A biobased lubricating oil composition with high oxidative stability and a method of making the same

Abstract

The application provides a kind of high oxidative stability bio-based lubricating oil composition and its preparation method, belong to bio-based lubricating oil technical field.The application is prepared by modifying bio-based cardanol to prepare functional base oil with hydroxyl as network construction unit;Dynamic crosslinking agent is introduced, which can be combined with base oil through reversible transesterification at high temperature, forming a dynamic three-dimensional network;Hydrophobic modified catalyst is introduced for catalytic decomposition of peroxide;There is a synergistic effect in the system: the polar microzone formed by the dynamic network can selectively enrich harmful peroxide, and then catalytic decomposition is carried out by the hydrophobic modified catalyst located in the network, thereby reducing the propagation rate of oxidative chain reaction;At the same time, the reversibility of the network enables the lubricating oil to maintain the necessary fluidity while providing protection, avoiding gelation.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of bio-based lubricating oil, and relates to a bio-based lubricating oil composition with high oxidation stability and a preparation method thereof. BACKGROUND

[0002] With the deepening of the concept of sustainable development, developing high-performance bio-based lubricating oil has become an important research direction in the field of lubricating technology. Bio-based ester lubricating oil represented by vegetable oil has attracted widespread attention due to its renewability and excellent biodegradability. However, the wide application of this kind of base oil still faces challenges brought by its inherent chemical structure. On the one hand, the ester bond in the molecule is prone to hydrolysis under high temperature and in the presence of trace water; on the other hand, the unsaturated double bond commonly existing in the fatty acid chain makes its oxidation stability weaker than that of traditional mineral oil, which to some extent limits its application in harsh working conditions such as high temperature and long service life.

[0003] To improve the oxidation stability of bio-based lubricating oil, the existing technology mainly relies on adding antioxidants. At present, the mainstream antioxidant technology mainly uses sacrificial additives such as hindered phenol and aromatic amine. These additives neutralize free radicals in the system by being oxidized themselves, and their action mode is stoichiometric. This means that their protective ability will gradually decrease over time, and once depleted, the oxidation of the lubricating oil will accelerate rapidly, resulting in a significant decline in its performance in the later stage of service. In addition, this passive protection mechanism based on random molecular collisions may be limited in response efficiency and protection efficiency when dealing with concentrated and high-intensity oxidation caused by metal catalysis or local overheating. Therefore, exploring new antioxidant systems with longer and more efficient protection mechanisms beyond the traditional “sacrificial” mode is one of the key technical problems in promoting the development of high-performance bio-based lubricating oil. SUMMARY

[0004] In view of the above problems, the purpose of the present application is to provide a bio-based lubricating oil composition with high oxidation stability and a preparation method thereof. The present application prepares a functionalized base oil with hydroxyl groups as a network building unit by modifying bio-based cardanol; introduces a dynamic crosslinking agent which can combine with the base oil through a reversible ester exchange reaction at high temperature to form a dynamic three-dimensional network; introduces a surface hydrophobic modified catalyst for catalytic decomposition of peroxides; there is a synergistic effect in the system: the polar microzone formed by the dynamic network can enrich harmful peroxides, which are then catalytically decomposed by the surface hydrophobic modified catalyst located in the network, thereby reducing the propagation of the oxidation chain reaction and prolonging the induction period; at the same time, the reversibility of the network enables the lubricating oil to maintain the necessary fluidity while providing protection, avoiding gelation.

[0005] To achieve this purpose, the present application adopts the following technical solutions:

[0006] In a first aspect, the present application provides a method for preparing a high-oxidation-stability bio-based lubricating oil composition, the method comprising:

[0007] S1: adding a catalyst, Raney Ni, to an ethanol dispersion of cardanol to obtain a reaction solution A, placing the reaction solution A in a high-pressure reaction kettle, reacting, filtering, and rotary evaporating to obtain a preliminary modified cardanol; mixing the preliminary modified cardanol, tetrabutylammonium bromide, and epichlorohydrin to obtain a mixture, adding an aqueous sodium hydroxide solution to obtain a reaction solution B, reacting, washing, drying, and purifying to obtain a cardanol glycidyl ether; mixing the cardanol glycidyl ether with glycerol, adding p-toluenesulfonic acid to obtain a reaction solution C, stirring and reacting to obtain a post-reaction solution, cooling to room temperature, adding an alkaline aluminum oxide powder, stirring and adsorbing, and then filtering to obtain a filtrate, and passing the filtrate through a thin film evaporator to obtain a functional base oil;

[0008] S2: dispersing a tetra(4-carboxyphenyl)porphyrin and manganese acetate tetrahydrate in N,N-dimethylformamide, adding ethanol to obtain a reaction solution D, reacting, centrifuging, and washing to obtain nanoparticles; dispersing the nanoparticles in toluene, adding octadecyltrichlorosilane and triethylamine to obtain a reaction solution E, stirring and reacting, centrifuging, washing, and freeze-drying to obtain a surface-hydrophobic-modified catalyst;

[0009] S3: mixing boric acid, 1,10-decanediol, and oleyl alcohol in toluene to obtain a reaction solution F, refluxing the reaction solution F until no water is generated, rotary evaporating, and vacuum drying to obtain a dynamic crosslinking agent;

[0010] S4: mixing the functional base oil with PAO4 (poly-alpha-olefin) and heating to obtain a mixed base oil, dividing the mixed base oil into two portions, adding the dynamic crosslinking agent to the first portion of the mixed base oil and stirring to obtain a first mixture, mixing the surface-hydrophobic-modified catalyst with the second portion of the mixed base oil, ultrasonically treating to obtain a concentrated mother liquor, adding the concentrated mother liquor to the first mixture, adding polyhexadecyl methacrylate and a non-silicon antifoaming agent, and continuing to stir, and cooling to obtain a high-oxidation-stability bio-based lubricating oil composition.

[0011] As a preferred technical solution of the present application, in step S1, the mass-volume ratio of cardanol to ethanol in the ethanol dispersion of cardanol is 1 g:(5-10) mL, for example, it can be 1 g:5.0 mL, 1 g:5.5 mL, 1 g:6.0 mL, 1 g:6.5 mL, 1 g:7.0 mL, 1 g:7.5 mL, 1 g:8.0 mL, 1 g:8.5 mL, 1 g:9.0 mL, 1 g:9.5 mL, or 1 g:10.0 mL, but is not limited to the listed values, and other values not listed in this range are also applicable.

