the diesel, forming an emulsion. This makes it difficult for the diesel anti-wear agent to form a complete lubricating film layer, thereby aggravating the frictional wear of the metal surface.

[0006] In summary, there is a need to provide a diesel anti-wear agent and its preparation method to solve the problems existing in the prior art. Summary of the Invention

[0007] In view of this, the present invention provides a diesel anti-wear agent and its preparation method, which can improve the anti-wear and demulsification properties of the diesel anti-wear agent.

[0008] To achieve the above objectives, the present invention provides a method for preparing a diesel anti-wear agent, comprising the following steps:

[0009] S1. Diisooctyl maleate and xylene were mixed and stirred, diethylenetriamine and deionized water were added, the mixture was heated and reacted, filtered and dried, toluene, 4-(aminomethyl)pyridine and ethylene oxide were added, the pH was adjusted to acidic, the mixture was reacted, filtered, and dried to obtain pyridinium-based polyester hollow capsules.

[0010] S2. Mix xylene, catechol, ethylenephosphonic acid, ammonium persulfate, and deionized water, heat to react, filter and dry, disperse in cyclohexane, add polyvinyl alcohol, octadecyl methacrylate, and azobisisobutyronitrile, mix and react, filter and dry to obtain catechol phosphonate nanoparticles.

[0011] S3. Mix fatty acid ester solution and pyridinium-based polyester hollow capsules, heat and stir, add catechol phosphonate nanoparticles, continue stirring, sonicate, and allow to stand to degas, to obtain diesel anti-wear agent.

[0012] The fatty acid ester solution in this invention is prepared by esterification of oleic acid and 2-ethylhexanol in an organic solvent. The fatty acid ester, as the main component, participates in the formation of the lubricating film. The pyridinium-based polyester hollow capsule is prepared by reacting diisooctyl maleate with diethylenetriamine to form a capsule, followed by grafting pyridinium groups. The long-chain hydrocarbons on the pyridinium-based polyester hollow capsule can entangle with the hydrocarbon chains of the fatty acid ester solution. This entanglement causes cross-contact between chain segments, forming a mutually restraining chain network, thereby promoting a more orderly arrangement of fatty acid ester molecules at the friction interface. Simultaneously, the pyridinium groups have strong polarity and can generate interfacial synergy with the metal surface, further promoting the uniform spread of fatty acid ester molecules on the metal surface. Due to the combined effects of entanglement and interfacial synergy, a dense and stable lubricating film can be formed on the metal surface, reducing localized voids and lubricating film rupture, thus improving the anti-wear performance of the diesel anti-wear agent.

[0013] Furthermore, the hollow structure of pyridinium-based polyester capsules makes them behave like "soft particles" in terms of mechanical properties. During the contact friction between diesel anti-wear agents and metal surfaces, pyridinium-based polyester hollow capsules do not cause secondary wear to the metal surface like hard inorganic fillers. Instead, they can deform under pressure, playing a buffering role and reducing frictional loss on the metal surface.

[0014] The catechol phosphonate nanoparticles of this invention are prepared by polymerizing catechol and ethylenephosphonic acid, followed by grafting octadecyl methacrylate, and using polyvinyl alcohol as a stabilizer to improve the dispersibility of the particles. The catechol groups on the nanoparticles can form complex bonds with the oxide layer on the metal surface, while the phosphonic acid groups can chemically adsorb onto the metal surface, enhancing the adhesion between fatty acid ester molecules and the metal surface. Simultaneously, the oily chains on the catechol phosphonate nanoparticles can also entangle with the hydrocarbon chains of the fatty acid ester molecules, making the lubricating film layer less prone to peeling under interfacial stress, further improving the anti-wear performance of the diesel anti-wear agent.

[0015] Optionally, in step S3, an oleoyl fluorocarbon copolymer is added before continuous stirring. The oleoyl fluorocarbon copolymer is mainly composed of 2-hydroxyethyl acrylate, which is copolymerized with fluorocarbon acrylate and then grafted with oleoyl chloride.

[0016] This invention improves the deemulsification properties of diesel anti-wear agents by introducing an oleoyl fluorocarbon copolymer. The fluorocarbon chains on the oleoyl fluorocarbon copolymer have strong hydrophobic properties, spontaneously orienting at the oil-water interface and repelling water molecules, thus disrupting the wetting stability of water droplets in the oil phase and preventing the formation of a stable emulsion interface film. Meanwhile, the oleoyl chains are compatible and entangled with the hydrocarbon chains of fatty acid ester molecules, ensuring that the oleoyl fluorocarbon copolymer is highly dispersed and stable in the diesel anti-wear agent, without precipitation or aggregation. Through the combined use of the fluorocarbon and oleoyl chains, the oleoyl fluorocarbon copolymer and fatty acid ester solution maintain good compatibility while providing a strong hydrophobic barrier at the water droplet contact interface, preventing water droplets from forming a stable dispersion system with fatty acid ester molecules, thereby improving the deemulsification properties of the diesel anti-wear agent. Furthermore, the enhanced deemulsification properties enable fatty acid ester molecules to continuously form a dense and stable lubricating film layer on the metal friction surface, preventing film gaps or localized peeling due to water droplet interference, thus improving the anti-wear performance of the diesel anti-wear agent.

