A nonionic surfactant, its preparation method and use

Abstract

The application provides a non-ionic surfactant, a preparation method and application thereof, and the non-ionic surfactant has a structure shown in the following formula: wherein m is 3-15. The non-ionic surfactant provided by the application is modified double-end hydroxyl 2-propyl heptyl alcohol polyoxyethylene ether, so that the non-ionic surfactant has excellent alkali resistance, emulsification and metal cleaning performance.

Description

Technical Field

[0001] This invention belongs to the field of surfactant technology, and particularly relates to a nonionic surfactant, its preparation method, and its application. Background Technology

[0002] Surfactants, as a type of fine chemical, are hailed as "industrial MSG" and are widely used in various fields. Based on their ionicity, they can be classified into anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants. Nonionic surfactants, with their excellent degreasing, wetting, emulsifying, and dispersing properties, are increasingly used in industrial cleaning. The hydrophilic and lipophilic groups of nonionic surfactants determine their effectiveness in industrial cleaning. Among them, 2-propylheptanol-based polyoxyethylene ethers are widely used in industrial cleaning.

[0003] Patent US5661121 reports that 2-propylheptanol polyoxyethylene ether exhibits excellent foaming and cleaning properties when used for hard surface cleaning. However, 2-propylheptanol polyoxyethylene ether also suffers from insufficient alkali resistance, poor emulsification properties, and its degreasing performance needs further improvement.

[0004] Therefore, developing a nonionic surfactant with high alkali resistance, excellent emulsifying properties, and high oil removal performance is an urgent technical problem to be solved. Summary of the Invention

[0005] In view of the problems existing in the prior art, the main objective of the present invention is to provide a nonionic surfactant with excellent alkali resistance, emulsification and metal cleaning properties.

[0006] The present invention also provides a method for preparing a nonionic surfactant, which can prepare the above-mentioned nonionic surfactant, and the process is simple and low in cost.

[0007] In a first aspect, the present invention provides a nonionic surfactant having the structure shown in formula (1):

[0008]

[0009] Where m takes values ​​of 3-15, preferably 4-7.

[0010] In this invention, the hydroxyl value of the nonionic surfactant is 126-321 mgKOH / g.

[0011] In this invention, the average molecular weight of the nonionic surfactant is 350-890 g / mol.

[0012] The nonionic surfactant shown in Formula 1 of the present invention has a double-terminated hydroxyl structure and can be prepared by reacting a system comprising 2-propylheptanol and a catalyst with ethylene oxide and propylene oxide in sequence.

[0013] Secondly, the present invention provides a method for preparing the nonionic surfactant as described above, comprising the following steps:

[0014] 1) Mix 2-propylheptanol, catalyst, and ethylene oxide for a single reaction;

[0015] 2) The reaction in step 1) involves the addition of glycidol for a secondary reaction to obtain the nonionic surfactant.

[0016] In the preparation method described above, the catalyst is one or more of potassium hydroxide, sodium hydroxide, sodium methoxide, potassium methoxide, and phosphazene catalyst, preferably one or more of potassium hydroxide and phosphazene catalyst;

[0017] The mass of the catalyst is 0.02-1% of the total mass of the 2-propylheptanol, ethylene oxide, and propylene oxide, preferably 0.1-0.3%.

[0018] The catalyst prepared by the method described above can also be a Zn / Co bimetallic catalyst;

[0019] The catalyst comprises 0.002-0.02% of the total mass of 2-propylheptanol, ethylene oxide, and propylene oxide, preferably 0.003-0.006%.

[0020] In the preparation method described above, the molar ratio of 2-propylheptanol to ethylene oxide is 1:3-15, preferably 1:4-7;

[0021] The molar ratio of 2-propylheptanol to glycidol is 1:1-1.2, preferably 1:1-1.1.

[0022] In the preparation method described above, the temperature of the first reaction in step 1) is 120-190℃, preferably 130-160℃, and the time is 1-8h, preferably 2-6h; the reaction pressure is controlled to be ≤0.6MPa.

[0023] The temperature of the secondary reaction in step 2) is 110-180℃, preferably 120-150℃, and the time is 0.5-4h, preferably 1-3h; the reaction pressure is controlled to be ≤0.4MPa.

