Phosphorus-boron-containing water-soluble unsaturated esters, processes for their preparation, polymeric lubricants, processes for their preparation and use

Abstract

This invention relates to the field of organic synthesis technology, and particularly to phosphorus-boron-containing water-soluble unsaturated esters and their preparation methods, as well as polymeric lubricants and their preparation processes and applications. The preparation method of the water-soluble unsaturated ester includes: mixing 2-aminoethyl (meth)acrylate hydrochloride, formylphenylboronic acid, and an alkaline catalyst, then adding dimethyl (ethyl) phosphite and mixing again, reacting at 60–80°C for 4–5 h, filtering the resulting reaction solution to obtain a filtrate; adding an alkanolamine compound to the filtrate, reacting at 60–100°C for 3–6 h, and vacuum drying the resulting solid product to obtain a phosphorus-boron-containing water-soluble unsaturated ester. Its nitrogen-containing borate ester structure can effectively improve the dispersion and extreme pressure anti-wear properties of the lubricant. The water-soluble polymeric lubricant of this invention incorporates phosphorus-boron-containing water-soluble unsaturated esters and other unsaturated ester monomers into its molecular structure, further enhancing the lubricating effect of the water-soluble polymeric lubricant.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, and in particular to phosphorus-boron-containing water-soluble unsaturated esters and their preparation methods, polymeric lubricants and their preparation processes and applications. Background Technology

[0002] In the industrial manufacturing sector, lubricants play a crucial role in reducing equipment friction and wear, minimizing mechanical damage, and improving energy and production efficiency. While widely used oil-based lubricants offer good lubrication, their poor cooling performance, flammability, tendency to carbonize, difficulty in cleaning, and environmental pollution are becoming increasingly prominent issues. With increasingly stringent environmental and energy-saving requirements, water-based lubricants, due to their superior cooling properties, high safety, and environmental friendliness, are gradually becoming an important choice in metal processing, stamping, and hydraulic systems.

[0003] However, traditional water-based lubricants still face significant challenges: on the one hand, to improve their dispersion stability and corrosion resistance, various additives are often required, leading to complex formulations, increased costs, and cumbersome processes; on the other hand, some formulations contain esters, greases, and graphite, which are prone to carbonization, making them difficult to treat and causing secondary pollution to the environment after discharge. These factors restrict the further promotion and application of water-based lubricants. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide phosphorus-boron-containing water-soluble unsaturated esters and their preparation methods, polymeric lubricants and their preparation processes and applications. Phosphorus-boron-containing water-soluble unsaturated esters can effectively improve the dispersion and extreme pressure anti-wear properties of lubricants; polymeric lubricants have advantages such as strong lubrication performance, good water dispersion stability, and green and environmentally friendly preparation processes.

[0005] The following is a summary of this disclosure to provide a basic understanding of some aspects. This summary is not intended to identify key or important elements, nor is it intended to limit the implementation or any aspects of the claims. Furthermore, this summary provides a simplified overview of some aspects that can be described in more detail in other parts of this disclosure.

[0006] The present invention solves the above-mentioned technical problems through the following technical means:

[0007] In a first aspect, embodiments of the present invention disclose a phosphorus-boron-containing water-soluble unsaturated ester, the structural formula of which is as follows:

[0008]

[0009] Wherein, R1 is hydrogen or methyl, R2 is methyl or ethyl, R3 is selected from one of hydrogen, methyl, ethyl, phenyl, hydroxyethyl, hydroxypropyl, 3-aminopropyl, and R4 is hydrogen or methyl.

[0010] Secondly, embodiments of the present invention also disclose a method for preparing the phosphorus-boron-containing water-soluble unsaturated ester described in the first aspect, comprising the following steps:

[0011] 2-Aminoethyl (meth)acrylate hydrochloride, formylphenylboronic acid and alkaline catalyst are mixed, and then dimethyl phosphite or diethyl phosphite is added and mixed. The mixture is reacted at 60-80℃ for 4-5 hours. The resulting reaction solution is filtered to remove the precipitate and obtain the filtrate.

[0012] An alcoholic amine compound was added to the filtrate and reacted at 60–100 °C for 3–6 h. The resulting solid product was dried under vacuum to obtain a water-soluble unsaturated ester containing phosphorus and boron.

[0013] In conjunction with the second aspect, in some embodiments, the molar ratio of 2-aminoethyl (meth)acrylate hydrochloride, formylphenylboronic acid, dimethyl (ethyl) phosphite, alkaline catalyst, and alkanolamine compound is (1.00–1.10):1:1:1.15:1, or the molar ratio of 2-aminoethyl (meth)acrylate hydrochloride, formylphenylboronic acid, diethyl phosphite, alkaline catalyst, and alkanolamine compound is (1.00–1.10):1:1:1.15:1.