[0017] Optionally, the oleoyl fluorocarbon copolymer is prepared by dissolving fluorocarbon acrylate and 2-hydroxyethyl acrylate in xylene, adding azobisisobutyronitrile, reacting at 65-75°C for 3-4 hours, cooling, adding oleoyl chloride and triethylamine, reacting at 40-50°C for 1-2 hours, precipitating with anhydrous ethanol, filtering, and vacuum drying at 50-60°C.

[0018] Polymerize at 65-75℃ for 3-4 hours to ensure full copolymerization of the fluorocarbon chain and hydroxyethyl acrylate and avoid incomplete reaction; then graft at 40-50℃ for 1-2 hours to stably introduce the oleoyl chain under mild conditions and improve the structural integrity of the oleoyl fluorocarbon copolymer.

[0019] Optionally, in step S1, diisooctyl maleate and xylene are mixed and stirred at 30-35°C. Diethylenetriamine and deionized water are added, and the mixture is reacted at 30-35°C for 3-4 hours. The mixture is then filtered, washed, and vacuum dried at 50-60°C. The mixture is dispersed in toluene, and 4-(aminomethyl)pyridine is added. The mixture is reacted at 50-60°C for 1-3 hours. After cooling, ethylene oxide is added, and the pH is adjusted to 3.5-4. The mixture is reacted at 50-60°C for 1-2 hours, filtered, and dried to obtain pyridinium-based polyester hollow capsules.

[0020] In step S1, the reaction is controlled at a low temperature of 30~35℃ to ensure uniform reaction between diisooctyl maleate and diethylenetriamine and avoid side reactions. Vacuum drying and solvent dispersion at 50~60℃ can effectively remove residual solvent and maintain the integrity of the hollow structure. Subsequently, the introduction of pyridinium groups under mild conditions of 50~60℃ avoids the collapse of the hollow structure caused by high temperature.

[0021] Optionally, in step S2, xylene, catechol, ethylenephosphonic acid, and ammonium persulfate are added to deionized water and reacted at 25-35°C for 2-3 hours. After filtration and washing, the mixture is vacuum dried at 50-60°C and dispersed in cyclohexane. Polyvinyl alcohol, octadecyl methacrylate, and azobisisobutyronitrile are then added and reacted at 60-80°C for 1-2 hours. After filtration and drying, catechol phosphonate nanoparticles are obtained.

[0022] In this invention, polyvinyl alcohol can not only act as a stabilizer to improve the dispersibility of catechol phosphonate nanoparticles at room temperature, but also inhibit particle aggregation and sedimentation under low temperature conditions, thereby improving the low temperature stability of diesel anti-wear agents.

[0023] In step S2, a temperature of 25-35°C is used to uniformly polymerize catechol and ethylenephosphonic acid under the initiation of ammonium persulfate; after filtration and vacuum drying at 50-60°C, residual moisture and solvent are effectively removed to improve the integrity of the colloidal structure; then, oily linking branches are carried out at 60-80°C, which not only helps to introduce octadecyl methacrylate, but also avoids agglomeration caused by excessive temperature.

[0024] Optionally, oleic acid, 2-ethylhexanol, p-toluenesulfonic acid, and xylene are mixed and refluxed at 120-140°C for 4-6 hours to remove water. The mixture is then cooled to 50-60°C, and a 5 wt% sodium carbonate aqueous solution is added. The mixture is stirred, allowed to stand for separation, and the lower aqueous phase is removed. The mixture is washed 3-5 times with deionized water, dried with anhydrous magnesium sulfate for 20-30 minutes, filtered, and vacuum distilled at 80-100°C for 60-90 minutes to obtain a fatty acid ester solution.

[0025] In this invention, a fatty acid ester solution is prepared by esterification of oleic acid and 2-ethylhexanol in an organic solvent. The fatty acid ester, as the main component of the diesel anti-wear agent of this invention, can spread and form a lubricating film at the metal friction interface. This step removes residual catalyst and byproducts by washing with water and separates impurities by vacuum distillation, thereby improving the purity and compositional stability of the fatty acid ester solution.

[0026] Optionally, in step S3, the fatty acid ester solution and pyridinium-based polyester hollow capsules are mixed, stirred at 60-70°C for 30-40 minutes, catechol phosphonate nanoparticles are added, and the mixture is stirred continuously for 20-30 minutes. The mixture is then cooled to 40-50°C, ultrasonically treated for 10-15 minutes, and allowed to stand to degas, thereby obtaining the diesel anti-wear agent.

