High-temperature-resistant polyester type lubricating oil and preparation method thereof

Abstract

The application discloses a high-temperature-resistant polyester type lubricating oil and a preparation method thereof, and belongs to the technical field of polyester type lubricating oils, and is used for solving the technical problems that the high-temperature resistance, flame resistance, oxidation resistance and wear resistance of the polyester type lubricating oil in the prior art need to be further improved, and specifically comprises the following components in parts by weight: 50-60 parts of polybutylene adipate, 10-20 parts of wear-resistant additives, 3-5 parts of dibutyl maleate, 2-3 parts of zinc dialkyldithiophosphate, 5-7 parts of reinforcing agents, 1-2 parts of antioxidants and 0.01-0.05 parts of dimethyl silicone oil. The high-temperature resistance, flame resistance, oxidation resistance and wear resistance of the polyester type lubricating oil are further improved by preparing the wear-resistant additives and the reinforcing agents.

Description

Technical Field

[0001] This invention relates to the field of polyester-based lubricating oil technology, and more specifically to a high-temperature resistant polyester-based lubricating oil and its preparation method. Background Technology

[0002] In modern industry and machinery operation, lubricating oil plays a vital role. Its performance directly affects the operating efficiency, lifespan, and safety of equipment. Polyester-based lubricating oil, as an important member of synthetic lubricating oils, has received much attention in recent years. Most traditional lubricants are based on mineral oil. However, mineral-based lubricating oils have poor biodegradability in the natural environment and tend to remain and accumulate over a long period of time, posing a threat to the ecological environment and human health. At the same time, as petroleum resources are gradually depleted and their prices continue to rise, people are actively exploring the use of renewable energy in the field of lubricants.

[0003] In existing technologies, ester-based lubricants are prone to degradation and coking at high temperatures, leading to lubrication failure and fire hazards. Taking steel strip oil as an example, its high-temperature resistance needs further improvement due to its single carboxyl group. It is easily oxidized to produce acidic sludge, which exacerbates equipment corrosion. The synergistic effect in terms of high-temperature resistance and flame retardancy still needs to be improved. Ultra-low viscosity oils in the transmissions of new energy vehicles are prone to wear and NVH problems. Therefore, the synergistic effect of common anti-wear additives and base oils also needs to be improved, leading to easy wear on metal surfaces and shortening equipment life. At the same time, lubricants are susceptible to oxidation and polymerization under the influence of oxygen, high temperature and metal catalysis during long-term use, resulting in performance degradation. Although traditional antioxidants have some effect, their synergistic effect with base oils and other components still needs to be improved, and they cannot effectively delay the aging process of lubricants, making it difficult to maintain long-term excellent performance.

[0004] In summary, developing a polyester-based lubricant with excellent high-temperature resistance, flame retardancy, wear resistance, and aging resistance, which can improve performance through the synergistic effect between components, is of great practical significance and urgent need. Therefore, a solution is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a high-temperature resistant polyester-based lubricating oil and its preparation method, in order to solve the technical problem that the high-temperature resistance, flame retardancy, oxidation resistance and anti-wear properties of polyester-based lubricating oil in the prior art need to be further improved.

[0006] The objective of this invention can be achieved through the following technical solution: a high-temperature resistant polyester lubricating oil, comprising the following components by weight: 50-60 parts polybutylene adipate, 10-20 parts wear-resistant additive, 3-5 parts dibutyl maleate, 2-3 parts zinc dialkyl dithiophosphate, 5-7 parts reinforcing agent, 1-2 parts antioxidant and 0.01-0.05 parts dimethyl silicone oil;

[0007] The antioxidant comprises, by weight, the following components: 0.5-1 part of 2,6-di-tert-butyl-p-cresol and 1-1.5 parts of phenyl-α-naphthylamine.

[0008] Furthermore, the preparation method of the wear-resistant additive is as follows: after ball milling the dispersant and graphite in a planetary ball mill for 1 hour, the mixture is added to a flask containing polydecene, stirred for 10-15 minutes, and then ultrasonically vibrated for 30-60 minutes to obtain the wear-resistant additive; the dispersant is polyisobutylene succinimide, and the ratio of the dispersant, graphite and polydecene is 1-2g:1g:40-60g.

[0009] Reaction principle:

[0010] The graphite particles are refined in polyisobutylene succinimide by the mechanical force of a planetary ball mill. At the same time, the polar groups of the dispersant are adsorbed on the newly formed graphite surface, and the non-polar segments extend outward to form steric hindrance. Then, it is added to polydecene and macroscopically mixed by stirring. The residual agglomerates are further broken down by the cavitation effect generated by ultrasonic vibration. Finally, the steric hindrance of the dispersant and the dispersing effect of ultrasound work together to make the graphite uniformly and stably dispersed in polydecene, thus obtaining a wear-resistant additive.

[0011] Furthermore, the preparation method of the reinforcing agent is as follows: olefin-modified cyclotriphosphazene, olefin-modified diphenylsilane, transfer agent and toluene are added to a three-hole caustic vessel. After stirring for 5-10 minutes under a nitrogen atmosphere at 40-50°C, an initiator is added every 10°C and reacted for 0.5-1 hours. This process is repeated until the temperature rises to 80°C, at which point the last batch of initiator is added and reacted for 0.5-1 hours. The temperature is then raised to 110-120°C and reacted for 5-6 hours. After post-treatment, the reinforcing agent is obtained.

