Polyester poly-alpha-olefin base oil as well as preparation method and application thereof

Abstract

The invention relates to the technical field of chemical lubricating base oil, in particular to polyester poly-alpha-olefin base oil as well as a preparation method and application thereof. The preparation method of the polyester poly-alpha-olefin base oil comprises the following steps: firstly, mixing dibutyl itaconate and an initiator to obtain a mixed solution; then, dropwise adding the mixed solution into alpha-olefin, and carrying out free radical addition polymerization reaction on carbon-carbon double bonds of dibutyl itaconate and carbon-carbon double bonds of alpha-olefin under the action of an initiator, so as to obtain the polyester poly-alpha-olefin base oil. The preparation method provided by the invention not only has the characteristics of mild reaction conditions, easiness in control, easily available raw materials, environmental protection and no pollution, but also effectively solves the problem that the quality of the existing polyester poly-alpha-olefin base oil is reduced due to self-polymerization of (methyl) acrylate, and the polyester poly-alpha-olefin base oil can be applied as the lubricating oil base oil.

Description

Technical Field

[0001] The invention relates to the technical field of chemical lubricating base oil, and in particular to a polyester poly-alpha-olefin base oil and a preparation method and application thereof. Background Art

[0002] In the field of lubricants, the selection of synthetic base oils is crucial to the performance of the product. Traditionally, synthetic esters and polyalphaolefins have been widely used due to their unique physical and chemical properties. However, these two base oils each have significant limitations. Although synthetic esters have excellent lubrication properties and thermal stability, their high polarity, strong water absorption and poor compatibility with rubber materials limit the use of synthetic esters in certain high-end applications. On the other hand, polyalphaolefins are favored for their good oxidation stability and low-temperature fluidity, but their incompatibility with ordinary sealing materials and poor compatibility with polar additives also pose challenges to their scope of application.

[0003] In order to overcome these defects, the existing technology uses copolymers of (meth)acrylates and α-olefins as an innovative attempt. By combining the advantages of both, the viscosity range of the product is significantly broadened. At 40°C, the kinematic viscosity of the product can be from 100mm 2 / s up to 90000mm 2 / s, bringing new possibilities to the field of lubricant additives. However, the high activity of (meth)acrylates makes them easy to self-polymerize, which not only reduces the quality of the product, but also makes the copolymerization conditions with α-olefins extremely harsh, requiring precise control to avoid side reactions. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a polyester poly-alpha-olefin base oil and a preparation method and application thereof. The present invention uses alpha-olefin and dibutyl itaconate as raw materials, and under the action of an initiator, the alpha-olefin and dibutyl itaconate undergo addition polymerization to obtain the polyester poly-alpha-olefin base oil. The preparation method of the present invention not only has the characteristics of mild reaction conditions, easy control, easy availability of raw materials, and environmental protection and pollution-free, but also effectively solves the problem of quality degradation of the existing polyester poly-alpha-olefin base oil due to (meth)acrylate self-polymerization, and the polyester poly-alpha-olefin base oil can be used as a lubricating oil base oil.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] The first object of the present invention is to provide a method for preparing a polyester poly-alpha-olefin base oil, comprising the following steps:

[0007] S1, mixing dibutyl itaconate and an initiator to obtain a mixed solution;

[0008] S2. Add the mixed liquid dropwise into the α-olefin. Under the action of the initiator, the carbon-carbon double bonds of dibutyl itaconate and the carbon-carbon double bonds of the α-olefin undergo free radical addition polymerization to obtain a polyester poly-α-olefin base oil.

[0009] Preferably, the molar ratio of α-olefin to dibutyl itaconate is 3 to 5:1, and the α-olefin is in excess to ensure that there are sufficient reaction sites for addition polymerization with dibutyl itaconate during the reaction. At the same time, the excess α-olefin acts as a diluent to reduce the concentration of each component in the reaction system, thereby reducing the probability of side reactions.

[0010] Preferably, the reaction conditions of the addition polymerization reaction are: at 115°C to 160°C, for 3h to 10h. If the reaction temperature is lower than 115°C, the reaction rate is too slow and the conversion rate is low; if the reaction temperature is higher than 160°C, the structure of the polyester poly-α-olefin base oil will be destroyed, reducing the quality and performance of the product.