[0012] In some optional embodiments, the mass ratio of the catalyst Raney Ni to cardanol is (1-2): 100, which can be, for example, 1.0: 100, 1.1: 100, 1.2: 100, 1.3: 100, 1.4: 100, 1.5: 100, 1.6: 100, 1.7: 100, 1.8: 100, 1.9: 100, or 2.0: 100, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0013] In some optional embodiments, the hydrogen pressure in the high-pressure reactor in which the reaction liquid A is reacted is 1-5 bar, which can be, for example, 1.0 bar, 1.4 bar, 1.8 bar, 2.2 bar, 2.6 bar, 3.0 bar, 3.4 bar, 3.8 bar, 4.2 bar, 4.6 bar, or 5.0 bar, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0014] In some optional embodiments, the temperature in the high-pressure reactor in which the reaction liquid A is reacted is 40-80°C, which can be, for example, 40°C, 44°C, 48°C, 52°C, 56°C, 60°C, 64°C, 68°C, 72°C, 76°C, or 80°C, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0015] In some optional embodiments, the time in the high-pressure reactor in which the reaction liquid A is reacted is 4-8 h, which can be, for example, 4.0 h, 4.4 h, 4.8 h, 5.2 h, 5.6 h, 6.0 h, 6.4 h, 6.8 h, 7.2 h, 7.6 h, or 8.0 h, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0016] In some optional embodiments, the molar ratio of the preliminary modified cardanol, tetrabutylammonium bromide, and epichlorohydrin is 1:0.02:(1.5-2), which can be, for example, 1:0.02:1.50, 1:0.02:1.55, 1:0.02:1.60, 1:0.02:1.65, 1:0.02:1.70, 1:0.02:1.75, 1:0.02:1.80, 1:0.02:1.85, 1:0.02:1.90, 1:0.02:1.95, or 1:0.02:2.00, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0017] In some optional embodiments, the mixture is added to the aqueous sodium hydroxide solution at 60-70 °C to obtain reaction liquid B, for example, can be added at 60 °C, 61 °C, 62 °C, 63 °C, 64 °C, 65 °C, 66 °C, 67 °C, 68 °C, 69 °C or 70 °C, but not limited to the listed values, other values not listed in the range of values are also applicable.

[0018] In some optional embodiments, the concentration of the aqueous sodium hydroxide solution is 30-40 wt.%, for example, can be 30 wt.%, 31 wt.%, 32 wt.%, 33 wt.%, 34 wt.%, 35 wt.%, 36 wt.%, 37 wt.%, 38 wt.%, 39 wt.% or 40 wt.%, but not limited to the listed values, other values not listed in the range of values are also applicable.

[0019] In some optional embodiments, the molar ratio of sodium hydroxide to the preliminary modified cardanol phenol in the reaction liquid B is (1-1.1):1, for example, can be 1.00:1, 1.01:1, 1.02:1, 1.03:1, 1.04:1, 1.05:1, 1.06:1, 1.07:1, 1.08:1, 1.09:1 or 1.10:1, but not limited to the listed values, other values not listed in the range of values are also applicable.

[0020] In some optional embodiments, the reaction liquid B is reacted for 4-6 h, for example, can be 4.0 h, 4.2 h, 4.4 h, 4.6 h, 4.8 h, 5.0 h, 5.2 h, 5.4 h, 5.6 h, 5.8 h or 6.0 h, but not limited to the listed values, other values not listed in the range of values are also applicable.

[0021] In some optional embodiments, the molar ratio of cardanol glycidyl ether to glycerol is 1:(0.5-0.7), for example, can be 1:0.50, 1:0.52, 1:0.54, 1:0.56, 1:0.58, 1:0.60, 1:0.62, 1:0.64, 1:0.66, 1:0.68 or 1:0.70, but not limited to the listed values, other values not listed in the range of values are also applicable.

[0022] In some optional embodiments, the molar ratio of p-toluenesulfonic acid to cardanol glycidyl ether is (0.5-1.5):100, which can be, for example, 0.5:100, 0.6:100, 0.7:100, 0.8:100, 0.9:100, 1.0:100, 1.1:100, 1.2:100, 1.3:100, 1.4:100, or 1.5:100, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0023] In some optional embodiments, the temperature for stirring reaction of the reaction solution C is 100-120°C, which can be, for example, 100°C, 102°C, 104°C, 106°C, 108°C, 110°C, 112°C, 114°C, 116°C, 118°C, or 120°C, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0024] In some optional embodiments, the time for stirring reaction of the reaction solution C is 2-4h, which can be, for example, 2.0h, 2.2h, 2.4h, 2.6h, 2.8h, 3.0h, 3.2h, 3.4h, 3.6h, 3.8h, or 4.0h, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0025] In some optional embodiments, the amount of the basic aluminum oxide powder added is 5-10% of the mass of the solution after reaction, which can be, for example, 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5%, 8.0%, 8.5%, 9.0%, 9.5%, or 10.0%, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0026] In some optional embodiments, the time for stirring adsorption is 40-60min, which can be, for example, 40min, 42min, 44min, 46min, 48min, 50min, 52min, 54min, 56min, 58min, or 60min, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0027] As a preferred technical solution of the present application, in step S2, the molar ratio of tetra(4-carboxyphenyl)porphyrin to manganese acetate tetrahydrate is 1:(1.5-3), which can be, for example, 1:1.50, 1:1.65, 1:1.80, 1:1.95, 1:2.10, 1:2.25, 1:2.40, 1:2.55, 1:2.70, 1:2.85, or 1:3.00, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0028] In some optional embodiments, the concentration of the tetra(4-carboxyphenyl) porphyrin in the reaction solution D is 5-10 mM, for example, it can be 5.0 mM, 5.5 mM, 6.0 mM, 6.5 mM, 7.0 mM, 7.5 mM, 8.0 mM, 8.5 mM, 9.0 mM, 9.5 mM or 10.0 mM, but not only limited to the listed values, other values not listed in the range are also applicable.

[0029] In some optional embodiments, the volume of the ethanol is 10-20% of the volume of N,N-dimethylformamide, for example, it can be 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19% or 20%, but not only limited to the listed values, other values not listed in the range are also applicable.

[0030] In some optional embodiments, the reaction temperature of the reaction solution D is 110-130°C, for example, it can be 110°C, 112°C, 114°C, 116°C, 118°C, 120°C, 122°C, 124°C, 126°C, 128°C or 130°C, but not only limited to the listed values, other values not listed in the range are also applicable.

[0031] In some optional embodiments, the reaction time of the reaction solution D is 12-24 h, for example, it can be 12.0 h, 13.2 h, 14.4 h, 15.6 h, 16.8 h, 18.0 h, 19.2 h, 20.4 h, 21.6 h, 22.8 h or 24.0 h, but not only limited to the listed values, other values not listed in the range are also applicable.

[0032] In some optional embodiments, the mass ratio of octadecyltrichlorosilane to nanoparticles is (0.5-1.5):1, for example, it can be 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1.0:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1 or 1.5:1, but not only limited to the listed values, other values not listed in the range are also applicable.