[0012] Reaction principle:

[0013] In an olefin-modified cyclotriphosphazene and 1,10-decanediol methacrylate oxydiphenylsilane, under a nitrogen atmosphere, azobisisobutyronitrile (AIBN) was added in batches with staged heating to gradually initiate free radical polymerization of the carbon-carbon double bonds, forming a polymer with reinforcing properties. Dodecyl mercaptan was used as a chain transfer agent to adjust the polymer molecular weight. The temperature was then raised to 110-120°C to promote complete polymerization. The solvent toluene was removed by vacuum distillation, and the product was washed with anhydrous ethanol to remove impurities. Finally, the product was purified by silica gel filtration and vacuum dried to obtain a high molecular weight reinforcing agent.

[0014] Furthermore, the transfer agent is n-dodecyl mercaptan; the initiator is azobisisobutyronitrile; the ratio of the olefin-modified cyclotriphosphazene, olefin-modified diphenylsilane, transfer agent, toluene, and initiator is 10g:10g:0.5-0.8g:300-500mL:1-2g; the post-treatment is as follows: the solution is poured into a vacuum distillation apparatus, distilled at 70℃ for 1-2h, then transferred to anhydrous ethanol, stirred and washed at 60-70℃ for 20-30min, filtered, the product is then dissolved in petroleum ether, filtered with 100-200 mesh silica gel, and the filter residue is placed in a vacuum drying oven and dried at 70℃ for 3-4h.

[0015] Furthermore, the preparation method of the olefin-modified cyclotriphosphazene is as follows: 1,10-decanediol methacrylate and triethylamine are added to a three-necked flask containing tetrahydrofuran and mixed thoroughly. The mixture is then heated to 60-65°C, and a hexachlorocyclotriphosphazene solution is added dropwise. The mixture is refluxed for 24 hours and then post-treated to obtain the olefin-modified cyclotriphosphazene.

[0016] Reaction principle:

[0017]

[0018] The hydroxyl group in 1,10-decanediol methacrylate generates a nucleophilic alkoxy anion under the action of triethylamine. This anion undergoes an aromatic nucleophilic substitution reaction with the chlorine atom in hexachlorocyclotriphosphazene to form an ether bond. The reaction is carried out under reflux in tetrahydrofuran solvent at 60-65℃ for 24 hours to ensure complete reaction. The generated hydrogen chloride is neutralized by triethylamine to form triethylamine hydrochloride precipitate. After the solution turns brownish-red, the precipitate is removed by filtration, the solvent is removed by rotary evaporation, and the product is purified by ethyl acetate-water extraction and dried by rotary evaporation to obtain olefin-modified cyclotriphosphazene.

[0019] The mass spectrometry analysis data are as follows:

[0020] Elemental Analysis: C, 63.73; H, 9.55; N, 2.65; O, 18.19; P, 5.87

[0021] Furthermore, the ratio of triethylamine, tetrahydrofuran, and hexachlorocyclotriphosphazene solution is 19g:150-250mL:100mL, and the amount of 1,10-decanediol methacrylate added is 6.05 times the total chlorine in hexachlorocyclotriphosphazene; the hexachlorocyclotriphosphazene solution is obtained by dissolving 10g of hexachlorocyclotriphosphazene in 100mL of tetrahydrofuran; the post-treatment is as follows: after the solution color turns brownish-red, filter to remove the precipitate, transfer to a rotary evaporator, remove the solvent tetrahydrofuran at 60℃, then extract the crude product with ethyl acetate and water, and then transfer it to a rotary evaporator to dry at 65℃ for 24h.

[0022] Furthermore, the preparation method of the olefin-modified diphenylsilane is as follows: 1,10-decanediol methacrylate and triethylamine are added to a three-necked flask containing tetrahydrofuran and mixed thoroughly. Then, a diphenyl dichlorosilane solution is added dropwise at 0°C. After the addition is complete, the temperature is raised to 60°C and refluxed for 24 hours. After post-treatment, the olefin-modified diphenylsilane is obtained.

[0023] Reaction principle:

[0024]

[0025] The hydroxyl group in 1,10-decanediol methacrylate generates an alkoxy anion under the action of triethylamine. When diphenyldichlorosilane is added dropwise at 0°C, the alkoxy anion acts as a nucleophile and undergoes a nucleophilic substitution reaction with the chlorine atom in diphenyldichlorosilane to form a silicon-oxygen bond. Subsequently, the temperature is raised to 60°C and refluxed for 24 h to promote the complete reaction. Triethylamine combines with the hydrogen chloride generated in the reaction to form a triethylamine hydrochloride precipitate. After filtering to remove the precipitate, the solvent tetrahydrofuran is removed by rotary evaporation. After purification by ethyl acetate-water extraction and drying by rotary evaporation, olefin-modified diphenylsilane is obtained.