[0014] In conjunction with the second aspect, in some embodiments, the formylphenylboronic acid is selected from at least one of 2-formylphenylboronic acid, 3-formylphenylboronic acid, and 4-formylphenylboronic acid; and / or,

[0015] The alkaline catalyst is selected from at least one of trimethylamine, triethylamine, and 4-dimethylaminopyridine; and / or,

[0016] The amine compound is selected from at least one of diethanolamine, triethanolamine, diisopropanol, triisopropanolamine, diethanol monoisopropanolamine, monoethanol diisopropanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N-phenyldiethanolamine, and N-(3-aminopropyl)diethanolamine.

[0017] Thirdly, embodiments of the present invention disclose a polymeric lubricant comprising the water-soluble unsaturated ester described in the first or second aspect.

[0018] In conjunction with the third aspect, in some embodiments, the polymeric lubricant further includes polyether macromonomers, unsaturated acids, unsaturated ester compounds, chain transfer agents, oxidants, reducing agents, and pH adjusters, wherein the molar ratio of the polyether macromonomers, unsaturated acids, water-soluble unsaturated esters, unsaturated ester compounds, chain transfer agents, oxidants, reducing agents, and pH adjusters is 1:(0.5-1.5):(1.0-3.0):(0.5-2.0):(0.2-0.5):(0.1-0.3):(0.02-0.04):(0.5-1.5).

[0019] In conjunction with the third aspect, in some embodiments, the molecular weight of the polyether macromonomer is 300 to 6000, and the polyether macromonomer is selected from at least one of polyethylene glycol monomethyl ether methacrylate, isobutylenyl polyoxyethylene ether, isopentenyl polyoxyethylene ether, vinyl polyethylene glycol ether, and ethyleneoxybutyl polyethylene glycol ether; and / or,

[0020] The unsaturated acid is selected from at least one of acrylic acid, methacrylic acid, maleic anhydride, itaconic acid, and fumaric acid; and / or,

[0021] The unsaturated ester compound is selected from at least one of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate and hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, 2-hydroxy-2-butyl acrylate, 2-hydroxy-2-methacrylate, 2-(dimethylamino)ethyl methacrylate, 2-(diethylamino)ethyl methacrylate, and 2-(diisopropylamino)ethyl methacrylate.

[0022] In conjunction with the third aspect, in some embodiments, the chain transfer agent is selected from at least one of sodium hypophosphite, mercaptoethanol, mercaptoacetic acid, and mercaptopropionic acid; and / or,

[0023] The oxidant is selected from at least one of hydrogen peroxide, ammonium persulfate, sodium persulfate, and potassium persulfate; and / or,

[0024] The reducing agent is selected from at least one of sodium formaldehyde sulfoxylate and L-ascorbic acid; and / or,

[0025] The pH adjuster is selected from at least one of sodium hydroxide, potassium hydroxide, diethanolamine, and triethanolamine.

[0026] Fourthly, the present invention also discloses a preparation process for the polymeric lubricant described in the third aspect, comprising the following steps:

[0027] Unsaturated acid, unsaturated ester compound, water-soluble unsaturated ester and water are mixed to obtain a first mixture; reducing agent and water are mixed to obtain a second mixture.

[0028] The polyether macromonomer, oxidant, chain transfer agent, and water are added to a reaction vessel and stirred to dissolve. The oxidant is then added and stirred. The first and second mixtures are added dropwise. After the addition is complete, the temperature of the reaction vessel is controlled at 10–80°C and the reaction is maintained at this temperature for 0.5–6 hours. A pH adjuster is added to adjust the pH to 7–8 to obtain a polymeric lubricant.

[0029] Fifthly, the present invention also discloses the application of the polymeric lubricant described in the third or fourth aspect in metalworking fluids, hydraulic fire-retardant fluids, and oil drilling and production.

[0030] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0031] (1) The phosphorus-boron-containing water-soluble unsaturated ester provided by the present invention introduces nitrogen-containing borate ester groups into the molecular structure of the unsaturated ester, which can improve the water solubility of the unsaturated ester and facilitate the synthesis of water-soluble polymer lubricants in water media. The nitrogen-containing borate ester structure can effectively improve the dispersion and extreme pressure anti-wear performance of the lubricant.

