Preparation method of modified vegetable oil

Abstract

The invention relates to the technical field of modified vegetable oil, in particular to a preparation method of modified vegetable oil. The preparation method comprises the following steps: saponifying tung oil, adding the saponified tung oil into epoxy rapeseed oil, oxidizing to obtain rapeseed oil grafted epoxy tung oil, connecting the rapeseed oil grafted epoxy tung oil with an amine compound, and adding hydroxylated nano boron nitride, modified nano titanium dioxide and tea polyphenol to obtain the modified vegetable oil. The tung oil is introduced, so that the modified vegetable oil has high kinematic viscosity and viscosity index. The addition of the amine compound improves the flash point of the modified vegetable oil and reduces the pour point. The hydroxylated nano boron nitride and the nano titanium dioxide improve the volume resistivity and the thermal conductivity of the modified vegetable oil. The tea polyphenol and the nano material are matched for use, so that the oxidation stability of the modified vegetable oil is good. The prepared modified vegetable oil reacts with isophorone diisocyanate, hydroxylated sesquisilane and other substances to obtain the polyurea material, and the material has the advantages of watertightness, high bonding strength and good heat-resistant effect.

Description

Technical Field

[0001] The invention relates to the technical field of modified vegetable oil, in particular to a method for preparing modified vegetable oil. Background Art

[0002] Oils can be divided into petroleum, vegetable oils, and synthetic oils according to their sources. Oils are widely used, such as in the synthesis of lubricating greases, materials for making clothing, houses, cars, and airplanes, and various industrial raw materials. As the demand for oils increases, oil resources become increasingly depleted, and petrochemical products are environmentally polluting, natural vegetable oils have attracted attention as a natural, renewable, biodegradable, and cheap raw material. Depending on the needs, natural vegetable oils are used to synthesize various raw materials.

[0003] The main structural components of vegetable oil are triglycerides, in addition to a small amount of diglycerides, monoglycerides and trace amounts of fatty acids. Usually, people synthesize materials by directly polymerizing the active functional groups of vegetable oils such as hydroxyl groups and double bonds, or by modifying the functional groups and then polymerizing them with other monomers, or by developing corresponding functional monomers to meet various usage requirements.

[0004] Patent CN108384641B discloses a "vegetable oil modified synthetic base oil and its preparation method", which uses rapeseed oil, sunflower oil, soybean oil, castor oil, cottonseed oil and palm oil as raw materials, and isomerizes and esterifies with polyols under the action of functional catalysts, and then copolymerizes to synthesize base oil. The base oil has a large kinematic viscosity and a high viscosity index, which meets the demand for high-viscosity ester base oils and solves the problem of generally low viscosity of ester base oils. In addition, the base oil can be used in high and low temperature environments.

[0005] Patent CN114317069B discloses "a vegetable oil-based nano-lubricant additive and its preparation method", which adds ultrafine boron nitride, nanoparticles prepared from graphene oxide, and preservatives to vegetable oil. The lubricant obtained from vegetable oil has good oxidation stability, high thermal stability, good lubricant dispersibility, and good extreme pressure wear resistance. It overcomes the problem of poor dispersibility and poor antioxidant effect after adding nanoparticles.

[0006] Patent CN106519954B discloses "a method for preparing a plant oil-based waterborne polyurethane coating and the coating prepared therefrom", using castor oil as a raw material, ring-opening after epoxidation, reacting with diisocyanate, hydroxyethyl acrylate and a chain extender to obtain an emulsion, and then prepolymerizing to obtain a polyurethane coating. The castor oil-based polyurethane coating has strong adhesion, good water resistance and cold resistance.

[0007] The poor insulation and heat dissipation of vegetable oil will limit its further application. Patent CN110819428B discloses "a graphene-modified vegetable insulating oil and its preparation method", which adds graphene and composite antioxidants to rapeseed oil to improve the oxidation stability and flame retardancy of the insulating oil, and also has good insulation and thermal conductivity. However, when graphene is added to rapeseed oil without modification, it has poor compatibility with rapeseed oil after long-term use and is easy to aggregate, thus affecting the conductivity of rapeseed oil.

[0008] In summary, although the research on modified vegetable oil has made certain progress, there are still many problems with modified vegetable oil under different usage requirements and conditions. It is urgent to develop a modified vegetable oil with good comprehensive performance and stability.

[0009] Therefore, a method for preparing modified vegetable oil is proposed. Summary of the invention

[0010] The object of the present invention is to provide a method for preparing modified vegetable oil, wherein tung oil is saponified, then added to epoxidized rapeseed oil, oxidized to obtain rapeseed oil grafted epoxidized tung oil, connected with diamine, and then hydroxylated nano boron nitride, modified nano titanium dioxide and tea polyphenol are added to obtain modified vegetable oil. By introducing the components of tung oil into the reaction system, controlling the amount of tung oil, the amount of catalyst, and the temperature and time of the reaction, the modified vegetable oil has high kinematic viscosity and the viscosity is less affected by temperature changes. By introducing long-chain cyclohexanediamine, the modified vegetable oil has both high temperature resistance and low temperature resistance. Hydroxylated nano boron nitride is covalently linked to the vegetable oil component, and surface-modified nano titanium dioxide is added, so that the modified vegetable oil has high volume resistivity and thermal conductivity. By adding antioxidant components and the synergistic effect between the components, the modified vegetable oil has good oxidation stability. The polyurea material is prepared by using modified vegetable oil as a raw material and reacting it with isophorone diisocyanate, hydroxylated silsesquiane and monoamine. The material is used in coatings and is impermeable after drying, has a small heating expansion rate and high bonding strength.