[0027] A diesel anti-wear agent comprises the following raw materials in parts by weight: 0.5-1.5 parts of pyridinium-based polyester hollow capsules, 0.3-1.0 parts of catechol phosphonate nanoparticles, and 90-100 parts of fatty acid ester solution;

[0028] The pyridinium-based polyester hollow capsule comprises the following raw materials in parts by weight: 5-6 parts of diisooctyl maleate, 86.7-90 parts of xylene, 2.5-3 parts of diethylenetriamine, 40-50 parts of toluene, 1.0-1.5 parts of 4-(aminomethyl)pyridine, and 0.8-1.2 parts of ethylene oxide.

[0029] Optionally, the catechol phosphonate nanoparticles comprise the following raw materials in parts by weight: xylene 80-90 parts, catechol 0.8-1.2 parts, ethylenephosphonic acid 0.4-0.8 parts, ammonium persulfate 0.05-0.1 parts, cyclohexane 40-50 parts, polyvinyl alcohol 0.15-0.25 parts, octadecyl methacrylate 0.3-0.6 parts, and azobisisobutyronitrile 0.02-0.05 parts; the fatty acid ester solution comprises the following raw materials in parts by weight: oleic acid 50-55 parts, 2-ethylhexanol 31-35 parts, p-toluenesulfonic acid 0.5-0.8 parts, xylene 85-90 parts, 5wt% sodium carbonate aqueous solution 3-4.5 parts, and anhydrous magnesium sulfate 5-8 parts.

[0030] Optionally, the diesel anti-wear agent also contains an oleoyl fluorocarbon copolymer, which comprises the following raw materials in parts by weight: 0.8-1.2 parts of fluorocarbon acrylate, 1-1.5 parts of 2-hydroxyethyl acrylate, 0.05-0.08 parts of azobisisobutyronitrile, 0.8-1.2 parts of oleoyl chloride, and 1-1.5 parts of triethylamine.

[0031] The above-described technical solution of the present invention has at least the following beneficial effects:

[0032] This invention introduces pyridinium-based polyester hollow capsules into a diesel anti-wear agent. The long-chain hydrocarbons on the surface of these capsules entangle with fatty acid ester molecules, forming a mutually restraining chain-like network that makes the fatty acid ester molecules more regularly arranged at the friction interface. The polarity of the pyridinium groups further enhances the interfacial synergy with the metal surface, reducing interfacial tension and allowing the fatty acid ester molecules to spread uniformly. This results in a dense and stable lubricating film layer on the metal surface, reducing film pores and cracks, and improving the anti-wear performance of the diesel anti-wear agent. Simultaneously, the hollow structure of the pyridinium-based polyester hollow capsules makes them behave as "soft particles" during friction, capable of deformation under pressure and acting as a buffer, thus avoiding secondary wear that may be caused by hard fillers and reducing frictional loss on the metal surface.

[0033] In addition, the catechol phosphonate nanoparticles further enhance the adhesion between the diesel anti-wear agent and the metal surface through the complexation of the catechol groups with the metal surface oxide layer and the chemical adsorption of the phosphonic acid groups. The oily chains on the surface are entangled with fatty acid ester molecules, making the lubricating film layer less likely to peel off under stress, thus further improving the overall anti-wear performance of the diesel anti-wear agent. Attached Figure Description

[0034] Figure 1 The image shows the anti-wear test results of the diesel anti-wear agent in Example 1 of this invention. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. The described embodiments are some embodiments of the present invention, and all other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0036] Example 1

[0037] 5g of diisooctyl maleate and 86.7g of xylene were mixed and dissolved by stirring at 30°C. 2.5g of diethylenetriamine and 40g of deionized water were added, and the mixture was reacted at 30°C for 3 hours. After filtration and washing with deionized water, the mixture was dried under vacuum at 50°C and dispersed in 40g of toluene. 1g of 4-(aminomethyl)pyridine was added, and the mixture was reacted at 50°C for 1 hour. After cooling to room temperature, 0.8g of ethylene oxide was added, and phosphoric acid was added to adjust the pH to 3.5. The mixture was reacted at 50°C for 1 hour, filtered, and dried to obtain pyridinium-based polyester hollow capsules.

[0038] 80g xylene, 0.8g catechol, 0.4g ethylenephosphonic acid, and 0.05g ammonium persulfate were added to 20g deionized water and reacted at 25℃ for 2h. After filtration and washing with deionized water, the mixture was vacuum dried at 50℃ and dispersed in 40g cyclohexane. Then, 0.15g polyvinyl alcohol, 0.3g octadecyl methacrylate, and 0.02g azobisisobutyronitrile were added, and the mixture was reacted at 60℃ for 1h. After filtration and drying, catechol phosphonate nanoparticles were obtained.

[0039] 0.8 g of fluorocarbon acrylate and 1 g of 2-hydroxyethyl acrylate were dissolved in 80 g of xylene, and 0.05 g of azobisisobutyronitrile was added. The mixture was reacted at 65 °C for 3 h. After cooling to room temperature, 0.8 g of oleoyl chloride and 1 g of triethylamine were added, and the mixture was reacted at 40 °C for 1 h. Anhydrous ethanol was poured in to precipitate the precipitate, and the mixture was filtered and dried under vacuum at 50 °C to obtain the oleoyl fluorocarbon copolymer.

