Synthesis method of epoxy-terminated polyether

Abstract

The invention provides a synthesis method of epoxy-terminated polyether, which comprises the following steps: solid strong base, polyether and seed crystal are added into a reaction container and stirred, the mass ratio of the solid strong base to the polyether is (1.2-1.6): 1, and the mass of the seed crystal is 0.1-0.5% of the mass of the polyether; the preparation method comprises the following steps: adding polyether into a reaction kettle, stirring at normal temperature for 10-30 minutes, dropwise adding epichlorohydrin according to the mass ratio of epichlorohydrin to polyether of (1.5-2): 1, controlling the rate of epichlorohydrin so as to control the reaction temperature to be 10-50 DEG C, and reacting for 4-14 hours; after the epoxy chloropropane is dripped, preserving heat for 3-5 hours to obtain a crude product; the crude product is filtered, an adsorbent is added into filtrate obtained through filtering, the adding amount of the adsorbent is 1.0%-3.0% of the mass of polyether, and the adsorbent is filtered out after mixing. The synthesis method provided by the invention is beneficial to improving the end capping rate of the product and reducing the color and luster, and is also beneficial to reducing the production time so as to reduce the energy consumption and the loss.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical engineering, and in particular to a method for synthesizing epoxy-terminated polyether. Background Art

[0002] At present, there are two main methods for synthesizing epoxy-terminated polyethers: (1) One-step method, i.e., phase transfer method: using polyether and propylene oxide as raw materials, the target product is directly produced in the presence of a phase transfer catalyst and a solid or solution of a base such as sodium hydroxide or potassium hydroxide. During the synthesis process of this method, epichlorohydrin is prone to undergo a ring-opening polymerization side reaction under alkaline conditions, resulting in low reaction efficiency, a large amount of oligomers in the product, and a tendency for the product color to darken. (2) Two-step method: using polyether and epichlorohydrin as raw materials, a ring-opening reaction is first carried out in the presence of an acid catalyst (such as concentrated sulfuric acid, boron trifluoride etherate, anhydrous tin tetrachloride, stannous chloride, and aluminum chloride, etc.) to obtain a chlorohydrin intermediate, and then the chlorohydrin intermediate is used to undergo a ring-closing reaction in an alkaline environment to remove hydrogen chloride to obtain the target product. This method has the problems of insufficient end-capping rate and long production time. Long production time is prone to increase side reactions and low production equipment utilization. Summary of the Invention

[0003] In order to overcome the deficiencies of the prior art, the present invention aims to provide a method for synthesizing epoxy-terminated polyether, which is beneficial for improving the end-capping rate of the product and reducing the color, and is also beneficial for reducing production time to reduce energy consumption and reduce losses.

[0004] In order to solve the above problems, the technical solutions adopted by the present invention are as follows:

[0005] A method for synthesizing epoxy-terminated polyether comprises the following steps:

[0006] Add a solid strong base, polyether and seed crystals into a reaction container and stir, wherein the ratio of the solid strong base to the polyether is 1.2-1.6:1, and the amount of the seed crystals is 0.1%-0.5% of the mass of the polyether;

[0007] After stirring at room temperature for 10-30 minutes, epichlorohydrin is added dropwise. The ratio of epichlorohydrin to polyether is 1.5-2:1. The reaction temperature is controlled at 10-50°C by controlling the rate of epichlorohydrin addition. The reaction time is 4-14 hours.

[0008] After the epichlorohydrin is added, the mixture is kept warm for 3-5 hours to obtain a crude product;

[0009] The crude product is filtered, and an adsorbent is added to the filtrate obtained by filtration, wherein the amount of the adsorbent added is 1.0% to 3.0% of the mass of the polyether. After mixing, the adsorbent is filtered out.

[0010] In some possible embodiments, the number average molecular weight of the polyether is 200-2100, and the polyether has RO(C2H4O) n (C3H6O) m H structure, R is one of methyl, ethyl, allyl or butyl, n is 4-45, m is 3-34, or the polyether has RO(C2H4O) n H structure, R is one of methyl, ethyl, propyl or butyl, and n is 4-45, or the polyether has RO(C3H6O) m The structure of H, R is one of methyl, ethyl, propyl or butyl, and m is 3-34.