[0011] To achieve the above object, the present invention provides the following technical solutions:

[0012] In one aspect, the present invention provides a method for preparing a modified vegetable oil, characterized in that it comprises the following steps:

[0013] 2.4-9.8 parts of tung oil, sodium hydroxide and water are added to a round-bottom flask, and the temperature is raised to react to obtain a saponified liquid; the saponified liquid is cooled to room temperature, neutralized, separated, centrifuged and dried to obtain sodium eleostearate; the sodium eleostearate is dissolved in a mixed solution of ethyl acetate and water to obtain a sodium eleostearate solution; the sodium eleostearate solution is added to an epoxidized rapeseed oil solution, and 0.3-0.7 parts of TBD are added to obtain a grafted liquid; the grafted liquid is heated to 60-150° C., and reacted for 8-13 hours to obtain rapeseed oil grafted tung oil; the rapeseed oil grafted tung oil is cooled, oxidized, and dried to obtain rapeseed oil grafted epoxidized tung oil;

[0014] The structure of the epoxidized rapeseed oil in the epoxidized rapeseed oil solution is shown in Formula I:

[0015]

[0016] The structure of the sodium eleostearate is shown in Formula II:

[0017]

[0018] Adding 0.4% to 0.8% by mass of sodium hydroxide solution and diamine to the rapeseed oil grafted tung oil, and heating the mixture to obtain a modified vegetable oil intermediate;

[0019] Ultrasonic stripping of boron nitride nano-dispersion liquid for 8-12 hours to obtain a stripping solution; the ultrasonic stripping power is 200-500W; the stripping solution is centrifuged, filtered, and dried to obtain hydroxylated nano-boron nitride;

[0020] 0-0.056 parts of the hydroxylated nano boron nitride are added to the modified vegetable oil intermediate, reacted at 90-110°C and 600rpm for 10 hours, and cooled to room temperature to obtain a modified vegetable oil precursor; anhydrous nano titanium dioxide is added to a ball mill, and then KH550 and sodium dodecyl sulfate are added for grinding to obtain modified nano titanium dioxide; the mass ratio of the anhydrous nano titanium dioxide, the KH550 and the sodium dodecyl sulfate is 3-19:0-14:1; 0-4.8 parts of tea polyphenol ethanol solution and 0-0.005 parts of the modified nano titanium dioxide are added to the modified vegetable oil precursor, stirred evenly and rotary evaporated to obtain modified vegetable oil.

[0021] Preferably, the diamine is one of 1,4-butanediamine, hexanediamine, 4-aminomethylcyclohexylamine, 1,8-octanediamine, decanediamine, 1,12-diaminododecane and 4,4'-diaminodicyclohexylmethane; and the diamine is used in an amount of 0-29.5 parts.

[0022] Preferably, the diamine is used in an amount of 11.8-29.5 parts.

[0023] Preferably, the mass ratio of the anhydrous nano-titanium dioxide, the KH550 and the sodium dodecyl sulfate is 3-6:6-14:1.

[0024] Preferably, the dosage of the hydroxylated nano-boron nitride is 0.016-0.056 parts.

[0025] Preferably, the amount of the modified nano titanium dioxide is 0.001-0.005 parts.

[0026] Preferably, the amount of the tea polyphenol ethanol solution is 1.6-4.8 parts.

[0027] Preferably, the modified vegetable oil is used to prepare a polyurea material; the preparation method of the polyurea material is as follows:

[0028] Dissolving cyanohexyltrimethoxysilane in THF to obtain a cyanohexyltrimethoxysilane solution; adding water and sodium hydroxide to the cyanohexyltrimethoxysilane solution under stirring, heating to 75° C., reflux reacting for 5 h and keeping the temperature for 18 h, then rotary evaporating and drying to obtain a hydroxylated silsesquiane precursor product;

[0029] The hydroxylated silsesquiane precursor product is dissolved in THF to obtain a precursor solution; the precursor solution is vigorously stirred at 4° C. and nitrogen is introduced, and acetic acid is added dropwise, and the reaction is stirred for 3 hours, and water is continuously added and stirred for 1 hour to obtain a hydroxylated silsesquiane intermediate product; the hydroxylated silsesquiane intermediate product is subjected to rotary evaporation to remove THF, and then extracted, washed and vacuum dried to obtain hydroxylated silsesquiane;

[0030] The modified vegetable oil is heated to 80°C, isophorone diisocyanate is dripped into the heated modified vegetable oil within 1 hour, and 1 part of triethylamine is added, and the reaction is stirred for 5 hours to obtain a polyurea material precursor; 0-227.0 parts of the hydroxylated silsesquiane are dissolved in THF to obtain a hydroxylated silsesquiane solution; the number volume ratio of the hydroxylated silsesquiane to the THF is 1:10; 0-24.1 parts of monoamine and the hydroxylated silsesquiane solution are added to the polyurea material precursor, the temperature is raised to 90°C, 0.5 parts of triethylamine is added, and the reaction is carried out for 12 hours to obtain the polyurea material intermediate; the polyurea material is obtained by removing the THF from the polyurea material intermediate.

[0031] Preferably, the dosage of the hydroxylated silsesquiane is 97.3-227.0 parts; and the monoamine is one of n-butylamine, dodecyl primary amine, tetradecylamine and hexadecylamine.

[0032] On the other hand, the present invention provides a modified vegetable oil, characterized in that: the modified vegetable oil comprises tung oil, epoxidized rapeseed oil, diamine, hydroxylated nano boron nitride, modified nano titanium dioxide and tea polyphenol ethanol solution; the modified vegetable oil is prepared by any one of the preparation methods described above; the kinematic viscosity of the modified vegetable oil at 100°C is 29.4-45.1 mm 2 / s, the viscosity index is 115-138, and no stratification occurs after 6 months of storage; the flash point of the modified vegetable oil is 204-249°C, the pour point is -30 to -44°C; the volume resistivity of the modified vegetable oil is 7.5×10 14 Ω·m-9.8×10 14 Ω·m, thermal conductivity is 0.106-0.246W·m -1 ·K -1 The test time of the oxidation stability of the modified vegetable oil is 46-95 minutes; the polyurea material prepared from the modified vegetable oil is impermeable for 120 minutes under a water pressure of 0.3 MPa after drying, the heating expansion rate is -4.2% to 0.3%, and the bonding strength is 2.2-7.1 MPa.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. The modified vegetable oil is prepared by saponifying tung oil to obtain sodium eleostearate, epoxidizing rapeseed oil to obtain epoxidized rapeseed oil, and then ring-opening under the action of a catalyst. The ring-opened rapeseed oil reacts with sodium eleostearate to obtain rapeseed oil grafted epoxidized tung oil, and finally preparing the modified vegetable oil. By introducing the components of tung oil into the reaction system, controlling the amount of tung oil, the amount of catalyst and the reaction conditions, the obtained modified vegetable oil has high kinematic viscosity and viscosity index, and no stratification occurs after storage. The modified vegetable oil has high viscosity and good stability.

