Method for preparing styrylphenol ethoxylate
By using Al-SBA-15 mesoporous molecular sieves and quaternary ammonium base catalysts, combined with specific reaction conditions, the problems of poor catalyst stability and wide molecular weight distribution in existing technologies have been solved. This has resulted in a reduction in the color value and a narrowing of the molecular weight distribution of styrene-based phenol polyoxyethylene ether, thereby improving product quality.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- ZHEJIANG HUANGMA TECH CO LTD
- Filing Date
- 2025-11-06
- Publication Date
- 2026-06-11
AI Technical Summary
In the current preparation of styrene-based phenol polyoxyethylene ether, the catalyst has many side reactions, limited activity, strong corrosivity, and poor reaction stability, resulting in a wide molecular weight distribution and dark product color, which affects the performance of the product.
Using Al-SBA-15 mesoporous molecular sieve and quaternary ammonium base as catalysts, and through specific reaction temperature and pressure control, combined with the regulation of acidic sites, the quaternary ammonium base is adsorbed and enters the pores to carry out ethoxylation reaction, thereby reducing the color value and narrowing the molecular weight distribution.
It effectively reduced the color value of styrene-based phenolic polyoxyethylene ether and narrowed the molecular weight distribution, thus improving the product's performance.
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Figure CN2025132904_11062026_PF_FP_ABST
Abstract
Description
A method for preparing styrene-based phenol polyoxyethylene ether Technical Field
[0001] This invention relates to the technical field of polyethers, and specifically to a method for preparing styrene-based phenolic polyoxyethylene ether. Background Technology
[0002] Styrene-based phenol polyoxyethylene ethers are typically obtained by the ethoxylation reaction of styrene-based phenol with ethylene oxide under the action of a catalyst. Common catalysts used for ethoxylation include BF3, SnCl4, AlCl3, NaOH, KOH, and CH3ONa. Among these catalysts, acidic catalysts suffer from numerous side reactions, limited activity, strong corrosivity, and poor reaction stability. Strong base catalysts, on the other hand, tend to result in a wider molecular weight distribution and a darker product color, thus affecting the product's performance. Summary of the Invention
[0003] In order to overcome the shortcomings of the prior art, the present invention aims to provide a method for preparing styrene-based phenol polyoxyethylene ether, thereby reducing the color value of styrene-based phenol polyoxyethylene ether and narrowing the molecular weight distribution coefficient of styrene-based phenol polyoxyethylene ether.
[0004] To solve the above problems, the technical solution adopted by the present invention is as follows:
[0005] A method for preparing a styrene-based phenol polyoxyethylene ether includes the following steps:
[0006] Step 1: Mix Al-SBA-15 mesoporous molecular sieve, quaternary ammonium base, and styrylphenol in a high-pressure reactor under nitrogen protection, and heat to 80℃-100℃. The initial reaction pressure is 0.1-0.3 MPa.
[0007] Step 2: Add ethylene oxide in metered form to carry out the polymerization reaction. When the reaction proceeds to the point where the pressure no longer drops significantly, stop the reaction, cool down and discharge the material to obtain styrene-based phenol polyoxyethylene ether.
[0008] The preparation of the Al-SBA-15 mesoporous molecular sieve includes:
[0009] P123 was dissolved in deionized water, the system was adjusted to acidity, and the solution was stirred at 35℃-45℃ to obtain a transparent solution.
[0010] Tetraethyl orthosilicate was added to the transparent solution;
[0011] Based on the amount of substance, NaAlO2 is added in a ratio of n(Si):n(Al) of 10-29:1, and the mixture is continuously stirred and dispersed evenly at 35℃-45℃ to obtain a mixed solution.
[0012] The mixture is transferred to a crystallizing axe for crystallization to obtain crystals at a temperature of 90°C-110°C.
[0013] The crystals were washed with deionized water and dried. Then, the temperature was raised to 530℃-580℃ and held for 4 to 6 hours to obtain the Al-SBA-15 mesoporous molecular sieve.
[0014] In some possible implementations, the n(Si):n(Al) ratio is 20-29:1 by amount of substance.
[0015] In some possible embodiments, the amount of the quaternary ammonium base is 30%-40% of the Al-SBA-15 mesoporous molecular sieve by weight, and the amount of the quaternary ammonium base is 0.4%-0.6% of the styrylphenol.