[0026] The mass spectrometry analysis data are as follows:

[0027] Elemental Analysis: C, 72.25; H, 9.09; O, 14.44; Si, 4.22

[0028] Furthermore, the ratio of triethylamine, tetrahydrofuran, and diphenyl dichlorosilane solution is 15g:100-200mL:100mL, and the amount of 1,10-decanediol methacrylate added is 2.05 times the total amount of silicon-chlorine bonds in diphenyl dichlorosilane; the diphenyl dichlorosilane solution is obtained by dissolving 15g of diphenyl dichlorosilane in 100mL of tetrahydrofuran; the post-treatment is as follows: after the reaction is completed, the precipitate is removed by filtration, the product is transferred to a rotary evaporator, the solvent is removed at 60℃, the crude product is extracted with ethyl acetate and water, and then transferred to a rotary evaporator and dried at 65℃ for 24h.

[0029] One method for preparing a high-temperature resistant polyester lubricating oil includes the following steps: adding polybutylene adipate, wear-resistant additives, and dibutyl maleate to a three-necked flask, stirring at 25-30°C for 15-20 minutes, raising the temperature to 40-50°C, adding zinc dialkyl dithiophosphate, antioxidants, and reinforcing agents, stirring for 30-40 minutes, finally cooling to 30-40°C, adding dimethyl silicone oil, stirring for 10-15 minutes, transferring to an ultrasonic homogenizer, sonicating for 20-30 minutes, and cooling to room temperature to obtain a high-temperature resistant polyester lubricating oil.

[0030] The present invention has the following beneficial effects:

[0031] 1. This invention introduces olefin-modified cyclotriphosphazene containing N=P and a cyclic structure, and olefin-modified diphenylsilane containing Si-O bonds and a benzene ring to form a reinforcing agent. The two work synergistically to construct a stable polymer network. N=P inhibits the combustion chain reaction through the flame-retardant mechanism of phosphorus, and the cyclic structure enhances molecular stability. The Si-O bond improves the system's high-temperature structural tolerance due to its high bond energy and chemical stability, and the benzene ring further strengthens molecular rigidity. The polymer network formed by the two can remain stable in high-temperature environments, providing core support for flame retardancy and high-temperature resistance. At the same time, the graphite in the wear-resistant additive, which is stably dispersed by a dispersant, enhances thermal stability with its high-temperature resistance properties, forming a synergistic thermal protection with the reinforcing agent. The antioxidant inhibits high-temperature oxidation and deterioration, reducing heat accumulation. The base oil and dibutyl maleate optimize interfacial compatibility to ensure the synergistic effect of each component, jointly hindering thermal decomposition and combustion reactions at high temperatures, significantly improving the high-temperature resistance and flame retardancy of the lubricating oil.

[0032] 2. The reinforcing agent formed by copolymerizing olefin-modified cyclotriphosphazene containing N=P and cyclic structures with olefin-modified diphenylsilane containing Si-O bonds and benzene rings of the present invention has polar molecular groups that can generate strong adsorption with metal surfaces, constructing a stable chemical adsorption layer; in the wear-resistant additive, polyisobutylene succinimide adsorbs graphite through polar groups, and non-polar segments are compatible with polydecene, so that graphite is uniformly dispersed and forms a physical lubrication layer at the friction interface, which reduces friction by interlayer sliding. The two are synergistic with the wear-resistant reaction film formed by zinc dialkyl dithiophosphate, and the combination of physical lubrication and chemical protection mechanisms isolates direct metal contact. The chemical activity of N=P and the structural stability of Si-O bonds are complementary. The base oil ensures that each component continuously acts on the friction interface, significantly improving the anti-wear performance of the lubricating oil.

[0033] 3. The present invention uses olefin-modified cyclotriphosphazene containing N=P and a cyclic structure to copolymerize with olefin-modified diphenylsilane containing Si-O bonds and a benzene ring to form a reinforcing agent. N=P can capture oxidative free radicals, and the cyclic structure delays molecular chain breakage. The high bond energy of the Si-O bond gives the system excellent high-temperature stability, and the benzene ring enhances the antioxidant inertness. The two work together to resist oxidative decomposition. The reinforcing agent and the antioxidants 2,6-di-tert-butyl-p-cresol and phenyl-α-naphthylamine form an antioxidant synergy, terminating the oxidation chain reaction at different stages. At the same time, the polyisobutylene succinimide in the wear-resistant additive disperses the oxidized sludge precursor in time to avoid aggregation and accelerated aging. The chemical inertness of graphite reduces the occurrence of oxidation reaction, and the base oil ensures the compatibility of each component. Together, they delay the aging process under high temperature and oxygen environment and significantly improve the aging resistance of lubricating oil. Detailed Implementation

[0034] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] In this application, the graphite is selected from Qingdao Yucheng Graphite Co., Ltd., with a particle size of 500μm, a fixed carbon content of 85-93%, and a product number of 8415452716;

[0036] In this application, polydecene is selected from Jingzhou Yinjie Chemical Co., Ltd., with CAS number 68037-01-4, active ingredient content of 99%, and model number jzyj202404261050;

[0037] In this application, the polyisobutylene succinimide is selected from Nantong Runfeng Petrochemical Co., Ltd., with a purity of 99% and a model number of T-155.

