Polyether base oil and preparation method thereof

Abstract

The invention relates to a preparation method of polyether base oil, which comprises the following steps: by taking C1-C10 fatty alcohol as an initiator, carrying out polymerization reaction on the initiator and epoxyalkane under the action of a phosphorus catalyst to obtain a basic polyether intermediate I, adding arylboronic acid, and reacting to obtain the polyether base oil, and continuously carrying out dehydration condensation reaction on the basic polyether intermediate I and arylboronic acid under the action of a phosphorus catalyst to obtain the polyether base oil product. The polyether base oil has excellent oxidation stability and extreme pressure wear resistance.

Description

Technical Field

[0001] The invention relates to the field of lubricating base oil, in particular to a polyether base oil and a preparation method thereof. Background Art

[0002] Screw air compressors are one of the mainstream compressors in the current air compressor market, among which oil-injected screw compressors are the most widely used type. Lubricating oil can be said to be the "blood" of the compressor, and is mainly used for lubrication of the moving parts of the air compressor cylinder and the exhaust valve. During the operation of the compressor, the compressor oil is pressed into the compressor by the oil pump to lubricate the bearings, etc., and the compressor oil is also sprayed into the compressor to absorb the heat generated during the compression process, and quickly form a layer of lubricating oil film, which can play a protective role in lubrication, sealing, cooling and cleaning.

[0003] In the use environment of air compressors, the compressor oil will be mixed with hot air in the form of mist and heated up rapidly. It will also absorb the friction heat of various components, so it will act at high temperature for a long time, and then be oxidized to generate various acidic substances, causing viscosity changes and even precipitation. The special working environment requires that the lubricating oil used in air compressors must have excellent viscosity-temperature performance, anti-emulsification, oxidation stability and extreme pressure and anti-wear properties.

[0004] The selected base oil determines the most basic performance of the air compressor oil. Traditional mineral oil lubricants are often oxidized due to high temperature in the application environment of air compressors, which easily forms carbon deposits and shortens the service life. In addition, some hydrocarbon gases will dissolve in mineral oil, causing its viscosity to decrease, which not only affects its use, but also poses a safety hazard. Therefore, synthetic base oils such as polyalphaolefins (PAO), polyethers and esters have emerged in this direction. Air compressor oils with PAO as the base oil have hydrolysis stability and oxidation stability, but poor wear resistance; ester base oils are used for air compressor oils with excellent cooling effect and wear resistance, but poor anti-emulsification and easy hydrolysis; polyethers are used as base oils to prepare air compressor oils, which have the advantages of good lubrication performance, high viscosity-temperature index, wide viscosity range, and less carbon deposits, but poor oxidation stability, poor compatibility with additives, poor compatibility with traditional engine oils, and more troublesome oil replacement. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies in the prior art and provide a polyether base oil with excellent oxidation stability and extreme pressure and anti-wear properties and a preparation method thereof.

[0006] In order to achieve the above-mentioned object, the first aspect of the present invention provides a method for preparing a polyether base oil, wherein the polyether base oil uses a C1-C10 fatty alcohol as an initiator, undergoes a polymerization reaction with an alkylene oxide under the action of a phosphorus catalyst to obtain a basic polyether intermediate I, wherein the alkylene oxide is propylene oxide and optionally ethylene oxide and / or butylene oxide, and then an aryl boronic acid is added, and the basic polyether intermediate I and the aryl boronic acid are further subjected to a dehydration condensation reaction under the action of a phosphorus catalyst to obtain the polyether base oil product.

[0007] The second aspect of the present invention provides a polyether base oil prepared by the above-mentioned method for preparing a polyether base oil.

[0008] Compared with the prior art, the present invention has the following beneficial effects:

[0009] The synthesis method of the polyether base oil provided by the present invention can obtain a polyether intermediate I with a very narrow molecular weight distribution and a high viscosity index by using a phosphorus catalyst, and can promote the condensation of the polyether intermediate I and the aryl boronic acid, realize an equivalent reaction without boric acid residue, and play a stabilizer role for the generated boric ester product. In contrast, inorganic base catalysts such as KOH inhibit the formation of boric esters, and bimetallic catalysts have a large amount of aryl boronic acid residues at a ratio of polyether intermediate I: aryl boronic acid = 2:1, which affects the acid value of the product base oil.