[0032] (2) The phosphorus-boron-containing water-soluble unsaturated ester provided by the present invention introduces phosphate ester groups into the molecular structure and is used in the synthesis of water-soluble polymer lubricants. This can change the molecular structure of the side chain of the water-soluble polymer lubricant molecule, so that the water-soluble polymer lubricant molecule can be quickly adsorbed on the surface of the metal workpiece to form a lubricating film, thereby realizing the lubrication performance of the water-soluble polymer lubricant.

[0033] (3) The water-soluble polymeric lubricant of the present invention has introduced phosphorus-boron-containing water-soluble unsaturated esters and other unsaturated ester monomers into its molecular structure, which further improves the lubrication effect of the water-soluble polymeric lubricant.

[0034] (4) The preparation process of the phosphorus-boron water-soluble unsaturated ester of the present invention is simple, easy to operate, pollution-free, and the equipment used is conventional equipment with low energy consumption, short production cycle, and easy to realize large-scale mass production.

[0035] (5) The water-soluble polymeric lubricant involved in this invention has excellent performance, with advantages such as strong lubrication properties, good water dispersion stability, and a green and environmentally friendly preparation process. It is expected to be used as a novel water-based lubricating additive in fields such as metal processing fluids, hydraulic fire-retardant fluids, and oil drilling and production. Attached Figure Description

[0036] Figure 1 This is the structural formula of the phosphorus-boron-containing water-soluble unsaturated ester of the present invention. Detailed Implementation

[0037] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0038] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0039] The structural formula of the water-soluble unsaturated ester of the present invention is as follows: Figure 1 As shown, Figure 1 In this context, R1 is hydrogen or methyl, R2 is methyl or ethyl, R3 is selected from one of hydrogen, methyl, ethyl, phenyl, hydroxyethyl, hydroxypropyl, and 3-aminopropyl, and R4 is hydrogen or methyl.

[0040] The polymeric lubricant of the present invention comprises the above-mentioned water-soluble unsaturated ester, as well as polyether macromonomer, unsaturated acid, unsaturated ester compound, chain transfer agent, oxidant, reducing agent and pH adjuster. The molar ratio of polyether macromonomer, unsaturated acid, water-soluble unsaturated ester, unsaturated ester compound, chain transfer agent, oxidant, reducing agent and pH adjuster is 1: (0.5~1.5): (1.0~3.0): (0.5~2.0): (0.2~0.5): (0.1~0.3): (0.02~0.04): (0.5~1.5). The polyether macromonomer has a molecular weight of 300–6000 and is selected from at least one of polyethylene glycol monomethyl ether methacrylate, isobutylene alcohol polyoxyethylene ether, isopentenyl alcohol polyoxyethylene ether, vinyl polyethylene glycol ether, and vinyloxybutyl polyethylene glycol ether. The unsaturated acid is selected from at least one of acrylic acid, methacrylic acid, maleic anhydride, itaconic acid, and fumaric acid. The unsaturated ester compound is selected from hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate and hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, and 2-hydroxy-2-propyl methacrylate. The formula includes at least one of butyl acrylate, butyl 2-hydroxy-2-methacrylate, ethyl 2-(dimethylamino)methacrylate, ethyl 2-(diethylamino)methacrylate, and ethyl 2-(diisopropylamino)methacrylate; a chain transfer agent selected from at least one of sodium hypophosphite, mercaptoethanol, mercaptoacetic acid, and mercaptopropionic acid; an oxidizing agent selected from at least one of hydrogen peroxide, ammonium persulfate, sodium persulfate, and potassium persulfate; a reducing agent selected from at least one of sodium formaldehyde sulfoxylate and L-ascorbic acid; and a pH adjuster selected from at least one of sodium hydroxide, potassium hydroxide, diethanolamine, and triethanolamine.

[0041] Example 1

[0042] This embodiment prepared a water-soluble unsaturated ester containing phosphorus and boron, and the preparation method is as follows:

[0043] Add 1000 mL of anhydrous ethanol to a clean reaction vessel, then add 165.6 g of 2-aminoethyl methacrylate hydrochloride, 150 g of 4-formylphenylboronic acid, and 116.4 g of triethylamine. Stir and dissolve completely to obtain a mixed solution. Add 110 g of dimethyl phosphite dropwise to the mixed solution, maintaining the temperature at 60 °C for 4 hours to obtain a reaction solution. Filter to remove the white precipitate to obtain a light yellow filtrate. Then add 120 g of N-methyldiethanolamine to the filtrate, maintaining the temperature at 70 °C for 3 hours to obtain a light brown liquid. Remove the ethanol by rotary evaporation to obtain a light brown solid. Vacuum dry to obtain a light brown solid powder, which is the phosphorus-boron-containing water-soluble unsaturated ester, designated PAB-1, with the following chemical structural formula:

[0044]

[0045] Example 2

[0046] This embodiment prepared a water-soluble unsaturated ester containing phosphorus and boron, and the preparation method is as follows:

[0047] Add 1000 mL of anhydrous ethanol to a clean reaction vessel, then add 165.6 g of 2-aminoethyl methacrylate hydrochloride, 150 g of 4-formylphenylboronic acid, and 116.4 g of triethylamine. Stir and dissolve completely to obtain a mixed solution. Add 138.1 g of diethyl phosphite dropwise to the mixed solution, maintaining the temperature at 60℃ for 4 hours to obtain a reaction solution. Filter to remove the white precipitate to obtain a light yellow filtrate. Then add 150 g of triethanolamine to the filtrate, maintaining the temperature at 70℃ for 3 hours to obtain a light brown liquid. Remove the ethanol by rotary evaporation to obtain a light brown solid. Vacuum dry to obtain a light brown solid powder, which is the phosphorus-boron-containing water-soluble unsaturated ester, designated PAB-2, with the following chemical structural formula:

[0048]

[0049] Example 3

[0050] This embodiment prepared a water-soluble unsaturated ester containing phosphorus and boron, and the preparation method is as follows:

[0051] Add 1000 mL of anhydrous ethanol to a clean reaction vessel, then add 165.6 g of 2-aminoethyl methacrylate hydrochloride, 150 g of 4-formylphenylboronic acid, and 116.4 g of triethylamine. Stir and dissolve completely to obtain a mixed solution. Add 138.1 g of diethyl phosphite dropwise to the mixed solution, maintaining the temperature at 60℃ for 4 hours to obtain a reaction solution. Filter to remove the white precipitate to obtain a light yellow filtrate. Then add 192.3 g of triisopropanolamine to the filtrate, maintaining the temperature at 70℃ for 3 hours to obtain a light brown liquid. Remove the ethanol by rotary evaporation to obtain a light brown solid. Vacuum dry to obtain a light brown solid powder, which is the phosphorus-boron-containing water-soluble unsaturated ester, designated PAB-3, with the following chemical structure:

[0052]

[0053] Example 4

[0054] This embodiment prepared a water-soluble unsaturated ester containing phosphorus and boron, and the preparation method is as follows:

[0055] Add 1000 mL of anhydrous ethanol to a clean reaction vessel, then add 165.6 g of 2-aminoethyl methacrylate hydrochloride, 150 g of 4-formylphenylboronic acid, and 116.4 g of triethylamine. Stir and dissolve completely to obtain a mixed solution. Add 138.1 g of diethyl phosphite dropwise to the mixed solution, maintaining the temperature at 60℃ for 4 hours to obtain a reaction solution. Filter to remove the white precipitate to obtain a light yellow filtrate. Then add 162.3 g of N-(3-aminopropyl)diethanolamine to the filtrate, maintaining the temperature at 70℃ for 3 hours to obtain a light brown liquid. Remove the ethanol by rotary evaporation to obtain a light brown solid. Vacuum dry to obtain a light brown solid powder, which is a water-soluble unsaturated ester containing phosphorus and boron, denoted as PAB-4, and its chemical structure is as follows:

[0056]

[0057] Example 5

[0058] This embodiment prepared a water-soluble unsaturated ester containing phosphorus and boron, and the preparation method is as follows:

[0059] Add 1000 mL of anhydrous ethanol to a clean reaction vessel, then add 197.4 g of 2-aminoethyl methacrylate hydrochloride, 150 g of 3-formylphenylboronic acid, and 122.2 g of 3-dimethylaminopyridine. Stir and dissolve completely to obtain a mixed solution. Add 110 g of dimethyl phosphite dropwise to the mixed solution and maintain the temperature at 60 °C for 5 h to obtain a reaction solution. Filter to remove the white precipitate to obtain a light yellow filtrate. Then add 120 g of N-methyldiethanolamine to the filtrate and maintain the temperature at 100 °C for 3 h to obtain a light brown liquid. Remove the ethanol by rotary evaporation to obtain a light brown solid. Dry under vacuum to obtain a light brown solid powder, which is the phosphorus-boron-containing water-soluble unsaturated ester.

