A method for preparing polyether and the prepared polyether

Abstract

This disclosure relates to a method for preparing polyethers and the prepared polyethers. The method includes: S1 contacting a portion of the epoxy monomers with a catalyst and an initiator to carry out a prepolymerization reaction; S2 adding another portion of the epoxy monomers to the mixture obtained in step S1 in a continuous feeding manner to carry out a polymerization reaction; the initiator is an alcohol or a phenol; the portion of epoxy monomers in step S1 accounts for 4-50% of the total mass fraction of all epoxy monomers. The method of this disclosure has simple operation steps and simple post-processing methods, and the prepared polyethers have a narrow molecular weight distribution, low unsaturation, high product quality, and diverse structures.

Description

Technical Field

[0001] This disclosure relates to the field of polyether preparation, and more specifically, to a method for preparing polyether and the prepared polyether. Background Technology

[0002] Polyether molecules possess both ether bonds and hydroxyl groups, combining the dual functions of surfactants and polymers. They exhibit the following characteristics: due to their relatively high molecular weight, they have weak penetrating power, low volatility, and low pour point; the presence of hydroxyl and ether bonds provides excellent emulsifying power, enabling the formation of stable emulsions; low surface tension results in low foaming power; they exhibit minimal coking and precipitation under high temperature and pressure, providing good lubrication; the presence of long-chain hydrocarbon groups enhances their dispersing and cohesive properties; and they have very low toxicity. Therefore, polyethers are commonly used as raw materials for lubricants, dispersants, emulsifiers, defoamers, detergents, and polyurethane foams, finding wide application in lubricant synthesis, oil extraction, textiles, plastics, metal processing, and synthetic rubber. Among these, polyether polyols are an important class of polyether compounds.

[0003] Currently, the main methods for synthesizing polyethers include anionic ring-opening polymerization, cationic ring-opening polymerization, and coordination polymerization. Among these, anionic ring-opening polymerization typically uses alkali metal hydroxides, metal oxides, and other anionic active species as catalysts. The reaction conditions are relatively mild and easy to control, the catalysts are inexpensive, and it is easy to industrialize. However, it suffers from drawbacks such as long reaction cycles, difficulty in removing metal ions, a wide molecular weight distribution in the product, and high unsaturation, which limits its application. Potassium hydroxide catalysts are the most widely used in industry. Patent CN110790913A discloses a "method for preparing oil-soluble fatty amine polyethers," which requires the pre-preparation of a polyether intermediate with a certain degree of polymerization, relatively increasing the number of reaction steps. The continuous addition of epoxides as feed causes intense exothermic reactions, resulting in severe side reactions and decreased product quality. The crude polyether product requires depotassium removal at high temperatures (90℃~110℃) through cyclic filtration, which is time-consuming, energy-intensive, and yields polyether products with poor dehydration and depotassium removal effects. The article "Synthesis of Hydrophobic Poly(alkylene oxide)s and Amphiphilic Poly(alkylene oxide)Block Copolymers" explores the synthesis of polyethers using potassium hydroxide catalysis under different initiation methods. The method of continuously injecting the sample into the reaction system resulted in excessively intense exothermic reaction, severe temperature rise, and a tendency for explosive polymerization, leading to a wider molecular weight distribution of the product and a decrease in product quality. The synthesized polyether product exhibited a wider molecular weight distribution. Summary of the Invention

[0004] The purpose of this disclosure is to provide a method for preparing polyethers and the prepared polyethers. The method is simple, easy to post-process, and the prepared polyethers have a narrow relative molecular weight distribution, low unsaturation, and high product quality.

[0005] To achieve the above objectives, the first aspect of this disclosure provides a method for preparing polyethers, the method comprising:

[0006] S1 involves contacting a portion of the epoxy monomers with the catalyst and initiator to carry out a prepolymerization reaction;

[0007] S2 adds another portion of the epoxy monomer to the mixture obtained in step S1 in a continuous feeding manner to carry out a polymerization reaction;

[0008] The initiator is an alcohol or a phenol;

[0009] The epoxy monomers in step S1 account for 4-50% of the total mass fraction of all epoxy monomers.

[0010] Optionally, the molar ratio of the initiator to all the epoxy monomers is 1:(1-60);

[0011] The portion of epoxy monomers mentioned in step S1 has a mass fraction of 5-40% of all epoxy monomers.