[0010] In the synthesis method of the polyether base oil provided by the present invention, the introduction of an aromatic borate structure containing or not containing an electron-withdrawing substituent provides benefits for the conjugation of lone pairs of electrons on the polyoxyethylene chain, and the overall potential energy of the molecule decreases, so that the base oil has excellent oxidation stability, no carbon deposits are generated, and the acid value hardly changes after long-term use; during the lubrication process, for parts that produce mechanical wear, the borate structure can preferentially react with the metal surface to fill the gap, thereby maintaining the lubrication effect, and thus has excellent extreme pressure and wear resistance; at the same time, the aromatic structure with lower polarity and greater steric hindrance also makes the base oil more compatible with most of the current high-polarity additives.

[0011] The polyether base oil provided by the invention has excellent oxidation stability, lubricity, anti-emulsification and additive compatibility, and also has a lower pour point, a higher flash point and certain defoaming performance. DETAILED DESCRIPTION

[0012] The present invention is further described below by means of specific embodiments. The embodiments of the present invention are only used as illustrations of the present invention and do not mean that the scope of the present invention is limited thereto.

[0013] The first aspect of the present invention provides a method for preparing a polyether base oil. The polyether base oil uses a C1-C10 fatty alcohol as an initiator, undergoes a polymerization reaction with an alkylene oxide under the action of a phosphorus catalyst to obtain a basic polyether intermediate I, wherein the alkylene oxide is propylene oxide and optionally ethylene oxide and / or butylene oxide, and then an aromatic boronic acid is added, and the basic polyether intermediate I and the aromatic boronic acid are further subjected to a dehydration condensation reaction under the action of a phosphorus catalyst to obtain the polyether base oil product.

[0014] In some embodiments, the phosphorus catalyst is a quaternary phosphonium salt catalyst or a phosphazene base catalyst. For example, the quaternary phosphonium salt catalyst may be tetrakisdiethylaminophosphonium bromide, di(piperidinyl)-(diethylamino)phosphonium bromide, tris(morpholinyl)-(diethylamino)phosphonium bromide, etc., and the phosphazene base catalyst may be tris[tris(dimethylamino)phosphoranylideneamino]methanolphosphonium, tetrakis[tris(dimethylamino)phosphoranylideneamino]phosphonium hydroxide, tetrakis[tris(dimethylamino)phosphoranylideneamino]methoxyphosphonium, etc.

[0015] In some embodiments, the mass ratio of the phosphorus catalyst to the C1-C10 fatty alcohol is 0.1:100 to 1:100.

[0016] In some embodiments, the C1-C10 fatty alcohol is a primary alcohol, a secondary alcohol or a diol.

[0017] In some embodiments, the mass ratio of the C1-C10 fatty alcohol to the alkylene oxide is 2:100 to 16:100.

[0018] In some embodiments, the molar ratio of ethylene oxide:propylene oxide:butylene oxide used in the alkylene oxide is (0-3):1:(0-10).

[0019] For the polyether base oil of the present invention, propylene oxide participates in the polymerization to provide basic lubricity for the base oil; as the amount of ethylene oxide in the alkylene oxide increases, it exhibits unique water solubility and has better cooling performance, and the dehydration condensation reaction rate of the obtained polyether intermediate I with aromatic boronic acid is faster; as the amount of butylene oxide in the alkylene oxide increases, it exhibits unique oil solubility and has better cleaning performance, and the dehydration condensation reaction rate of the obtained polyether intermediate I with aromatic boronic acid is slowed down.

[0020] The molecular weight distribution of the polyether intermediate I obtained by the method of the present invention is very narrow, PDI=1.010-1.030, so that a high viscosity index can be obtained, and the condensation of the polyether intermediate I and the aromatic boronic acid can be promoted to achieve an equivalent reaction without residual boric acid.

[0021] In some embodiments, the aryl boronic acid is one or more aromatic boronic acids selected from phenyl boronic acid with or without substitution, naphthyl boronic acid with or without substitution, or quinoline boronic acid with or without substitution.

[0022] Preferably, the aromatic boronic acid is one or more aromatic boronic acids selected from phenyl boronic acid containing a substituent, naphthyl boronic acid containing a substituent or quinoline boronic acid containing a substituent, and the substituent is an electron-withdrawing substituent, preferably one or more of cyano, nitro and acetyl.