[0033] In some optional embodiments, the molar ratio of triethylamine to octadecyltrichlorosilane is (0.5-1):1, for example, it can be 0.5:1, 0.55:1, 0.6:1, 0.65:1, 0.7:1, 0.75:1, 0.8:1, 0.85:1, 0.9:1, 0.95:1 or 1:1, but not only limited to the listed values, other values not listed in the range are also applicable.

[0034] In some optional embodiments, the temperature for the stirring reaction of the reaction solution E is 30-50℃, for example, it can be 30℃, 32℃, 34℃, 36℃, 38℃, 40℃, 42℃, 44℃, 46℃, 48℃ or 50℃, but not only limited to the listed values, other values not listed in the range are also applicable.

[0035] In some optional embodiments, the time for the stirring reaction of the reaction solution E is 8-16h, for example, it can be 8.0h, 8.8h, 9.6h, 10.4h, 11.2h, 12.0h, 12.8h, 13.6h, 14.4h, 15.2h or 16.0h, but not only limited to the listed values, other values not listed in the range are also applicable.

[0036] As a preferred technical solution of the present application, in step S3, the molar ratio of the boric acid to 1,10-decanediol is 1:(0.7-0.9), for example, it can be 1:0.70, 1:0.72, 1:0.74, 1:0.76, 1:0.78, 1:0.80, 1:0.82, 1:0.84, 1:0.86, 1:0.88 or 1:0.90, but not only limited to the listed values, other values not listed in the range are also applicable.

[0037] In some optional embodiments, the molar ratio of the boric acid to oleyl alcohol is 1:(0.3-0.5), for example, it can be 1:0.30, 1:0.32, 1:0.34, 1:0.36, 1:0.38, 1:0.40, 1:0.42, 1:0.44, 1:0.46, 1:0.48 or 1:0.50, but not only limited to the listed values, other values not listed in the range are also applicable.

[0038] In some optional embodiments, the mass volume ratio of the total mass of the boric acid, 1,10-decanediol and oleyl alcohol to toluene is 1g:(4-6)mL, for example, it can be 1g:4.0mL, 1g:4.2mL, 1g:4.4mL, 1g:4.6mL, 1g:4.8mL, 1g:5.0mL, 1g:5.2mL, 1g:5.4mL, 1g:5.6mL, 1g:5.8mL or 1g:6.0mL, but not only limited to the listed values, other values not listed in the range are also applicable.

[0039] In some optional embodiments, the temperature of the reaction liquid F backflow reaction is 110-120℃, for example, it can be 110℃, 111℃, 112℃, 113℃, 114℃, 115℃, 116℃, 117℃, 118℃, 119℃ or 120℃, but not only limited to the listed values, other values in the range of values are also applicable.

[0040] In some optional embodiments, the temperature of the vacuum drying is 110-130℃, for example, it can be 110℃, 112℃, 114℃, 116℃, 118℃, 120℃, 122℃, 124℃, 126℃, 128℃ or 130℃, but not only limited to the listed values, other values in the range of values are also applicable.

[0041] In some optional embodiments, the time of the vacuum drying is 1-3h, for example, it can be 1.0h, 1.2h, 1.4h, 1.6h, 1.8h, 2.0h, 2.2h, 2.4h, 2.6h, 2.8h or 3.0h, but not only limited to the listed values, other values in the range of values are also applicable.

[0042] As a preferred technical solution of the present application, in step S4, the mass ratio of the functional base oil to PAO4 in the mixed base oil is (6:4)-(7:3), for example, it can be 6:4, 6.1:3.9, 6.2:3.8, 6.3:3.7, 6.4:3.6, 6.5:3.5, 6.6:3.4, 6.7:3.3, 6.8:3.2, 6.9:3.1 or 7:3, but not only limited to the listed values, other values in the range of values are also applicable.

[0043] In some optional embodiments, after the functional base oil is mixed with PAO4, it is heated to a temperature of 60-80℃, for example, it can be heated to 60℃, 62℃, 64℃, 66℃, 68℃, 70℃, 72℃, 74℃, 76℃, 78℃ or 80℃, but not only limited to the listed values, other values in the range of values are also applicable.

[0044] In some optional embodiments, the mass ratio of the dynamic crosslinking agent to the first portion of the mixed base oil in the first mixture is (1-3):100, for example, it can be 1.0:100, 1.2:100, 1.4:100, 1.6:100, 1.8:100, 2.0:100, 2.2:100, 2.4:100, 2.6:100, 2.8:100 or 3.0:100, but not only limited to the listed values, other values in the range of values are also applicable.

[0045] In some optional embodiments, the mass ratio of the surface-hydrophobically modified catalyst to the second part of mixed base oil in the concentrated mother liquor is (0.2-0.8):100, for example, it can be 0.20:100, 0.26:100, 0.32:100, 0.38:100, 0.44:100, 0.50:100, 0.56:100, 0.62:100, 0.68:100, 0.74:100 or 0.80:100, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0046] In some optional embodiments, the mass ratio of the dynamic crosslinking agent to the surface hydrophobically modified catalyst in the second mixture is (2-5):1, for example, it can be 2.0:1, 2.3:1, 2.6:1, 2.9:1, 3.2:1, 3.5:1, 3.8:1, 4.1:1, 4.4:1, 4.7:1 or 5.0:1, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0047] In some optional embodiments, the stirring time after adding polyhexadecyl methacrylate and non-silicone antifoaming agent to the second mixture is 1-2 hours, for example, 1.0h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h or 2.0h, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0048] In some optional embodiments, the amount of polyhexadecyl methacrylate fed is 2-5% of the mass of the second mixture, for example, it can be 2.0%, 2.3%, 2.6%, 2.9%, 3.2%, 3.5%, 3.8%, 4.1%, 4.4%, 4.7% or 5.0%, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0049] In some optional embodiments, the amount of the non-silicone antifoaming agent added is 50-200 ppm of the mass of the second mixture, for example, it can be 50 ppm, 65 ppm, 80 ppm, 95 ppm, 110 ppm, 125 ppm, 140 ppm, 155 ppm, 170 ppm, 185 ppm or 200 ppm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0050] Secondly, the present invention provides a bio-based lubricating oil composition with high oxidation stability.

[0051] The application modifies the bio-based cardanol to prepare a functionalized base oil as the matrix and dynamic network building unit of the entire lubricating system. First, through catalytic hydrogenation reaction, the unsaturated double bond on the side chain of cardanol molecule which is easy to oxidize is converted into a saturated single bond with more stable chemical properties, improving the inherent antioxidant capacity of the base oil skeleton. Then, through etherification reaction, the phenolic hydroxyl group of cardanol is converted into an epoxy group as a subsequent functionalization reaction site. Finally, glycerol is used to partially open the ring of the epoxy group, introducing multiple hydroxyl functional groups at one end of the molecule. These hydroxyl groups serve as pre-set reaction anchors, providing reversible binding sites for dynamic cross-linking agents in the subsequent lubricating oil working environment, and are the structural basis for realizing in-situ self-assembly behavior of the entire system.