[0012] Optionally, the amount of catalyst used is 0.5-6.0% relative to the mass of the initiator;

[0013] The catalyst is selected from one or more alkali metal elements and strong bases;

[0014] Preferably, the catalyst is selected from one or more of potassium hydroxide, sodium hydroxide, magnesium hydroxide, calcium hydroxide, and elemental sodium.

[0015] Optionally, the initiator has the structure shown in Formula 1;

[0016] R0-OH

[0017] Formula 1;

[0018] R0 is selected from one of C1-C15 alkyl groups and C7-C26 alkyl-substituted phenyl groups;

[0019] Preferably, the initiator is selected from one of 4-pentylphenol, 4-nonylphenol, dodecylphenol, pentadecylphenol, dodecyl alcohol, and n-butanol.

[0020] Optionally, the epoxy monomer has the structure shown in Formula 2:

[0021]

[0022] R1 and R2 may be the same or different, and are each independently selected from hydrogen and C1-C3 alkyl groups.

[0023] Optionally, the epoxy monomer is selected from one or more of ethylene oxide, propylene oxide, and butane oxide.

[0024] Optionally, the epoxy monomer includes a first epoxy monomer and a second epoxy monomer, and the method includes:

[0025] (1) A portion of the first epoxy monomer is contacted with the catalyst and the initiator to carry out a first prepolymerization reaction;

[0026] (2) Add another portion of the first epoxy monomer to the first mixture obtained in step (1) in a continuous feeding manner to carry out the first polymerization reaction;

[0027] (3) A portion of the second epoxy monomer is brought into contact with the second mixture obtained in step (2) to carry out a second prepolymerization reaction;

[0028] (4) Add another portion of the second epoxy monomer to the third mixture obtained in step (3) in a continuous feeding manner to carry out the second polymerization reaction;

[0029] The ring-opening activity of the second epoxy monomer is higher than that of the first epoxy monomer.

[0030] Optionally,

[0031] The prepolymerization reaction is carried out at a temperature of 90-120℃, a pressure of 0.1-0.6MPa, and a time of 0.5-2h.

[0032] The polymerization reaction is carried out at a temperature of 90-120℃ and a pressure of 0.1-0.6MPa.

[0033] The continuous feeding rate is 2-8 mL / min.

[0034] Optionally, the method further includes: pretreating the catalyst and the initiator before step S1, the pretreatment comprising the following steps:

[0035] a. The catalyst is dried under vacuum for 10-15 hours;

[0036] b. Mix the dried catalyst with the initiator and dehydrate it under vacuum for 1-2 hours at a temperature of 80-120°C.

[0037] Optionally, the method further includes: post-processing the reaction product obtained in step S2 to obtain the polyether;

[0038] The post-processing includes the following steps:

[0039] A. Reduce the temperature of the reaction product to below 50°C, and then adjust the pH value to 5-7;

[0040] B. Filter the mixture obtained in step A using a magnesium silicate filter cake;

[0041] C. The filtrate obtained in step B is subjected to vacuum distillation to obtain the polyether.

[0042] The second aspect of this disclosure provides polyethers prepared using the methods described in the first aspect of this disclosure.

[0043] Optionally, the polyether comprises polymer molecules having the structure shown in Formula 3:

[0044]

[0045] Among them, R3, R4, R5 and R6 may be the same or different, and are independently selected from hydrogen and C1-C3 alkyl groups;

[0046] R0 is selected from one of C1-C15 alkyl groups and C7-C26 alkyl-substituted phenyl groups;

[0047] x and y may be the same or different, and each is an independent integer from 0 to 50, and x and y are not both 0 at the same time.

[0048] Optionally, the polyether has a dispersion of 1.05-1.20 and a number-average molecular weight of 600-5000.

[0049] Through the above technical solution, the method for preparing polyether disclosed herein uses phenol or alcohol as a starting agent and epoxy monomer as a polymerization monomer. The epoxy monomer is added in two parts, and the epoxy monomer added later is added continuously. The whole synthesis process is simple and easy to operate, the reaction conditions are mild, and the prepared polyether product has a narrow molecular weight distribution, low unsaturation, high product quality and diverse structure.

[0050] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Detailed Implementation

[0051] The following provides a detailed description of specific embodiments of this disclosure. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of this disclosure.