[0040] 50g of oleic acid, 31g of 2-ethylhexanol, 0.5g of p-toluenesulfonic acid, and 85g of xylene were added to a three-necked flask. The mixture was refluxed at 120°C for 4 hours under a nitrogen atmosphere, while removing water using a water separator. The mixture was cooled to 50°C, and 3g of 5wt% sodium carbonate aqueous solution was slowly added. After stirring until homogeneous, the mixture was poured into a separatory funnel, allowed to stand for separation, and the lower aqueous phase was removed. The mixture was washed three times with deionized water, dried for 20 minutes with 5g of anhydrous magnesium sulfate, filtered, and vacuum distilled at 80°C for 60 minutes to obtain a fatty acid ester solution.

[0041] 90g of fatty acid ester solution and 0.5g of pyridinium-based polyester hollow capsules were mixed and magnetically stirred at 60℃ for 30min. Then, 0.3g of catechol phosphonate nanoparticles and 0.2g of oleoyl fluorocarbon copolymer were slowly added and magnetically stirred for 20min. The mixture was then cooled to 40℃ and ultrasonically treated for 10min. After standing and degassing, diesel anti-wear agent was obtained.

[0042] It should be understood that the diesel anti-wear agent prepared in this invention is a fatty acid ester type diesel anti-wear agent.

[0043] Example 2

[0044] 5.5 g of diisooctyl maleate and 88 g of xylene were mixed and dissolved by stirring at 32 °C. 2.8 g of diethylenetriamine and 45 g of deionized water were added, and the mixture was reacted at 33 °C for 3.5 h. After filtration and washing with deionized water, the mixture was dried under vacuum at 55 °C and dispersed in 45 g of toluene. 1.3 g of 4-(aminomethyl)pyridine was added, and the mixture was reacted at 55 °C for 2 h. After cooling to room temperature, 1 g of ethylene oxide was added, and phosphoric acid was added to adjust the pH to 3.8. The mixture was reacted at 55 °C for 1.5 h, filtered, and dried to obtain pyridinium-based polyester hollow capsules.

[0045] 85g xylene, 1g catechol, 0.6g ethylenephosphonic acid, and 0.075g ammonium persulfate were added to 25g deionized water and reacted at 30℃ for 2.5h. After filtration and washing with deionized water, the mixture was vacuum dried at 55℃ and dispersed in 45g cyclohexane. Then, 0.2g polyvinyl alcohol, 0.45g octadecyl methacrylate, and 0.04g azobisisobutyronitrile were added, and the mixture was reacted at 70℃ for 1.5h. After filtration and drying, catechol phosphonate nanoparticles were obtained.

[0046] 1 g of fluorocarbon acrylate and 1.3 g of 2-hydroxyethyl acrylate were dissolved in 90 g of xylene, and 0.07 g of azobisisobutyronitrile was added. The mixture was reacted at 70 °C for 3.5 h. After cooling to room temperature, 1 g of oleoyl chloride and 1.2 g of triethylamine were added, and the mixture was reacted at 45 °C for 1.5 h. Anhydrous ethanol was poured in to precipitate the precipitate, and the mixture was filtered and dried under vacuum at 55 °C to obtain the oleoyl fluorocarbon copolymer.

[0047] 53g of oleic acid, 33g of 2-ethylhexanol, 0.75g of p-toluenesulfonic acid, and 88g of xylene were added to a three-necked flask. The mixture was refluxed at 130°C for 5 hours under a nitrogen atmosphere, while removing water using a water separator. The mixture was cooled to 55°C, and 4g of 5wt% sodium carbonate aqueous solution was slowly added. After stirring until homogeneous, the mixture was poured into a separatory funnel and allowed to stand for separation. The lower aqueous phase was removed, and the mixture was washed four times with deionized water. 6.5g of anhydrous magnesium sulfate was added and the mixture was dried for 25 minutes. The mixture was filtered and vacuum distilled at 90°C for 80 minutes to obtain a fatty acid ester solution.

[0048] 95g of fatty acid ester solution and 1g of pyridinium-based polyester hollow capsule were mixed and magnetically stirred at 65°C for 35min. 0.6g of catechol phosphonate nanoparticles and 0.5g of oleoyl fluorocarbon copolymer were slowly added and magnetically stirred for 25min. The mixture was then cooled to 45°C and ultrasonically treated for 12min. After standing and degassing, diesel anti-wear agent was obtained.

[0049] It should be understood that the diesel anti-wear agent prepared in this invention is a fatty acid ester type diesel anti-wear agent.