[0038] Example 1

[0039] This embodiment provides a high-temperature resistant polyester-based lubricating oil and its preparation method, including the following steps:

[0040] S1, Preparation of olefin-modified cyclotriphosphazene

[0041] Weigh out 10g of hexachlorocyclotriphosphazene and dissolve it in 100mL of tetrahydrofuran to obtain a hexachlorocyclotriphosphazene solution;

[0042] Weigh out: Calculate the amount of 1,10-decanediol methacrylate to be added based on 6.05 times the total chlorine content in hexachlorocyclotriphosphazene. Add it together with 19g of triethylamine to a three-necked flask containing 150mL of tetrahydrofuran. Mix well and heat to 60℃. Add 100mL of hexachlorocyclotriphosphazene solution dropwise. Reflux for 24h until the solution turns brownish-red. Filter to remove the precipitate and transfer to a rotary evaporator. Remove the solvent tetrafluorofuran at 60℃. Extract the crude product with ethyl acetate and water, then transfer it to a rotary evaporator and dry at 65℃ for 24h to obtain olefin-modified cyclotriphosphazene.

[0043] S2, Preparation of olefin-modified diphenylsilane

[0044] Weigh out 15g of diphenyldichlorosilane and dissolve it in 100mL of tetrahydrofuran to obtain a diphenyldichlorosilane solution;

[0045] Weigh out the amount of 1,10-decanediol methacrylate to be added, calculated as 2.05 times the total amount of silicon-chlorine bonds in diphenyldichlorosilane. Add it together with 15g of triethylamine to a three-necked flask containing 100mL of tetrahydrofuran and mix well. Then, add 100mL of diphenyldichlorosilane solution dropwise at 0℃. After the addition is complete, heat to 60℃ and reflux for 24h. After the reaction is complete, filter to remove the precipitate and transfer to a rotary evaporator. Remove the solvent tetrahydrofuran at 60℃. Extract the crude product with ethyl acetate and water, then transfer it to a rotary evaporator and dry at 65℃ for 24h to obtain olefin-modified diphenylsilane.

[0046] S3, Preparation of reinforcing agent

[0047] Weigh out 10g of olefin-modified cyclotriphosphazene, 10g of olefin-modified diphenylsilane, 0.5g of n-dodecyl mercaptan, and 300mL of toluene and add them to a three-necked caustic vessel. Stir for 5 minutes at 40°C under a nitrogen atmosphere. For every 10°C increase in temperature, add 0.2g of azobisisobutyronitrile and react for 0.5 hours. Repeat this process until the temperature reaches 80°C, then add the last batch of azobisisobutyronitrile and react for 0.5 hours. Finally, raise the temperature to 110°C and react for 5 hours. Pour the solution into a vacuum distillation apparatus and distill at 70°C for 1 hour. Transfer the solution to anhydrous ethanol, stir and wash at 60°C for 20 minutes, filter, dissolve the product in petroleum ether, filter with 100-mesh silica gel, and place the filter residue in a vacuum drying oven and dry at 70°C for 3 hours to obtain the reinforcing agent.

[0048] S4. Preparation of wear-resistant additives

[0049] Weigh out 1g of polyisobutylene succinimide and 1g of graphite and put them into a planetary ball mill and ball mill for 1 hour. Then add them into a flask containing 40g of polydecene, stir for 10 minutes, and then sonicate for 30 minutes to obtain the wear-resistant additive.

[0050] S5. Preparation of high-temperature resistant polyester-based lubricating oil

[0051] Weigh out 0.5 parts by weight of 2,6-di-tert-butyl-p-cresol and 1 part of phenyl-α-naphthylamine, mix them evenly to obtain an antioxidant;

[0052] Weigh out 50 parts by weight of polybutylene adipate, 10 parts by weight of wear-resistant additive and 3 parts by weight of dibutyl maleate and add them to a three-necked flask. Stir at 25°C for 15 min, heat to 40°C, add 2 parts by weight of zinc dialkyl dithiophosphate, 1 part by weight of antioxidant and 5 parts by weight of reinforcing agent, stir for 30 min, cool to 30°C, add 0.01 parts by weight of dimethyl silicone oil, stir for 10 min, transfer to an ultrasonic homogenizer and sonicate for 20 min, cool to room temperature to obtain a high-temperature resistant polyester lubricating oil.

[0053] Example 2

[0054] This embodiment provides a high-temperature resistant polyester-based lubricating oil and its preparation method, including the following steps:

[0055] S1, Preparation of olefin-modified cyclotriphosphazene

[0056] Weigh out 10g of hexachlorocyclotriphosphazene and dissolve it in 100mL of tetrahydrofuran to obtain a hexachlorocyclotriphosphazene solution;

[0057] Weigh out: Calculate the amount of 1,10-decanediol methacrylate to be added based on 6.05 times the total chlorine content in hexachlorocyclotriphosphazene. Add it together with 19g of triethylamine into a three-necked flask containing 200mL of tetrahydrofuran. Mix well and heat to 60℃. Add 100mL of hexachlorocyclotriphosphazene solution dropwise. Reflux for 24h until the solution turns brownish-red. Filter to remove the precipitate and transfer to a rotary evaporator. Remove the solvent tetrafluorofuran at 60℃. Extract the crude product with ethyl acetate and water, then transfer it to a rotary evaporator and dry at 65℃ for 24h to obtain olefin-modified cyclotriphosphazene.