[0011] In some possible embodiments, the seed crystals are selected from at least one of calcium chloride, zinc chloride, calcium sulfate, magnesium chloride, disodium hydrogen phosphate, sodium dihydrogen phosphate, dipotassium hydrogen phosphate, potassium dihydrogen phosphate, magnesium silicate, and aluminum silicate.

[0012] In some possible embodiments, the solid strong base is selected from at least one of potassium hydroxide and sodium hydroxide.

[0013] In some possible implementations, the adsorbent is selected from at least one of white clay, diatomaceous earth, and magnesium polysilicate.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] In the present application, a strong base acts as a catalyst in the reaction system, having both a closed-loop effect and a ring-opening effect, thereby saving production costs. The temperature of the reaction system is regulated by controlling the dripping rate of epichlorohydrin, generally without the need for additional heating and cooling, thereby reducing energy consumption. The present invention adds seed crystals in the initial feeding stage to make the salt in the reaction system easier to filter, thereby facilitating shortening the crude product filtration time. After the crude product is filtered, the pH is almost neutral and does not require acid neutralization, and the filter cake is very dry to facilitate reducing crude product losses during the filtration stage. In addition, the dosage of the solid strong base, polyether, and epichlorohydrin is coordinated to improve the end-capping rate and reduce product color.

[0016] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a flow chart of a method for synthesizing an epoxy-terminated polyether provided in one embodiment of the present application. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0020] The following embodiments of the present invention are described in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0021] An embodiment of the present application provides a method for synthesizing epoxy-terminated polyether, comprising the following steps.

[0022] Step S101: Add a solid strong base, polyether, and seed crystals into a reaction vessel and stir. The solid strong base:polyether ratio is 1.2-1.6:1. The seed crystals are present in an amount of 0.1%-0.5% of the mass of the polyether.

[0023] In some embodiments, the solid strong base is selected from at least one of potassium hydroxide and sodium hydroxide.

[0024] In some embodiments, the number average molecular weight of the polyether is 200-2100. For example, the number average molecular weight of the polyether can be any value from 200-208, any value from 208-2046, or any value from 2046-2100. The polyether has RO(C2H4O) n (C3H6O) m H structure, R is one of methyl, ethyl, propyl or butyl, n is 4-45, m is 3-34, or the polyether has RO(C2H4O) n H structure, R is one of methyl, ethyl, propyl or butyl, and n is 4-45, or the polyether has RO(C3H6O) m The structure of H, R is one of methyl, ethyl, propyl or butyl, and m is 3 to 34. The selection of the molecular weight and structure of the polyether is conducive to further improving the end-capping rate.

[0025] In some embodiments, the seed crystals are selected from at least one of calcium chloride, zinc chloride, calcium sulfate, magnesium chloride, disodium hydrogen phosphate, sodium dihydrogen phosphate, dipotassium hydrogen phosphate, potassium dihydrogen phosphate, magnesium silicate, and aluminum silicate, thereby improving the stability of salt crystallization, thereby being more conducive to the smooth progress of the auxiliary filtration link and reducing the time and energy consumption of the filtration link.

[0026] Step S102: After stirring at room temperature for 10-30 minutes, epichlorohydrin is added dropwise. The ratio of epichlorohydrin to polyether is 1.5-2:1. The reaction temperature is controlled at 10-50° C. by controlling the rate of epichlorohydrin addition. The reaction time is 4-14 hours.

[0027] The solid strong base has both a ring-closing effect and a ring-opening effect. The coordination of the amounts of the solid strong base, polyether and epichlorohydrin can solve the technical problem of insufficient end-capping rate caused by side reactions.

[0028] Step S103: After the epichlorohydrin is added, the mixture is kept warm for 3-5 hours to obtain a crude product.

[0029] Step S104: filtering the crude product, adding an adsorbent to the filtrate obtained by filtration, wherein the amount of the adsorbent added is 1.0% to 3.0% of the mass of the polyether, and filtering out the adsorbent after mixing.

[0030] In some embodiments, the adsorbent is selected from at least one of clay, diatomaceous earth, and magnesium polysilicate.

[0031] In some embodiments, condensation recovery may be performed after filtering out the adsorbent.