[0023] In some embodiments, the molar ratio of the base polyether intermediate I to the arylboronic acid is 1.8:1 to 2.2:1. The molecular weight of the polyether intermediate I is not particularly limited in the present invention and can be appropriately selected according to the needs. In addition, the molecular weight of the polyether intermediate I can be measured or deduced by conventional means in the art, such as by the hydroxyl value titration method of the polyether polyol.

[0024] In some embodiments, the polymerization reaction temperature is 110-130° C., and the reaction pressure is less than or equal to 0.3 MPa.

[0025] In some embodiments, the temperature of the dehydration condensation reaction is 100-120°C.

[0026] In a specific embodiment, the specific synthesis steps of the polyether base oil are: adding C1-C10 fatty alcohol and an appropriate amount of phosphorus catalyst to a reactor, replacing with nitrogen 3 times, evacuating to -0.095MPa or lower, heating to 110-130°C, and then starting to uniformly introduce alkylene oxide (propylene oxide and optional ethylene oxide and / or butylene oxide) into the reactor, controlling the reaction temperature at 110-130°C, and the reaction pressure is less than or equal to 0.3MPa; the alkylene oxide feed amount After reaching the set value of the formula, aging begins until the pressure reaches -0.05 to -0.095 MPa, the mixture is cooled to 100°C, and vacuum is applied for 8 to 10 minutes to obtain a polyether intermediate I. Subsequently, the polyether intermediate I and aromatic boronic acid are added into a reaction vessel with an agitator at a molar ratio of 1.8 to 2.2:1, the temperature is maintained at 100 to 120°C, and the reaction is carried out for 1 to 3 hours under stirring conditions. During the process, water produced during the reaction is continuously distilled under reduced pressure to obtain a polyether base oil product.

[0027] In some embodiments, the C1-C10 fatty alcohol is a short-chain alcohol, such as a C1-C5 fatty alcohol, for example, methanol, n-butanol, etc. The polyether base oil product prepared from the short-chain alcohol exhibits excellent wettability and cooling performance.

[0028] In some embodiments, the C1-C10 fatty alcohol is a long-chain alcohol, such as a C6-C10 alcohol, for example, isooctyl alcohol, n-octanol, n-heptanol, etc. The polyether base oil product prepared from the long-chain alcohol exhibits excellent anti-foaming properties and better compatibility with traditional oils.

[0029] The polyether base oil prepared by the above method can be obtained by adjusting the proportion of epoxide in alkylene oxide to obtain water-soluble, water-insoluble or oil-soluble lubricating oil base oil, and the viscosity range at 40°C covers 20 to 320 grades, and the viscosity index is between 180 and 320.

[0030] The second aspect of the present invention provides a polyether base oil prepared by the above-mentioned method for preparing a polyether base oil.

[0031] The present invention will be further described below by means of some embodiments, but the use of the present invention is not limited thereto.

[0032] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in the field can be used. If no manufacturer is specified for the reagents or instruments used, they are all conventional reagent products that can be obtained commercially.

[0033] Example 1

[0034] 100 g of n-butanol and 0.14 g of tetrakisdiethylaminophosphonium bromide were added to a reactor, stirring was started, the gas was replaced with nitrogen for 3 times, and then vacuumed to -0.095 MPa, the temperature was raised to 110° C., and 755 g of ethylene oxide and 497 g of propylene oxide were uniformly mixed and introduced into the reactor, the reaction temperature was controlled at 120° C., and the reaction pressure was ≤0.3 MPa; after the feeding was completed, the pressure was aged to -0.085 MPa, cooled to 100° C., and vacuumed for 8 minutes to obtain a polyether intermediate I with PDI=1.014 and Mw=1002 g / mol; then 1000 g of the polyether intermediate I and 85.8 g of α-naphthyl boronic acid were added to a reaction vessel with a stirrer, the temperature was maintained at 105° C., the reaction was carried out under stirring, and water generated in the reaction process was continuously distilled under reduced pressure to remove water, and no α-naphthyl boronic acid residue was detected after 1 hour, so as to obtain a water-soluble polyether base oil product.