[0016] In some possible implementations, the amount of the quaternary ammonium base used is 32%-38% by weight of the Al-SBA-15 mesoporous molecular sieve.
[0017] In some possible embodiments, the hydrocarbon group of the quaternary ammonium base is an aliphatic hydrocarbon group, and one of the hydrocarbon groups of the quaternary ammonium base is methyl.
[0018] In some possible implementations, the quaternary ammonium base is tetramethylammonium hydroxide.
[0019] In some possible implementations, the ethylene oxide is fed over a period of 1.5-2 hours.
[0020] In some possible implementations, step three is also included:
[0021] The molecular sieve in the product is separated by filtration, washed with deionized water, and dried at 130℃-150℃. After drying, it is calcined at 530℃-580℃ to recover the Al-SBA-15 mesoporous molecular sieve.
[0022] In some possible embodiments, the preparation of the styrylphenol includes:
[0023] Phenol and alkylation catalyst are heated to 95-100°C under nitrogen, and styrene is added dropwise with stirring. The dropwise addition is completed in 2-2.5 hours. The molar ratio of phenol to styrene is 1:2-2.5, and the amount of alkylation catalyst used is 0.15%-0.2% of the mass of phenol.
[0024] After the addition is complete, keep the reaction at a constant temperature for 1.8-2 hours until the product refractive index reaches 1.5985-1.6020. After the reaction is complete, degas and cool to room temperature to obtain styrene-based phenol.
[0025] In some possible implementations, the alkylation catalyst is selected from either methanesulfonic acid or p-toluenesulfonic acid.
[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0027] In this application, an Al-SBA-15 mesoporous molecular sieve with appropriate acidic sites is prepared by a specific method. The quaternary ammonium base is adsorbed into the polymerization reaction channel by the molecular sieve. The quaternary ammonium base, as a catalyst for the ethoxylation reaction, combined with the pore channel, specific reaction temperature and reaction pressure, is beneficial to reduce the color value of styrene-based phenol polyoxyethylene ether and narrow the molecular weight distribution coefficient of the polyether.
[0028] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Attached Figure Description
[0029] Figure 1 is a flowchart of the preparation of styrene-based phenol polyoxyethylene ether according to an embodiment of this application. Detailed Implementation
[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.
[0032] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.
[0033] One embodiment of this application provides a method for preparing styrene-based phenol polyoxyethylene ether, comprising the following steps:
[0034] Step S101: Place Al-SBA-15 mesoporous molecular sieve, quaternary ammonium base, and styrylphenol in a high-pressure reactor and mix them under nitrogen protection. Then, heat the mixture to 80℃-100℃ and the initial reaction pressure is 0.1-0.3MPa.
[0035] The preparation of the Al-SBA-15 mesoporous molecular sieve includes:
[0036] P123 (another name for a triblock copolymer of polyethylene oxide-polypropylene oxide-polyethylene oxide) is dissolved in deionized water, and the system is adjusted to acidity. The solution is then stirred at 35°C-45°C to obtain a clear solution. P123 is used as a template agent. For example, hydrochloric acid can be added to the system to adjust the pH; the concentration of hydrochloric acid can be 1-3 mol / L. -1 .
[0037] Tetraethyl orthosilicate is added to the transparent solution.
[0038] NaAlO2 is added in a metered amount according to a Si:Al ratio of 10-29:1, and the mixture is continuously stirred and dispersed at 35℃-45℃ to obtain a homogeneous solution. For example, the stirring and dispersion time can be at least 15 hours.
[0039] In some embodiments, the n(Si):n(Al) ratio is 20-29:1. Further limiting the raw material ratio helps to reduce pore collapse, thereby improving the utilization rate of mesoporous molecular sieves and further ensuring the size of the polymerization reaction site to help improve the molecular weight distribution coefficient.
[0040] The mixture is transferred to a crystallizing axe for crystallization to obtain crystals at a temperature of 90°C-110°C. For example, the crystallization time can be 2 days or more, or for example, 2 to 4 days.
[0041] The crystallized material is washed with deionized water and dried, then heated to 530℃-580℃ and held for 4 to 6 hours to obtain the Al-SBA-15 mesoporous molecular sieve. Vacuum drying can be used as an example.