[0032] The material ratio of the solid strong base, polyether and epichlorohydrin in the present application is conducive to controlling the end-capping rate of the product. The use of the material ratio in the present application is conducive to obtaining a higher product end-capping rate by adding a smaller amount of materials.

[0033] In the present application, a strong base acts as a catalyst in the reaction system, having both a closed-loop effect and a ring-opening effect, thereby saving production costs. The temperature of the reaction system is regulated by controlling the dripping rate of epichlorohydrin, generally without the need for additional heating and cooling, thereby reducing energy consumption. The present invention adds seed crystals in the initial feeding stage to make the salt in the reaction system easier to filter, thereby facilitating shortening the crude product filtration time. After the crude product is filtered, the pH is almost neutral and does not require acid neutralization, and the filter cake is very dry to facilitate reducing crude product losses during the filtration stage. In addition, the dosage of the solid strong base, polyether, and epichlorohydrin is coordinated to improve the end-capping rate and reduce product color.

[0034] Example 1

[0035] In a 3L reactor, 1040.0 g of methoxy polyether (number average molecular weight 208, n value 4, m value 0, corresponding R is methyl, structural formula CH3O(C2H4O)4H) and 320.0 g of sodium hydroxide (calcinated by amount of substance, the solid strong base: the polyether is 1.6:1) and 5.2 g of calcium chloride (seed, the amount of the seed is 0.5% of the mass of the polyether) were added respectively. The stirrer was turned on, nitrogen was replaced once, and after stirring at room temperature for 30 minutes, 925.0 g of epichlorohydrin (calcinated by amount of substance, the epichlorohydrin: the polyether is 2:1) was started dropwise, and the dripping rate was controlled to control the reaction temperature at 45-50°C. The reaction time was 14 h. After the dripping was completed, the mixture was kept warm for 5 h to obtain a crude product.

[0036] The crude product was filtered, with a time of 2 minutes and 20 seconds per 1000 g. The pH was measured at 7.2. Neutralization was not required. 31.2 g of diatomaceous earth (adsorbent, 3.0% of the polyether mass) was added. After refined post-treatment (e.g., condensation), the product was stripped to remove residual epichlorohydrin. Finally, the product was dehydrated and filtered to obtain the finished product. The end-capping ratio of the obtained product was 95.2%, and the color was 15 (Pt-Co).

[0037] Example 2

[0038] Ethoxy polyether (number average molecular weight 1576, n value 15, m value 15, corresponding R is ethyl, the structural formula of polyether is C2H5O(C2H4O)) was added into a 3L reactor. 15 (C3H6O) 15 H) 1576.0g and potassium hydroxide 67.2g (based on the amount of substance, the solid strong base: the polyether is 1.2:1) and potassium dihydrogen phosphate 1.6g (seed crystals, the amount of the seed crystals is 0.1% of the mass of the polyether), the stirrer is turned on, nitrogen is replaced once, and after stirring at room temperature for 30 minutes, 138.8g of epichlorohydrin (based on the amount of substance, the epichlorohydrin: the polyether is 1.5:1) is added dropwise, the dripping rate is controlled to control the reaction temperature at 10-20°C, the reaction time is 4h, and the temperature is kept for 3h after the dripping is completed to obtain a crude product.

[0039] The crude product was filtered, with a time of 5 minutes and 35 seconds per 1000 g. The pH was measured at 7.1. Neutralization was not required. 15.8 g of magnesium polysilicate (adsorbent, 1.0% of the polyether mass) was added. After refined post-treatment, residual epichlorohydrin was removed by steam stripping, and the product was dehydrated and filtered to obtain the finished product. The resulting product had an end-capping ratio of 92.2% and a color of 25 (Pt-Co).

[0040] Example 3

[0041] Propoxy polyether (number average molecular weight 2016, n value 5, m value 30, corresponding R is propyl, structural formula C3H7O(C2H4O)5(C3H6O)) was added into a 3L reactor. 30 H) 2016g and potassium hydroxide 75.6g (based on the amount of substance, the solid strong base: the polyether is 1.35:1) and magnesium silicate 3.98g (seed crystals, the amount of the seed crystals is 0.2% of the mass of the polyether), the stirrer is turned on, nitrogen is replaced once, and after stirring at room temperature for 30 minutes, 165.6g of epichlorohydrin (based on the amount of substance, the epichlorohydrin: the polyether is 1.79:1) is added dropwise, and the dripping rate is controlled to control the reaction temperature at 30-50°C, the reaction time is 5h, and the temperature is kept for 4h after the dripping is completed to obtain a crude product.