[0060] The chemical structural formula of the phosphorus-boron-containing water-soluble unsaturated ester in this embodiment is as follows:

[0061]

[0062] Example 6

[0063] This embodiment prepared a water-soluble unsaturated ester containing phosphorus and boron, and the preparation method is as follows:

[0064] Add 1000 mL of anhydrous ethanol to a clean reaction vessel, then add 197.4 g of 2-aminoethyl methacrylate hydrochloride, 150 g of 2-formylphenylboronic acid, and 140.5 g of 2-dimethylaminopyridine. Stir and dissolve completely to obtain a mixed solution. Add 110 g of dimethyl phosphite dropwise to the mixed solution and maintain the temperature at 80 °C for 4.5 h to obtain a reaction solution. Filter to remove the white precipitate to obtain a light yellow filtrate. Then add 133.2 g of N-ethyldiethanolamine to the filtrate and maintain the temperature at 60 °C for 6 h to obtain a light brown liquid. Remove the ethanol by rotary evaporation to obtain a light brown solid. Dry under vacuum to obtain a light brown solid powder, which is the phosphorus-boron-containing water-soluble unsaturated ester.

[0065] The chemical structural formula of the phosphorus-boron-containing water-soluble unsaturated ester in this embodiment is as follows:

[0066]

[0067] Example 7

[0068] In this embodiment, the phosphorus-boron-containing water-soluble unsaturated ester (PAB-1) from Example 1 is used in a polymerization reaction to prepare a water-soluble polymeric lubricant. The preparation process is as follows:

[0069] Weigh 8g of acrylic acid, 12g of hydroxyethyl acrylate, 58g of PAB-1 and 10g of water, mix them evenly to obtain the first mixture; weigh 0.6g of L-ascorbic acid and 40g of water, mix them evenly to obtain the second mixture.

[0070] 310g of vinyl polyethylene glycol ether (VPEG) with a molecular weight of 3000, 4.4g of sodium hypophosphite, and 350g of water were added to a reaction vessel and stirred to dissolve. The initial temperature inside the reaction vessel was controlled at 15℃. 2.5g of 27.5% hydrogen peroxide solution was added to the reaction solvent all at once. After stirring for 5 minutes, the first and second mixtures were added dropwise. The first mixture was added dropwise over 35 minutes, and the second mixture over 45 minutes. After the second mixture was added, the reaction was maintained at 15℃ for 60 minutes. Triethanolamine was then added to adjust the pH to 7-8, and water was added to adjust the lubricant concentration, resulting in a water-soluble polymeric lubricant, denoted as WPL-1, with a solid content controlled at 40%. Its structural formula is as follows:

[0071]

[0072] Example 8

[0073] In this embodiment, the phosphorus-boron-containing water-soluble unsaturated ester (PAB-2) from Example 2 is used in a polymerization reaction to prepare a water-soluble polymeric lubricant. The preparation process is as follows:

[0074] Weigh 8g of acrylic acid, 12g of hydroxyethyl acrylate, 62.7g of PAB-2 and 10g of water, mix them evenly to obtain the first mixture; weigh 0.6g of L-ascorbic acid and 40g of water, mix them evenly to obtain the second mixture.

[0075] 310g of vinyl polyethylene glycol ether (VPEG) with a molecular weight of 3000, 4.4g of sodium hypophosphite, and 350g of water were added to a reaction vessel and stirred to dissolve. The initial temperature inside the reaction vessel was controlled at 15℃. 2.5g of 27.5% hydrogen peroxide solution was added to the reaction solvent all at once. After stirring for 5 minutes, the first and second mixtures were added dropwise. The first mixture was added dropwise over 35 minutes, and the second mixture over 45 minutes. After the second mixture was added, the reaction was maintained at 15℃ for 60 minutes. Triethanolamine was then added to adjust the pH to 7-8, and water was added to adjust the lubricant concentration, resulting in a water-soluble polymeric lubricant, denoted as WPL-2, with a solid content controlled at 40%. Its structural formula is as follows:

[0076]

[0077] Example 9

[0078] In this embodiment, the phosphorus-boron-containing water-soluble unsaturated ester (PAB-3) from Example 3 is used in a polymerization reaction to prepare a water-soluble polymeric lubricant. The preparation process is as follows:

[0079] Weigh 8g of acrylic acid, 12g of hydroxyethyl acrylate, 69.4g of PAB-3 and 10g of water, mix them evenly to obtain the first mixture; weigh 0.6g of L-ascorbic acid and 40g of water, mix them evenly to obtain the second mixture.