[0052] The application introduces a surface hydrophobic modified catalyst to catalyze the decomposition of harmful peroxides. The catalyst is a metal-organic framework nanoparticle with manganese ions as the metal center and porphyrin derivatives as the organic ligand. The use of manganese ions with redox activity and porphyrin ligands enables the nanoparticle to have catalytic function. In order to enable it to be stably dispersed in non-polar base oil, long-chain alkyl groups are grafted onto its surface through silanization reaction. This hydrophobic modification solves the problem of interfacial compatibility between the nanomaterial and the oil phase matrix, enabling the surface hydrophobic modified catalyst to be uniformly dispersed, thereby providing long-term catalytic action in the entire lubricating oil system.

[0053] The application introduces a dynamic cross-linking agent to respond to external environmental changes and connect dispersed base oil molecules into a three-dimensional network. The multiple borate ester bonds contained in the molecular chain have reversible chemical properties. When the temperature of the lubricating oil increases or the local polarity increases, these borate ester bonds can react with the hydroxyl groups on the functionalized base oil molecules. Thus, individual base oil molecules are temporarily bridged to form a micro-region rich in polar species and a reversible network. The long alkoxy groups at the chain ends ensure their own solubility in the base oil.

[0054] There is a synergistic antioxidant effect of the enrichment of oxidation products based on the dynamic network and the catalytic removal of the products by the surface hydrophobic modified catalyst in the application. The network formed by the self-assembly of the dynamic cross-linking agent and the functionalized base oil at high temperature can selectively adsorb and enrich the polar peroxides produced during the oxidation process. Second, the surface hydrophobic modified catalyst is embedded in the network or near the polar micro-region, and the local concentration of peroxides increases due to the enrichment of peroxides, which improves the removal efficiency of the surface hydrophobic modified catalyst. The surface hydrophobic modified catalyst catalyzes the decomposition of peroxides, thereby inhibiting the propagation of the oxidation chain reaction and prolonging the induction period. In addition, the ester exchange reaction formed by the network and the presence of water in the system constitute a dynamic balance, so that the network can provide protection while reorganizing under shear force, maintaining the flowability of the lubricating oil and avoiding permanent gelation.

[0055] Compared with the prior art, the application has the following beneficial effects:

[0056] The functional base oil prepared by modifying the bio-based cardanol in the application is used as the matrix and dynamic network construction unit of the entire lubricating system. The side chain double bond of the cardanol is saturated by catalytic hydrogenation to improve its inherent oxidation stability; and multiple hydroxyl groups are introduced at the molecular terminal through etherification and glycerol ring-opening reaction. These hydroxyl groups act as reversible reaction sites to combine with the dynamic crosslinking agent, thereby providing a structural basis for in-situ self-assembly of the entire system.

[0057] The surface hydrophobic modified catalyst is introduced in the application to catalytically decompose harmful peroxides in the lubricating oil. In order to solve the dispersion problem of the catalyst in the non-polar oil phase, the surface of the surface hydrophobic modified catalyst is hydrophobically modified by grafting long alkyl chains, so that it can be stably and uniformly dispersed in the base oil, thereby enabling it to play a long-acting catalytic antioxidant function in the entire lubricating system.

[0058] The dynamic crosslinking agent is introduced in the application, which reacts with the hydroxyl groups of the functional base oil through its reversible borate ester bond when the temperature rises or the local polarity increases, thereby connecting the dispersed base oil molecules into a dynamic three-dimensional network. The crosslinking agent gives the lubricating oil system self-adaptive ability. At the same time, the long alkoxy chain segment in its molecular structure ensures its solubility in the oil phase.

[0059] There is a synergistic antioxidant effect in the application. The polar microzones generated by the self-assembly of the polar microzones and the reversible network at high temperatures can selectively enrich and concentrate harmful polar peroxides generated during the oxidation process; secondly, the surface hydrophobic modified catalyst located in the network or microzone can more efficiently catalytically decompose the peroxides due to the increase in local peroxide concentration, thereby inhibiting the propagation of the oxidation chain reaction and prolonging the induction period. In addition, the reversibility of the network ensures that the lubricating oil can maintain the necessary fluidity while providing protection, avoiding gelation.

[0060] The dynamic borate ester network in the application tends to reassemble after being disturbed by shearing or thermal oxidation through the reversible borate bond, promoting the recovery of the microstructure and the oil film carrying capacity; at the same time, the surface hydrophobic modified catalyst as a catalytic node helps to continuously remove active oxygen and peroxides, slows down the accumulation of oxidation byproducts and the deactivation of the metal surface, supports the resorption and reconstruction of the boundary lubrication film. The two work together to make the system more easily maintain stable viscosity and interface protection under conditions such as start-stop and load fluctuation, reduce the tendency of varnish and deposit formation, thereby facilitating the extension of the service period and improving the operation reliability. DETAILED DESCRIPTION

[0061] The technical solutions of the present application will be described in detail below with specific examples. The examples described herein are specific embodiments of the present application, which are used to illustrate the concept of the present application; these descriptions are all explanatory and exemplary, and should not be understood as limiting the embodiments of the present application and the protection scope of the present application. In addition to the examples described herein, those skilled in the art can also employ other technical solutions that are obvious based on the content disclosed in the claims and the description of the present application, which include technical solutions that employ any obvious substitutions and modifications to the examples described herein.

[0062] The chemical reagents used in the examples and comparative examples of the present application are all commercially available products, which are not further purified or treated.

[0063] Example 1

[0064] The present example provides a high-oxidation-stability bio-based lubricating oil composition and a preparation method thereof, and the preparation method of the high-oxidation-stability bio-based lubricating oil composition specifically comprises the following steps:

[0065] S1: adding a catalyst Raney Ni to an ethanol dispersion solution of cardanol to obtain a reaction solution A, wherein the mass-volume ratio of cardanol to ethanol is 1 g:8 mL, and the mass ratio of the catalyst Raney Ni to cardanol is 1.8:100, the reaction solution A is placed in a high-pressure reaction kettle, and reacted at 70℃ under a hydrogen pressure of 4bar for 7h, filtered, and rotary evaporated to obtain a preliminary modified cardanol; the preliminary modified cardanol, tetrabutylammonium bromide and epichlorohydrin are mixed to obtain a mixture, wherein the molar ratio of the preliminary modified cardanol, tetrabutylammonium bromide and epichlorohydrin is 1:0.02:1.8, and a 32wt.% sodium hydroxide aqueous solution is added at 68℃ to obtain a reaction solution B, the molar ratio of sodium hydroxide to preliminary modified cardanol in the reaction solution B is 1.08:1, and the reaction is carried out for 5.5h, washed, dried and purified to obtain a cardanol glycidyl ether; the cardanol glycidyl ether and glycerol are mixed at a molar ratio of 1:0.65, and p-toluenesulfonic acid is added to obtain a reaction solution C, wherein the molar ratio of p-toluenesulfonic acid to cardanol glycidyl ether is 1.2:100, and the reaction solution C is stirred at 115℃ for 3.5h to obtain a post-reaction solution, which is cooled to room temperature, and an alkaline alumina powder with a dosage of 8% of the mass of the post-reaction solution is added, and stirred for 55min to obtain a filtrate, which is evaporated by a thin film to obtain a functionalized base oil;