[0042] The crude product was filtered, with a time of 7 minutes and 15 seconds per 1000 g. The pH was measured to be 7.2. Neutralization was not required. 40.3 g of diatomaceous earth (adsorbent, 2% of the polyether mass) was added. After post-treatment, the product was filtered to obtain the finished product. The end-capping rate of the obtained product was 91.1%, and the color was 28 (Pt-Co).

[0043] Example 4

[0044] In a 3L reactor, butanol oxypolyether (number average molecular weight 2046, m value 34, corresponding R is butyl, structural formula C4H9O(C3H6O)) was added respectively. 34 The reaction mixture was added with 2046.0 g of H) and 62.0 g of sodium hydroxide (calculated by the amount of substance, the ratio of the solid strong base to the polyether was 1.55:1) and 29.3 g of zinc chloride (seed crystals, the amount of the seed crystals being 0.2% by mass of the polyether), the stirrer was turned on, the nitrogen was replaced once, and after stirring at room temperature for 30-10 minutes, 175.8 g of epichlorohydrin (calculated by the amount of substance, the ratio of the epichlorohydrin to the polyether was 1.9:1) was started dropwise, and the dropping rate was controlled to control the reaction temperature at 20-40° C. The reaction time was 6 h, and the mixture was kept warm for 4 h after the dropping was completed to obtain a crude product.

[0045] The crude product was filtered, with a time of 5 minutes and 15 seconds per 1000 g. The pH was measured at 7.1. Neutralization was not required. 29.3 g of diatomaceous earth (adsorbent, 2.0% of the polyether mass) was added. After refined post-treatment, residual epichlorohydrin was removed by steam stripping, and the product was dehydrated and filtered to obtain the finished product. The resulting product had an end-capping rate of 92.7% and a color of 23 (Pt-Co).

[0046] Example 5

[0047] Methoxy polyether (number average molecular weight 2012, n value 45, corresponding R is methyl, the structural formula of polyether is CH3O(C2H4O)) was added into a 3L reactor. 45 The reaction mixture was added with 1006.0 g of H) and 39.2 g of potassium hydroxide (calculated by the amount of substance, the ratio of the solid strong base to the polyether is 1.4:1) and 2.9 g of dipotassium hydrogen phosphate (seed crystals, the amount of the seed crystals being 0.29% by mass of the polyether). The stirrer was turned on, the nitrogen was replaced once, and after stirring at room temperature for 30 minutes, 80.0 g of epichlorohydrin (calculated by the amount of substance, the ratio of the epichlorohydrin to the polyether is 1.73:1) was started dropwise. The dropping rate was controlled to control the reaction temperature at 30-45° C. The reaction time was 4 h, and the mixture was kept warm for 3 h after the dropping was completed to obtain a crude product.

[0048] The crude product was filtered, with a time of 3 minutes and 24 seconds per 1000 g. The pH was measured to be 7.1. Neutralization was not required. 25 g of diatomaceous earth (adsorbent, 2.4% of the polyether mass) was added. After post-treatment, the product was filtered to obtain the finished product. The end-capping rate was 93.8%, and the color was 20 (Pt-Co).

[0049] Example 6

[0050] In a 3L reactor, 1170.0 g of propoxy polyether (number average molecular weight 234, m value 3, corresponding R is propyl, structural formula C3H7O(C3H6O)3H) and 378.0 g of potassium hydroxide (calculated by amount of substance, the solid strong base: the polyether is 1.35:1) and 2.34 g of aluminum silicate (seed crystals, the amount of the seed crystals is 0.2% of the mass of the polyether) were added respectively. The stirrer was turned on, nitrogen was replaced once, and after stirring at room temperature for 30 minutes, 786.3 g of epichlorohydrin (calculated by amount of substance, the epichlorohydrin: the polyether is 1.7:1) was started dropwise, and the dripping rate was controlled to control the reaction temperature at 20-40°C. The reaction time was 6 h. After the dripping was completed, the mixture was kept warm for 4 h to obtain a crude product.