[0050] Example 3

[0051] 6g of diisooctyl maleate and 90.0g of xylene were mixed and dissolved by stirring at 35°C. 3g of diethylenetriamine and 50g of deionized water were added, and the mixture was reacted at 35°C for 4 hours. After filtration and washing with deionized water, the mixture was dried under vacuum at 60°C and dispersed in 50g of toluene. 1.5g of 4-(aminomethyl)pyridine was added, and the mixture was reacted at 60°C for 3 hours. After cooling to room temperature, 1.2g of ethylene oxide was added, and phosphoric acid was added to adjust the pH to 4. The mixture was reacted at 60°C for 2 hours, filtered, and dried to obtain pyridinium-based polyester hollow capsules.

[0052] 90g xylene, 1.2g catechol, 0.8g ethylenephosphonic acid, and 0.1g ammonium persulfate were added to 30g deionized water and reacted at 35℃ for 3h. After filtration and washing with deionized water, the mixture was vacuum dried at 60℃ and dispersed in 50g cyclohexane. Then, 0.25g polyvinyl alcohol, 0.6g octadecyl methacrylate, and 0.05g azobisisobutyronitrile were added, and the mixture was reacted at 80℃ for 2h. After filtration and drying, catechol phosphonate nanoparticles were obtained.

[0053] 1.2 g of fluorocarbon acrylate and 1.5 g of 2-hydroxyethyl acrylate were dissolved in 100 g of xylene, and 0.08 g of azobisisobutyronitrile was added. The mixture was reacted at 75 °C for 4 h. After cooling to room temperature, 1.2 g of oleoyl chloride and 1.5 g of triethylamine were added, and the mixture was reacted at 50 °C for 2 h. Anhydrous ethanol was poured in to precipitate the precipitate, and the mixture was filtered and dried under vacuum at 60 °C to obtain the oleoyl fluorocarbon copolymer.

[0054] 55g of oleic acid, 35g of 2-ethylhexanol, 0.8g of p-toluenesulfonic acid, and 90g of xylene were added to a three-necked flask. The mixture was refluxed at 140℃ for 6 hours under a N2 atmosphere, while removing water using a water separator. The mixture was cooled to 60℃, and 4.5g of 5wt% sodium carbonate aqueous solution was slowly added. After stirring until homogeneous, the mixture was poured into a separatory funnel, allowed to stand for separation, and the lower aqueous phase was removed. The mixture was washed 5 times with deionized water, dried for 30 minutes with 8g of anhydrous magnesium sulfate, filtered, and vacuum distilled at 100℃ for 90 minutes to obtain a fatty acid ester solution.

[0055] 100g of fatty acid ester solution and 1.5g of pyridinium-based polyester hollow capsules were mixed and magnetically stirred at 70℃ for 40min. 1g of catechol phosphonate nanoparticles and 0.8g of oleoyl fluorocarbon copolymer were slowly added and magnetically stirred for 30min. The mixture was then cooled to 50℃ and ultrasonically treated for 15min. After standing and degassing, diesel anti-wear agent was obtained.

[0056] It should be understood that the diesel anti-wear agent prepared in this invention is a fatty acid ester type diesel anti-wear agent.

[0057] Example 4

[0058] 5g of diisooctyl maleate and 86.7g of xylene were mixed and dissolved by stirring at 30°C. 2.5g of diethylenetriamine and 40g of deionized water were added, and the mixture was reacted at 30°C for 3 hours. After filtration and washing with deionized water, the mixture was dried under vacuum at 50°C and dispersed in 40g of toluene. 1g of 4-(aminomethyl)pyridine was added, and the mixture was reacted at 50°C for 1 hour. After cooling to room temperature, 0.8g of ethylene oxide was added, and phosphoric acid was added to adjust the pH to 3.5. The mixture was reacted at 50°C for 1 hour, filtered, and dried to obtain pyridinium-based polyester hollow capsules.

[0059] 80g xylene, 0.8g catechol, 0.4g ethylenephosphonic acid, and 0.05g ammonium persulfate were added to 20g deionized water and reacted at 25℃ for 2h. After filtration and washing with deionized water, the mixture was vacuum dried at 50℃ and dispersed in 40g cyclohexane. Then, 0.15g polyvinyl alcohol, 0.3g octadecyl methacrylate, and 0.02g azobisisobutyronitrile were added, and the mixture was reacted at 60℃ for 1h. After filtration and drying, catechol phosphonate nanoparticles were obtained.

[0060] 50g of oleic acid, 31g of 2-ethylhexanol, 0.5g of p-toluenesulfonic acid, and 85g of xylene were added to a three-necked flask. The mixture was refluxed at 120°C for 4 hours under a nitrogen atmosphere, while removing water using a water separator. The mixture was cooled to 50°C, and 3g of 5wt% sodium carbonate aqueous solution was slowly added. After stirring until homogeneous, the mixture was poured into a separatory funnel, allowed to stand for separation, and the lower aqueous phase was removed. The mixture was washed three times with deionized water, dried for 20 minutes with 5g of anhydrous magnesium sulfate, filtered, and vacuum distilled at 80°C for 60 minutes to obtain a fatty acid ester solution.