[0035] Example 2

[0036] 100 g of n-butanol and 0.16 g of tetrakisdiethylaminophosphonium bromide were added to a reactor, stirring was started, the gas was replaced with nitrogen three times, and then vacuumed to -0.095 MPa, the temperature was raised to 110° C., and 1390 g of propylene oxide was uniformly mixed and introduced into the reactor, the reaction temperature was controlled at 110° C., and the reaction pressure was ≤0.3 MPa; after the feeding was completed, the pressure was aged to -0.07 MPa, cooled to 100° C., and vacuumed for 8 minutes to obtain a polyether intermediate I with PDI=1.011 and Mw=1102 g / mol; then 1000 g of the polyether intermediate I and 74.4 g of 4-acetylphenylboric acid were added to a reaction vessel with a stirrer, the temperature was maintained at 105° C., and the reaction was carried out under stirring. During the process, water generated during the reaction was continuously distilled under reduced pressure to remove water, and no 4-acetylphenylboric acid was detected after 2 hours, so as to obtain a water-insoluble polyether base oil product.

[0037] Example 3

[0038] 100 g of n-butanol and 0.13 g of tris[tris(dimethylamino)phosphoranylideneamino]phosphonium methanol were added to a reactor, stirring was started, the gas was replaced with nitrogen three times and then vacuumed to -0.095 MPa, the temperature was raised to 110° C., and 74 g of propylene oxide and 918 g of butylene oxide were uniformly mixed and introduced into the reactor, the reaction temperature was controlled at 110° C., and the reaction pressure was ≤0.3 MPa; after the feeding was completed, the pressure was aged to -0.06 MPa, cooled to 100° C., and vacuumed for 8 minutes to obtain a polyether intermediate I with PDI=1.011 and Mw=807 g / mol; then 1000 g of the polyether intermediate I and 91 g of 4-cyanophenylboric acid were added to a reaction vessel with a stirrer, the temperature was maintained at 110° C., and the reaction was reacted under stirring. During the process, water generated during the reaction was continuously distilled under reduced pressure to remove water. After 3 hours, no 4-cyanophenylboric acid residue was detected, and an oil-soluble polyether base oil product was obtained.

[0039] Example 4

[0040] 200 g of isooctyl alcohol and 0.23 g of tris[tris(dimethylamino)phosphoranylideneamino]phosphonium methanol were added to the reactor, stirring was started, the gas was replaced with nitrogen three times and then evacuated to -0.095 MPa, the temperature was raised to 110 ° C, and 534 g of ethylene oxide and 534 g of propylene oxide were uniformly mixed into the reactor, the reaction temperature was controlled at 125 ° C, and the reaction pressure was ≤ 0.3 MPa; after the feeding was completed, the pressure was aged to -0.08 MPa, cooled to 100 ° C, and evacuated for 8 minutes to obtain a polyether intermediate I with PDI = 1.021 and Mw = 825 g / mol; then 1000 g of the polyether intermediate I and 104.8 g of 8-Quinolineboric acid was added into a reaction vessel with a stirrer, the temperature was maintained at 110° C., and the reaction was carried out under stirring. During the process, water produced during the reaction was continuously distilled under reduced pressure. After 1.5 hours, no 8-quinolineboric acid residue was detected, and a water-soluble polyether base oil product was obtained.

[0041] Example 5

[0042] 100 g of n-butanol and 0.16 g of tetradiethylaminophosphonium bromide were added to the reactor, stirring was started, the gas was replaced with nitrogen three times, and then vacuumed to -0.095 MPa, the temperature was raised to 115 ° C, and 55 g of ethylene oxide, 820 g of propylene oxide, and 220 g of butylene oxide were uniformly mixed in the reactor, the reaction temperature was controlled at 110 ° C, and the reaction pressure was ≤ 0.3 MPa; after the feeding was completed, the pressure was aged to -0.07 MPa, cooled to 100 ° C, and vacuumed for 8 minutes to obtain a polyether intermediate I with PDI = 1.018 and Mw = 941 g / mol; then 1000 g of polyether intermediate I and 74.4 g 4-Fluorophenylboric acid was added into a reaction vessel with a stirrer, the temperature was maintained at 115°C, and the reaction was carried out under stirring. During the process, water produced during the reaction was continuously distilled under reduced pressure. After 2 hours, no 4-acetylphenylboric acid residue was detected, and a water-insoluble polyether base oil product was obtained.

[0043] Comparative Example 1

[0044] The process was carried out in the same manner as in Example 1, except that 0.14 g of tetrakisdiethylaminophosphonium bromide catalyst was replaced by 2.7 g of KOH catalyst. The obtained polyether intermediate I had PDI=1.061, Mw=974 g / mol, and the dehydration condensation process failed to proceed, with α-naphthaleneboric acid remaining completely.