[0042] In Al-SBA-15 mesoporous molecular sieves, the incorporation of Al into the silicon-oxygen framework creates acidic sites on the inner surface of the sieve. These acidic sites can adsorb N from quaternary ammonium bases. + This allows quaternary ammonium bases to be introduced into the pores for catalytic reactions. The ratio of Si to Al can regulate the content of acidic sites. Since the ethoxylation catalyst can be an acidic catalyst, if the content of acidic sites is too high, the Al-SBA-15 mesoporous molecular sieve may catalyze ethoxylation, thus affecting the base catalysis process. In this application, the Al ratio is controlled to control the content of acidic sites for introducing the base catalyst into the reaction pores, followed by the base catalyst catalyzing the ethoxylation reaction.
[0043] In some embodiments, the amount of the quaternary ammonium base is 30%-40% by weight of the Al-SBA-15 mesoporous molecular sieve, in order to ensure the adsorption effect of the Al-SBA-15 mesoporous molecular sieve, reduce the dispersion of the quaternary ammonium base outside the reaction channels, and thereby improve the controllability of the reaction.
[0044] In some embodiments, the amount of the quaternary ammonium base is 32%-38% by weight of the Al-SBA-15 mesoporous molecular sieve, in order to further adjust the balance between acidic sites and ethoxylation catalyst, thereby further facilitating the control of catalyst outflow and acidic site residue.
[0045] In some embodiments, the amount of the quaternary ammonium base is 0.4%-0.6% of the styrylphenol. Controlling the amount of ethoxylation catalyst helps control side reactions in the polymerization process, thereby further helping to reduce the color value and further narrow the molecular weight distribution.
[0046] In some embodiments, the hydrocarbon group of the quaternary ammonium base is an aliphatic hydrocarbon group, and one of the hydrocarbon groups of the quaternary ammonium base is methyl, thereby reducing the steric hindrance of the quaternary ammonium base to ensure the adsorption strength of the catalyst. For example, the quaternary ammonium base may include one of tetramethylammonium hydroxide, trimethyl-ethylammonium hydroxide, trimethyl-propylammonium hydroxide, or dimethyl-diethylammonium hydroxide.
[0047] In some embodiments, the quaternary ammonium base is tetramethylammonium hydroxide, which helps to reduce both adsorption steric hindrance and catalytic hindrance.
[0048] In another embodiment, one of the hydrocarbon groups of the quaternary ammonium base may be an aromatic group; in another embodiment, the quaternary ammonium base is tetraethylammonium hydroxide.
[0049] In some embodiments, the preparation of the styrylphenol includes:
[0050] Phenol and alkylation catalyst are heated to 95-100°C under nitrogen, and styrene is added dropwise with stirring. The dropwise addition is completed in 2-2.5 hours. The molar ratio of phenol to styrene is 1:2-2.5, and the amount of alkylation catalyst used is 0.15%-0.2% of the mass of phenol.
[0051] After the addition is complete, maintain the temperature for 1.8-2 hours until the product refractive index reaches 1.5985-1.6020 (25℃, measured according to GB / 6488-2008, Method for Determination of Refractive Index of Chemical Products, tested 3 times under the same conditions, and the average value is taken as the test result). After the reaction is complete, degas and cool to room temperature to obtain styrene-based phenol. Degassing can remove unreacted styrene material.
[0052] The styrene-based phenol prepared under the above conditions can reduce the self-polymerization behavior of styrene and reduce phenol oxidation, thereby facilitating a further reduction in the color value (Pt-Co) of styrene-based phenol polyoxyethylene ether.
[0053] In another embodiment, styrene can also be added dropwise to a mixture of phenol and alkylation catalyst to prepare styrene-based phenol, but the alkylation reaction temperature can be changed, for example, the reaction can be carried out within 80-95°C. Similarly, the time for adding styrene can be changed, for example, the addition time can be set to within 1 to 2 hours. The holding time can also be changed, for example, the holding time can be less than 1.8 hours.
[0054] In some embodiments, the alkylation catalyst is selected from either methanesulfonic acid or p-toluenesulfonic acid. Using an organic catalyst helps to control the reaction activity, thereby avoiding the generation of excessive byproducts.