[0052] The first aspect of this disclosure provides a method for preparing polyethers, the method comprising:

[0053] S1 involves contacting a portion of the epoxy monomers with the catalyst and initiator to carry out a prepolymerization reaction;

[0054] S2 adds another portion of the epoxy monomer to the mixture obtained in step S1 in a continuous feeding manner to carry out a polymerization reaction;

[0055] The initiator is an alcohol or a phenol;

[0056] The epoxy monomers in step S1 account for 4-50% of the total mass fraction of all epoxy monomers.

[0057] The method disclosed herein involves adding epoxy monomers in two parts, with the latter part added continuously. The ratio of the two epoxy monomers is controlled to conduct an in-situ prepolymerization reaction, generating a low molecular weight polyether compound. Subsequently, a continuous feeding method is used to achieve synchronous growth of the polyether chain, reduce the occurrence of side reactions, and result in a polyether product with a narrow molecular weight distribution and low unsaturation. This method can achieve copolymerization or homopolymerization of epoxy monomers to prepare polyether products with diverse structures and high product yield.

[0058] In one embodiment of this disclosure, the portion of epoxy monomers in step S1 has a mass fraction of 5-40% of all epoxy monomers.

[0059] According to this disclosure, when there are two or more types of epoxy monomers, the epoxy monomers are added one by one for prepolymerization and polymerization reactions, that is, after the reaction of one type of epoxy monomer is completed, the next type of epoxy monomer is added; "a portion of the epoxy monomer and the mass fraction of all said epoxy monomers" refers to the mass fraction of the first portion of a certain type of epoxy monomer added.

[0060] In one embodiment of this disclosure, the molar ratio of the initiator to all epoxy monomers is 1:(1-60); preferably 1:(1-50), wherein when there are two or more types of epoxy monomers, the "molar ratio of the initiator to all epoxy monomers" refers to the ratio of the initiator to the total molar amount of all types of epoxy monomers. The above ratio range enables the theoretically designed polyether target product of the corresponding molecular weight to be obtained in high yield, and the raw material utilization rate is high.

[0061] In one embodiment of this disclosure, the amount of catalyst used is 0.5-6.0% relative to the mass of the initiator, preferably 1.5-4.0%. When the amount of catalyst meets the above range, a higher product yield and a faster reaction rate can be obtained.

[0062] In one embodiment of this disclosure, the catalyst is a conventional catalyst for preparing polyethers, such as an alkaline catalyst. The catalyst may be selected from one or more alkali metals and strong bases; preferably, the catalyst is selected from one or more of potassium hydroxide, sodium hydroxide, magnesium hydroxide, calcium hydroxide, and elemental sodium, specifically potassium hydroxide.

[0063] In one embodiment of this disclosure, the initiator can be any type of alcohol or phenol, and its parameters such as the number of carbon atoms, molecular weight, and degree of unsaturation are not required. Preferably, the initiator has the structure shown in Formula 1:

[0064] R0-OH

[0065] Formula 1;

[0066] R0 is selected from one of C1-C15 alkyl groups and C7-C26 alkyl-substituted phenyl groups; specifically, the initiator may be, for example, one of 4-pentylphenol, 4-nonylphenol, dodecylphenol, pentadecylphenol, dodecyl alcohol and n-butanol.

[0067] In this disclosure, "C7-C26 alkyl-substituted phenyl" means that the total number of carbon atoms of the alkyl substituent and the phenyl group is 7-26.

[0068] In one embodiment of this disclosure, the epoxy monomer is a three-membered ring epoxy compound or its homologue, preferably having the structure shown in Formula 2:

[0069]

[0070] R1 and R2 may be the same or different, and are each independently selected from hydrogen and C1-C3 alkyl groups; more preferably, the epoxy monomer is selected from one or more of ethylene oxide, propylene oxide and butane oxide.

[0071] In this disclosure, there can be two or more types of epoxy monomers. When there are two or more types of epoxy monomers, they are added one by one in order of increasing ring-opening activity, i.e., the low-ring-opening-activity epoxy monomers are polymerized first. This operation method can ensure the smooth progress of the copolymerization reaction and obtain a polyether product with the expected mixed monomer ratio. Each epoxy monomer is added in two parts, and the second part is added continuously, with the next epoxy monomer added only after the previous one has reacted. For example, when there are three types of epoxy monomers, i.e., the epoxy monomers include a first epoxy monomer, a second epoxy monomer, and a third epoxy monomer, the method includes:

[0072] (1) A portion of the first epoxy monomer is contacted with the catalyst and the initiator to carry out the first prepolymerization reaction.