[0011] Preferably, the initiator is selected from di-tert-butyl peroxide or tert-butyl perbenzoate.

[0012] Preferably, the mass of the initiator accounts for 1% to 8% of the total mass of the α-olefin and dibutyl itaconate.

[0013] Preferably, dibutyl itaconate is selected from industrial grade dibutyl itaconate, and the mass fraction of dibutyl itaconate in the industrial grade dibutyl itaconate is ≥95%.

[0014] Preferably, the α-olefin is selected from one or two of α-octene, α-decene, α-dodecene or α-tetradecene, and the α-olefins are all industrial grade.

[0015] The second object of the present invention is to provide a polyester poly-α-olefin base oil prepared by the above preparation method.

[0016] Preferably, the structural formula of the polyester poly-alpha-olefin base oil is:

[0017] Among them, m is 2 to 100; n is 2 to 100.

[0018] The third object of the present invention is to provide the use of the above polyester poly-α-olefin base oil in the preparation of lubricating oil base oil, anti-emulsification additive or cutting fluid.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The present invention provides a method for preparing polyester poly-α-olefin base oil, wherein α-olefin and dibutyl itaconate are used as raw materials. Under the action of an initiator, the carbon-carbon double bonds in the dibutyl itaconate molecules are activated to form active free radicals, which react with the carbon-carbon double bonds of the α-olefin to form new active centers and initiate chain growth. In this process, α-olefin and dibutyl itaconate molecules are alternately or randomly added to the polymer chain to form a polyester poly-α-olefin structure. When the active center encounters other active centers, the polymerization is terminated, thereby obtaining a polyester poly-α-olefin base oil.

[0021] Among them, the reaction activity of dibutyl itaconate is much lower than that of (meth)acrylate. In the present invention, a mixed solution of dibutyl itaconate and an initiator is added to the reaction system in a dropwise manner to ensure that the α-olefin is in an excess state, effectively preventing the self-polymerization of dibutyl itaconate to form small molecular self-polymers, and also ensuring that no unreacted dibutyl itaconate remains after the reaction is completed; after the reaction is completed, the initiator and the unreacted α-olefin are recovered by vacuum distillation, thereby significantly improving the purity and quality of the polyester polyα-olefin base oil; compared with (meth)acrylate, the present invention solves the problem in the prior art that the self-polymerization of (meth)acrylate leads to a decrease in the quality of the polyester polyα-olefin base oil, so that the performance of the final product is more stable and reliable.

[0022] 2. The present invention provides a polyester poly-alpha-olefin base oil. Compared with the copolymer of (meth)acrylate and alpha-olefin in the prior art, the polyester poly-alpha-olefin base oil of the present invention has a high viscosity index and a low pour point, which ensures its stable lubrication performance and good fluidity in a wide temperature range, and its excellent oxidation stability, that is, the oxidation induction time exceeds 80 minutes, which significantly extends the service life of the oil product; in addition, the present invention also significantly improves the compatibility of the polyester poly-alpha-olefin base oil with various additives, and effectively inhibits the common emulsification tendency of ester base oils, and can replace the existing copolymer of (meth)acrylate and alpha-olefin for use.

[0023] Among them, polyester poly-alpha-olefin base oil is polymerized from alpha-olefin and dibutyl itaconate, and its molecular structure contains long-chain alkyl and ester groups, which enables the base oil to form good compatibility with a variety of additives and lubricating components; poly-alpha-olefin, as a non-polar component, does not contain strong polar functional groups in its molecular structure, which helps to reduce the interaction with other polar substances and avoid unnecessary phase separation or precipitation. At the same time, as a non-polar component, poly-alpha-olefin does not contain any functional groups that react with water in its molecular structure. This characteristic not only effectively reduces the polarity of the copolymer with the increase of the alpha-olefin content, but also significantly enhances its hydrophobicity, greatly reducing the chance of interaction between polyester and water molecules, thereby effectively inhibiting the common emulsification tendency of ester base oils.