[0024] As described above, after the reaction in step 2) is completed, the preparation method also includes post-processing such as cooling, neutralization, and degassing, which are routine operations in the field and are not specifically limited by this invention.

[0025] The nonionic surfactant provided by this invention is a hydroxyl-terminated polyoxyethylene ether, which gives the nonionic surfactant excellent alkali resistance, emulsification and metal cleaning properties. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0027] In a first aspect, the present invention provides a nonionic surfactant having the structure shown in Formula 1:

[0028]

[0029] In the formula, m takes values ​​from 3 to 15.

[0030] The nonionic surfactants provided by this invention have hydroxyl values ​​of 126-321 mgKOH / g, such as 126 mgKOH / g, 140 mgKOH / g, 160 mgKOH / g, 180 mgKOH / g, 200 mgKOH / g, 220 mgKOH / g, 240 mgKOH / g, 260 mgKOH / g, 280 mgKOH / g, 300 mgKOH / g, 321 mgKOH / g, etc.

[0031] The nonionic surfactants provided by this invention have a molecular weight of 350-890 g / mol, such as 350 g / mol, 450 g / mol, 550 g / mol, 650 g / mol, 750 g / mol, 850 g / mol, 890 g / mol, etc.

[0032] The nonionic surfactant provided by this invention has the structure shown in Formula 1 above, namely, a structure with bihydroxyl-terminated polyoxyethylene ethers. This structural characteristic gives the nonionic surfactant excellent alkali resistance, emulsification, and metal cleaning properties. The reason for this is likely that the presence of bihydroxyl groups enhances the hydrogen bonding of the nonionic surfactant molecules in water, increasing solubility and improving alkali resistance. Furthermore, the bihydroxyl-terminated polyoxyethylene segments make the surfactant adsorption at the aqueous and oil phase interfaces more stable, better reducing the tension at the liquid / liquid interface and exhibiting superior emulsification properties. Its excellent wetting and emulsification properties result in superior degreasing effects in the field of metal cleaning.

[0033] The nonionic surfactant provided by this invention is a double-hydroxyl-terminated polyoxyethylene ether, which gives the nonionic surfactant excellent alkali resistance, emulsification and metal cleaning properties.

[0034] In some embodiments of the present invention, m is 3-15, for example 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, etc.

[0035] In this invention, as a preferred embodiment, when m is 4-7, the metal cleaning performance of the nonionic surfactant can be further improved.

[0036] In some embodiments of the present invention, the nonionic surfactant is prepared by a method comprising the following process:

[0037] Ethylene oxide and propylene oxide were added sequentially to a system comprising 2-propylheptanol and a catalyst to carry out the reaction. The reaction product was then subjected to post-treatment including cooling, neutralization, and degassing to obtain the nonionic surfactant.

[0038] The raw materials for preparing the nonionic surfactant in this invention include 2-propylheptanol, a catalyst, ethylene oxide, and propylene oxide. Specifically, 2-propylheptanol and the catalyst can be mixed, purged with nitrogen, dehydrated and heated (for example, the moisture content in the reactor is controlled to be below 50 ppm), ethylene oxide can be slowly added, and after the reaction is complete, propylene oxide can be slowly introduced. After the reaction, the mixture is cooled, neutralized, and degassed to obtain the nonionic surfactant.

[0039] In some embodiments of the present invention, the catalyst is one or more selected from potassium hydroxide, sodium hydroxide, sodium methoxide, potassium methoxide, and phosphazene catalyst, and the mass of the catalyst is 0.05%-1% of the total mass of 2-propylheptanol, ethylene oxide, and propylene oxide. Preferably, it is one or more selected from potassium hydroxide and phosphazene catalyst, and more preferably, the mass is 0.1%-0.3%.

[0040] In some embodiments of the present invention, the catalyst may also be a Zn / Co bimetallic catalyst, wherein the mass of the catalyst is 0.002%-0.02% of the total mass of 2-propylheptanol, ethylene oxide, and propylene oxide, preferably 0.003%-0.006%.

[0041] In some embodiments of the present invention, the molar ratio of 2-propylheptanol to ethylene oxide is 1:3-15, such as 1:3, 1:5, 1:7, 1:9, 1:11, 1:13, 1:15, etc., preferably 1:4-7.

[0042] The molar ratio of 2-propylheptanol to glycidol is 1:1-1.2, preferably 1:1-1.1.