[0058] S2, Preparation of olefin-modified diphenylsilane

[0059] Weigh out 15g of diphenyldichlorosilane and dissolve it in 100mL of tetrahydrofuran to obtain a diphenyldichlorosilane solution;

[0060] Weigh out the amount of 1,10-decanediol methacrylate to be added, calculated as 2.05 times the total amount of silicon-chlorine bonds in diphenyldichlorosilane. Add it together with 15g of triethylamine to a three-necked flask containing 150mL of tetrahydrofuran and mix well. Then, add 100mL of diphenyldichlorosilane solution dropwise at 0℃. After the addition is complete, heat to 60℃ and reflux for 24h. After the reaction is complete, filter to remove the precipitate and transfer to a rotary evaporator. Remove the solvent tetrahydrofuran at 60℃. Extract the crude product with ethyl acetate and water, then transfer it to a rotary evaporator and dry at 65℃ for 24h to obtain olefin-modified diphenylsilane.

[0061] S3, Preparation of reinforcing agent

[0062] Weigh out 10g of olefin-modified cyclotriphosphazene, 10g of olefin-modified diphenylsilane, 0.6g of n-dodecyl mercaptan, and 400mL of toluene and add them to a three-necked caustic vessel. Stir for 8 minutes at 45°C under a nitrogen atmosphere. For every 10°C increase in temperature, add 0.3g of azobisisobutyronitrile and react for 0.5 hours. Repeat this process until the temperature reaches 80°C, then add the last batch of azobisisobutyronitrile and react for 0.5 hours. Finally, raise the temperature to 115°C and react for 5.5 hours. Pour the solution into a vacuum distillation apparatus and distill at 70°C for 1.5 hours. Transfer the solution to anhydrous ethanol, stir and wash at 65°C for 25 minutes, filter, dissolve the product in petroleum ether, filter with 100-mesh silica gel, and place the filter residue in a vacuum drying oven and dry at 70°C for 3.5 hours to obtain the reinforcing agent.

[0063] S4. Preparation of wear-resistant additives

[0064] Weigh out 1.5g of polyisobutylene succinimide and 1g of graphite and put them into a planetary ball mill. After ball milling for 1 hour, add them into a flask containing 50g of polydecene. Stir for 10 minutes and then sonicate for 40 minutes to obtain the wear-resistant additive.

[0065] S5. Preparation of high-temperature resistant polyester-based lubricating oil

[0066] Weigh out 0.7 parts by weight of 2,6-di-tert-butyl-p-cresol and 1.2 parts by weight of phenyl-α-naphthylamine, mix them evenly to obtain an antioxidant;

[0067] Weigh out 55 parts by weight of polybutylene adipate, 15 parts by weight of wear-resistant additive and 4 parts by weight of dibutyl maleate and add them to a three-necked flask. Stir at 25°C for 15 min, raise the temperature to 45°C, add 2 parts by weight of zinc dialkyl dithiophosphate, 1 part by weight of antioxidant and 6 parts by weight of reinforcing agent, stir for 35 min, and finally lower the temperature to 35°C. Add 0.03 parts by weight of dimethyl silicone oil, stir for 10 min, transfer to an ultrasonic homogenizer and sonicate for 20 min. Cool to room temperature to obtain a high-temperature resistant polyester lubricating oil.

[0068] Example 3

[0069] This embodiment provides a high-temperature resistant polyester-based lubricating oil and its preparation method, including the following steps:

[0070] S1, Preparation of olefin-modified cyclotriphosphazene

[0071] Weigh out 10g of hexachlorocyclotriphosphazene and dissolve it in 100mL of tetrahydrofuran to obtain a hexachlorocyclotriphosphazene solution;

[0072] Weigh out: Calculate the amount of 1,10-decanediol methacrylate to be added based on 6.05 times the total chlorine content in hexachlorocyclotriphosphazene. Add it together with 19g of triethylamine to a three-necked flask containing 250mL of tetrahydrofuran. Mix well and heat to 65℃. Add 100mL of hexachlorocyclotriphosphazene solution dropwise. Reflux for 24h until the solution turns brownish-red. Filter to remove the precipitate and transfer to a rotary evaporator. Remove the solvent tetrafluorofuran at 60℃. Extract the crude product with ethyl acetate and water, then transfer it to a rotary evaporator and dry at 65℃ for 24h to obtain olefin-modified cyclotriphosphazene.

[0073] S2, Preparation of olefin-modified diphenylsilane

[0074] Weigh out 15g of diphenyldichlorosilane and dissolve it in 100mL of tetrahydrofuran to obtain a diphenyldichlorosilane solution;

[0075] Weigh out the amount of 1,10-decanediol methacrylate to be added, calculated as 2.05 times the total amount of silicon-chlorine bonds in diphenyldichlorosilane. Add it together with 15g of triethylamine to a three-necked flask containing 200mL of tetrahydrofuran and mix well. Then, add 100mL of diphenyldichlorosilane solution dropwise at 0℃. After the addition is complete, heat to 60℃ and reflux for 24h. After the reaction is complete, filter to remove the precipitate and transfer to a rotary evaporator. Remove the solvent tetrahydrofuran at 60℃. Extract the crude product with ethyl acetate and water, then transfer it to a rotary evaporator and dry at 65℃ for 24h to obtain olefin-modified diphenylsilane.