[0035] 2. By introducing a long chain with amino groups at both ends of the molecule into the system, the rapeseed oil grafted epoxy tung oil is covalently linked to it through a condensation reaction under alkaline conditions. By controlling the type and amount of diamine, and also controlling the mass fraction of sodium hydroxide under alkaline conditions, the modified vegetable oil obtained has a higher flash point and a lower pour point. The long-chain alkanes and cycloalkanes contained in the diamine improve the high temperature resistance of the vegetable oil. At the same time, the modified vegetable oil has the property of low temperature resistance, is suitable for low temperature working conditions, and has high safety in use.

[0036] 3. By introducing nano boron nitride into the modified vegetable oil, the structure of the liquid is changed, the energy transfer process inside the modified vegetable oil is improved, and thus the thermal conductivity of the modified vegetable oil is enhanced; the modified vegetable oil obtained by using hydroxylated nano boron nitride in combination with modified nano titanium dioxide has good electrical conductivity and thermal conductivity. The hydroxylated nano boron nitride obtained by controlling the stripping conditions is chemically bonded to the system, has good dispersibility in the modified vegetable oil, and is not easy to aggregate; the surface-modified nano titanium dioxide is added to the modified vegetable oil, and the nano titanium dioxide has good compatibility with the system.

[0037] 4. The modified vegetable oil is obtained by adding hydroxylated nano boron nitride, modified aluminum oxide and tea polyphenols into the system, and the amount of each component is controlled, so that the modified vegetable oil has good oxidation stability and strong antioxidant capacity. Tea polyphenols play a role in scavenging free radicals, prolonging the formation of cycloalkyl free radicals and peroxide free radicals, thereby prolonging the oxidation induction period of the modified vegetable oil. When used together with hydroxylated nano boron nitride and modified aluminum oxide, the three work synergistically to improve the antioxidant property of the modified vegetable oil.

[0038] 5. Using cyanohexyltrimethoxysilane as the main reaction raw material, reflux reaction under alkaline conditions and hydrolysis under acidic conditions to prepare hydroxylated silsesquiane; using the prepared modified vegetable oil as a precursor, adding isophorone diisocyanate to react to form a compound with a polyurea or polyurethane structure, and the isocyanate group of isophorone diisocyanate reacts with hydroxylated silsesquiane or monoamine to form a uniform polyurea material colloid. The colloid is used for coatings, and the obtained material is impermeable, has a small heating expansion rate, and has high bonding strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a graph showing the volume resistivity test results of modified vegetable oil in Example 39 of the present invention;

[0040] Figure 2 This is a graph showing the test results of thermal conductivity of modified vegetable oil in Example 39 of the present invention. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0042] See also Figure 1 to Figure 2 The present invention provides a method for preparing modified vegetable oil, and the technical scheme is as follows:

[0043] The substance information involved in the examples and comparative examples of the present invention is as follows:

[0044] Tetrabutylene diamine (bis(thioperoxydicarbonyl)tetrabutylene) TBD, CAS: 1634-02-2; 1,4-butylene diamine, CAS: 110-60-1; hexanediamine CAS: 124-09-4; 1,8-octanediamine CAS: 373-44-4; decanediamine CAS: 646-25-3; 1,12-diaminododecane, CAS: 2783-17-7; 4-aminomethylcyclohexylamine, CAS: 13338-82-4; cyanohexyltrimethoxysilane , CAS: 17865-54-2; n-butylamine, CAS: 109-73-9; dodecyl primary amine, CAS: 124-22-1; tetradecylamine, CAS: 2016-42-4; hexadecylamine, CAS: 143-27-1; cyanohexyltrimethoxysilane, CAS: 17865-54-2; isophorone diisocyanate, CAS: 4098-71-9; nano-boron nitride and nano-titanium dioxide were purchased from Jiangsu Xianfeng Nanomaterial Technology Co., Ltd.

[0045] Examples 1-12

[0046] 9.8 parts of tung oil are added into a round-bottom flask, and then 1.3 parts of sodium hydroxide and 5 parts of water are added, and the temperature is raised to 90°C to obtain a solution to be saponified; the solution to be saponified is reacted at a speed of 500 rpm to obtain a saponified solution; the saponified solution is cooled to room temperature, and acetic acid is added to neutralize it, and then the solution is separated, centrifuged, and dried to obtain sodium eleostearate;

[0047] 7.3 parts of rapeseed oil and 7.8 parts of acetic acid are uniformly mixed to obtain a liquid to be oxidized; the liquid to be oxidized is heated to 60° C., 26.4 parts of hydrogen peroxide solution is dripped into the liquid under stirring, and the reaction is carried out for 12 hours to obtain an epoxidized rapeseed oil solution; the mass fraction of the hydrogen peroxide solution is 20%; the hydrogen peroxide solution is dripped within 2 hours;

[0048] Sodium eleostearate is dissolved in a mixture of 20 parts of ethyl acetate and water to obtain a sodium eleostearate solution; the mass ratio of ethyl acetate to water is 4:1; the sodium eleostearate solution is added to the epoxy rapeseed oil solution, and 0.7 parts of TBD are added to obtain a grafted solution; the grafted solution is heated to 150°C and reacted for 10 hours to obtain rapeseed oil grafted tung oil; the rapeseed oil grafted tung oil is cooled to 60°C, 50 parts of hydrogen peroxide solution is continuously added thereto, reacted for 15 hours, and then dried in layers to obtain rapeseed oil grafted epoxy tung oil;

[0049] Add 30 parts by mass of 0.5% sodium hydroxide solution and 11.8 parts by mass of 1,4-diamine to the rapeseed oil grafted tung oil, raise the temperature to 90°C, and react for 6 hours to obtain a modified vegetable oil intermediate;

[0050] Disperse 1 part of nano boron nitride in 200 parts of ethanol-water solution, and ultrasonically treat for 1 hour to obtain a boron nitride nano dispersion; the mass ratio of ethanol to water in ethanol-water is 2:1; ultrasonically strip the boron nitride nano dispersion for 12 hours using an ultrasonic cleaner to obtain a stripping solution; the ultrasonic stripping power is 200W; the supernatant obtained by centrifuging the stripping solution is filtered, and then dried in an oven overnight to obtain hydroxylated nano boron nitride;