[0024] 3. The present invention provides a method for preparing polyester poly-α-olefin base oil, which has simple process and strong operability; mild reaction conditions, easy control, and high yield; raw materials are easily available and environmentally friendly, and have little environmental pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is the technical roadmap for synthesizing polyester poly-α-olefin base oil in Examples 1 to 9 of the present invention.

[0026] Figure 2 This is the infrared spectrum of the polyester poly-α-olefin base oil synthesized in Example 1 of the present invention.

[0027] Figure 3 This is the hydrogen nuclear magnetic resonance spectrum of the polyester poly-alpha-olefin base oil synthesized in Example 1 of the present invention. DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be clearly and completely described below in combination with the data in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] It should be noted that the professional terms used in the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the scope of protection of the present invention. Unless otherwise specified, the various raw materials, reagents, instruments and equipment used in the following embodiments of the present invention can be purchased from the market or prepared by existing methods. The α-tetradecene, α-dodecene, α-octene and α-decene used in the present invention are all industrial grade, purchased from Aladdin Reagent Company; dibutyl itaconate is industrial grade, purchased from Shenzhen Jintenglong Industrial Co., Ltd.; di-tert-butyl peroxide is industrial grade, purchased from Aladdin Reagent Company; tert-butyl peroxybenzoate is industrial grade, purchased from Aladdin Reagent Company.

[0030] The testing method of the present invention is as follows:

[0031] Kinematic viscosity: Tested in accordance with GB / T 265-1988 petroleum product kinematic viscosity determination method and dynamic viscosity calculation method.

[0032] Viscosity index: calculated according to GB / T 1995-1998 Viscosity index calculation method for petroleum products.

[0033] Pour point: Tested in accordance with GB / T3535-2006 Pour point determination method for petroleum products.

[0034] In the prior art, synthetic esters and poly-α-olefins have their own advantages as lubricant base oils, but both have significant limitations: synthetic esters are limited in their use in high-end applications due to their high polarity, strong water absorption and poor compatibility with rubber materials; poly-α-olefins face the challenges of incompatibility with ordinary sealing materials and poor compatibility with polar additives. In addition, although the copolymerization of (meth)acrylates and α-olefins can broaden the viscosity range, the high activity of (meth)acrylates can easily lead to self-polymerization, reducing the quality of polyester poly-α-olefin base oils and increasing the difficulty of controlling reaction conditions. These problems and defects limit the further improvement of the performance of lubricant base oils.

[0035] In view of the problems existing in the prior art, the present invention provides a method for preparing a polyester poly-alpha-olefin base oil, comprising the following steps: mixing dibutyl itaconate and an initiator to obtain a mixed solution; and dripping the mixed solution into alpha-olefin to carry out addition polymerization reaction to obtain the polyester poly-alpha-olefin base oil.

[0036] The invention uses alpha-olefin and dibutyl itaconate as raw materials, performs addition polymerization under the action of an initiator, and successfully prepares a polyester poly-alpha-olefin base oil; wherein the reaction activity of dibutyl itaconate is relatively low, when the alpha-olefin is ensured to be in an excess state, the mixed solution of dibutyl itaconate and the initiator is added to the reaction system in a dropwise manner, the dibutyl itaconate will not self-polymerize to form small molecular self-polymers, and it is also ensured that no unreacted dibutyl itaconate remains after the reaction is completed, thereby significantly improving the purity and quality of the product; compared with (meth)acrylate, the preparation method of the polyester poly-alpha-olefin base oil provided by the invention not only successfully avoids the common self-polymerization problem of (meth)acrylate, but also significantly improves the comprehensive performance and purity of the polyester poly-alpha-olefin base oil; in addition, the polyester poly-alpha-olefin base oil prepared by the invention has a high viscosity index, a good pour point index, and excellent product performance, and can not only effectively make up for the defects of traditional poly-alpha-olefin base oil and ester base oil, but also has its cost-effectiveness advantage, and becomes an ideal choice for replacing or partially replacing these relatively expensive materials.

[0037] The reaction mechanism of the present invention is as follows:

[0038]

[0039] Among them, m is 2 to 100; n is 2 to 100.