[0045] Comparative Example 2

[0046] The process was carried out in the same manner as in Example 1, except that 0.14 g of tetrakisdiethylaminophosphonium bromide catalyst was replaced by 0.07 g of bimetallic catalyst. The obtained polyether intermediate I had a PDI of 1.024 and a Mw of 996 g / mol. After the polyether intermediate I was subjected to a dehydration condensation reaction with α-naphthalene boronic acid for 6 hours, the conversion rate of α-naphthalene boronic acid was 40%, and an incompletely borated polyether borate base oil was obtained.

[0047] Comparative Example 3

[0048] Preparation of polyether intermediate 1: Add 100g of n-butanol and 0.30g of tetradiethylaminophosphonium bromide to a reactor, start stirring, replace with nitrogen three times, and then evacuate to -0.095MPa, raise the temperature to 110°C, and then uniformly mix and introduce 1652g of ethylene oxide and 1098g of propylene oxide into the reactor, control the reaction temperature at 120°C, and the reaction pressure ≤0.3MPa; after the feeding is completed, age to a pressure of -0.086MPa, cool to 100°C, and evacuate for 8 minutes to obtain polyether intermediate 1, PDI = 1.014, Mw = 2123g / mol. Add 2wt% of α-naphthalene boric acid pinacol ester to polyether intermediate 1 and mix to obtain base oil 1A.

[0049] When polyether intermediate 1 and boric acid ester are directly mixed at a molar ratio of approximately 2:1, there is a problem of incomplete compatibility, so boric acid ester is added at a conventional lubricating oil additive amount of 2 wt%. Similar situations also occur in the following comparative examples 4, 5 and 6.

[0050] Comparative Example 4

[0051] Preparation of polyether intermediate 2: Add 100g of n-butanol and 0.33g of tetradiethylaminophosphonium bromide to a reactor, start stirring, replace with nitrogen three times, and then evacuate to -0.095MPa, raise the temperature to 110°C, and then start to uniformly mix and introduce 3035g of propylene oxide into the reactor, control the reaction temperature at 110°C, and the reaction pressure ≤0.3MPa; after the feeding is completed, age to a pressure of -0.083MPa, cool to 100°C, and evacuate for 8 minutes to obtain polyether intermediate 2, PDI = 1.011, Mw = 2315g / mol. Add 2wt% of 4-acetylphenylboronic acid pinacol ester to polyether intermediate 2 and mix to obtain base oil 2A.

[0052] Comparative Example 5

[0053] The polyether intermediate I in Example 1 was directly mixed with 2 wt % of α-naphthyl boric acid pinacol ester to obtain base oil 1B.

[0054] Comparative Example 6

[0055] The polyether intermediate I in Example 2 was directly mixed with 2 wt % of 4-acetylphenylboronic acid pinacol ester to obtain base oil 2B.

[0056] The various properties of the polyether base oils prepared in the examples and comparative examples are shown in Table 1 below.

[0057]

[0058] Experimental Example 1

[0059] The oxidative stability of the base oil was determined by the rotating oxygen bomb (RBOT) method. The oxidative stability of the base oils provided in Examples 1 and 2 and Comparative Examples 3, 4, 5, and 6 was evaluated according to the test method of SH / T 0193-2008, and the results are shown in the following table.

[0060] Table 2 Oxidation stability parameters of base oils

[0061]

[0062] As can be seen from the above table, the method of directly adding the corresponding boric acid ester to the polyether base oil or the intermediate I in Comparative Examples 3, 4, 5, and 6 has almost no improvement on the oxidation stability of the base oil, while the oxidation stability of the polyether base oil obtained by promoting the dehydration condensation of polyether and aryl boronic acid, especially aryl boronic acid with an electron-withdrawing group, by a phosphorus catalyst is significantly improved, which reflects that the polyether base oil proposed in the present invention has obvious oxidation stability advantages.

[0063] Experimental Example 2

[0064] The comprehensive wear of the base oil was determined by a four-ball friction test (GB / T 3142), and the extreme pressure and anti-wear properties of the base oils provided in Examples 1 and 2 and Comparative Examples 3, 4, 5, and 6 were evaluated. The results are shown in the following table.