[0055] Step S102: Ethylene oxide is added in metered quantity to carry out the polymerization reaction. When the reaction proceeds to the point where the pressure no longer drops significantly, the reaction is stopped, the temperature is lowered, and the material is discharged to obtain styrene-based phenol polyoxyethylene ether.
[0056] In some embodiments, the ethylene oxide is fed for 1.5-2 hours. Controlling the feeding time helps control the exothermic polymerization and ensures the uniformity of reactant participation in the reaction, thereby reducing by-products, lowering the color value, and narrowing the molecular weight distribution.
[0057] Step S103: Filtration separates the molecular sieve from the product. The separated molecular sieve is rinsed with deionized water and dried at 130℃-150℃. After drying, it is calcined at 530℃-580℃ to recover the Al-SBA-15 mesoporous molecular sieve, thereby achieving effective separation of the catalyst, molecular sieve, and product. For example, the calcination time can be at least 4 hours. The setting of deionized water and drying temperature facilitates the desorption and decomposition of the quaternary ammonium base. Therefore, step S103 is beneficial for purifying the polymer product. Furthermore, it is evident that using a combination of molecular sieve and quaternary ammonium base as a catalyst facilitates subsequent product processing, and the molecular sieve can be reused, which also reduces production costs to some extent.
[0058] In this application, an Al-SBA-15 mesoporous molecular sieve with appropriate acidic sites is prepared by a specific method. The quaternary ammonium base is adsorbed into the polymerization reaction channel by the molecular sieve. The quaternary ammonium base, as a catalyst for the ethoxylation reaction, combined with the pore channel, specific reaction temperature and reaction pressure, is beneficial to reduce the color value of styrene-based phenol polyoxyethylene ether and narrow the molecular weight distribution coefficient of the polyether.
[0059] Specifically:
[0060] Example 1:
[0061] Phenol and an alkylation catalyst, namely methanesulfonic acid, were added to a four-necked flask. The flask was heated to 98-100°C under nitrogen, and styrene was added dropwise with stirring. The addition was completed after 2 hours. The molar ratio of phenol to styrene was 1:2, and the amount of alkylation catalyst was 0.15% of the mass of phenol.
[0062] After the addition was completed, the reaction was kept at a constant temperature for 1.8 hours until the refractive index of the product reached 1.5985-1.6020 (25℃, measured according to GB / 6488-2008, the method for determining the refractive index of chemical products, tested 3 times under the same conditions, and the average value was taken as the test result). After the reaction was complete, the product was degassed and cooled to room temperature to obtain styrene-based phenol.
[0063] Al-SBA-15 mesoporous molecular sieve, quaternary ammonium base, and the styrene-based phenol were mixed in an autoclave under nitrogen protection and heated to 80-85°C. The initial reaction pressure was set at 0.1-0.2 MPa. Due to the exothermic nature of the reaction, both pressure and temperature fluctuate during the reaction; therefore, the temperature and pressure are typically controlled within a certain range, rather than fixed values. By weight, the amount of quaternary ammonium base is 40% of the Al-SBA-15 mesoporous molecular sieve, and the amount of quaternary ammonium base is 0.4% of the styrene-based phenol. The quaternary ammonium base is tetramethylammonium hydroxide.
[0064] Specifically, the preparation of the Al-SBA-15 mesoporous molecular sieve includes:
[0065] Dissolve 4g of P123 in 30g of deionized water, add 120g of 2mol / Ld HCl to adjust the system to acidity, and stir continuously at 40℃ for 18 hours to obtain a transparent solution.
[0066] Tetraethyl orthosilicate is added to the transparent solution.
[0067] NaAlO2 was added in a metered amount according to the molar ratio of n(Si):n(Al) of 10:1, and the mixture was stirred continuously at 40°C for 18 hours until the system was evenly dispersed to obtain a mixed solution.
[0068] The mixture was transferred to a crystallizing axe for crystallization to obtain crystals. The crystallization temperature was 100°C and the crystallization time was 3 days.
[0069] The crystals were washed with deionized water and dried (vacuum drying at 80°C), then heated to 550°C and held for 4 to 4.5 hours to obtain the Al-SBA-15 mesoporous molecular sieve.
[0070] Ethylene oxide was metered and added to initiate a polymerization reaction. When the pressure no longer decreased significantly, the reaction was stopped, the mixture was cooled, and the product was discharged to obtain styrene-based phenolic polyoxyethylene ether. The ethylene oxide was added over a period of 2 hours.