[0061] 90g of fatty acid ester solution and 0.5g of pyridinium-based polyester hollow capsules were mixed and magnetically stirred at 60℃ for 30min. Then, 0.3g of catechol phosphonate nanoparticles were slowly added and magnetically stirred for 20min. The mixture was then cooled to 40℃ and ultrasonically treated for 10min. After standing and degassing, diesel anti-wear agent was obtained.

[0062] It should be understood that the diesel anti-wear agent prepared in this invention is a fatty acid ester type diesel anti-wear agent.

[0063] Example 5

[0064] 5.5 g of diisooctyl maleate and 88 g of xylene were mixed and dissolved by stirring at 32 °C. 2.8 g of diethylenetriamine and 45 g of deionized water were added, and the mixture was reacted at 33 °C for 3.5 h. After filtration and washing with deionized water, the mixture was dried under vacuum at 55 °C and dispersed in 45 g of toluene. 1.3 g of 4-(aminomethyl)pyridine was added, and the mixture was reacted at 55 °C for 2 h. After cooling to room temperature, 1 g of ethylene oxide was added, and phosphoric acid was added to adjust the pH to 3.8. The mixture was reacted at 55 °C for 1.5 h, filtered, and dried to obtain pyridinium-based polyester hollow capsules.

[0065] 85g xylene, 1g catechol, 0.6g ethylenephosphonic acid, and 0.075g ammonium persulfate were added to 25g deionized water and reacted at 30℃ for 2.5h. After filtration and washing with deionized water, the mixture was vacuum dried at 55℃ and dispersed in 45g cyclohexane. Then, 0.2g polyvinyl alcohol, 0.45g octadecyl methacrylate, and 0.04g azobisisobutyronitrile were added, and the mixture was reacted at 70℃ for 1.5h. After filtration and drying, catechol phosphonate nanoparticles were obtained.

[0066] 53g of oleic acid, 33g of 2-ethylhexanol, 0.75g of p-toluenesulfonic acid, and 88g of xylene were added to a three-necked flask. The mixture was refluxed at 130°C for 5 hours under a nitrogen atmosphere, while removing water using a water separator. The mixture was cooled to 55°C, and 4g of 5wt% sodium carbonate aqueous solution was slowly added. After stirring until homogeneous, the mixture was poured into a separatory funnel and allowed to stand for separation. The lower aqueous phase was removed, and the mixture was washed four times with deionized water. 6.5g of anhydrous magnesium sulfate was added and the mixture was dried for 25 minutes. The mixture was filtered and vacuum distilled at 90°C for 80 minutes to obtain a fatty acid ester solution.

[0067] 95g of fatty acid ester solution and 1g of pyridinium-based polyester hollow capsule were mixed and magnetically stirred at 65℃ for 35min. 0.6g of catechol phosphonate nanoparticles were slowly added and magnetically stirred for 25min. The mixture was then cooled to 45℃ and ultrasonically treated for 12min. After standing and degassing, diesel anti-wear agent was obtained.

[0068] It should be understood that the diesel anti-wear agent prepared in this invention is a fatty acid ester type diesel anti-wear agent.

[0069] Example 6

[0070] 6.0 g of diisooctyl maleate and 90 g of xylene were mixed and dissolved by stirring at 35 °C. 3 g of diethylenetriamine and 50 g of deionized water were added, and the mixture was reacted at 35 °C for 4 h. After filtration and washing with deionized water, the mixture was dried under vacuum at 60 °C and dispersed in 50 g of toluene. 1.5 g of 4-(aminomethyl)pyridine was added, and the mixture was reacted at 60 °C for 3 h. After cooling to room temperature, 1.2 g of ethylene oxide was added, and phosphoric acid was added to adjust the pH to 4. The mixture was reacted at 60 °C for 2 h, filtered, and dried to obtain pyridinium-based polyester hollow capsules.

[0071] 90g xylene, 1.2g catechol, 0.8g ethylenephosphonic acid, and 0.1g ammonium persulfate were added to 30g deionized water and reacted at 35℃ for 3h. After filtration and washing with deionized water, the mixture was vacuum dried at 60℃ and dispersed in 50g cyclohexane. Then, 0.25g polyvinyl alcohol, 0.6g octadecyl methacrylate, and 0.05g azobisisobutyronitrile were added, and the mixture was reacted at 80℃ for 2h. After filtration and drying, catechol phosphonate nanoparticles were obtained.

[0072] 55g of oleic acid, 35g of 2-ethylhexanol, 0.8g of p-toluenesulfonic acid, and 90g of xylene were added to a three-necked flask. The mixture was refluxed at 140℃ for 6 hours under a N2 atmosphere, while removing water using a water separator. The mixture was cooled to 60℃, and 4.5g of 5wt% sodium carbonate aqueous solution was slowly added. After stirring until homogeneous, the mixture was poured into a separatory funnel, allowed to stand for separation, and the lower aqueous phase was removed. The mixture was washed 5 times with deionized water, dried for 30 minutes with 8g of anhydrous magnesium sulfate, filtered, and vacuum distilled at 100℃ for 90 minutes to obtain a fatty acid ester solution.