[0051] The crude product was filtered, with a time of 4 minutes and 21 seconds per 1000 g. The pH was measured at 7.2. Neutralization was not required. 28.1 g of diatomaceous earth (adsorbent, 2.4% of the polyether mass) was added. After post-treatment, the product was filtered to obtain the finished product. The end-capping rate was 92.8%, and the color was 23 (Pt-Co).

[0052] Example 7

[0053] Example 7 differs from Example 1 in that calcium sulfate was used as seed crystals. The crude product was filtered, with a filtration time of 2 minutes and 50 seconds per 1000 g. The pH was measured to be 7.1. Neutralization was not required. 31.2 g of diatomaceous earth (adsorbent, the amount of which was 3.0% of the polyether's mass) was added. After refined post-treatment (e.g., condensation), the product was stripped to remove residual epichlorohydrin. Finally, it was dehydrated and filtered to obtain the finished product. The resulting product had an end-capping rate of 94.1% and a color of 19 (Pt-Co).

[0054] Example 8

[0055] Example 8 differs from Example 2 in that magnesium chloride was used as seed crystals. The crude product was filtered, with a filtration time of 6 minutes and 22 seconds per 1000 g. The pH was measured to be 7.1. Neutralization was not required. 15.8 g of magnesium polysilicate (adsorbent, the amount of which was 1.0% of the polyether mass) was added. After refined post-treatment, the product was stripped to remove residual epichlorohydrin, and finally dehydrated and filtered to obtain the finished product. The resulting product had an end-capping ratio of 91.8% and a color of 27 (Pt-Co).

[0056] Example 9

[0057] Example 9 differs from Example 3 in that disodium hydrogen phosphate was used as seed crystals. The crude product was filtered, with a filtration time of 6 minutes and 25 seconds per 1000 g. The pH was measured to be 7.1, and no neutralization was required. 39.8 g of diatomaceous earth (adsorbent, the amount of which was 2% of the polyether's mass) was added. After post-treatment, the product was filtered to obtain the finished product. The end-capping rate of the resulting product was 92.1%, and the color was 26 (Pt-Co).

[0058] Example 10

[0059] Example 10 differs from Example 5 in that sodium dihydrogen phosphate was used as seed crystals. The crude product was filtered, with a pH of 7.2 measured at 3 minutes and 45 seconds per 1000 g. Neutralization was not required. 25 g of diatomaceous earth (adsorbent, 2.4% of the polyether mass) was added, and the product was post-treated and filtered to obtain the finished product. The resulting product had an end-capping rate of 93.4% and a color of 22 (Pt-Co).

[0060] Comparative Example 1

[0061] In a 3L reactor, 1040.0 g of methoxy polyether (number average molecular weight 208, n value 4, m value 0, corresponding R is methyl, structural formula CH3O(C2H4O)4H) and 320.0 g of sodium hydroxide (calculated by the amount of substance, the solid strong base: the polyether is 1.6:1) were added respectively, the stirrer was turned on, the nitrogen was replaced once, and after stirring at room temperature for 30 minutes, 925.0 g of epichlorohydrin (calculated by the amount of substance, the epichlorohydrin: the polyether is 2:1) was started dropwise, and the dripping rate was controlled to control the reaction temperature at 45-50°C. The reaction time was 14 h, and the mixture was kept warm for 5 h after the dripping was completed to obtain a crude product.

[0062] The crude product was filtered, taking 35 minutes and 20 seconds to filter 1000g. The pH was measured to be 8.2. It was first neutralized with acid to approximately 7, and then 31.2g of diatomaceous earth was added. After post-treatment, the product was filtered to obtain the finished product. The end-capping rate of the obtained product was 94.0%, and the color was 18 (Pt-Co).

[0063] Comparative Example 2

[0064] Ethoxy polyether (number average molecular weight 1576, n value 15, m value 15, corresponding R is ethyl, the structural formula of polyether is C2H5O(C2H4O)) was added into a 3L reactor. 15 (C3H6O) 15 H) 1576.0g and potassium hydroxide 67.2g (according to the amount of substance, the solid strong base: the polyether is 1.2:1), the stirrer is turned on, the nitrogen is replaced once, and after stirring at room temperature for 30 minutes, 138.8g of epichlorohydrin (according to the amount of substance, the epichlorohydrin: the polyether is 1.5:1) is started dropwise, the dripping rate is controlled to control the reaction temperature at 10-20°C, the reaction time is 4h, and the temperature is kept for 3h after the dripping is completed to obtain a crude product.