[0071] The molecular sieve in the product is separated by filtration, the separated molecular sieve is washed with deionized water and dried at 130°C, and then calcined at 580°C for 4 to 4.5 hours to separate the polymerization product from the molecular sieve.
[0072] Example 2:
[0073] The difference from Example 1 is that after adding phenol and alkylation catalyst to a four-necked flask, the temperature was raised to 95°C-98°C under nitrogen. The alkylation catalyst was p-toluenesulfonic acid. Styrene was added dropwise over 2.5 hours. The molar ratio of phenol to styrene was 1:2.4, and the amount of alkylation catalyst was 0.17% of the mass of phenol. After the styrene addition was completed, the reaction was maintained at this temperature for 2 hours.
[0074] Al-SBA-15 mesoporous molecular sieve, quaternary ammonium base, and styrene-based phenol were mixed in an autoclave and heated to 85℃-90℃. The initial reaction pressure was set to 0.2-0.3 MPa. By weight, the amount of quaternary ammonium base was 35% of the Al-SBA-15 mesoporous molecular sieve, and the amount of quaternary ammonium base was 0.5% of the styrene-based phenol. By molarity, n(Si):n(Al) was 15:1. The ethylene oxide was added over 1.5 hours. The separated molecular sieve was rinsed with deionized water and dried at 150℃, followed by calcination at 530℃ for 4.5 to 5 hours.
[0075] Example 3:
[0076] The difference from Example 1 is that the quaternary ammonium base is trimethyl ethyl ammonium hydroxide. After mixing Al-SBA-15 mesoporous molecular sieve, quaternary ammonium base and styrene-based phenol in a high-pressure reactor, the temperature is raised to 95℃-100℃.
[0077] Example 4:
[0078] The difference from Example 2 is that the styrene was added dropwise over 2.2 hours, and the molar ratio of phenol to styrene was 1:2.5. The amount of alkylation catalyst used was 0.2% of the mass of phenol. The molar ratio of n(Si):n(Al) was 20:1.
[0079] Example 5:
[0080] The difference from Example 4 is that, by weight, the amount of the quaternary ammonium base is 38% of the Al-SBA-15 mesoporous molecular sieve.
[0081] Example 6:
[0082] The difference from Example 1 is that, by weight, the amount of the quaternary ammonium base is 32% of the Al-SBA-15 mesoporous molecular sieve, and by molar amount, n(Si):n(Al) is 29:1.
[0083] Example 7:
[0084] The difference from Example 1 is that, by weight, the amount of the quaternary ammonium base is 34% of the Al-SBA-15 mesoporous molecular sieve, and by molarity, n(Si):n(Al) is 25:1.
[0085] Example 8:
[0086] The difference from Example 1 is that the ethylene oxide is fed over a period of 2.5 hours.
[0087] Example 9:
[0088] The difference from Example 1 is that the ethylene oxide is fed over a period of 1.4 hours.
[0089] Comparative Example 1:
[0090] The difference from Example 1 is that the quaternary ammonium base is omitted, and the prepared Al-SBA-15 mesoporous molecular sieve and styrene-based phenol are mixed and reacted in a high-pressure reactor.
[0091] Comparative Example 2:
[0092] The difference from Example 1 is that the Al-SBA-15 mesoporous molecular sieve is omitted, and the quaternary ammonium base and styrene-based phenol are mixed and reacted in a high-pressure reactor.
[0093] Since the raw materials used in the above embodiments and comparative examples are all conventional reagents that can be purchased from the market, the manufacturers and brands of the raw materials will not be described again.
[0094] The color value of the polyether product was determined by a platinum-cobalt colorimeter: three tests were conducted under the same conditions, and the average value was taken as the test result. The machine model was SD9012A.
[0095] The molecular weight dispersion coefficient of the polyether product was determined by high performance liquid chromatography (Agilent 1200 liquid chromatograph). The analytical conditions were: column XDB-C18-B2, column temperature 40℃, methanol / water as solvent, and flow rate 1.0 mL / min.
[0096] The test results of the above embodiments and comparative examples are shown in the table below.