[0080] 310g of vinyl polyethylene glycol ether (VPEG) with a molecular weight of 3000, 4.4g of sodium hypophosphite, and 350g of water were added to a reaction vessel and stirred to dissolve. The initial temperature inside the reaction vessel was controlled at 15℃. 2.5g of 27.5% hydrogen peroxide solution was added to the reaction solvent all at once. After stirring for 5 minutes, the first and second mixtures were added dropwise. The first mixture was added dropwise over 35 minutes, and the second mixture over 45 minutes. After the second mixture was added, the reaction was maintained at 15℃ for 60 minutes. Triethanolamine was then added to adjust the pH to 7-8, and water was added to adjust the lubricant concentration, resulting in a water-soluble polymeric lubricant, designated WPL-3, with a solid content of 40%. Its structural formula is as follows:

[0081]

[0082] Example 10

[0083] In this embodiment, the phosphorus-boron-containing water-soluble unsaturated ester (PAB-4) from Example 4 is used in a polymerization reaction to prepare a water-soluble polymeric lubricant. The preparation process is as follows:

[0084] Weigh 8g of acrylic acid, 12g of hydroxyethyl acrylate, 64.8g of PAB-4 and 10g of water, mix them evenly to obtain the first mixture; weigh 0.6g of L-ascorbic acid and 40g of water, mix them evenly to obtain the second mixture.

[0085] 310g of vinyl polyethylene glycol ether (VPEG) with a molecular weight of 3000, 4.4g of sodium hypophosphite, and 350g of water were added to a reaction vessel and stirred to dissolve. The initial temperature inside the reaction vessel was controlled at 15℃. 2.5g of 27.5% hydrogen peroxide solution was added to the reaction solvent all at once. After stirring for 5 minutes, the first and second mixtures were added dropwise. The first mixture was added dropwise over 35 minutes, and the second mixture over 45 minutes. After the second mixture was added, the reaction was maintained at 15℃ for 60 minutes. Triethanolamine was then added to adjust the pH to 7-8, and water was added to adjust the lubricant concentration, resulting in a water-soluble polymeric lubricant, designated WPL-4, with a solid content of 40%. Its structural formula is as follows:

[0086]

[0087] Comparative Example 1

[0088] The preparation process of the polymeric lubricant in this comparative example is as follows:

[0089] Weigh 8g of acrylic acid, 12g of hydroxyethyl acrylate, 24.6g of ethyl 2-(dimethylamino)methacrylate and 10g of water, mix them evenly to obtain the first mixture; weigh 0.6g of L-ascorbic acid and 40g of water, mix them evenly to obtain the second mixture.

[0090] 310g of vinyl polyethylene glycol ether (VPEG) with a molecular weight of 3000, 4.4g of sodium hypophosphite, and 350g of water were added to a reaction vessel and stirred to dissolve. The initial temperature inside the reaction vessel was controlled at 15℃. 2.5g of 27.5% hydrogen peroxide solution was added to the reaction solvent all at once. After stirring for 5 minutes, the first and second mixtures were added dropwise. The first mixture was added dropwise over 35 minutes, and the second mixture over 45 minutes. After the second mixture was added, the reaction was maintained at 15℃ for 60 minutes. Triethanolamine was then added to adjust the pH to 7-8, and water was added to adjust the lubricant concentration, resulting in a conventional water-soluble polymeric lubricant, denoted as D1, with a solid content of 40%. Its structural formula is as follows:

[0091]

[0092] Comparative Example 2

[0093] The preparation process of the polymeric lubricant in this comparative example is as follows:

[0094] Weigh 8g of acrylic acid, 12g of hydroxyethyl acrylate, 35.7g of 2-hydroxyethyl methacrylate phosphate and 10g of water, mix them evenly to obtain the first mixture; weigh 0.6g of L-ascorbic acid and 40g of water, mix them evenly to obtain the second mixture.

[0095] 310g of vinyl polyethylene glycol ether (VPEG) with a molecular weight of 3000, 4.4g of sodium hypophosphite, and 350g of water were added to a reaction vessel and stirred to dissolve. The initial temperature inside the reaction vessel was controlled at 15℃. 2.5g of 27.5% hydrogen peroxide solution was added to the reaction solvent all at once. After stirring for 5 minutes, the first and second mixtures were added dropwise. The first mixture was added dropwise over 35 minutes, and the second mixture over 45 minutes. After the second mixture was added, the reaction was maintained at 15℃ for 60 minutes. Triethanolamine was then added to adjust the pH to 7-8, and water was added to adjust the lubricant concentration, resulting in a conventional water-soluble polymeric lubricant, denoted as D2, with a solid content of 40%. Its structural formula is as follows:

[0096]

[0097] The water-soluble polymeric lubricants (WPL-1, WPL-2, WPL-3 and WPL-4) synthesized in Examples 7-10 and the water-soluble polymeric lubricants (D1 and D2) synthesized in Comparative Examples 1-2 were used as samples, and the following effect tests were conducted respectively.

[0098] (1) A lubrication comparison was made between the water-soluble polymer lubricants in the examples and the comparative examples.