[0066] S2: tetra(4-carboxyphenyl)porphyrin and manganese acetate tetrahydrate were dispersed in N,N-dimethylformamide at a molar ratio of 1:2.5, and ethanol was added to obtain a reaction solution D, the concentration of tetra(4-carboxyphenyl)porphyrin in the reaction solution D was 8 mM, and the volume of ethanol was 12% of the volume of N,N-dimethylformamide, the reaction solution D was reacted at 125℃ for 20 h, and then centrifuged and washed to obtain nanoparticles; the nanoparticles were dispersed in toluene, and octadecyltrichlorosilane and triethylamine were added to obtain a reaction solution E, wherein the mass ratio of octadecyltrichlorosilane to nanoparticles was 1.2:1, and the molar ratio of triethylamine to octadecyltrichlorosilane was 0.8:1, the reaction solution E was stirred at 45℃ for 14 h, and then centrifuged, washed and freeze-dried to obtain a surface hydrophobic modified catalyst;

[0067] S3: boric acid, 1,10-decanediol and oleyl alcohol were mixed in toluene to obtain a reaction solution F, wherein the molar ratio of boric acid to 1,10-decanediol was 1:0.85, the molar ratio of boric acid to oleyl alcohol was 1:0.45, and the mass-volume ratio of the total mass of solutes boric acid, 1,10-decanediol and oleyl alcohol to the mass of solvent toluene was 1 g:5.5 mL, the reaction solution F was refluxed at 118℃ until no water was generated, rotary evaporated, and vacuum dried at 115℃ for 2.5 h to obtain a dynamic crosslinking agent;

[0068] S4: the functionalized base oil and PAO4 were mixed at a mass ratio of 7:3 and heated to 75℃, the mixed base oil was divided into two parts, the dynamic crosslinking agent was added to the first part of the mixed base oil to obtain a first mixture, the mass ratio of the dynamic crosslinking agent to the first part of the mixed base oil in the first mixture was 2.5:100, the surface hydrophobic modified catalyst was mixed with the second part of the mixed base oil, and ultrasonic treatment was performed to obtain a concentrated mother liquor, the mass ratio of the surface hydrophobic modified catalyst to the mixed base oil in the concentrated mother liquor was 0.6:100, the concentrated mother liquor was added to the first mixture to obtain a second mixture, the mass ratio of the dynamic crosslinking agent to the surface hydrophobic modified catalyst in the second mixture was 4:1, polyhexadecyl methacrylate and a non-silicon antifoaming agent were added and stirring was continued for 1.8 h, wherein the amount of polyhexadecyl methacrylate added was 4% of the mass of the second mixture, and the amount of the non-silicon antifoaming agent added was 150 ppm of the mass of the second mixture, and cooling was performed to obtain a high-oxidation-stability bio-based lubricating oil composition.

[0069] Example 2

[0070] The present embodiment provides a high-oxidation-stability bio-based lubricating oil composition and a preparation method thereof, and the preparation method of the high-oxidation-stability bio-based lubricating oil composition specifically comprises the following steps:

[0071] S1: adding catalyst Raney Ni to an ethanol dispersion solution of cardanol to obtain reaction liquid A, wherein the mass-volume ratio of cardanol to ethanol is 1 g:5 mL, and the mass ratio of catalyst Raney Ni to cardanol is 1:100, and the reaction liquid A is placed in a high-pressure reaction kettle, and is reacted at 40°C under a hydrogen pressure of 1 bar for 4 h, and is filtered, and rotary evaporation is performed to obtain preliminary modified cardanol; the preliminary modified cardanol, tetrabutylammonium bromide and epichlorohydrin are mixed to obtain a mixture, wherein the molar ratio of the preliminary modified cardanol, tetrabutylammonium bromide and epichlorohydrin is 1:0.02:1.5, and a 40 wt.% sodium hydroxide aqueous solution is added to obtain reaction liquid B, wherein the molar ratio of sodium hydroxide to preliminary modified cardanol in the reaction liquid B is 1:1, and the reaction is performed for 4 h, and is washed, dried and purified to obtain cardanol glycidyl ether; the cardanol glycidyl ether and glycerol are mixed in a molar ratio of 1:0.5, and p-toluenesulfonic acid is added to obtain reaction liquid C, wherein the molar ratio of p-toluenesulfonic acid to cardanol glycidyl ether is 0.5:100, and the reaction is performed at 100°C under stirring for 2 h to obtain a post-reaction solution, and the post-reaction solution is cooled to room temperature, and an amount of basic alumina powder is added, which is 5% of the mass of the post-reaction solution, and after stirring adsorption for 40 min, filtration is performed to obtain a filtrate, and the filtrate is subjected to thin film evaporation to obtain a functional base oil;

[0072] S2: dispersing tetra(4-carboxyphenyl)porphyrin and manganese acetate tetrahydrate in N,N-dimethylformamide at a molar ratio of 1:1.5, adding ethanol to obtain reaction liquid D, the concentration of tetra(4-carboxyphenyl)porphyrin in the reaction liquid D is 5 mM, and the volume of ethanol is 20% of the volume of N,N-dimethylformamide, and the reaction is performed at 110°C for 12 h, and after centrifugation and washing, nanoparticles are obtained; dispersing the nanoparticles in toluene, adding octadecyltrichlorosilane and triethylamine to obtain reaction liquid E, wherein the mass ratio of octadecyltrichlorosilane to nanoparticles is 0.5:1, and the molar ratio of triethylamine to octadecyltrichlorosilane is 0.7:1, and the reaction is performed at 30°C under stirring for 8 h, and after centrifugation, washing and freeze-drying, a surface hydrophobic modified catalyst is obtained;

[0073] S3: mixing boric acid, 1,10-decanediol and oleyl alcohol in toluene to obtain reaction liquid F, wherein the molar ratio of boric acid to 1,10-decanediol is 1:0.7, and the molar ratio of boric acid to oleyl alcohol is 1:0.3, and the mass-volume ratio of the total mass of solutes boric acid, 1,10-decanediol and oleyl alcohol to the mass of solvent toluene is 1 g:4 mL, and the reaction liquid F is refluxed at 110°C until no water is generated, rotary evaporation is performed, and vacuum drying is performed at 130°C for 1 h to obtain a dynamic crosslinking agent;

[0074] S4: the functionalized base oil is mixed with PAO4 at a mass ratio of 6.5:3.5 and heated to 60℃, the mixed base oil is divided into two parts, a dynamic crosslinking agent is added to the first part of the mixed base oil to obtain a first mixture, the mass ratio of the dynamic crosslinking agent to the first part of the mixed base oil in the first mixture is 1:100, the surface hydrophobic modified catalyst is mixed with the second part of the mixed base oil to obtain a concentrated mother liquor, the mass ratio of the surface hydrophobic modified catalyst to the mixed base oil in the concentrated mother liquor is 0.2:100, the concentrated mother liquor is added to the first mixture to obtain a second mixture, the mass ratio of the dynamic crosslinking agent to the surface hydrophobic modified catalyst in the second mixture is 2:1, polyhexadecyl methacrylate and a non-silicon antifoaming agent are added and continue to stir for 1h, wherein the amount of polyhexadecyl methacrylate added is 2% of the mass of the second mixture, and the amount of the non-silicon antifoaming agent added is 50ppm of the mass of the second mixture, and a high-oxidation-stability bio-based lubricating oil composition is obtained after cooling.