[0051] 0.016 parts of hydroxylated nano boron nitride were added to the modified vegetable oil intermediate, reacted at 90℃ and 600rpm for 10h, and cooled to room temperature to obtain the modified vegetable oil precursor; the nano titanium dioxide was placed in an oven to dry to obtain anhydrous nano titanium dioxide; the anhydrous nano titanium dioxide was added to a ball mill, and then KH550 and sodium dodecyl sulfate were added for grinding to obtain modified nano titanium dioxide; the mass ratio of anhydrous nano titanium dioxide, KH550 and sodium dodecyl sulfate was 6:13:1; 2.4 parts of 1% tea polyphenol ethanol solution and 0.002 parts of modified nano titanium dioxide were added to the modified vegetable oil precursor, stirred evenly and rotary evaporated to obtain modified vegetable oil. All preparation reactions were carried out in a nitrogen atmosphere.

[0052] The detailed information of the preparation process of the embodiment is shown in Table 1.

[0053] Table 1 Detailed preparation information of rapeseed oil grafted epoxidized tung oil

[0054] Group Tung oil dosage (parts) TBD dosage (portion) Heating temperature(℃) Reaction time (h) Example 1 9.8 0.7 150 10 Example 2 8.7 0.7 150 10 Example 3 7.3 0.7 150 10 Example 4 5.8 0.7 150 10 Example 5 4.8 0.7 150 10 Example 6 2.4 0.7 150 10 Example 7 8.7 0.8 150 10 Example 8 8.7 0.5 150 10 Example 9 8.7 0.3 150 10 Example 10 8.7 0.5 160 9 Embodiment 11 8.7 0.5 165 8.5 Example 12 8.7 0.5 170 8 Comparative Example 1 8.7 0.5 60 13

[0055] Comparative Example 2

[0056] The difference from Example 1 is that a sodium eleostearate solution is added to an epoxidized rapeseed oil solution to obtain a mixture of epoxidized rapeseed oil and sodium eleostearate; the mixture of epoxidized rapeseed oil and sodium eleostearate is heated to 60°C, 50 parts of a hydrogen peroxide solution is added thereto, the mixture is reacted for 15 hours, and then the mixture is dried in layers to obtain a mixture of rapeseed oil and epoxidized tung oil; and finally a modified vegetable oil is prepared.

[0057] Example 13

[0058] The modified vegetable oils prepared in Examples 1-12 and Comparative Examples 1 and 2 were subjected to performance tests. The viscosity and apparent stability of the modified vegetable oils were mainly tested. The kinematic viscosity and viscosity index of the modified vegetable oils at 100°C were tested according to GB / T 11137-1989 "Determination of kinematic viscosity of dark petroleum products (countercurrent method) and calculation method of dynamic viscosity"; the modified vegetable oils were sealed and stored at room temperature of 25°C in a dark place for 6 months, and the stratification of the modified vegetable oils was observed with the naked eye. The final test results are shown in Table 2.

[0059] Table 2 Viscosity and apparent stability test results of modified vegetable oil

[0060] Group <![CDATA[Kinematic viscosity (mm 2 / s)]]> Viscosity Index Apparent stability Example 1 44.0 138 No stratification Example 2 44.3 137 No stratification Example 3 43.5 135 No stratification Example 4 41.7 132 No stratification Example 5 40.2 131 No stratification Example 6 38.4 128 No stratification Example 7 44.7 136 No stratification Example 8 45.1 135 No stratification Example 9 43.9 133 No stratification Example 10 43.0 129 No stratification Embodiment 11 42.5 130 No stratification Example 12 41.3 126 No stratification Comparative Example 1 36.8 122 Slightly delaminated Comparative Example 2 29.4 115 Severe stratification

[0061] The kinematic viscosity of the modified vegetable oil prepared by the present invention at 100°C is 29.4-45.1 mm 2 / s, the viscosity index is 115-138, and the modified vegetable oil in the embodiment did not show stratification after 6 months of storage. Kinematic viscosity characterizes the kinematic index of the oil, and the higher the value, the greater the viscosity; the viscosity index reflects the relationship between the viscosity of the modified vegetable oil and the temperature. The larger the value, the less the oil viscosity is affected by the temperature. By saponifying tung oil to obtain elastinate, rapeseed oil is oxidized by hydrogen peroxide to obtain epoxidized rapeseed oil, and the epoxidized rapeseed oil is opened and reacted with elastinate to obtain a grafted product. The unsaturated bonds in the product continue to form epoxy bonds under the action of hydrogen peroxide, and then further react to obtain the modified vegetable oil. In Examples 1-6, as the amount of tung oil decreases, the kinematic viscosity and viscosity index both show a downward trend. After grafting, the addition of components in tung oil increases the viscosity of the modified vegetable oil and improves the stability of the modified vegetable oil. The results of Examples 2, 8, and 9 show that when other conditions remain unchanged, the catalytic reaction effect is best when the amount of Example TBD is 0.5 parts, at which time the kinematic viscosity is the highest and the viscosity index is relatively high. The results of Examples 8, 10-12 show that when the grafting reaction temperature is in the range of 150-170°C and the reaction time is in the range of 8-10h, the kinematic viscosity and viscosity index are relatively high, and the modified vegetable oil does not delaminate after storage. The reaction temperature of Comparative Example 1 is too low, resulting in incomplete fusion of rapeseed oil and tung oil, so the final performance is reduced. The components in rapeseed oil and tung oil in Comparative Example 2 are not connected by chemical bonds, and the compatibility of the two is poor after mixing. After storage, the modified vegetable oil shows serious delamination.