[0043] The temperature of the primary reaction is 120-190℃, preferably 130-160℃; the time is 1-8h, preferably 2-6h; and the reaction pressure is controlled to be ≤0.6MPa, preferably 0.1-0.6MPa.

[0044] The temperature of the secondary reaction is 110-180℃, preferably 120-150℃; the time is 0.5-4h, preferably 1-3h; and the reaction pressure is controlled to be ≤0.4MPa, preferably 0.1-0.4MPa.

[0045] In some embodiments of the present invention, after the reaction is completed, conventional post-treatment processes such as cooling, neutralization, and degassing are also included. For example, after the reaction is completed, the temperature is lowered to 85°C, lactic acid is added to neutralize to pH=6, and vacuum degassing is performed.

[0046] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0047] Example 1

[0048] The preparation method of the nonionic surfactant in this embodiment includes the following steps:

[0049] Add 158 g of 2-propylheptanol (1 mol) and 0.5 g of potassium hydroxide to the reactor, heat to 130 °C, and dehydrate under vacuum for 1 h, controlling the moisture content in the reactor to below 50 ppm. Slowly add 176 g of ethylene oxide (4 mol) to the reactor, controlling the pressure to <0.6 MPa, and react for 2 h. Heat to 150 °C, slowly add 74 g of propylene oxide (1 mol), controlling the pressure to <0.4 MPa, and react for 1 h. After the reaction is complete, cool to 85 °C, add lactic acid to neutralize to pH = 6, and degas under vacuum to obtain product 1 (m is taken as 4).

[0050] 13 CNMR (100MHz, CDCl3) δ104.5, 78.5, 70.6, 70.4, 69.1, 66.2, 37.9, 33.2, 31.6, 31.1, 26.9, 22.3, 20.2, 14.1, 14.0.

[0051] The hydroxyl value of the obtained product was 279.8 mg KOH / g, and the calculated molecular weight was approximately 401.0 g / mol.

[0052] Example 2

[0053] The preparation method of the nonionic surfactant in this embodiment includes the following steps:

[0054] Add 158 g of 2-propylheptanol (1 mol) and 1.6 g of sodium hydroxide to the reactor, heat to 160 °C, and dehydrate under vacuum for 1 h, controlling the moisture content in the reactor to below 50 ppm. Slowly add 308 g of ethylene oxide (7 mol) to the reactor, controlling the pressure to <0.6 MPa, and react for 6 h. Cool to 120 °C, slowly add 74 g of propylene oxide (1 mol), controlling the pressure to <0.4 MPa, and react for 1.5 h. After the reaction is complete, cool to 85 °C, add acetic acid to neutralize to pH = 6, and degas under vacuum to obtain product 2 (m is taken as 7).

[0055] The hydroxyl value of the obtained product was 209.7 mg KOH / g, and the calculated molecular weight was approximately 535.1 g / mol.

[0056] Example 3

[0057] The preparation method of the nonionic surfactant in this embodiment includes the following steps:

[0058] Add 316 g of 2-propylheptanol (2 mol) and 1.8 g of sodium methoxide to the reactor, heat to 145 °C, and dehydrate under vacuum for 1 h, controlling the moisture content in the reactor to below 50 ppm. Slowly add 440 g of 10 mol of ethylene oxide to the reactor, controlling the pressure to <0.6 MPa, and react for 3.5 h. Cool to 135 °C, slowly add 162 g of 2.2 mol of propylene oxide, controlling the pressure to <0.4 MPa, and react for 3 h. After the reaction is complete, cool to 85 °C, add acetic acid to neutralize to pH = 6, and degas under vacuum to obtain product 3 (m is taken as 5).

[0059] The obtained product has a hydroxyl value of 247.5 mg KOH / g and a calculated molecular weight of approximately 453 g / mol.

[0060] Example 4

[0061] The preparation method of the nonionic surfactant in this embodiment includes the following steps:

[0062] 237 g of 2-propylheptanol (1.5 mol) and 7.4 g of potassium methoxide were added to the reactor. The temperature was raised to 180 °C, and the reactor was dehydrated under vacuum for 1 hour, controlling the water content in the reactor to be below 50 ppm. 396 g (9 mol) of ethylene oxide was slowly added to the reactor, controlling the pressure to <0.6 MPa, and the reaction was carried out for 8 hours. While maintaining the temperature at 180 °C, 116 g of glycidol (1.6 mol) was slowly added, controlling the pressure to <0.4 MPa, and the reaction was carried out for 4 hours. After the reaction was completed, the temperature was lowered to 85 °C, lactic acid was added to neutralize to pH = 6, and the product was degassed under vacuum to obtain product 4 (m is taken as 6).