[0073] 100g of fatty acid ester solution and 1.5g of pyridinium-based polyester hollow capsules were mixed and magnetically stirred at 70℃ for 40min. 1g of catechol phosphonate nanoparticles were slowly added and magnetically stirred for 30min. The mixture was then cooled to 50℃ and ultrasonically treated for 15min. After standing and degassing, diesel anti-wear agent was obtained.

[0074] It should be understood that the diesel anti-wear agent prepared in this invention is a fatty acid ester type diesel anti-wear agent.

[0075] The present invention also includes comparative examples and related experiments.

[0076] Comparative Example 1

[0077] The only difference from Example 1 is that in step S3, pyridinium-based polyester hollow capsules were not added. The other components and preparation steps are completely the same, and a diesel anti-wear agent is obtained.

[0078] Comparative Example 2

[0079] The only difference from Example 1 is that 4-(aminomethyl)pyridine was not added in step S1. The other components and preparation steps are completely the same, and a diesel anti-wear agent is obtained.

[0080] Comparative Example 3

[0081] The only difference from Example 1 is that in step S3, catechol phosphonate nanoparticles were not added. The other components and preparation steps are completely the same, and a diesel anti-wear agent is obtained.

[0082] Comparative Example 4

[0083] The only difference from Example 1 is that catechins were not added in step S2, while the other components and preparation steps were completely the same, resulting in a diesel anti-wear agent.

[0084] The performance of the diesel anti-wear agents prepared in Examples 1-6 and Comparative Examples 1-4 was tested. Lubricity was tested according to standard Q / SHCG 57-2017 "Technical Requirements for Diesel Anti-wear Agents"; acid value and pour point were tested according to NB / SH / T 6074-2023 "Diesel Anti-wear Agents". The test results are shown in Table 1.

[0085] The demulsification performance was tested using the following method: 200g of ultra-low sulfur diesel oil, 2g of diesel anti-wear agent, and 2g of deionized water were mixed and magnetically stirred at 800rpm for 5 minutes, then allowed to stand for 10 minutes. The condition of the diesel oil was observed. If the diesel oil was clear and transparent, it indicated that the demulsification performance of the diesel anti-wear agent was good; if the diesel oil was semi-transparent or opaque, it indicated that the demulsification performance of the diesel anti-wear agent was poor. The test results are shown in Table 1.

[0086] Table 1

[0087]

[0088] As shown in Table 1, compared with Examples 4-6, Examples 1-3, due to the addition of oleoyl fluorocarbon copolymer, have fluorocarbon chains that can repel water molecules at the oil-water interface, disrupting the wetting stability of water droplets in the oil phase and preventing the formation of a stable emulsion film. At the same time, the oleoyl chains are compatible with and entangled with the hydrocarbon chains of fatty acid ester solution molecules, making the copolymer uniformly dispersed in the oil phase, thereby improving the demulsification performance of the diesel anti-wear agent.

[0089] Furthermore, as shown in Table 1, the acid values ​​of the diesel anti-wear agents in Examples 1 to 6 are in the range of 0.79 to 0.86 mg / g, all of which meet the requirement of ≤1.0 mg / g as required by standard NB-SH-T6074-2023; moreover, the pour points are in the range of -31 to -34℃, which meets the requirement of ≤-16℃ as required by standard NB-SH-T6074-2023. This indicates that the diesel anti-wear agent of the present invention not only has a low risk of corrosion, but also maintains good reliability in low-temperature environments.

[0090] Compared to Comparative Example 1, Example 1 introduced a pyridinium-based polyester hollow capsule. Its hollow "soft particle" structure acts as a buffer during friction, and its long-chain hydrocarbons entangle with the hydrocarbon chains of fatty acid ester molecules. Furthermore, the pyridinium groups synergistically interact with the metal surface, thereby improving the wear resistance. The wear resistance test results of Example 1 are shown below. Figure 1 However, the absence of this hollow bladder in Comparative Example 1 resulted in a decrease in the anti-wear properties of the diesel anti-wear agent.

[0091] Compared to Comparative Example 2, Example 1 grafted 4-(aminomethyl)pyridine onto the surface of the hollow capsule to form a pyridinium group, giving it strong polarity. This allows it to interact synergistically with the metal surface, enhancing the adhesion and uniformity of the lubricating film, thereby improving its anti-wear performance. In contrast, Comparative Example 2 did not introduce 4-(aminomethyl)pyridine, resulting in decreased adhesion of the lubricating film and reduced anti-wear performance of the diesel anti-wear agent.