[0062] Examples 14-25

[0063] 9.2 parts of tung oil are added into a round-bottom flask, and then 1.3 parts of sodium hydroxide and 5 parts of water are added, and the temperature is raised to 90°C to obtain a solution to be saponified; the solution to be saponified is reacted at a speed of 500 rpm to obtain a saponified solution; the saponified solution is cooled to room temperature, and acetic acid is added to neutralize it, and then the solution is separated, centrifuged, and dried to obtain sodium eleostearate;

[0064] 7.3 parts of rapeseed oil and 7.8 parts of acetic acid are uniformly mixed to obtain a liquid to be oxidized; the liquid to be oxidized is heated to 60° C., 26.4 parts of hydrogen peroxide solution is dripped into the liquid under stirring, and the reaction is carried out for 12 hours to obtain an epoxidized rapeseed oil solution; the mass fraction of the hydrogen peroxide solution is 20%; the hydrogen peroxide solution is dripped within 2 hours;

[0065] Sodium eleostearate is dissolved in a mixture of 20 parts of ethyl acetate and water to obtain a sodium eleostearate solution; the mass ratio of ethyl acetate to water is 4:1; the sodium eleostearate solution is added to the epoxy rapeseed oil solution, and 0.6 parts of TBD are added to obtain a grafted solution; the grafted solution is heated to 150°C and reacted for 10 hours to obtain rapeseed oil grafted tung oil; the rapeseed oil grafted tung oil is cooled to 60°C, 50 parts of hydrogen peroxide solution is continuously added thereto, reacted for 15 hours, and then dried in layers to obtain rapeseed oil grafted epoxy tung oil;

[0066] Add 30 parts by mass of 0.5% sodium hydroxide solution and diamine to the rapeseed oil grafted tung oil, raise the temperature to 90°C, and react for 6 hours to obtain a modified vegetable oil intermediate;

[0067] Disperse 1 part of nano boron nitride in 200 parts of ethanol-water solution, and ultrasonically treat for 1 hour to obtain a boron nitride nano dispersion; the mass ratio of ethanol to water in ethanol-water is 2:1; ultrasonically strip the boron nitride nano dispersion for 12 hours using an ultrasonic cleaner to obtain a stripping solution; the ultrasonic stripping power is 200W; the supernatant obtained by centrifuging the stripping solution is filtered, and then dried in an oven overnight to obtain hydroxylated nano boron nitride;

[0068] 0.016 parts of hydroxylated nano boron nitride were added to the modified vegetable oil intermediate, reacted at 90℃ and 600rpm for 10h, and cooled to room temperature to obtain the modified vegetable oil precursor; the nano titanium dioxide was placed in an oven to dry to obtain anhydrous nano titanium dioxide; the anhydrous nano titanium dioxide was added to a ball mill, and then KH550 and sodium dodecyl sulfate were added for grinding to obtain modified nano titanium dioxide; the mass ratio of anhydrous nano titanium dioxide, KH550 and sodium dodecyl sulfate was 6:13:1; 2.4 parts of 1% tea polyphenol ethanol solution and 0.002 parts of modified nano titanium dioxide were added to the modified vegetable oil precursor, stirred evenly and rotary evaporated to obtain modified vegetable oil. All preparation reactions were carried out in a nitrogen atmosphere.

[0069] The types and amounts of substances used in the preparation of modified vegetable oil intermediates changed, and the specific preparation information is shown in Table 3.

[0070] Table 3 Type and dosage of amines and mass fraction of sodium hydroxide

[0071]

[0072]

[0073] Embodiment 26, 27

[0074] Different from Example 14, the mass ratios of anhydrous nano-titanium dioxide, KH550 and sodium dodecyl sulfate are 3:6:1 and 5:14:1 respectively.

[0075] Comparative Example 4

[0076] Different from Example 14, the mass ratio of anhydrous nano-titanium dioxide, KH550 and sodium dodecyl sulfate is 19:0:1.

[0077] Embodiment 28

[0078] The modified vegetable oils prepared in Examples 14-27 and Comparative Examples 3 and 4 were tested for flash point and pour point. Combustible liquids can volatilize into steam and enter the air. When the volatilized steam and air mixture are close to the fire source, sparks will flash. This short combustion process is called flash combustion. The lowest temperature at which flash combustion occurs is called flash point. The higher the flash point, the better the safety of the modified vegetable oil. The flash point of the modified vegetable oil is determined according to GB / T 3536-2008 "Cleveland Open Cup Method for Determination of Flash Point and Ignition Point of Petroleum Products". The pour point is the lowest temperature at which the liquid surface flows when the liquid is tilted. The specific test method is carried out in accordance with GB / T3535-2006 "Determination of Pour Point of Petroleum Products". The final test results are shown in Table 4.

[0079] Table 4 Test results of flash point and pour point of modified vegetable oil

[0080]

[0081]

[0082] The modified vegetable oil prepared by the present invention has a flash point of 204-249°C and a pour point of -30 to -44°C. By adding a dilute alkali solution to the rapeseed oil grafted tung oil, and adding a diamine, the epoxy group in the rapeseed oil grafted tung oil is ring-opened under the reaction condition of 90°C and TBD catalysis, and hydroxylamine condensation is carried out with the amino group at one end of the diamine, and the diamine is connected to the rapeseed oil grafted tung oil through a chemical bond. In Examples 14-20, the molar addition amount of different types of diamines remains consistent, wherein when the type of diamine in Example 20 is 4,4'-diaminodicyclohexylmethane, the flash point of the modified vegetable oil is the highest, which is 245°C, and the pour point is -41°C; the diamine containing cycloalkyl is beneficial to improve the flash point of the vegetable oil. The results of Examples 20-22 show that when the amount of 4,4'-diaminodicyclohexylmethane in Example 21 is 28.4 parts, the flash point is the highest and the pour point is relatively low. In Examples 21, 23-25, by changing the mass fraction of the dilute alkali solution, the pour point is in the range of -38°C to -40°C. In Comparative Example 3, no diamine is added, and the modified vegetable oil obtained has a lower flash point and an increased pour point compared with the examples. The results of Examples 14, 26, and 27 show that when the mass ratio of anhydrous nano-titanium dioxide, KH550, and sodium dodecyl sulfate in Example 27 is 5:14:1, the modified vegetable oil has the lowest pour point of -44°C. The addition of KH550 improves the compatibility of nano-titanium dioxide and the oil component, and on the other hand improves the low-temperature ability of the modified vegetable oil, so that the modified vegetable oil has a lower pour point. As shown in Comparative Example 4, the flash point of the modified vegetable oil prepared without adding KH550 does not change significantly, and the pour point is reduced. In summary, the modified vegetable oil prepared by the present invention has a higher flash point and a lower pour point, and meets the use conditions of high and low temperatures.