[0073] (2) Add another portion of the first epoxy monomer to the first mixture obtained in step (1) in a continuous feeding manner to carry out the first polymerization reaction;

[0074] (3) A portion of the second epoxy monomer is brought into contact with the second mixture obtained in step (2) to carry out a second prepolymerization reaction;

[0075] (4) Add another portion of the second epoxy monomer to the third mixture obtained in step (3) in a continuous feeding manner to carry out the second polymerization reaction;

[0076] (5) A portion of the third epoxy monomer is brought into contact with the fourth mixture obtained in step (4) to carry out the third prepolymerization reaction;

[0077] (6) Add another part of the third epoxy monomer to the fifth mixture obtained in step (5) in a continuous feeding manner to carry out the third polymerization reaction;

[0078] Among them, the ring-opening activity of the first epoxy monomer, the second epoxy monomer, and the third epoxy monomer gradually increases.

[0079] In one embodiment of this disclosure, the epoxy monomer includes a first epoxy monomer and a second epoxy monomer, and the method includes:

[0080] (1) A portion of the first epoxy monomer is contacted with the catalyst and the initiator to carry out the first prepolymerization reaction.

[0081] (2) Add another portion of the first epoxy monomer to the first mixture obtained in step (1) in a continuous feeding manner to carry out the first polymerization reaction;

[0082] (3) A portion of the second epoxy monomer is brought into contact with the second mixture obtained in step (2) to carry out a second prepolymerization reaction;

[0083] (4) Add another portion of the second epoxy monomer to the third mixture obtained in step (3) in a continuous feeding manner to carry out the second polymerization reaction;

[0084] The second epoxy monomer exhibits higher ring-opening activity than the first epoxy monomer.

[0085] In one embodiment of this disclosure, the prepolymerization reaction is carried out at a temperature of 90-120°C, a pressure of 0.1-0.6 MPa, and a time of 0.5-2 h; preferably, the temperature is 100-110°C and the pressure is 0.1-0.3 MPa; the polymerization reaction is carried out at a temperature of 90-120°C and a pressure of 0.1-0.6 MPa; preferably, the temperature is 100-110°C and the pressure is 0.1-0.3 MPa; in a specific embodiment, the prepolymerization reaction and the polymerization reaction are carried out at the same temperature. The above temperature range can avoid the disadvantages of low product yield, high bromine value, and poor product quality caused by the intensification of chain transfer reactions. When there are two or more types of epoxy monomers, the temperature of each prepolymerization reaction is 90-120℃, the pressure is 0.1-0.6MPa, and the time is 0.5-2h; preferably, the temperature is 100-110℃ and the pressure is 0.1-0.3MPa; the temperature of each polymerization reaction is 90-120℃ and the pressure is 0.1-0.6MPa; preferably, the temperature is 100-110℃ and the pressure is 0.1-0.3MPa.

[0086] In one embodiment of this disclosure, the continuous feed rate is 2-8 mL / min, preferably 4-6 mL / min. When the continuous feed rate meets the above range, the reaction can proceed smoothly and the product quality is stable.

[0087] In one embodiment of this disclosure, the method further includes: pretreating the catalyst and initiator before step S1, the pretreatment comprising the following steps:

[0088] a. Dry the catalyst under vacuum conditions for 10-15 hours;

[0089] b. The dried catalyst is mixed with the initiator and dehydrated under vacuum for 1-2 hours at a temperature of 80-120°C. The drying and dehydration methods are conventional in the field and will not be described in detail here.

[0090] In one embodiment of this disclosure, the method further includes: post-processing the reaction product obtained in step S2 to obtain the polyether; specifically, the post-processing includes the following steps:

[0091] A. Cool the temperature of the reaction product to below 50°C, then adjust the pH to 5-7 and stir.

[0092] B. Filter the mixture obtained in step A using a magnesium silicate filter cake;

[0093] C. The filtrate obtained in step B is subjected to vacuum distillation to obtain the polyether;

[0094] The pH value can be adjusted by adding appropriate amounts of water and glacial acetic acid; vacuum distillation can remove low molecular weight byproducts and unreacted raw materials from the filtrate; and stirring time is 5-15 minutes. The above post-treatment method is simple to operate, avoiding the heating, repeated mixing, and filtration steps required by existing methods, and can obtain high-quality polyether products. The magnesium silicate filter cake can be reused at least 12 times, saving preparation costs.