[0076] S3, Preparation of reinforcing agent

[0077] Weigh out 10g of olefin-modified cyclotriphosphazene, 10g of olefin-modified diphenylsilane, 0.8g of n-dodecyl mercaptan, and 500mL of toluene and add them to a three-necked caustic vessel. Stir for 10min at 50℃ under a nitrogen atmosphere. For every 10℃ increase in temperature, add 0.4g of azobisisobutyronitrile and react for 1h. Repeat this process until the temperature reaches 80℃, then add the last batch of azobisisobutyronitrile and react for 1h. Then, raise the temperature to 120℃ and react for 6h. Pour the solution into a vacuum distillation apparatus and distill at 70℃ for 2h. Transfer the solution to anhydrous ethanol, stir and wash at 70℃ for 30min, filter, dissolve the product in petroleum ether, filter with 200-mesh silica gel, and place the filter residue in a vacuum drying oven and dry at 70℃ for 4h to obtain the reinforcing agent.

[0078] S4. Preparation of wear-resistant additives

[0079] Weigh out 2g of polyisobutylene succinimide and 1g of graphite and put them into a planetary ball mill and ball mill for 1 hour. Then add them into a flask containing 60g of polydecene, stir for 15 minutes, and then sonicate for 60 minutes to obtain the wear-resistant additive.

[0080] S5. Preparation of high-temperature resistant polyester-based lubricating oil

[0081] Weigh out 1 part of 2,6-di-tert-butyl-p-cresol and 1.5 parts of phenyl-α-naphthylamine by weight, mix them evenly to obtain an antioxidant;

[0082] Weigh out 60 parts by weight of polybutylene adipate, 20 parts by weight of wear-resistant additive and 5 parts by weight of dibutyl maleate and add them to a three-necked flask. Stir at 30°C for 20 min, then heat to 50°C, add 3 parts by weight of zinc dialkyl dithiophosphate, 2 parts by weight of antioxidant and 7 parts by weight of reinforcing agent, stir for 40 min, and finally cool to 40°C. Add 0.05 parts by weight of dimethyl silicone oil, stir for 15 min, transfer to an ultrasonic homogenizer and sonicate for 30 min. Cool to room temperature to obtain a high-temperature resistant polyester lubricating oil.

[0083] Comparative Example 1

[0084] The difference between this comparative example and Example 3 is that step S1 is omitted, and olefin-modified cyclotriphosphazene is not added in step S3.

[0085] Comparative Example 2

[0086] The difference between this comparative example and Example 3 is that step S2 is omitted, and olefin-modified diphenylsilane is not added in step S3.

[0087] Comparative Example 3

[0088] The difference between this comparative example and Example 3 is that steps S1 and S2 are omitted, and olefin-modified cyclotriphosphazene and olefin-modified diphenylsilane in step S3 are replaced with 1,10-decanediol methacrylate.

[0089] Comparative Example 4

[0090] The difference between this comparative example and Example 3 is that step S4 is omitted and wear-resistant additives are not added in step S5.

[0091] The flash point of the high-temperature resistant polyester lubricating oils prepared in Examples 1-3 and Comparative Examples 1-4 was determined according to the standard GB / T 21789-2008 "Determination of flash point of petroleum products and other liquids - Abel closed cup method".

[0092] The acid value and anti-wear properties of the high-temperature resistant polyester lubricating oils prepared in Examples 1-3 and Comparative Examples 1-4 were determined according to the standard NB / SH / T 6074-2023 "Diesel Anti-wear Agents". The anti-wear properties were expressed as the average wear scar diameter.

[0093] The viscosity of the high-temperature resistant polyester lubricating oils prepared in Examples 1-3 and Comparative Examples 1-4 was determined according to standard SH / T 0618-1995 "Determination of dynamic viscosity of lubricating oils under high shear conditions (Revanfeldt method)". The specific test results are shown in Table 1 below:

[0094] Table 1 - Basic Performance Test Data of the Samples

[0095] Group Project Ignition point (°C) Viscosity (mPa·s) <![CDATA[Acid value (calculated as KOH) / mg·g -1 > Average wear scar diameter (μm) Example 1 347 14.2 0.8 242 Example 2 348 14.6 0.7 239 Example 3 351 15.1 0.5 235 Comparative Example 1 305 12.9 1.2 392 Comparative Example 2 298 12.5 1.0 387 Comparative Example 3 291 12.1 1.3 399 Comparative Example 4 346 13.7 1.5 418

[0096] The viscosity, acid value, and average wear scar diameter of the high-temperature resistant polyester lubricating oils prepared in Examples 1-3 and Comparative Examples 1-4 after oxidation were determined according to standard NB / SH / T 0193-2022 "Determination of Oxidation Stability of Lubricating Oils - Rotating Bomb Oxygen Method". The specific test results are shown in Table 2 below:

[0097] Table 2 - Test data on oxidation resistance of the samples

[0098] Group Project Viscosity (mPa·s) <![CDATA[Acid value (calculated as KOH) / mg·g -1 > Average wear scar diameter (μm) Example 1 11.9 1.4 292 Example 2 12.5 1.3 284 Example 3 13.2 1.1 274 Comparative Example 1 10.8 1.9 479 Comparative Example 2 10.5 1.6 465 Comparative Example 3 10.2 1.8 490 Comparative Example 4 12.1 2.1 501

[0099] Data Analysis:

[0100] Comparative Example 1 omitted the addition of olefin-modified cyclotriphosphazene, thus lacking the flame-retardant mechanism of the N=P double bond and its synergistic effect with the Si-O bond in the reinforcing agent. This resulted in an ignition point of 305℃, significantly lower than that of Example 3, and a substantial decrease in high-temperature resistance and flame-retardant performance. Simultaneously, the lack of adsorption of the N=P double bond's chemical activity on the metal surface and its synergistic effect with other anti-wear components led to an average wear scar diameter of 392 μm, much larger than that of Example 3, resulting in poorer anti-wear properties. Furthermore, the N=P double bond's ability to scavenge free radicals was lost, preventing it from synergistically inhibiting oxidation with antioxidants, resulting in an acid value of 1.2 mg·g⁻¹. -1 The viscosity after oxidation was 10.8 mPa·s, and the acid value was 1.9 mg·g, which was higher than that in Example 3. -1 The wear scar diameter is 479 μm;

[0101] Comparative Example 2 omitted the addition of olefin-modified diphenylsilane, thus lacking the support of the high bond energy and chemical stability of the Si-O bonds in the reinforcing agent for the high-temperature structure of the system. This resulted in a flash point of 298°C, lower than that of Example 3, and easy decomposition of the structure at high temperatures, leading to decreased high-temperature resistance. The lack of contribution of Si-O bonds to the stability of the polymer network of the reinforcing agent weakened the synergistic effect of the components in the system, resulting in a viscosity of 12.5 mPa·s, lower than that of Example 3. The stable oil film required for anti-wear was difficult to form, and the average wear scar diameter was 387 μm, greater than that of Example 3. At the same time, the lack of resistance to oxidative decomposition of Si-O bonds prevented them from synergistically delaying aging with antioxidants, resulting in an acid value of 1.0 mg·g. -1 The viscosity after oxidation is 10.5 mPa·s, which is higher than that of Example 3, and the acid value is 1.6 mg·g.-1 The wear scar diameter is 465 μm;

[0102] Comparative Example 3 eliminated components containing N=P double bonds and Si-O bonds, replacing the reinforcing agent only with 1,10-decanediol methacrylate. This resulted in the reinforcing agent losing the synergistic effect of the N=P double bonds and Si-O bonds, lacking both the flame retardancy and free radical scavenging ability of the N=P double bonds and the high-temperature structural stability of the Si-O bonds. Consequently, the reinforcing agent could not form an effective polymer network support system. As a result, its ignition point was 291°C, the lowest among all groups, indicating severely insufficient high-temperature resistance and flame retardancy. In terms of wear resistance, the lack of adsorption of both bonds on the metal surface and synergy with wear-resistant additives resulted in an average wear scar diameter of 399 μm, significantly larger than that of Example 3. During oxidation, due to the absence of the anti-decomposition effect of the two bonds and synergy with antioxidants, the acid value was 1.3 mg·g. -1 The highest performance was achieved after oxidation, with a viscosity of 10.2 mPa·s and an acid value of 1.8 mg·g. -1 The wear scar diameter is 490 μm;

[0103] Comparative Example 4 omitted the addition of wear-resistant additives, thus lacking the dispersing effect of polyisobutylene succinimide on graphite and the physical lubrication layer formed by graphite at the friction interface. This resulted in graphite failing to disperse uniformly and exert its interlayer sliding friction-reducing effect. Simultaneously, the synergistic effect of the wear-resistant additives and zinc dialkyl dithiophosphate was missing, leading to a combination of physical lubrication and chemical reaction film, increasing the probability of direct contact between the metal surfaces. The average wear scar diameter was 418 μm, significantly larger than in Example 3, resulting in a significant decrease in wear resistance. Furthermore, the role of polyisobutylene succinimide in dispersing oxidation products was absent, causing the sludge precursor to easily aggregate during oxidation, with an acid value of 1.5 mg·g. -1 The average wear scar diameter after oxidation was 501 μm, which was higher than that in Example 3. The synergistic effect of aging resistance and wear resistance disappeared, and the overall performance declined.