[0083] Embodiment 29

[0084] Disperse 1 part of nano boron nitride in 200 parts of ethanol-water solution, and ultrasonically treat for 1 hour to obtain a boron nitride nano dispersion; the mass ratio of ethanol to water in ethanol-water is 2:1; ultrasonically strip the boron nitride nano dispersion for 11 hours using an ultrasonic cleaner to obtain a stripping solution; the ultrasonic stripping power is 300W; the supernatant obtained by centrifuging the stripping solution is filtered, and then dried in an oven overnight to obtain hydroxylated nano boron nitride;

[0085] 0.016 parts of hydroxylated nano boron nitride were added to the modified vegetable oil intermediate, reacted at 90°C and 600 rpm for 10 hours, and cooled to room temperature to obtain a modified vegetable oil precursor; the added amount of modified nano titanium dioxide was 0.002 parts.

[0086] The other preparation processes and conditions were consistent with those in Example 24, and modified vegetable oil was finally prepared.

[0087] Examples 30-37

[0088] Different from Example 29, the following preparation method is adjusted, as shown in Table 5.

[0089] Table 5 Detailed information on preparation method

[0090]

[0091] Embodiment 38

[0092] The difference from Example 29 is that the added amount of modified nano titanium dioxide is 0.003 parts.

[0093] Comparative Example 5

[0094] No hydroxylated nano-boron nitride was added, and other preparation methods remained consistent with Example 29.

[0095] Comparative Example 6

[0096] The difference from Example 29 is that the modified nano titanium dioxide is replaced by 0.002 parts of nano titanium dioxide.

[0097] Embodiment 39

[0098] The modified vegetable oils prepared in Examples 29-38 and Comparative Examples 5 and 6 were tested for electrical properties and thermal conductivity. The electrical properties are characterized by volume resistivity. The value of volume resistivity characterizes the insulation performance of the material. The volume resistivity at 90°C is tested with reference to GB / T5654-2007 "Measurement of relative permittivity, dielectric loss factor and DC resistivity of liquid insulating materials". The test is performed using a NDYJS-V fully automatic oil dielectric loss and resistivity tester. The thermal conductivity is characterized by the thermal conductivity coefficient. The higher the thermal conductivity coefficient, the better the thermal conductivity of the modified vegetable oil. The test is performed using a thermal conductivity tester with reference to the ISO22007-2 standard. The final test results are shown in Figure 1 and Figure 2 middle.

[0099] like Figure 1 and Figure 2 The results show that the volume resistivity of the modified vegetable oil prepared by the present invention is 7.5×10 14 Ω·m-9.8×10 14 Ω·m, thermal conductivity is 0.106-0.246W·m -1 ·K -1, with good insulation and thermal conductivity. Nano boron nitride is peeled off by ultrasound to obtain nano boron nitride with hydroxyl groups on the surface. After heating, part of the hydroxylated nano boron nitride condenses with the unreacted amino groups of diamine, and part of it is connected with the hydroxyl groups in the modified vegetable oil through hydrogen bonding. The nano boron nitride is well dispersed in the modified vegetable oil and is not easy to aggregate. By modifying the nano titanium dioxide, its compatibility with the vegetable oil is improved, and its dispersibility is also improved. Example 29-33 By changing the power and time of the peeling, the volume resistivity of the modified vegetable oil prepared is 9.0×10 14 Ω·m-9.2×10 14 Ω·m, thermal conductivity is 0.187-0.230W·m -1 ·K -1 . The test results of Examples 33-36 show that with the increase in the amount of modified nano-boron nitride, the thermal conductivity shows a trend of first increasing and then decreasing. The modified nano-boron nitride has a higher thermal conductivity. The introduction into the vegetable oil changes the structure of the liquid and improves the energy transfer process inside the modified vegetable oil, thereby enhancing the thermal conductivity of the modified vegetable oil. Therefore, Comparative Example 5 does not add hydroxylated nano-boron nitride, so the thermal conductivity of the prepared modified vegetable oil is significantly reduced, and the volume resistivity is also reduced compared with the embodiment. The reaction temperature of Example 37 is too high, which is not conducive to the good compatibility of nano-boron nitride with the system, so the thermal conductivity is reduced. The surface of nano-titanium dioxide is modified by KH550, and a surfactant is added to improve the organic properties of nano-titanium dioxide, and finally increase the volume resistivity and thermal conductivity. Therefore, Comparative Example 6 replaces the modified nano-titanium dioxide with nano-titanium dioxide, and the electrical properties and thermal conductivity of the modified vegetable oil are reduced.

[0100] Examples 40-47

[0101] Comparative Examples 7-9

[0102] Different from Example 24, the following preparation conditions are changed, as shown in Table 6.

[0103] Embodiment 48

[0104] The modified vegetable oils prepared in Examples 40-47 and Comparative Examples 7-9 were tested for oxidation stability to examine the antioxidant capacity of the modified vegetable oils. The test was conducted with reference to SH / T 0193-2008 "Determination of oxidation stability of lubricating oils - Rotating oxygen bomb method", where the modified vegetable oil, water and copper coil were placed in an oxygen bomb, filled with oxygen to a pressure of 620 kPa, and the time required for the pressure in the oxygen bomb to drop to 175 kPa was recorded after axial rotation. The time required was used to measure oxidation stability.