[0075] Example 3

[0076] The present embodiment provides a high-oxidation-stability bio-based lubricating oil composition and a preparation method thereof, and the preparation method of the high-oxidation-stability bio-based lubricating oil composition specifically comprises the following steps:

[0077] S1: a catalyst Raney Ni is added to an ethanol dispersion solution of cardanol to obtain a reaction solution A, wherein the mass-volume ratio of cardanol to ethanol is 1g:7mL, and the mass ratio of the catalyst Raney Ni to cardanol is 1.2:100, the reaction solution A is placed in a high-pressure reaction kettle, and reacted at a hydrogen pressure of 2bar and a temperature of 50℃ for 5h, filtered, and rotary evaporated to obtain a preliminary modified cardanol; the preliminary modified cardanol, tetrabutylammonium bromide and epichlorohydrin are mixed to obtain a mixture, wherein the molar ratio of the preliminary modified cardanol, tetrabutylammonium bromide and epichlorohydrin is 1:0.02:1.7, a 38wt.% sodium hydroxide aqueous solution is added to obtain a reaction solution B, the molar ratio of sodium hydroxide to preliminary modified cardanol in the reaction solution B is 1.02:1, and the reaction is carried out at 62℃ for 4.5h, washed, dried and purified to obtain a cardanol glycidyl ether; the cardanol glycidyl ether and glycerol are mixed at a molar ratio of 1:0.55, and p-toluenesulfonic acid is added to obtain a reaction solution C, wherein the molar ratio of p-toluenesulfonic acid to cardanol glycidyl ether is 0.8:100, the reaction solution C is stirred at 105℃ for 2.5h to obtain a post-reaction solution, cooled to room temperature, and 6% of the mass of the post-reaction solution of basic alumina powder is added, stirred for 45min, and then filtered to obtain a filtrate, which is evaporated by a thin film to obtain a functionalized base oil;

[0078] S2: tetra(4-carboxyphenyl)porphyrin and manganese acetate tetrahydrate were dispersed in N,N-dimethylformamide at a molar ratio of 1:2, and ethanol was added to obtain a reaction solution D, the concentration of tetra(4-carboxyphenyl)porphyrin in the reaction solution D was 6 mM, and the volume of ethanol was 18% of the volume of N,N-dimethylformamide, and the reaction solution D was reacted at 115°C for 15 h, and then centrifuged and washed to obtain nanoparticles; the nanoparticles were dispersed in toluene, and octadecyltrichlorosilane and triethylamine were added to obtain a reaction solution E, wherein the mass ratio of octadecyltrichlorosilane to nanoparticles was 0.8:1, and the molar ratio of triethylamine to octadecyltrichlorosilane was 0.5:1, and the reaction solution E was stirred at 35°C for 10 h, and then centrifuged, washed and freeze-dried to obtain a surface hydrophobic modified catalyst;

[0079] S3: boric acid, 1,10-decanediol and oleyl alcohol were mixed in toluene to obtain a reaction solution F, wherein the molar ratio of boric acid to 1,10-decanediol was 1:0.75, the molar ratio of boric acid to oleyl alcohol was 1:0.35, and the mass-volume ratio of the total mass of solutes boric acid, 1,10-decanediol and oleyl alcohol to the mass of solvent toluene was 1 g:4.5 mL, and the reaction solution F was refluxed at 112°C until no water was generated, and then rotary evaporated, and vacuum dried at 125°C for 1.5 h to obtain a dynamic crosslinking agent;

[0080] S4: the functionalized base oil and PAO4 were mixed at a mass ratio of 6:4 and heated to 65°C, and the mixed base oil was divided into two parts, the first part of the mixed base oil was added with the dynamic crosslinking agent to obtain a first mixture, and the mass ratio of the dynamic crosslinking agent to the first part of the mixed base oil in the first mixture was 1.5:100, the surface hydrophobic modified catalyst was mixed with the second part of the mixed base oil, and ultrasonic treatment was performed to obtain a concentrated mother liquor, and the mass ratio of the surface hydrophobic modified catalyst to the mixed base oil in the concentrated mother liquor was 0.4:100, the concentrated mother liquor was added to the first mixture to obtain a second mixture, and the mass ratio of the dynamic crosslinking agent to the surface hydrophobic modified catalyst in the second mixture was 3:1, polyhexadecyl methacrylate and a non-silicon antifoaming agent were added and continuously stirred for 1.2 h, and the amount of polyhexadecyl methacrylate added was 3% of the mass of the second mixture, and the amount of the non-silicon antifoaming agent added was 80 ppm of the mass of the second mixture, and cooling was performed to obtain a high-oxidation-stability bio-based lubricating oil composition.

[0081] Example 4

[0082] The embodiment provides a high-oxidation-stability bio-based lubricating oil composition and a preparation method thereof, and the preparation method of the high-oxidation-stability bio-based lubricating oil composition specifically comprises the following steps:

[0083] S1: adding catalyst Raney Ni to an ethanol dispersion solution of cardanol to obtain reaction liquid A, wherein the mass-volume ratio of cardanol to ethanol is 1 g:10 mL, and the mass ratio of catalyst Raney Ni to cardanol is 2:100, and the reaction liquid A is placed in a high-pressure reaction kettle, and is reacted at 80°C under a hydrogen pressure of 5 bar for 8 h, and is filtered, and rotary evaporation is performed to obtain preliminary modified cardanol; the preliminary modified cardanol, tetrabutylammonium bromide and epichlorohydrin are mixed to obtain a mixture, wherein the molar ratio of the preliminary modified cardanol, tetrabutylammonium bromide and epichlorohydrin is 1:0.02:2, and a 30 wt.% sodium hydroxide aqueous solution is added to obtain reaction liquid B at 70°C, and the molar ratio of sodium hydroxide to preliminary modified cardanol in the reaction liquid B is 1.1:1, and the reaction is performed for 6 h, and is washed, dried and purified to obtain cardanol glycidyl ether; the cardanol glycidyl ether and glycerol are mixed in a molar ratio of 1:0.7, and p-toluenesulfonic acid is added to obtain reaction liquid C, wherein the molar ratio of p-toluenesulfonic acid to cardanol glycidyl ether is 1.5:100, and the reaction is performed at 120°C under stirring for 4 h to obtain a post-reaction solution, and the post-reaction solution is cooled to room temperature, and an amount of basic alumina powder is added, which is 10% of the mass of the post-reaction solution, and after stirring adsorption for 60 min, filtration is performed to obtain a filtrate, and the filtrate is subjected to thin film evaporation to obtain a functional base oil;