[0063] The hydroxyl value of the obtained product was 152.6 mg KOH / g, and the calculated molecular weight was approximately 735 g / mol.

[0064] Example 5

[0065] The preparation method of the nonionic surfactant in this embodiment includes the following steps:

[0066] Add 316 g of 2-propylheptanol (2 mol) and 9.1 g of phosphazene catalyst to the reactor, heat to 140 °C, and dehydrate under vacuum for 1 h, controlling the moisture content in the reactor to below 50 ppm. Slowly add 440 g of ethylene oxide (10 mol) to the reactor, controlling the pressure to <0.6 MPa, and react for 5 h. Maintaining 140 °C, slowly add 155 g of propylene oxide (2.1 mol), controlling the pressure to <0.4 MPa, and react for 2 h. After the reaction is complete, cool to 85 °C, add lactic acid to neutralize to pH = 6, and degas under vacuum to obtain product 5 (m is taken as 5).

[0067] The 5-hydroxyl value of the obtained product was 251.5 mg KOH / g, and the calculated molecular weight was approximately 446 g / mol.

[0068] Example 6

[0069] The preparation method of the nonionic surfactant in this embodiment includes the following steps:

[0070] Add 316 g of 2-propylheptanol (2 mol) and 0.028 g of Zn / Co bimetallic catalyst to the reactor, heat to 150 °C, and dehydrate under vacuum for 1 h, controlling the moisture content in the reactor to below 50 ppm. Slowly add 440 g of 10 mol ethylene oxide to the reactor, controlling the pressure to <0.6 MPa, and react for 4 h. Maintain 150 °C, slowly add 148 g of 2 mol propylene oxide, controlling the pressure to <0.4 MPa, and react for 1.5 h. After the reaction is complete, cool to 85 °C, add lactic acid to neutralize to pH = 6, and degas under vacuum to obtain product 6 (m is taken as 5).

[0071] The 6-hydroxyl value of the obtained product was 252.8 mg KOH / g, and the calculated molecular weight was approximately 443 g / mol.

[0072] Example 7

[0073] The preparation method of the nonionic surfactant in this embodiment includes the following steps:

[0074] Add 158 g of 2-propylheptanol (1 mol) and 0.4 g of potassium hydroxide to the reactor, heat to 130 °C, and dehydrate under vacuum for 1 h, controlling the moisture content in the reactor to below 50 ppm. Slowly add 132 g of ethylene oxide (3 mol) to the reactor, controlling the pressure to <0.6 MPa, and react for 2 h. Heat to 150 °C, slowly add 74 g of glycidol (1 mol), controlling the pressure to <0.4 MPa, and react for 1 h. After the reaction is complete, cool to 85 °C, add lactic acid to neutralize to pH = 6, and degas under vacuum to obtain product 7 (m is taken as 3).

[0075] The 7-hydroxyl value of the obtained product was 312.1 mg KOH / g, and the calculated molecular weight was approximately 359.5 g / mol.

[0076] Example 8

[0077] The preparation method of the nonionic surfactant in this embodiment includes the following steps:

[0078] Add 158 g of 2-propylheptanol (1 mol) and 2.7 g of sodium hydroxide to the reactor, heat to 160 °C, and dehydrate under vacuum for 1 h, controlling the moisture content in the reactor to below 50 ppm. Slowly add 660 g of ethylene oxide (15 mol) to the reactor, controlling the pressure to <0.6 MPa, and react for 8 h. Cool to 120 °C, slowly add 74 g of propylene oxide (1 mol), controlling the pressure to <0.4 MPa, and react for 1.5 h. After the reaction is complete, cool to 85 °C, add acetic acid to neutralize to pH = 6, and degas under vacuum to obtain product 8 (m is taken as 15).

[0079] The hydroxyl value of the obtained product was 127.6 mg KOH / g, and the calculated molecular weight was approximately 879.3 g / mol.