[0105] During storage and use, the modified vegetable oil is easily oxidized and deteriorated due to light or heat, as well as under the action of oxygen and other factors, resulting in darkening of color, generation of a large number of harmful reactions and substances such as acidic compounds and colloidal sediments, so antioxidant property is an important indicator, and the longer the time, the better the oxidative stability. The oxidative stability time of the modified vegetable oil obtained by the present invention is 46-95min. Except for the comparative example, the modified vegetable oil obtained in the embodiment has a good antioxidant effect. The results of Examples 40 and 41 show that under the cool condition where the amount of hydroxylated nano-boron nitride and tea polyphenol ethanol solution remains unchanged, the oxidative stability is best when 0.002 parts of modified aluminum oxide is added. The results of Examples 41-44 show that with the increase of the amount of tea polyphenol, the oxidative stability gradually increases. In the early stage of oxidation of the modified vegetable oil, tea polyphenol plays a role in scavenging free radicals, prolonging the formation of slow alkyl free radicals and peroxide free radicals, thereby prolonging the oxidation induction period of the modified vegetable oil. In Examples 45-47, when the dosages of the three components of Example 46 were 0.020 parts, 0.001 parts, and 4.8 parts, respectively, the modified vegetable oil prepared had the best oxidation stability, and the time was 95 minutes. The results of Comparative Examples 7-9 showed that without adding any of hydroxylated nano-boron nitride, modified aluminum oxide, and tea polyphenol ethanol solution, the oxidation stability of the modified vegetable oil decreased. In addition to the antioxidant effect of tea polyphenol, hydroxylated nano-boron nitride also had good antioxidant properties. At the same time, modified aluminum oxide chelated with the metal that caused the oxidation process reaction. The three synergistically prevented the oxidation process of the modified vegetable oil.

[0106] Table 6 Dosages of hydroxylated nano-boron nitride, modified nano-titanium dioxide and tea polyphenol ethanol solution

[0107]

[0108] Embodiment 49

[0109] 24.4 parts of cyanohexyltrimethoxysilane were dissolved in 150 mL of THF to obtain a cyanohexyltrimethoxysilane solution; 2.7 parts of water and 2.1 parts of sodium hydroxide were added to the cyanohexyltrimethoxysilane solution under stirring, the temperature was raised to 75° C., refluxed for 5 hours and stirred for 18 hours, and then rotary evaporated and dried to obtain a hydroxylated silsesquiane precursor product;

[0110] Dissolve 10 parts of a hydroxylated silsesquiane precursor product in 100 mL of THF to obtain a precursor solution; vigorously stir the precursor solution at 4° C. and introduce nitrogen, dropwise add 8.2 parts of acetic acid into the reaction system, stir and react for 3 hours, continue to add 100 parts of water and stir and react for 1 hour to obtain a hydroxylated silsesquiane intermediate product; remove THF from the hydroxylated silsesquiane intermediate product by rotary evaporation, and then extract, wash and vacuum dry to obtain hydroxylated silsesquiane;

[0111] The modified vegetable oil prepared in Example 24 was heated to 80°C, 52 parts of isophorone diisocyanate were dripped into the heated modified vegetable oil within 1 hour, and 1 part of triethylamine was added, and the reaction was stirred for 5 hours to obtain a polyurea material precursor; 48.6 parts of hydroxylated silsesquiane were dissolved in THF to obtain a hydroxylated silsesquiane solution; the number volume ratio of hydroxylated silsesquiane to THF was 1:10; 24.1 parts of n-butylamine and the hydroxylated silsesquiane solution were added to the polyurea material precursor, the temperature was raised to 90°C, 0.5 parts of triethylamine were added, and the reaction was carried out for 12 hours to obtain a polyurea material intermediate; after removing the organic solvent from the polyurea material intermediate, a polyurea material was obtained.

[0112] Examples 50-56

[0113] Different from Example 49, the following preparation conditions are changed, as shown in Table 7.

[0114] Table 7 Types and dosage information of hydroxylated silsesquiane and monoamine compounds

[0115]

[0116] Embodiment 57

[0117] The polyurea materials prepared in Examples 49-56 and Comparative Examples 10 and 11 were tested for waterproofness, heat resistance and bonding strength. The various properties of the polyurea materials were tested according to the method of GB / T 19250-2013 "Polyurethane Waterproof Coatings", and the final test results are shown in Table 8.

[0118] Table 8 Test results of water resistance, heat resistance and bonding strength of polyurea materials

[0119] Group Waterproofness (0.3MPa, 120min) Heating expansion ratio (%) Bond strength (MPa) Embodiment 49 impermeable -1.8 3.1 Embodiment 50 impermeable -0.9 4.3 Embodiment 51 impermeable -0.7 4.6 Embodiment 52 impermeable 0.3 4.8 Embodiment 53 impermeable 0.8 6.5 Embodiment 54 impermeable -0.5 5.6 Embodiment 55 impermeable -0.5 6.7 Embodiment 56 impermeable -0.4 7.0 Comparative Example 10 permeable -4.2 2.2 Comparative Example 11 impermeable -2.6 7.1

[0120] The modified vegetable oil prepared by the present invention is used to prepare a polyurea material. The material is impermeable for 120 minutes under a water pressure of 0.3 MPa (except for comparative example 10), and the heating expansion rate is in the range of -4.2% to 0.3%. The smaller the absolute value of the heating expansion rate, the better the heat resistance, and the bonding strength is 2.2-7.1 MPa. After the modified vegetable oil is heated, the isocyanate group at one end of isophorone diisocyanate reacts with the unreacted amino group or hydroxyl group in the modified vegetable oil under the action of a catalyst to obtain a compound having a polyurea or polyurethane structure, and then the isocyanate group of isophorone diisocyanate reacts with hydroxylated silsesquiane or monoamine to form a polyurea material with uniform and viscous properties, which can be applied to coatings and has good performance after drying. Among them, the polyurea materials obtained in Examples 49-53 are all impermeable to water. In the heated state, the hydroxylated silsesquiane expands when heated, and the other components curl and shrink. As the amount of hydroxylated silsesquiane increases, the expanded part offsets the contracted part to a certain extent, so the absolute value of the heating expansion rate shows a trend of first decreasing and then increasing. The bonding strength reaches the highest under the preparation conditions of Example 53, which is 6.5MPa. The results of Examples 54-56 show that by changing the type and amount of monoamine, the modified vegetable oil obtained has a small heating expansion rate and high bonding strength. The water resistance and heat resistance of the polyurea material are improved by adding hydroxylated silsesquiane, and the bonding strength of the polyurea material is improved by using it in combination with monoamine. As shown in Comparative Example 10, the material without adding hydroxylated silsesquiane is water-permeable, and the bonding strength is reduced, and the absolute value of the heating expansion rate is increased; Comparative Example 11 does not add monoamine, the amount of hydroxylated silsesquiane is increased, and the absolute value of the heating expansion rate is improved.