[0084] S2: dispersing tetra(4-carboxyphenyl)porphyrin and manganese acetate tetrahydrate in N,N-dimethylformamide at a molar ratio of 1:3, and adding ethanol to obtain reaction liquid D, wherein the concentration of tetra(4-carboxyphenyl)porphyrin in the reaction liquid D is 10 mM, and the volume of ethanol is 10% of the volume of N,N-dimethylformamide, and the reaction is performed at 130°C for 24 h, and after centrifugation and washing, nanoparticles are obtained; dispersing the nanoparticles in toluene, and adding octadecyltrichlorosilane and triethylamine to obtain reaction liquid E, wherein the mass ratio of octadecyltrichlorosilane to nanoparticles is 1.5:1, and the molar ratio of triethylamine to octadecyltrichlorosilane is 1:1, and the reaction is performed at 50°C under stirring for 16 h, and after centrifugation, washing and freeze-drying, a surface hydrophobic modified catalyst is obtained;

[0085] S3: mixing boric acid, 1,10-decanediol and oleyl alcohol in toluene to obtain reaction liquid F, wherein the molar ratio of boric acid to 1,10-decanediol is 1:0.9, and the molar ratio of boric acid to oleyl alcohol is 1:0.5, and the mass-volume ratio of the total mass of solutes boric acid, 1,10-decanediol and oleyl alcohol to the mass of solvent toluene is 1 g:6 mL, and the reaction liquid F is refluxed at 120°C until no water is generated, and rotary evaporation is performed, and vacuum drying is performed at 110°C for 3 h to obtain a dynamic crosslinking agent;

[0086] S4: the functionalized base oil and PAO4 were mixed at a mass ratio of 6.8:3.2 and heated to 80℃, the mixed base oil was divided into two parts, a dynamic crosslinking agent was added to the first part of the mixed base oil and stirred to obtain a first mixture, wherein the mass ratio of the dynamic crosslinking agent to the first part of the mixed base oil in the first mixture was 3:100, the surface hydrophobic modified catalyst was mixed with the second part of the mixed base oil, and the mixture was ultrasonically treated to obtain a concentrated mother liquor, wherein the mass ratio of the surface hydrophobic modified catalyst to the mixed base oil in the concentrated mother liquor was 0.8:100, the concentrated mother liquor was added to the first mixture to obtain a second mixture, wherein the mass ratio of the dynamic crosslinking agent to the surface hydrophobic modified catalyst in the second mixture was 5:1, polyhexadecyl methacrylate and a non-silicon antifoaming agent were added and stirring was continued for 2h, wherein the amount of polyhexadecyl methacrylate added was 5% of the mass of the second mixture, and the amount of the non-silicon antifoaming agent added was 200ppm of the mass of the second mixture, and a high-oxidation-stability bio-based lubricating oil composition was obtained after cooling.

[0087] Comparative Example 1

[0088] This comparative example provides a high-oxidation-stability bio-based lubricating oil composition, which is different from Example 1 in that, in S4, no dynamic crosslinking agent is added, and the other operation steps and process parameters are exactly the same as those of Example 1.

[0089] Comparative Example 2

[0090] This comparative example provides a high-oxidation-stability bio-based lubricating oil composition, which is different from Example 1 in that, in S4, no surface hydrophobic modified catalyst is added, and the other operation steps and process parameters are exactly the same as those of Example 1.

[0091] Comparative Example 3

[0092] This comparative example provides a high-oxidation-stability bio-based lubricating oil composition, which is different from Example 1 in that, cashew phenol glycidyl ether is used instead of the functionalized base oil, and the other operation steps and process parameters are exactly the same as those of Example 1.

[0093] Comparative Example 4

[0094] This comparative example provides a high-oxidation-stability bio-based lubricating oil composition, which is different from Example 1 in that, nano-silicon dioxide that is also hydrophobically modified by octadecyltrichlorosilane is used instead of the surface hydrophobic modified catalyst, and the other operation steps and process parameters are exactly the same as those of Example 1.

[0095] The high-oxidation-stability bio-based lubricating oil compositions of Examples 1-4 and Comparative Examples 1-4 described above were subjected to performance testing, and the specific process was as follows:

[0096] The oxidation induction time of the sample was tested according to ASTM D2272;

[0097] The samples were aged by forced air oxidation at 150 °C for 100 h, and then tested for peroxide value according to ASTM D3703;

[0098] The samples were tested for high temperature high shear viscosity at 150 °C according to ASTM D4683;

[0099] The test results are shown in Table 1.

[0100] Table 1. Test results of high oxidative stability of bio-based lubricating oil compositions of Examples 1-4 and Comparative Examples 1-4

[0101]

[0102] From the test results of Example 1 and Comparative Example 1 in Table 1, it can be seen that without adding the dynamic crosslinking agent in S4, the system cannot form microzones rich in polar species and reversible network structure at high temperature. Without the targeted enrichment of oxidation products by the network, the surface hydrophobic modified catalyst mainly relies on molecular free diffusion and collision, and the efficiency is reduced, resulting in a shortened oxidation induction time and an increased peroxide value after aging due to insufficient catalytic efficiency. At the same time, due to the lack of the network structure to enhance the oil film, the viscosity of the sample under high temperature and high shear conditions decreases, indicating that the high temperature oil film strength is insufficient.

[0103] From the test results of Example 1 and Comparative Example 2 in Table 1, it can be seen that without adding the surface hydrophobic modified catalyst in S4, the system can form microzones rich in polar species and reversible network, but lacks the core functional unit for efficient removal of oxidation products. The peroxide accumulated in the dynamic network cannot be decomposed in time, resulting in an increased peroxide value after aging, accelerating the overall oxidation of the oil product and reducing the oxidation induction time. The high temperature and high shear viscosity changes little, verifying the formation of the network structure.