[0095] According to this disclosure, both the prepolymerization reaction and the polymerization reaction are carried out in a reactor. When the pressure inside the reactor is lower than 0.01 MPa and remains constant for 1-2 hours, the polymerization reaction ends.

[0096] According to this disclosure, the method for adding the epoxy monomer in the first part is conventional in the art, such as adding it by means of an injection pump.

[0097] The second aspect of this disclosure provides polyethers prepared using the methods described in the first aspect of this disclosure.

[0098] In one embodiment of this disclosure, the polyether comprises polymer molecules having the structure shown in Formula 3:

[0099]

[0100] Among them, R3, R4, R5 and R6 may be the same or different, and are independently selected from hydrogen and C1-C3 alkyl groups;

[0101] R0 is selected from one of C1-C15 alkyl groups and C7-C26 alkyl-substituted phenyl groups; for example, it can be pentylphenyl, nonylphenyl, dodecylphenyl, pentadecylphenyl, n-butyl, etc. x and y may be the same or different, and are each an independent integer from 0 to 50, and x and y are not both 0.

[0102] In one embodiment of this disclosure, the polyether has a number-average molecular weight of 600-5000 and a dispersity of 1.05-1.20, preferably 1.07-1.15. Here, dispersity refers to the ratio M of the polyether's weight-average molecular weight to its number-average molecular weight. w / M n The polyethers provided in this disclosure have low dispersion and a narrow molecular weight distribution.

[0103] The following embodiments further illustrate specific implementations of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of this disclosure.

[0104] Unless otherwise specified, all reagents used in the examples and comparative examples were commercially available.

[0105] The hydroxyl value of the polyether product was determined by the phthalic anhydride method in GB / T7383-2007 and recorded as mg[KOH] / g.

[0106] Dalton number-average molecular weight M of polyether products n and weight average molecular weight M w The determination was performed using a Waters 1515 gel permeation chromatography (GPC) system, with tetrahydrofuran as the mobile phase, a column temperature of 35°C, and sample concentrations of 1.5–2.5 mg / mL. Polystyrene was used as the standard for calibration.

[0107] The bromine value of polyether products was determined according to SH / T 0630-1996 and recorded as g / (100mL).

[0108] The kinematic viscosity of the polyether product was determined according to GB / T 30515-2014, using a Cannon Cav-2100 viscometer at 40°C. The instrument was calibrated using a mineral oil reference standard of known viscosity, and the results were recorded in mm. 2 / s.

[0109] The determination of water content in polyether products shall be in accordance with SH / T 0246-1992.

[0110] The potassium ion content of polyether products was determined according to ICP-OTHER and recorded as mg / kg.

[0111] The method for calculating the molecular weight dispersion of polyether products is as follows: the weight-average molecular weight M is measured above. w Number-average molecular weight M n The ratio of .

[0112] The formula for calculating the degree of unsaturation of polyether products is as follows: That is, 62.58 × bromine value, in mmol / L.

[0113] Preparation method of magnesium silicate filter cake: Take a 100mL vacuum filtration funnel with a sand plate and a diameter of 5cm, pour magnesium silicate particles into it to form a thickness of 1cm, then spread a 1cm thick layer of quartz sand on top, add solvent under negative pressure and compact it, and set it aside for use.

[0114] Example 1

[0115] Polyether product A1 was prepared using the following steps:

[0116] (1) Potassium hydroxide was dried under vacuum for 12 hours. 4-Nonylphenol and the dried potassium hydroxide were placed in a reaction vessel and purged three times with high-purity nitrogen. The mixture was then dehydrated under vacuum at 120°C for 1 hour. The temperature was adjusted to 100-110°C and the pressure was 0.1-0.3 MPa (the temperatures of the first prepolymerization reaction, the second prepolymerization reaction, the first polymerization reaction, and the second polymerization reaction were all 100-110°C and the pressure was 0.1-0.3 MPa).

[0117] (2) A portion of the epoxy butane was injected into the reactor using an injection pump to carry out the first prepolymerization reaction for 0.5 h;

[0118] (3) Add another part of the epoxy butane to the first mixture obtained in step (2) in a continuous feeding manner to carry out the first polymerization reaction. The continuous feeding rate is 5 mL / min.

[0119] (4) When the pressure in the reactor is below 0.01 MPa and remains constant for 1-2 hours, the reaction ends. Then, a portion of the propylene oxide is added to the second mixture obtained in step (3) to carry out the second prepolymerization reaction for 0.5 hours.