[0121] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a modified vegetable oil, characterized in that: The following steps are involved: 2.4-9.8 parts of tung oil, sodium hydroxide and water are added into a round-bottom flask, and the temperature is raised to react to obtain a saponified solution; the saponified solution is cooled to room temperature, neutralized, separated, centrifuged and dried to obtain sodium eleostearate; the sodium eleostearate is dissolved in a mixture of ethyl acetate and water to obtain a sodium eleostearate solution; the sodium eleostearate solution is added into an epoxidized rapeseed oil solution, and 0.3-0.7 parts of TBD are added to obtain a solution to be grafted; The grafted liquid is heated to 60-150° C. and reacted for 8-13 hours to obtain rapeseed oil grafted tung oil; the rapeseed oil grafted tung oil is cooled, oxidized, and dried to obtain rapeseed oil grafted epoxidized tung oil; Adding 0.4% to 0.8% by mass of sodium hydroxide solution and diamine to the rapeseed oil grafted tung oil, and heating the mixture to obtain a modified vegetable oil intermediate; Ultrasonic stripping of boron nitride nano-dispersion liquid for 8-12 hours to obtain a stripping solution; the ultrasonic stripping power is 200-500W; the stripping solution is centrifuged, filtered, and dried to obtain hydroxylated nano-boron nitride; 0-0.056 parts of the hydroxylated nano boron nitride are added to the modified vegetable oil intermediate, reacted at 90-110°C and 600rpm for 10 hours, and cooled to room temperature to obtain a modified vegetable oil precursor; anhydrous nano titanium dioxide is added to a ball mill, and then KH550 and sodium dodecyl sulfate are added for grinding to obtain modified nano titanium dioxide; the mass ratio of the anhydrous nano titanium dioxide, the KH550 and the sodium dodecyl sulfate is 3-19:0-14:1; 0-4.8 parts of tea polyphenol ethanol solution and 0-0.005 parts of the modified nano titanium dioxide are added to the modified vegetable oil precursor, stirred evenly and rotary evaporated to obtain modified vegetable oil.

2. The method for preparing a modified vegetable oil according to claim 1, characterized in that: The diamine is one of 1,4-butanediamine, hexanediamine, 4-aminomethylcyclohexylamine, 1,8-octanediamine, decanediamine, 1,12-diaminododecane and 4,4'-diaminodicyclohexylmethane; and the amount of the diamine used is 0-29.5 parts.

3. The method for preparing a modified vegetable oil according to claim 1, characterized in that: The diamine is used in an amount of 11.8-29.5 parts.

4. The method for preparing a modified vegetable oil according to claim 1, characterized in that: The mass ratio of the anhydrous nano titanium dioxide, the KH550 and the sodium dodecyl sulfate is 3-6:6-14:

1.

5. The method for preparing a modified vegetable oil according to claim 1, characterized in that: The dosage of the hydroxylated nano boron nitride is 0.016-0.056 parts.

6. The method for preparing a modified vegetable oil according to claim 1, characterized in that: The dosage of the modified nano titanium dioxide is 0.001-0.005 parts.

7. The method for preparing a modified vegetable oil according to claim 1, characterized in that: The dosage of the tea polyphenol ethanol solution is 1.6-4.8 parts.

8. The method for preparing a modified vegetable oil according to claim 1, characterized in that: The modified vegetable oil is used to prepare a polyurea material; the preparation method of the polyurea material is as follows: Dissolving cyanohexyltrimethoxysilane in THF to obtain a cyanohexyltrimethoxysilane solution; adding water and sodium hydroxide to the cyanohexyltrimethoxysilane solution under stirring, heating to 75° C., reflux reacting for 5 h and keeping the temperature for 18 h, then rotary evaporating and drying to obtain a hydroxylated silsesquiane precursor product; The hydroxylated silsesquiane precursor product is dissolved in THF to obtain a precursor solution; the precursor solution is vigorously stirred at 4° C. and nitrogen is introduced, and acetic acid is added dropwise, and the reaction is stirred for 3 hours, and water is continuously added and stirred for 1 hour to obtain a hydroxylated silsesquiane intermediate product; the hydroxylated silsesquiane intermediate product is subjected to rotary evaporation to remove THF, and then extracted, washed and vacuum dried to obtain hydroxylated silsesquiane; The modified vegetable oil is heated to 80°C, isophorone diisocyanate is dripped into the heated modified vegetable oil within 1 hour, and 1 part of triethylamine is added, and the reaction is stirred for 5 hours to obtain a polyurea material precursor; 0-227.0 parts of the hydroxylated silsesquiane are dissolved in THF to obtain a hydroxylated silsesquiane solution; the number volume ratio of the hydroxylated silsesquiane to the THF is 1:10; 0-24.1 parts of monoamine and the hydroxylated silsesquiane solution are added to the polyurea material precursor, the temperature is raised to 90°C, 0.5 parts of triethylamine is added, and the reaction is carried out for 12 hours to obtain the polyurea material intermediate; the polyurea material is obtained by removing the THF from the polyurea material intermediate.

9. The method for preparing a modified vegetable oil according to claim 8, characterized in that: The dosage of the hydroxylated silsesquiane is 97.3-227.0 parts; the monoamine is one of n-butylamine, dodecyl primary amine, tetradecylamine and hexadecylamine.

10. A modified vegetable oil, characterized in that: The modified vegetable oil comprises tung oil, epoxidized rapeseed oil, diamine, hydroxylated nano boron nitride, modified nano titanium dioxide and tea polyphenol ethanol solution; the modified vegetable oil is prepared by the preparation method according to any one of claims 1 to 9; the kinematic viscosity of the modified vegetable oil at 100° C. is 29.4-45.1 mm 2 / s, viscosity index was 115-138, and no stratification occurred after 6 months of storage; The flash point of the modified vegetable oil is 204-249°C, the pour point is -30 to -44°C; the volume resistivity of the modified vegetable oil is 7.5×10 14 Ω·m-9.8×10 14 Ω·m, thermal conductivity is 0.106-0.246W·m -1 ·K -1 The test time of the oxidation stability of the modified vegetable oil is 46-95 minutes; the polyurea material prepared from the modified vegetable oil is impermeable for 120 minutes under a water pressure of 0.3 MPa after drying, the heating expansion rate is -4.2% to 0.3%, and the bonding strength is 2.2-7.1 MPa.

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