[0065] Table 3 Extreme pressure and anti-wear parameters of base oil

[0066]

[0067] As can be seen from the above table, the method of directly adding the corresponding boric acid ester to the polyether base oil or the intermediate I in Comparative Examples 3, 4, 5, and 6 slightly improves the extreme pressure and anti-wear properties of the base oil, while the extreme pressure and anti-wear properties of the polyether base oil prepared by promoting the dehydration condensation of polyether and aromatic boronic acid, especially aromatic boronic acid with an electron-withdrawing group, by a phosphorus catalyst are significantly improved, indicating that the polyether base oil structure proposed in the present invention has an advantage in improving the extreme pressure and anti-wear properties.

Claims

1. A method for preparing a polyether base oil, characterized in that: The polyether base oil uses C1-C10 fatty alcohol as an initiator, and undergoes a polymerization reaction with alkylene oxide under the action of a phosphorus catalyst to obtain a basic polyether intermediate I, wherein the alkylene oxide is propylene oxide and optionally ethylene oxide and / or butylene oxide, and then an aromatic boronic acid is added, and the basic polyether intermediate I and the aromatic boronic acid are further subjected to a dehydration condensation reaction under the action of a phosphorus catalyst to obtain the polyether base oil product.

2. The method for preparing a polyether base oil according to claim 1, characterized in that: The phosphorus catalyst is a quaternary phosphonium salt catalyst or a phosphazene base catalyst; Preferably, the quaternary phosphonium salt catalyst is tetrakisdiethylaminophosphonium bromide, di(piperidinyl)-(diethylamino)phosphonium bromide or tris(morpholinyl)-(diethylamino)phosphonium bromide, and / or the phosphazene base catalyst is tris[tris(dimethylamino)phosphanylideneamino]methanolphosphonium, tetrakis[tris(dimethylamino)phosphanylideneamino]phosphonium hydroxide or tetrakis[tris(dimethylamino)phosphanylideneamino]methoxyphosphonium.

3. The method for preparing a polyether base oil according to claim 2, characterized in that: The mass ratio of the phosphorus catalyst to the C1-C10 fatty alcohol is 0.1:100 to 1:

100.

4. The method for preparing a polyether base oil according to claim 1, characterized in that: The C1-C10 fatty alcohol is a primary alcohol, a secondary alcohol or a diol.

5. The method for preparing a polyether base oil according to claim 1, characterized in that: The mass ratio of the C1-C10 fatty alcohol to the alkylene oxide is 2:100 to 16:

100.

6. The method for preparing a polyether base oil according to claim 1, characterized in that: The molar ratio of ethylene oxide:propylene oxide:butylene oxide used in the alkylene oxide is (0-3):1:(0-10).

7. The method for preparing a polyether base oil according to claim 1, characterized in that: The aryl boronic acid is one or more of phenyl boronic acid with or without a substituent, naphthyl boronic acid with or without a substituent, and quinoline boronic acid with or without a substituent; Preferably, the aryl boronic acid is one or more of phenyl boronic acid containing a substituent, naphthyl boronic acid containing a substituent and quinoline boronic acid containing a substituent, and the substituent is an electron-withdrawing substituent, preferably one or more of cyano, nitro and acetyl.

8. The method for preparing a polyether base oil according to claim 1, characterized in that: The molar ratio of the basic polyether intermediate I to the aryl boronic acid is 1.8:1 to 2.2:

1.

9. The method for preparing a polyether base oil according to claim 1, characterized in that: The polymerization reaction temperature is 110-130° C., and the reaction pressure is ≤0.3 MPa; And / or, the temperature of the dehydration condensation reaction is 100-120°C; Preferably, the preparation method is: adding the C1-C10 fatty alcohol and the phosphorus catalyst into a reactor, replacing with nitrogen, evacuating to -0.095 MPa or lower, heating to 110-130°C, then starting to introduce the alkylene oxide into the reactor, controlling the reaction temperature at 110-130°C, and the reaction pressure is less than or equal to 0.3 MPa; when the feed amount of the alkylene oxide reaches the formula setting value, aging begins to occur until the pressure is -0.05 to -0.095 MPa, cooling to 100°C, evacuating to obtain the polyether intermediate I; then mixing the polyether intermediate I and the aromatic boronic acid, maintaining the temperature at 100-120°C, reacting under stirring, and continuously distilling under reduced pressure to obtain the polyether base oil.

10. The polyether base oil prepared by the method for preparing the polyether base oil according to any one of claims 1 to 9.

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