[0080] Example 9

[0081] The preparation method of the nonionic surfactant in this embodiment includes the following steps:

[0082] Add 316 g of 2-propylheptanol (2 mol) and 1.8 g of sodium methoxide to the reactor, heat to 145 °C, and dehydrate under vacuum for 1 h, controlling the moisture content in the reactor to below 50 ppm. Slowly add 880 g of 20 mol of ethylene oxide to the reactor, controlling the pressure to <0.6 MPa, and react for 3.5 h. Cool to 135 °C, slowly add 162 g of 2.2 mol of propylene oxide, controlling the pressure to <0.4 MPa, and react for 3 h. After the reaction is complete, cool to 85 °C, add acetic acid to neutralize to pH = 6, and degas under vacuum to obtain product 9 (m is taken as 10).

[0083] The hydroxyl value of the obtained product was 190.6 mg KOH / g, and the calculated molecular weight was approximately 588.7 g / mol.

[0084] Comparative Example 1

[0085] The preparation method of the nonionic surfactant in Comparative Example 1 includes the following steps:

[0086] 158 g of 2-propylheptanol (1 mol) and 0.5 g of potassium hydroxide were added to the reactor, and the temperature was raised to 130 °C. The reactor was then dehydrated under vacuum for 1 hour, maintaining a moisture content below 50 ppm. 176 g (4 mol) of ethylene oxide was slowly added to the reactor, maintaining a pressure <0.6 MPa, and the reaction was allowed to proceed for 2 hours. After the reaction was complete, the temperature was lowered to 85 °C, and lactic acid was added to neutralize the pH to 6. The reactor was then degassed under vacuum to obtain product 10 (2-propylheptanol polyoxyethylene ether (4EO)).

[0087] Comparative Example 2

[0088] The preparation method of the nonionic surfactant in Comparative Example 2 includes the following steps:

[0089] 316 g of 2-propylheptanol (2 mol) and 9.1 g of phosphazene catalyst were added to the reactor, and the temperature was raised to 140 °C. The reactor was then dehydrated under vacuum for 1 hour, maintaining a moisture content below 50 ppm. 440 g (10 mol) of ethylene oxide was slowly added to the reactor, maintaining a pressure <0.6 MPa, and the reaction was allowed to proceed for 5 hours. After the reaction was complete, the temperature was lowered to 85 °C, and lactic acid was added to neutralize the pH to 6. The mixture was then degassed under vacuum to obtain product 11 (2-propylheptanol polyoxyethylene ether (5EO)).

[0090] Comparative Example 3

[0091] The preparation method of the nonionic surfactant in Comparative Example 3 includes the following steps:

[0092] 316 g of 2-propylheptanol (2 mol) and 0.028 g of Zn / Co bimetallic catalyst were added to the reactor. The temperature was raised to 150 °C, and the reactor was dehydrated under vacuum for 1 h, controlling the moisture content in the reactor to be below 50 ppm. 440 g (10 mol) of ethylene oxide was slowly added to the reactor, controlling the pressure to <0.6 MPa, and the reaction was carried out for 4 h. After the reaction was completed, the temperature was lowered to 85 °C, lactic acid was added to neutralize to pH = 6, and the reactor was degassed under vacuum to obtain product 12 (2-propylheptanol polyoxyethylene ether (5EO)).

[0093] Comparative Example 4

[0094] The method is the same as in Example 1, except that glycidol is replaced with an equal mass of propylene oxide, while other operations and conditions remain unchanged.

[0095] Performance testing:

[0096] The nonionic surfactants prepared in the examples and comparative examples were tested for alkali resistance, emulsification and metal cleaning ability. The test methods are as follows, and the results are shown in Table 1.

[0097] Alkali resistance: Weigh 1g of sample and add it to 99g of aqueous solutions with different sodium hydroxide concentrations. After stirring and dissolving, transfer the solution to a colorimetric tube and observe at 25℃ for 2 hours. The critical sodium hydroxide concentration at which oil bleeds out is the alkali resistance concentration.

[0098] Emulsification: The paraffin emulsification phase separation method was used for testing. 40 ml of liquid paraffin and 40 ml of 1 g / L emulsifier aqueous solution were poured into a beaker, stirred and emulsified at 1000 rpm for 1 min, and then quickly poured into a graduated cylinder. The time taken to separate 10 ml of aqueous phase was recorded.