[0040] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in conjunction with specific embodiments. The specific synthetic route is as follows: Figure 1 As shown:

[0041] Example 1

[0042] A method for preparing polyester poly-alpha-olefin base oil comprises the following steps:

[0043] S1. In a four-necked reaction flask equipped with a temperature controller, a stirrer, a condenser and a dropping funnel, add 3 mol of α-tetradecene, heat to 145°C, mix 1 mol of dibutyl itaconate and 50 g of di-tert-butyl peroxide, and then uniformly drop them into the four-necked reaction flask for 2 hours.

[0044] S2. After the addition is completed, the reaction is continued at 145° C. for 3 h, and then the temperature is increased to 210° C. to distill the α-tetradecene that has not participated in the reaction under reduced pressure to obtain a polyester polyα-olefin base oil.

[0045] The physical and chemical indicators of polyester poly-alpha-olefin base oil are: 40℃ kinematic viscosity is 175mm 2 / s, kinematic viscosity at 100℃ is 21.99mm 2 / s, viscosity index is 150 and pour point is -24℃.

[0046] Example 2

[0047] A method for preparing a polyester poly-alpha-olefin base oil is the same as the method for preparing the polyester poly-alpha-olefin base oil in Example 1, except that, in S1, alpha-tetradecene is replaced by alpha-dodecene, the amount of di-tert-butyl peroxide is replaced by 50 g by 7.5 g, the dropping time is replaced by 2 h by 1.5 h, and the continuous reaction time in S2 is replaced by 3 h by 1.5 h, comprising the following steps:

[0048] S1. In a four-necked reaction flask equipped with a temperature controller, a stirrer, a condenser and a dropping funnel, add 3 mol of α-dodecene, heat to 145°C, mix 1 mol of dibutyl itaconate and 7.5 g of di-tert-butyl peroxide, and uniformly add them dropwise to the four-necked reaction product for 1.5 h.

[0049] S2. After the addition is completed, the reaction is continued at 145° C. for 1.5 h, and then the temperature is increased to 210° C. to distill the α-dodecene that has not participated in the reaction under reduced pressure to obtain a polyester polyα-olefin base oil.

[0050] The physical and chemical indicators of polyester poly-alpha-olefin base oil are: 40℃ kinematic viscosity is 141.73mm 2 / s, kinematic viscosity at 100℃ is 17.92mm 2 / s, viscosity index is 141 and pour point is -35℃.

[0051] Example 3

[0052] A method for preparing a polyester poly-alpha-olefin base oil is the same as the method for preparing the polyester poly-alpha-olefin base oil in Example 1, except that in S1, the amount of alpha-tetradecene is replaced by 5 mol, the amount of di-tert-butyl peroxide is replaced by 50 g by 24.44 g, the dropping time is replaced by 2 h by 3 h, the continued reaction time in S2 is replaced by 3 h by 5 h, and the reaction temperature is replaced by 145 ° C by 160 ° C, comprising the following steps:

[0053] S1. In a four-necked reaction flask equipped with a temperature controller, a stirrer, a condenser and a dropping funnel, add 5 mol of α-tetradecene, heat to 160°C, mix 1 mol of dibutyl itaconate and 24.44 g of di-tert-butyl peroxide, and uniformly add them dropwise to the four-necked reaction product for 3 hours.

[0054] S2. After the addition is completed, the reaction is continued at 160° C. for 5 hours, and then the temperature is increased to 210° C. to distill the α-tetradecene that has not participated in the reaction under reduced pressure to obtain a polyester polyα-olefin base oil.

[0055] The physical and chemical indicators of polyester poly-alpha-olefin base oil are: 40℃ kinematic viscosity is 195.3mm 2 / s, kinematic viscosity at 100℃ is 24.27mm 2 / s, viscosity index is 154 and pour point is -24℃.