[0065] The crude product was filtered, taking 1 hour, 25 minutes, and 20 seconds to filter 1000 grams. The pH was measured to be 8.1, requiring neutralization with acid to approximately 7. 15.8 grams of magnesium polysilicate was then added. After post-treatment, the product was filtered to obtain the finished product. The end-capping rate was 91.6%, and the color was 28 (Pt-Co).

[0066] Comparative Example 3

[0067] Propoxy polyether (number average molecular weight 2016, n value 5, m value 30, corresponding R is propyl, structural formula C3H7O(C2H4O)5(C3H6O)) was added into a 3L reactor. 30H) 2016g and potassium hydroxide 75.6g (according to the amount of substance, the solid strong base: the polyether is 1.35:1), the stirrer is turned on, the nitrogen is replaced once, and after stirring at room temperature for 30 minutes, 165.6g of epichlorohydrin (according to the amount of substance, the epichlorohydrin: the polyether is 1.79:1) is started dropwise, and the dripping rate is controlled to control the reaction temperature at 30-50°C, the reaction time is 5h, and the temperature is kept for 4h after the dripping is completed to obtain a crude product.

[0068] The crude product was filtered, taking 2 hours, 5 minutes, and 30 seconds to filter 1000 g. The pH was measured to be 8.2. It was first neutralized with acid to approximately 7, and then 40.3 g of diatomaceous earth was added. After post-treatment, the product was filtered to obtain the finished product. The end-capping rate of the obtained product was 90.8%, and the color was 30 (Pt-Co).

[0069] The color value in the above examples and comparative examples was determined by platinum-cobalt colorimetry, and the epoxy value was determined by hydrochloric acid acetone method. The end-capping rate of the product was obtained by calculating the percentage of the measured epoxy value and the epoxy value of the product with a theoretical end-capping rate of 100%.

[0070] The above embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and replacements made by technicians in this field on the basis of the present invention fall within the scope of protection required by the present invention.

Claims

1. A method for synthesizing epoxy-terminated polyether, characterized in that: The following steps are involved: Add a solid strong base, polyether and seed crystals into a reaction container and stir, wherein the ratio of the solid strong base to the polyether is 1.2-1.6:1, and the amount of the seed crystals is 0.1%-0.5% of the mass of the polyether; After stirring at room temperature for 10-30 minutes, epichlorohydrin is added dropwise. The ratio of epichlorohydrin to polyether is 1.5-2:

1. The reaction temperature is controlled at 10-50°C by controlling the rate of epichlorohydrin addition. The reaction time is 4-14 hours. After the epichlorohydrin is added, the mixture is kept warm for 3-5 hours to obtain a crude product; The crude product is filtered, and an adsorbent is added to the filtrate obtained by filtration, wherein the amount of the adsorbent added is 1.0% to 3.0% of the mass of the polyether. After mixing, the adsorbent is filtered out.

2. The synthesis method according to claim 1, wherein The number average molecular weight of the polyether is 200-2100, and the polyether has RO(C2H4O) n (C3H6O) m H structure, R is one of methyl, ethyl, propyl or butyl, n is 4-45, m is 3-34, or the polyether has RO(C2H4O) n H structure, R is one of methyl, ethyl, propyl or butyl, and n is 4-45, or the polyether has RO(C3H6O) m The structure of H, R is one of methyl, ethyl, propyl or butyl, and m is 3-34.

3. The synthesis method according to any one of claims 1 to 2, characterized in that The seed crystal is selected from at least one of calcium chloride, zinc chloride, calcium sulfate, magnesium chloride, disodium hydrogen phosphate, sodium dihydrogen phosphate, dipotassium hydrogen phosphate, potassium dihydrogen phosphate, magnesium silicate, and aluminum silicate.

4. The synthesis method according to claim 3, wherein The solid strong base is selected from at least one of potassium hydroxide and sodium hydroxide.

5. The synthesis method according to claim 1, wherein The adsorbent is selected from at least one of white clay, diatomaceous earth, and magnesium polysilicate.

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