[0104] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A high-temperature resistant polyester-based lubricating oil, characterized in that, It comprises the following components by weight: 50-60 parts polybutylene adipate, 10-20 parts wear-resistant additive, 3-5 parts dibutyl maleate, 2-3 parts zinc dialkyl dithiophosphate, 5-7 parts reinforcing agent, 1-2 parts antioxidant and 0.01-0.05 parts dimethyl silicone oil; The antioxidant comprises the following components in parts by weight: 0.5-1 part of 2,6-di-tert-butyl-p-cresol and 1-1.5 parts of phenyl-α-naphthylamine; The preparation method of the wear-resistant additive is as follows: after ball milling the dispersant and graphite in a planetary ball mill for 1 hour, the mixture is added to a flask containing polydecene, stirred for 10-15 minutes, and then ultrasonically vibrated for 30-60 minutes to obtain the wear-resistant additive; the dispersant is polyisobutylene succinimide, and the ratio of the dispersant, graphite and polydecene is 1-2g:1g:40-60g; The preparation method of the reinforcing agent is as follows: olefin-modified cyclotriphosphazene, olefin-modified diphenylsilane, transfer agent and toluene are added to a three-necked flask, stirred for 5-10 min under a nitrogen atmosphere at 40-50℃, and then an initiator is added and reacted for 0.5-1 h for every 10℃ increase in temperature. This process is repeated until the temperature is raised to 80℃, then the last batch of initiator is added and reacted for 0.5-1 h. The temperature is then raised to 110-120℃ and reacted for 5-6 h. After post-treatment, the reinforcing agent is obtained. The preparation method of the olefin-modified cyclotriphosphazene is as follows: 1,10-decanediol methacrylate and triethylamine are added to a three-necked flask containing tetrahydrofuran and mixed well. The mixture is then heated to 60-65°C, and a hexachlorocyclotriphosphazene solution is added dropwise. The mixture is refluxed for 24 hours and then post-treated to obtain the olefin-modified cyclotriphosphazene. The preparation method of the olefin-modified diphenylsilane is as follows: 1,10-decanediol methacrylate and triethylamine are added to a three-necked flask containing tetrahydrofuran and mixed well. Then, a diphenyl dichlorosilane solution is added dropwise at 0°C. After the addition is complete, the temperature is raised to 60°C and refluxed for 24 hours. After post-treatment, the olefin-modified diphenylsilane is obtained.

2. The high-temperature resistant polyester-based lubricating oil according to claim 1, characterized in that, In the preparation method of the reinforcing agent, the transfer agent is n-dodecyl mercaptan; the initiator is azobisisobutyronitrile; the ratio of the amount of olefin-modified cyclotriphosphazene, olefin-modified diphenylsilane, transfer agent, toluene and initiator is 10g:10g:0.5-0.8g:300-500mL:1-2g; the post-treatment is as follows: the solution is poured into a vacuum distillation apparatus, distilled at 70℃ for 1-2h, then transferred to anhydrous ethanol, stirred and washed at 60-70℃ for 20-30min, filtered, the product is then dissolved in petroleum ether, filtered with 100-200 mesh silica gel, and the filter residue is placed in a vacuum drying oven and dried at 70℃ for 3-4h.

3. The high-temperature resistant polyester-based lubricating oil according to claim 1, characterized in that, In the preparation method of the olefin-modified cyclotriphosphazene, the ratio of triethylamine, tetrahydrofuran, and hexachlorocyclotriphosphazene solution is 19g:150-250mL:100mL, and the amount of 1,10-decanediol methacrylate added is 6.05 times the total chlorine in hexachlorocyclotriphosphazene; the hexachlorocyclotriphosphazene solution is obtained by dissolving 10g of hexachlorocyclotriphosphazene in 100mL of tetrahydrofuran; the post-treatment is as follows: after the solution color turns brownish-red, filter to remove the precipitate, transfer to a rotary evaporator, remove the solvent at 60℃, extract the crude product with ethyl acetate and water, transfer it to a rotary evaporator again, and dry at 65℃ for 24h.

4. The high-temperature resistant polyester-based lubricating oil according to claim 1, characterized in that, In the preparation method of the olefin-modified diphenylsilane, the ratio of triethylamine, tetrahydrofuran, and diphenyldichlorosilane solution is 15g:100-200mL:100mL, and the amount of 1,10-decanediol methacrylate added is 2.05 times the total amount of silicon-chlorine bonds in diphenyldichlorosilane; the diphenyldichlorosilane solution is obtained by dissolving 15g of diphenyldichlorosilane in 100mL of tetrahydrofuran; the post-treatment is as follows: after the reaction is completed, the precipitate is filtered off, transferred to a rotary evaporator, the solvent is removed at 60℃, the crude product is extracted with ethyl acetate and water, and then transferred to a rotary evaporator and dried at 65℃ for 24h.

5. A method for preparing a high-temperature resistant polyester-based lubricating oil according to any one of claims 1-4, characterized in that, The process includes the following steps: adding polybutylene adipate, wear-resistant additives, and dibutyl maleate to a three-necked flask, stirring at 25-30°C for 15-20 minutes, raising the temperature to 40-50°C, adding zinc dialkyl dithiophosphate, antioxidants, and reinforcing agents, stirring for 30-40 minutes, finally cooling to 30-40°C, adding dimethyl silicone oil, stirring for 10-15 minutes, transferring to an ultrasonic homogenizer, sonicating for 20-30 minutes, and cooling to room temperature to obtain a high-temperature resistant polyester lubricating oil.

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