[0056] Example 4

[0057] A method for preparing a polyester poly-alpha-olefin base oil is the same as the method for preparing the polyester poly-alpha-olefin base oil in Example 2, except that in S1, the amount of alpha-dodecene is replaced by 4 mol from 3 mol, di-tert-butyl peroxide is replaced by benzoic acid peroxide, the amount of which is replaced by 27.42 g from 7.5 g, the dropping time is replaced by 2 h from 1.5 h, the continuous reaction time in S2 is replaced by 5 h from 1.5 h, and the reaction temperature is replaced by 115 ° C from 145 ° C, comprising the following steps:

[0058] S1. In a four-necked reaction flask equipped with a temperature controller, a stirrer, a condenser and a dropping funnel, add 4 mol of α-dodecene, heat to 115°C, mix 1 mol of dibutyl itaconate and 27.42 g of tert-butyl perbenzoate, and uniformly add the mixture dropwise to the four-necked reaction flask for 2 hours.

[0059] S2. After the addition is completed, the reaction is continued at 115° C. for 5 hours, and then the temperature is increased to 210° C. to distill the α-dodecene that has not participated in the reaction under reduced pressure to obtain a polyester polyα-olefin base oil.

[0060] The physical and chemical indicators of polyester poly-alpha-olefin base oil are: 40℃ kinematic viscosity is 142.31mm 2 / s, kinematic viscosity at 100℃ is 18.36mm 2 / s, viscosity index is 145 and pour point is -36℃.

[0061] Example 5

[0062] A method for preparing a polyester poly-alpha-olefin base oil is the same as the method for preparing a polyester poly-alpha-olefin base oil in Example 1, except that, in S1, α-tetradecene is replaced by α-decene, di-tert-butyl peroxide is replaced by tert-butyl peroxybenzoate, the amount thereof is replaced by 50 g to 26.48 g, the dropping time is replaced by 2 h to 5 h, the continued reaction time in S2 is replaced by 3 h to 5 h, and the reaction temperature is replaced by 145 ° C to 125 ° C, comprising the following steps:

[0063] S1. In a four-necked reaction flask equipped with a temperature controller, a stirrer, a condenser and a dropping funnel, add 3 mol of α-decene, heat to 125°C, mix 1 mol of dibutyl itaconate and 26.48 g of tert-butyl perbenzoate, and uniformly add the mixture dropwise to the four-necked reaction flask for 5 hours.

[0064] S2. After the addition is completed, the reaction is continued at 125°C for 5 hours, and then the temperature is increased to 210°C to distill the α-decene that has not participated in the reaction under reduced pressure to obtain a polyester polyα-olefin base oil.

[0065] The physical and chemical indicators of polyester poly-alpha-olefin base oil are: 40℃ kinematic viscosity is 129.41mm 2 / s, kinematic viscosity at 100℃ is 15.73mm 2 / s, viscosity index is 128 and pour point is -46℃.

[0066] Example 6

[0067] A method for preparing a polyester poly-alpha-olefin base oil is the same as the method for preparing the polyester poly-alpha-olefin base oil in Example 5, except that in S1, the amount of alpha-decene is replaced by 4 mol from 3 mol, the amount of di-tert-butyl peroxide is replaced by 64.16 g from 50 g, the dropping time is replaced by 4 h from 2 h, the continued reaction time in S2 is replaced by 5 h from 3 h, and the reaction temperature is replaced by 160 ° C from 125 ° C, comprising the following steps:

[0068] S1. In a four-necked reaction flask equipped with a temperature controller, a stirrer, a condenser and a dropping funnel, add 4 mol of α-decene, heat to 160°C, mix 1 mol of dibutyl itaconate and 64.16 g of di-tert-butyl peroxide, and uniformly add them dropwise to the four-necked reaction product for 4 hours.

[0069] S2. After the addition is completed, the reaction is continued at 160°C for 5 hours, and then the temperature is increased to 210°C to distill the α-decene that has not participated in the reaction under reduced pressure to obtain a polyester polyα-olefin base oil.

[0070] The physical and chemical indicators of polyester poly-alpha-olefin base oil are: 40℃ kinematic viscosity is 135.33mm 2 / s, kinematic viscosity at 100℃ is 16.71mm 2 / s, viscosity index is 130 and pour point is -49°C.