[0097] Comparing the above examples and comparative examples, it can be seen that the synergistic effect of Al-SBA-15 mesoporous molecular sieve and quaternary ammonium base, combined with specific reaction temperature and pressure, is beneficial to reducing the color value and distribution coefficient of the polyether product, resulting in a color value of less than or equal to 20 and a molecular weight distribution coefficient of less than 1.1 for the styrene-phenol polyoxyethylene ether provided in this application. Comparing Examples 1-3 and Examples 4-7, it can be seen that further reducing the ratio of the quaternary ammonium base to the Al-SBA-15 mesoporous molecular sieve and the elemental ratio in the mesoporous molecular sieve is beneficial to further reducing the color value and distribution coefficient of the polyether product. Comparing Examples 1 and Examples 7 and 8, it can be seen that further limiting the feeding time of ethylene oxide also helps to further reduce the color value of the polyether and narrow the molecular weight distribution of the polyether.
[0098] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.
Claims
1. A method for preparing styrene-based phenol polyoxyethylene ether, characterized in that, Includes the following steps: Step 1: Mix Al-SBA-15 mesoporous molecular sieve, quaternary ammonium base, and styrylphenol in a high-pressure reactor under nitrogen protection, and heat to 80℃-100℃. The initial reaction pressure is 0.1-0.3 MPa. Step 2: Add ethylene oxide in metered form to carry out the polymerization reaction. When the reaction proceeds to the point where the pressure no longer drops significantly, stop the reaction, cool down and discharge the material to obtain styrene-based phenol polyoxyethylene ether. The preparation of the Al-SBA-15 mesoporous molecular sieve includes: P123 was dissolved in deionized water, the system was adjusted to acidity, and the solution was stirred at 35℃-45℃ to obtain a transparent solution. Tetraethyl orthosilicate was added to the transparent solution; Based on the amount of substance, NaAlO2 is added in a ratio of n(Si):n(Al) of 10-29:1, and the mixture is continuously stirred and dispersed evenly at 35℃-45℃ to obtain a mixed solution. The mixture is transferred to a crystallizing axe for crystallization to obtain crystals at a temperature of 90°C-110°C. The crystals were washed with deionized water and dried. Then, the temperature was raised to 530℃-580℃ and held for 4 to 6 hours to obtain the Al-SBA-15 mesoporous molecular sieve.
2. The preparation method according to claim 1, characterized in that, The ratio of n(Si):n(Al) is 20-29:1 based on the amount of substance.
3. The preparation method according to claim 2, characterized in that, The amount of the quaternary ammonium base used is 30%-40% of the Al-SBA-15 mesoporous molecular sieve by weight, and the amount of the quaternary ammonium base used is 0.4%-0.6% of the styrylphenol.
4. The preparation method according to claim 3, characterized in that, The amount of the quaternary ammonium base used is 32%-38% of the Al-SBA-15 mesoporous molecular sieve by weight.
5. The preparation method according to claim 2, characterized in that, The hydrocarbon group of the quaternary ammonium base is an aliphatic hydrocarbon group, and one of the hydrocarbon groups of the quaternary ammonium base is methyl.
6. The preparation method according to claim 5, characterized in that, The quaternary ammonium base is tetramethylammonium hydroxide.
7. The preparation method according to claim 1, characterized in that, The feeding time for the ethylene oxide is 1.5-2 hours.
8. The preparation method according to claim 1, characterized in that, It also includes step three: The molecular sieve in the product is separated by filtration, washed with deionized water, and dried at 130℃-150℃. After drying, it is calcined at 530℃-580℃ to recover the Al-SBA-15 mesoporous molecular sieve.
9. The preparation method according to claim 1, characterized in that, The preparation of the styrylphenol includes: Phenol and alkylation catalyst are heated to 95-100°C under nitrogen, and styrene is added dropwise with stirring. The dropwise addition is completed in 2-2.5 hours. The molar ratio of phenol to styrene is 1:2-2.5, and the amount of alkylation catalyst used is 0.15%-0.2% of the mass of phenol. After the addition is complete, keep the reaction at a constant temperature for 1.8-2 hours until the product refractive index reaches 1.5985-1.6020. After the reaction is complete, degas and cool to room temperature to obtain styrene-based phenol.
10. The preparation method according to claim 9, characterized in that, The alkylation catalyst is selected from either methanesulfonic acid or p-toluenesulfonic acid.