[0092] Compared to Comparative Example 3, Example 1 added catechol phosphonate nanoparticles. The catechol groups on the surface of these nanoparticles can form complex bonds with the metal oxide layer, and the phosphonate groups enhance the adhesion of the lubricating film through chemical adsorption, making the lubricating film more stable and thus improving its anti-wear performance. In contrast, Comparative Example 3 lacked catechol phosphonate nanoparticles, resulting in weaker adhesion of the lubricating film and reduced anti-wear performance of the diesel anti-wear agent.

[0093] Compared to Comparative Example 4, Example 1, by introducing catechol, can form complex bonds with the metal surface, enhancing the adhesion and stability of the lubricating film layer, thereby improving the anti-wear properties of the diesel anti-wear agent. Comparative Example 4, lacking catechol, suffers from reduced bonding between the diesel anti-wear agent and the metal surface, resulting in decreased anti-wear performance.

[0094] The above are preferred embodiments of the present invention. Those skilled in the art can make several improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a diesel anti-wear agent, characterized in that, Includes the following steps: S1. Diisooctyl maleate and xylene are mixed and stirred at 30-35°C. Diethylenetriamine and deionized water are added, and the mixture is reacted at 30-35°C for 3-4 hours. The mixture is then filtered, washed, and dried under vacuum at 50-60°C. It is dispersed in toluene, and 4-(aminomethyl)pyridine is added. The mixture is reacted at 50-60°C for 1-3 hours. After cooling, ethylene oxide is added, and the pH is adjusted to 3.5-4. The mixture is reacted at 50-60°C for 1-2 hours. After filtration and drying, pyridinium-based polyester hollow capsules are obtained, wherein, by weight: diisooctyl maleate 5-6 parts, xylene 86.7-90 parts, diethylenetriamine 2.5-3 parts, toluene 40-50 parts, 4-(aminomethyl)pyridine 1.0-1.5 parts, and ethylene oxide 0.8-1.2 parts. S2. Xylene, catechol, ethylenephosphonic acid, and ammonium persulfate are added to deionized water and reacted at 25-35℃ for 2-3 hours. After filtration and washing, the mixture is vacuum dried at 50-60℃ and dispersed in cyclohexane. Polyvinyl alcohol, octadecyl methacrylate, and azobisisobutyronitrile are added and reacted at 60-80℃ for 1-2 hours. After filtration and drying, catechol phosphonate nanoparticles are obtained. The contents, by weight, are: xylene 80-90 parts, catechol 0.8-1.2 parts, ethylenephosphonic acid 0.4-0.8 parts, ammonium persulfate 0.05-0.1 parts, cyclohexane 40-50 parts, polyvinyl alcohol 0.15-0.25 parts, octadecyl methacrylate 0.3-0.6 parts, and azobisisobutyronitrile 0.02-0.05 parts. S3. Mix the fatty acid ester solution and pyridinium-based polyester hollow capsules, stir at 60-70℃ for 30-40 min, add catechol phosphonate nanoparticles, continue stirring for 20-30 min, cool to 40-50℃, sonicate for 10-15 min, let stand to degas, and obtain the diesel anti-wear agent. The composition, by weight, is: 0.5-1.5 parts of pyridinium-based polyester hollow capsules, 0.3-1.0 parts of catechol phosphonate nanoparticles, and 90-100 parts of fatty acid ester solution.

2. The method for preparing a diesel anti-wear agent according to claim 1, characterized in that, In step S3, an oleoyl fluorocarbon copolymer was added before continuous stirring. The oleoyl fluorocarbon copolymer was prepared by copolymerizing 2-hydroxyethyl acrylate with fluorocarbon acrylate and then grafting it with oleoyl chloride.

3. The method for preparing a diesel anti-wear agent according to claim 2, characterized in that, The oleoyl fluorocarbon copolymer is prepared by dissolving fluorocarbon acrylate and 2-hydroxyethyl acrylate in xylene, adding azobisisobutyronitrile, reacting at 65-75°C for 3-4 hours, cooling, adding oleoyl chloride and triethylamine, reacting at 40-50°C for 1-2 hours, precipitating with anhydrous ethanol, filtering, and vacuum drying at 50-60°C.

4. The method for preparing a diesel anti-wear agent according to claim 1, characterized in that, The preparation of the fatty acid ester solution comprises the following raw materials in parts by weight: 50-55 parts oleic acid, 31-35 parts 2-ethylhexanol, 0.5-0.8 parts p-toluenesulfonic acid, 85-90 parts xylene, 3-4.5 parts 5wt% sodium carbonate aqueous solution, and 5-8 parts anhydrous magnesium sulfate.

5. The method for preparing a diesel anti-wear agent according to claim 1, characterized in that, The diesel anti-wear agent also contains an oleoyl fluorocarbon copolymer, which is prepared by the following parts by weight of raw materials: 0.8-1.2 parts of fluorocarbon acrylate, 1-1.5 parts of 2-hydroxyethyl acrylate, 0.05-0.08 parts of azobisisobutyronitrile, 0.8-1.2 parts of oleoyl chloride, and 1-1.5 parts of triethylamine.

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