[0099] Metal oil removal rate: Tested according to the national standard QBT2117-1995 for general water-based metal cleaners.

[0100] Table 1. Performance test results of the examples and comparative examples.

[0101] Group Alkali resistance g / L Emulsifying properties / s Metal degreasing rate % Example 1 22 292 75.8 Example 2 56 365 74.9 Example 3 32 387 82.1 Example 4 42 302 76.4 Example 5 40 402 88.5 Example 6 42 394 92.5 Example 7 16 146 60.2 Example 8 86 298 59.6 Example 9 68 306 66.8 Comparative Example 1 8 108 52.8 Comparative Example 2 14 112 68.4 Comparative Example 3 16 123 72.3 Comparative Example 4 6 232 56.4

[0102] As shown in Table 1, compared with the comparative example, the nonionic surfactant provided by the present invention is a double-hydroxyl-terminated polyoxyethylene polyoxypropylene ether, which makes the nonionic surfactant have excellent alkali resistance, emulsification and metal cleaning ability.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A nonionic surfactant, characterized in that, It has the structure shown in equation (1): Where m takes values ​​from 3 to 15.

2. The nonionic surfactant according to claim 1, characterized in that, m takes values ​​from 4 to 7.

3. The nonionic surfactant according to claim 1, characterized in that, The hydroxyl value is 126-321 mg KOH / g.

4. The nonionic surfactant according to claim 1, characterized in that, The average molecular weight is 350-890 g / mol.

5. The nonionic surfactant according to claim 1, characterized in that, The product was prepared by reacting ethylene oxide and propylene oxide sequentially with a system comprising 2-propylheptanol and a catalyst.

6. A method for preparing a nonionic surfactant according to any one of claims 1-5, characterized in that, Includes the following steps: 1) Mix 2-propylheptanol, catalyst, and ethylene oxide for a single reaction; 2) The reaction in step 1) involves the addition of glycidol for a secondary reaction to obtain the nonionic surfactant.

7. The preparation method according to claim 6, characterized in that, The catalyst is one or more of potassium hydroxide, sodium hydroxide, sodium methoxide, potassium methoxide, and phosphazene catalyst.

8. The preparation method according to claim 7, characterized in that, The catalyst is one or more of potassium hydroxide and phosphazene catalyst.

9. The preparation method according to claim 7, characterized in that, The mass of the catalyst is 0.02-1% of the total mass of the 2-propylheptanol, ethylene oxide, and propylene oxide.

10. The preparation method according to claim 9, characterized in that, The mass of the catalyst is 0.1-0.3% of the total mass of the 2-propylheptanol, ethylene oxide, and propylene oxide.

11. The preparation method according to claim 6, characterized in that, The catalyst is a Zn / Co bimetallic catalyst.

12. The preparation method according to claim 11, characterized in that, The catalyst comprises 0.002-0.02% of the total mass of 2-propylheptanol, ethylene oxide, and propylene oxide.

13. The preparation method according to claim 12, characterized in that, The mass of the catalyst is 0.003-0.006% of the total mass of 2-propylheptanol, ethylene oxide, and propylene oxide.

14. The preparation method according to claim 6, characterized in that, The molar ratio of 2-propylheptanol to ethylene oxide is 1:3-15; and / or The molar ratio of 2-propylheptanol to glycidol is 1:1-1.

2.

15. The preparation method according to claim 14, characterized in that, The molar ratio of 2-propylheptanol to ethylene oxide is 1:4-7.

16. The preparation method according to claim 14, characterized in that, The molar ratio of 2-propylheptanol to glycidol is 1:1-1.

1.

17. The preparation method according to claim 6, characterized in that, Step 1) The temperature of the first reaction is 120-190℃, the time is 1-8h, and the reaction pressure is controlled to be ≤0.6MPa.

18. The preparation method according to claim 17, characterized in that, The temperature of the first reaction is 130-160℃, and the time is 2-6 hours.

19. The preparation method according to claim 6, characterized in that, The temperature of the secondary reaction in step 2) is 110-180℃, the time is 0.5-4h, and the reaction pressure is controlled to be ≤0.4MPa.

20. The preparation method according to claim 19, characterized in that, The secondary reaction is carried out at a temperature of 120-150℃ for 1-3 hours.

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