[0099] The lubricating performance of the lubricant was tested using the SRV-V fretting and wear testing machine from Optimol Grease GmbH, Germany. This machine measures the change of frictional force over time and can measure the coefficient of friction under different speeds and forces. In this experiment, a ball-disc contact method was used. Both the GCr15 steel ball (10 mm in diameter) and the steel disk (24 mm in diameter, 7.9 mm in height) were pre-cleaned ultrasonically with petroleum ether and anhydrous ethanol, respectively. The friction pair employed a reciprocating motion. The experimental parameters were set as follows: frequency 25 Hz, amplitude 1 mm, load 100 N, ambient temperature 25 ℃, relative humidity 20%–40%, and test duration 30 min. The coefficient of friction was automatically recorded by computer during the test. After the test, the steel disk was cleaned again with anhydrous ethanol, and its wear volume was measured using a fully automated true-color confocal microscope.

[0100] Table 1. Test results of lubrication performance of the samples.

[0101]

[0102] As can be seen from the data in Table 1, at the same concentration, Examples 7-10 and Comparative Examples 1-2 exhibit lower coefficients of friction compared to pure water, indicating that the water-soluble polymeric lubricant of the present invention has excellent anti-friction properties. The lower coefficient of friction in Examples 7-10 compared to Comparative Examples 1-2 indicates that the simultaneous introduction of phosphate ester and nitrogen-containing borate ester structures into the structure of the water-soluble polymeric lubricant of the present invention significantly enhances its extreme pressure anti-wear properties. The wear volume data also show that, at the same concentration, Examples 7-10 and Comparative Examples 1-2 exhibit smaller wear volumes compared to pure water, indicating that the water-soluble polymeric lubricant of the present invention has excellent anti-wear properties. Compared to Comparative Example 1, Comparative Example 2 showed a 21.7% reduction in wear volume, indicating that introducing phosphate ester groups into the structure of the polymeric lubricant can improve its anti-wear performance. Compared to Comparative Example 2, Examples 7-10 showed a further reduction in wear volume of more than 42.2%, indicating that simultaneously introducing phosphate ester groups and nitrogen-containing borate ester groups into the structure of the polymeric lubricant can significantly improve its anti-wear performance, and has the effect of phosphorus-boron synergistic enhancement of lubrication performance.

[0103] (2) Hard water adaptability test of water-soluble polymeric lubricants in the examples and comparative examples.

[0104] The procedure was carried out in accordance with JB / T 7452-2013 "Semi-synthetic Cutting Fluids". 100 mL of the diluted solution (10%) was placed in a beaker, and at room temperature (15~35 ℃), a Ca ion concentration of 1000×10⁻⁶ was added. -6 100 mL of artificially hardened water was added, shaken well, and then visually inspected. Specific experimental data are shown in Table 2.

[0105] Table 2 Results of Hard Water Adaptability Test for Samples

[0106]

[0107] As can be seen from the data in Table 2, no flocculent matter or precipitate appeared in Examples 7-10 and Comparative Examples 1-2 of the present invention during the 24-hour hard water adaptability test, which indicates that the water-soluble polymeric lubricant of the present invention has excellent hard water resistance.

[0108] In summary, the water-soluble polymeric lubricant of this invention possesses excellent anti-friction, anti-wear, and hard water resistance properties. Therefore, the water-soluble polymeric lubricant of this invention can be applied in metalworking fluids, hydraulic fire-retardant fluids, and oil drilling and production.

[0109] The foregoing description includes examples from this specification. Of course, for the purposes of describing this specification, it is impossible to describe every conceivable combination of components or methods; however, those skilled in the art will understand that many other combinations and arrangements are possible. Therefore, this specification is intended to cover all such changes, modifications, and variations that fall within the spirit and scope of the appended claims. Furthermore, with regard to the use of the term "comprising" in the detailed description or claims, the term is intended to be inclusive in a manner similar to the term "including," as interpreted when "comprising" is used as a transitional word in the claims.

[0110] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A water-soluble unsaturated ester containing phosphorus and boron, characterized in that, The structural formula of the water-soluble unsaturated ester is as follows: Wherein, R1 is hydrogen or methyl, R2 is methyl or ethyl, R3 is selected from one of hydrogen, methyl, ethyl, phenyl, hydroxyethyl, hydroxypropyl, 3-aminopropyl, and R4 is hydrogen or methyl.