[0071] Example 7

[0072] A method for preparing a polyester poly-alpha-olefin base oil is the same as the method for preparing in Example 1, except that, in S1, α-tetradecene is replaced by α-octene, di-tert-butyl peroxide is replaced by tert-butyl peroxybenzoate, the amount thereof is replaced by 56.14 g, the dropping time is replaced by 2 h by 4 h, the continued reaction time in S2 is replaced by 3 h by 4 h, and the reaction temperature is replaced by 145 ° C by 115 ° C, comprising the following steps:

[0073] S1. In a four-necked reaction flask equipped with a temperature controller, a stirrer, a condenser and a dropping funnel, add 5 mol of α-octene, heat to 115°C, mix 1 mol of dibutyl itaconate and 56.14 g of di-tert-butyl peroxide, and uniformly add them dropwise to the four-necked reaction product for 4 hours.

[0074] S2. After the addition is completed, the reaction is continued at 115° C. for 4 hours, and then the temperature is increased to 210° C. to distill the α-octene that has not participated in the reaction under reduced pressure to obtain a polyester polyα-olefin base oil.

[0075] The physical and chemical indicators of polyester poly-alpha-olefin base oil are: 40℃ kinematic viscosity is 115.34mm 2 / s, kinematic viscosity at 100℃ is 13.51mm 2 / s, viscosity index is 114 and pour point is -50℃.

[0076] Example 8

[0077] A method for preparing a polyester poly-alpha-olefin base oil is the same as the method for preparing the polyester poly-alpha-olefin base oil in Example 1, except that, in S1, α-tetradecene is replaced by a mixture of α-octene and α-decene, di-tert-butyl peroxide is replaced by tert-butyl peroxybenzoate, and the amount thereof is replaced by 31 g from 50 g, the reaction time in S2 is replaced by 2 h from 3 h, and the reaction temperature is replaced by 125 ° C from 145 ° C, and the method comprises the following steps:

[0078] S1. In a four-necked reaction flask equipped with a temperature controller, a stirrer, a condenser and a dropping funnel, add 3 mol of a mixture of α-octene and α-decene, heat to 125°C, mix 1 mol of dibutyl itaconate and 31 g of tert-butyl perbenzoate, and uniformly add them dropwise to the four-necked reaction flask for 2 hours.

[0079] S2. After the addition is completed, the reaction is continued at 125° C. for 2 hours, and then the temperature is increased to 180° C. to distill the mixture of α-octene and α-decene that have not participated in the reaction under reduced pressure to obtain polyester polyα-olefin base oil.

[0080] The physical and chemical indicators of polyester poly-alpha-olefin base oil are: 40℃ kinematic viscosity is 115.34mm 2 / s, kinematic viscosity at 100℃ is 13.51mm 2 / s, viscosity index is 114 and pour point is -45℃.

[0081] Example 9

[0082] A method for preparing a polyester poly-alpha-olefin base oil is the same as the method for preparing the polyester poly-alpha-olefin base oil in Example 1, except that, in S1, alpha-tetradecene is replaced by a mixture of alpha-octene and alpha-decene, the amount of di-tert-butyl peroxide is replaced by 52.22 g from 50 g, the dropping time is replaced by 3 h from 2 h, and the reaction temperature is replaced by 130 ° C from 145 ° C, comprising the following steps:

[0083] S1. In a four-necked reaction flask equipped with a temperature controller, a stirrer, a condenser and a dropping funnel, add 4 mol of a mixture of α-octene and α-decene, heat to 130°C, mix 1 mol of dibutyl itaconate and 52.22 g of di-tert-butyl peroxide, and uniformly add them dropwise to the four-necked reaction product for 3 hours.

[0084] S2. After the addition is completed, the reaction is continued at 130° C. for 3 hours, and then the temperature is increased to 180° C. to distill the mixture of α-octene and α-decene that have not participated in the reaction under reduced pressure to obtain polyester polyα-olefin base oil.

[0085] The physical and chemical indicators of polyester poly-alpha-olefin base oil are: 40℃ kinematic viscosity is 118.46mm 2 / s, kinematic viscosity at 100℃ is 13.97mm 2 / s, viscosity index is 116 and pour point is -47℃.