[0104] From the test results of Example 1 and Comparative Example 3 in Table 1, it can be seen that using cardanol glycidyl ether to replace the functionalized base oil, due to the lack of hydroxyl sites in its molecular structure for ester exchange reaction with the dynamic crosslinking agent, the dynamic network cannot be formed. This makes the synergistic antioxidant effect of the system ineffective, resulting in a decreased oxidation induction time. At the same time, due to the lack of enrichment of the network structure, the catalytic efficiency of the surface hydrophobic modified catalyst is reduced, and the accumulation of peroxide after aging is increased. The high temperature and high shear viscosity decreases, indicating that due to the failure to form the dynamic network, the high temperature oil film strength is insufficient.

[0105] From the test results of Example 1 and Comparative Example 4 in Table 1, it can be seen that, when the surface hydrophobic modified catalyst is replaced by nano-silica which is also hydrophobically modified by octadecyltrichlorosilane, the system can form micro-regions and reversible networks enriched in polar species, but since the nano-silica does not have the ability to catalytically decompose peroxide, the highly active peroxide enriched in the network cannot be effectively removed and accumulates in large quantities. These accumulated peroxides accelerate the overall degradation of the oil, resulting in a decrease in the oxidation induction time. The peroxide value after aging increases. The high-temperature high-shear viscosity changes little, indicating that the dynamic network structure is formed and plays a role in enhancing the oil film.

[0106] The above description is merely a specific implementation of the present application, but the protection scope of the present application is not limited thereto. It should be understood by those skilled in the art that any changes or replacements within the technical scope disclosed by the present application can be easily conceived by those skilled in the art, and all such changes and replacements fall within the protection scope and disclosure scope of the present application.

Claims

1. A process for the preparation of a biobased lubricating oil composition with high oxidative stability, characterized in that, The preparation method comprises: S1: adding a catalyst Raney Ni into an ethanol dispersion solution of cardanol to obtain a reaction solution A, placing the reaction solution A into a high-pressure reaction kettle, reacting, filtering, and rotary evaporating to obtain a preliminary modified cardanol; mixing the preliminary modified cardanol, tetrabutylammonium bromide, and epichlorohydrin to obtain a mixture, adding an aqueous sodium hydroxide solution to obtain a reaction solution B, reacting, washing, drying, and purifying to obtain a cardanol glycidyl ether; mixing the cardanol glycidyl ether and glycerol, adding p-toluenesulfonic acid to obtain a reaction solution C, stirring and reacting to obtain a post-reaction solution, cooling to room temperature, adding an alkaline aluminum oxide powder, stirring and adsorbing, and then filtering to obtain a filtrate, and evaporating the filtrate through a thin film to obtain a functional base oil; S2: dispersing tetra(4-carboxyphenyl)porphyrin and manganese acetate tetrahydrate in N,N-dimethylformamide, adding ethanol to obtain a reaction solution D, reacting, centrifuging, and washing to obtain nanoparticles; dispersing the nanoparticles in toluene, adding octadecyltrichlorosilane and triethylamine to obtain a reaction solution E, stirring and reacting, centrifuging, washing, and freeze-drying to obtain a surface hydrophobic modified catalyst; S3: mixing boric acid, 1,10-decanediol, and oleyl alcohol in toluene to obtain a reaction solution F, refluxing the reaction solution F until no water is generated, rotary evaporating, and vacuum drying to obtain a dynamic crosslinking agent; S4: mixing the functional base oil and PAO4 and heating to obtain a mixed base oil, dividing the mixed base oil into two parts, adding the dynamic crosslinking agent to the first part of the mixed base oil to obtain a first mixture, mixing the surface hydrophobic modified catalyst with the second part of the mixed base oil, ultrasonic treating to obtain a concentrated mother liquor, adding the concentrated mother liquor to the first mixture to obtain a second mixture, adding polyhexadecyl methacrylate and a non-silicon antifoaming agent and continuing to stir, and cooling to obtain a high-oxidation-stability bio-based lubricating oil composition.

2. The process for the preparation of a biobased lubricating oil composition with high oxidative stability according to claim 1, characterized in that, In S1: The mass-volume ratio of cardanol to ethanol in the ethanol dispersion solution of cardanol is 1 g:(5-10) mL; The mass ratio of the catalyst Raney Ni to cardanol is (1-2):

100.

3. The process for preparing a biobased lubricating oil composition with high oxidative stability according to claim 1, characterized in that, In S1: The molar ratio of the preliminary modified cardanol, tetrabutylammonium bromide, and epichlorohydrin is 1:0.02:(1.5-2); The molar ratio of sodium hydroxide to the preliminary modified cardanol in the reaction solution B is (1-1.1):

1.

4. The process for preparing a biobased lubricating oil composition with high oxidative stability according to claim 1, characterized in that, In S1: The molar ratio of the cardanol glycidyl ether to glycerol is 1:(0.5-0.7); The molar ratio of p-toluenesulfonic acid to the cardanol glycidyl ether is (0.5-1.5):100; The amount of the alkaline aluminum oxide powder is 5-10% of the mass of the post-reaction solution.

5. The process for preparing a biobased lubricating oil composition with high oxidative stability according to claim 1, characterized in that, In S2: The molar ratio of tetra(4-carboxyphenyl)porphyrin to manganese acetate tetrahydrate is 1:(1.5-3); The concentration of tetra(4-carboxyphenyl)porphyrin in the reaction solution D is 5-10 mM; The volume of ethanol is 10-20% of the volume of N,N-dimethylformamide.

6. The process for preparing a biobased lubricating oil composition with high oxidative stability according to claim 1, characterized in that, In S2: The mass ratio of octadecyltrichlorosilane to nanoparticles is (0.5-1.5):1; The molar ratio of triethylamine to octadecyltrichlorosilane is (0.5-1):

1.

7. The method of claim 1, wherein the biobased lubricating oil composition has a high oxidative stability. In S3: the molar ratio of the boronic acid to 1,10-decanediol is 1:(0.7-0.9); the molar ratio of the boronic acid to oleyl alcohol is 1:(0.3-0.5); the mass volume ratio of the total mass of the boronic acid, 1,10-decanediol and oleyl alcohol to toluene is 1g:(4-6)mL.

8. The method of claim 1, wherein the biobased lubricating oil composition has a high oxidative stability. In S4: the mass ratio of the functionalized base oil to PAO4 in the mixed base oil is (6:4)-(7:3); the mass ratio of the dynamic crosslinking agent to the first portion of the mixed base oil in the first mixture is (1-3):100; the mass ratio of the surface hydrophobic modified catalyst to the second portion of the mixed base oil in the concentrated mother liquor is (0.2-0.8):

100.

9. The method of claim 1, wherein the biobased lubricating oil composition has a high oxidative stability. In S4: the mass ratio of the dynamic crosslinking agent to the surface hydrophobic modified catalyst in the second mixture is (2-5):1; the feeding amount of the polyhexadecyl methacrylate is 2-5% of the mass of the second mixture; the addition amount of the non-silicon antifoam agent is 50-200ppm of the mass of the second mixture.

10. A bio-based lubricating oil composition with high oxidative stability prepared according to the preparation method of any one of claims 1-9.

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