2. The method for preparing the phosphorus-boron-containing water-soluble unsaturated ester according to claim 1, characterized in that, Includes the following steps: 2-Aminoethyl (meth)acrylate hydrochloride, formylphenylboronic acid and alkaline catalyst are mixed, and then dimethyl phosphite or diethyl phosphite is added and mixed. The mixture is reacted at 60-80℃ for 4-5 hours. The resulting reaction solution is filtered to remove the precipitate and obtain the filtrate. An alcoholic amine compound was added to the filtrate and reacted at 60–100 °C for 3–6 h. The resulting solid product was dried under vacuum to obtain a water-soluble unsaturated ester containing phosphorus and boron.

3. The preparation method according to claim 2, characterized in that, The molar ratio of 2-aminoethyl (meth)acrylate hydrochloride, formylphenylboronic acid, dimethyl phosphite, alkaline catalyst, and alkanolamine compound is (1.00–1.10):1:1:1.15:1, or the molar ratio of 2-aminoethyl (meth)acrylate hydrochloride, formylphenylboronic acid, diethyl phosphite, alkaline catalyst, and alkanolamine compound is (1.00–1.10):1:1:1.15:

1.

4. The preparation method according to claim 2, characterized in that, The formylphenylboronic acid is selected from at least one of 2-formylphenylboronic acid, 3-formylphenylboronic acid, and 4-formylphenylboronic acid; and / or The alkaline catalyst is selected from at least one of trimethylamine, triethylamine, and 4-dimethylaminopyridine; and / or, The amine compound is selected from at least one of diethanolamine, triethanolamine, diisopropanol, triisopropanolamine, diethanol monoisopropanolamine, monoethanol diisopropanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N-phenyldiethanolamine, and N-(3-aminopropyl)diethanolamine.

5. A polymeric lubricant, characterized in that, Includes the water-soluble unsaturated esters as described in any one of claims 1-4.

6. The polymeric lubricant according to claim 5, characterized in that, The polymeric lubricant further includes polyether macromonomers, unsaturated acids, unsaturated ester compounds, chain transfer agents, oxidants, reducing agents, and pH adjusters. The molar ratio of the polyether macromonomers, unsaturated acids, water-soluble unsaturated esters, unsaturated ester compounds, chain transfer agents, oxidants, reducing agents, and pH adjusters is 1:(0.5-1.5):(1.0-3.0):(0.5-2.0):(0.2-0.5):(0.1-0.3):(0.02-0.04):(0.5-1.5).

7. The polymeric lubricant according to claim 6, characterized in that, The polyether macromonomer has a molecular weight of 300-6000, and is selected from at least one of polyethylene glycol monomethyl ether methacrylate, isobutylene alcohol polyoxyethylene ether, isopentenyl alcohol polyoxyethylene ether, vinyl polyethylene glycol ether, and ethylene oxybutyl polyethylene glycol ether; and / or, The unsaturated acid is selected from at least one of acrylic acid, methacrylic acid, maleic anhydride, itaconic acid, and fumaric acid; and / or, The unsaturated ester compound is selected from at least one of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate and hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, 2-hydroxy-2-butyl acrylate, 2-hydroxy-2-methacrylate, 2-(dimethylamino)ethyl methacrylate, 2-(diethylamino)ethyl methacrylate, and 2-(diisopropylamino)ethyl methacrylate.

8. The polymeric lubricant according to claim 6, characterized in that, The chain transfer agent is selected from at least one of sodium hypophosphite, mercaptoethanol, mercaptoacetic acid, and mercaptopropionic acid; and / or, The oxidant is selected from at least one of hydrogen peroxide, ammonium persulfate, sodium persulfate, and potassium persulfate; and / or, The reducing agent is selected from at least one of sodium formaldehyde sulfoxylate and L-ascorbic acid; and / or, The pH adjuster is selected from at least one of sodium hydroxide, potassium hydroxide, diethanolamine, and triethanolamine.

9. The preparation process of the polymeric lubricant according to claim 6, 7, or 8, characterized in that, Includes the following steps: Unsaturated acid, unsaturated ester compound, water-soluble unsaturated ester and water are mixed to obtain a first mixture; reducing agent and water are mixed to obtain a second mixture. The polyether macromonomer, oxidant, chain transfer agent, and water are added to a reaction vessel and stirred to dissolve. The oxidant is then added and stirred. The first and second mixtures are added dropwise. After the addition is complete, the temperature of the reaction vessel is controlled at 10–80°C and the reaction is maintained at this temperature for 0.5–6 hours. A pH adjuster is added to adjust the pH to 7–8 to obtain a polymeric lubricant.

10. The application of the polymeric lubricant according to claim 6, 7 or 8 in metalworking fluids, hydraulic fire-retardant fluids and oil drilling and production.

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