[0086] Figure 2 This is the infrared spectrum of the polyester poly-α-olefin base oil synthesized in Example 1 of the present invention. Figure 2 It is known that at 3000cm -1 ~3100cm -1There is no obvious carbon-carbon double bond absorption peak in the range, indicating that during the synthesis process, the addition polymerization reaction between dibutyl itaconate and α-olefin was very thorough, and the carbon-carbon double bonds in the raw materials were almost completely converted into saturated bonds in the polyester polyα-olefin polymer. Therefore, the infrared spectrum not only verifies the successful progress of the polymerization reaction.

[0087] Figure 3 This is the hydrogen nuclear magnetic resonance spectrum of the polyester poly-alpha-olefin base oil synthesized in Example 1 of the present invention. Figure 3 It is known that in the range of 4.5ppm to 6.0ppm, the signal of hydrogen atoms near the carbon-carbon double bond in olefin compounds usually corresponds to the signal of hydrogen atoms near the carbon-carbon double bond in olefin compounds. Figure 3 No obvious peaks were observed in the results of the infrared spectrum, which further confirmed the results of the infrared spectrum, that is, the double bonds between dibutyl itaconate and α-olefins have been completely consumed by the addition polymerization reaction, generating polyester poly-α-olefin polymers without carbon-carbon double bonds. This feature of the nuclear magnetic resonance hydrogen spectrum not only proves the completeness of the polymerization reaction, but also reflects the stability and consistency of the product structure. Combining the results of the infrared spectrum and the nuclear magnetic resonance hydrogen spectrum, it can be proved that the present invention successfully synthesized a polyester poly-α-olefin base oil with a stable structure.

[0088] It should be noted that when the present invention involves a numerical range, it should be understood that the two endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as those in the embodiments, in order to avoid redundancy, the present invention describes a preferred embodiment. Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the attached claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0089] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for preparing a polyester poly-alpha-olefin base oil, characterized in that: The following steps are involved: Mixing dibutyl itaconate and an initiator to obtain a mixed solution; The mixed liquid is added dropwise to the α-olefin, and under the action of the initiator, the carbon-carbon double bonds of dibutyl itaconate and the carbon-carbon double bonds of the α-olefin undergo free radical addition polymerization to obtain a polyester polyα-olefin base oil.

2. The method for preparing a polyester poly-alpha-olefin base oil according to claim 1, characterized in that: The molar ratio of α-olefin to dibutyl itaconate is 3 to 5:

1.

3. The method for preparing a polyester poly-alpha-olefin base oil according to claim 1, characterized in that: The reaction conditions of the addition polymerization reaction are: reaction at 115°C to 160°C for 3h to 10h.

4. The method for preparing a polyester poly-alpha-olefin base oil according to claim 1, characterized in that: The initiator is selected from di-tert-butyl peroxide or tert-butyl perbenzoate.

5. The method for preparing a polyester poly-alpha-olefin base oil according to claim 1, characterized in that: The mass of the initiator accounts for 1% to 8% of the total mass of the α-olefin and dibutyl itaconate.

6. The method for preparing a polyester poly-alpha-olefin base oil according to claim 1, characterized in that: The dibutyl itaconate is selected from industrial-grade dibutyl itaconate, and the mass fraction of dibutyl itaconate in the industrial-grade dibutyl itaconate is ≥95%.

7. The method for preparing a polyester poly-alpha-olefin base oil according to claim 1, characterized in that: The α-olefin is selected from one or two of α-octene, α-decene, α-dodecene and α-tetradecene.

8. A polyester poly-alpha-olefin base oil prepared by the method for preparing the polyester poly-alpha-olefin base oil according to any one of claims 1 to 7.

9. The polyester poly-alpha-olefin base oil according to claim 8, characterized in that The structural formula of the polyester poly-alpha-olefin base oil is: Among them, m is 2 to 100; n is 2 to 100.

10. Use of the polyester poly-α-olefin base oil according to claim 8 in the preparation of lubricating oil base oil, anti-emulsification additive or cutting fluid.

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