[0120] (5) Add another part of propylene oxide to the third mixture obtained in step (4) in a continuous feeding manner to carry out the second polymerization reaction. The continuous feeding rate is 5 mL / min.

[0121] (6) When the pressure in the reactor drops below 0.01 MPa and remains constant for 1-2 hours, the reaction ends.

[0122] (7) Post-processing: Reduce the temperature of the pre-product obtained in step (6) to below 50°C, add an appropriate amount of water and glacial acetic acid to adjust the pH to 5-7, stir for 5-15 minutes, filter the obtained solid-liquid mixture with magnesium silicate filter cake, and distill the obtained filtrate under reduced pressure to obtain polyether product A1.

[0123] Of these, 25% is propylene oxide by mass.

[0124] A portion of the epoxide and all of the epoxide have a mass fraction of 25%;

[0125] The molar ratio of 4-nonylphenol, propylene oxide, and butane oxide is 1:9:4;

[0126] The amount of potassium hydroxide used was 3.0% relative to the mass of 4-nonylphenol; the property parameters and yield of polyether product A1 are listed in Table 1.

[0127] Example 2

[0128] Polyether product A2 was prepared using the method of Example 1, with the only difference being that the molar ratio of 4-nonylphenol, propylene oxide, and butylene oxide was 1:4:8. The property parameters and yield of polyether product A2 are listed in Table 1.

[0129] Example 3

[0130] Polyether product A3 was prepared using the method of Example 1, with the only difference being that the molar ratio of 4-nonylphenol, propylene oxide, and butylene oxide was 1:6:6. The property parameters and yield of polyether product A3 are listed in Table 1.

[0131] Example 4

[0132] Polyether product A4 was prepared using the method of Example 1, except that epoxide was not added and the molar ratio of 4-nonylphenol to propylene oxide was 1:14. The property parameters and yield of polyether product A4 are listed in Table 1.

[0133] Example 5

[0134] Polyether product A5 was prepared using the method of Example 1, except that propylene oxide was not added and dodecylphenol was used as the initiator with a molar ratio of dodecylphenol to butane oxide of 1:11. The properties and yield of polyether product A5 are listed in Table 1.

[0135] Example 6

[0136] Polyether product A6 was prepared using the method of Example 1, the only difference being that the following post-processing steps were performed:

[0137] The pH of the mixture obtained from the reaction was adjusted to 5-7 by adding an appropriate amount of glacial acetic acid, followed by the addition of an appropriate amount of water. The mixture was stirred at 90°C for 0.5 h, then magnesium silicate was added, and the mixture was stirred at 90°C for another 1.5 h. The mixture was filtered while hot, and the filtrate was distilled under reduced pressure to obtain the polyether product. The amount of magnesium silicate used was 4.0% relative to the mass of the polyether product. The properties and yield of the polyether product A6 are listed in Table 1.

[0138] Example 7

[0139] Polyether product A7 was prepared using the method of Example 4, the only difference being that the temperature of the prepolymerization reaction and the polymerization reaction was 110-120℃. The property parameters and yield of polyether product A7 are listed in Table 1.

[0140] Example 8

[0141] Polyether product A8 was prepared using the method of Example 4, the only difference being that the amount of catalyst used was 1.0%. The property parameters and yield of polyether product A8 are listed in Table 1.

[0142] Example 9

[0143] Polyether product A9 was prepared using the method of Example 4, the only difference being that the molar ratio of 4-nonylphenol to all propylene oxides was 1:55. The property parameters and yield of polyether product A9 are listed in Table 1.

[0144] Example 10

[0145] Polyether product A10 was prepared using the method of Example 4, the only difference being that the molar ratio of 4-nonylphenol to all propylene oxides was 1:65. The property parameters and yield of polyether product A10 are listed in Table 1.

[0146] Comparative Example 1

[0147] Polyether product D1 was prepared using existing techniques, employing the same raw material ratios and post-processing methods as in Example 4, except that the catalyst dosage was 0.6% of the theoretical mass of the polyether product. The specific steps included:

[0148] Potassium hydroxide was dried under vacuum for 10 hours. 4-Nonylphenol and the dried potassium hydroxide were placed in a reactor and purged three times with high-purity nitrogen. The reactor was then dehydrated under vacuum at 120°C for 1.5 hours. The temperature was adjusted to 100-110°C, and propylene oxide was continuously added to the reactor at a feed rate of 7 mL / min. The reaction pressure was controlled at 0.1-0.3 MPa. After the feed was complete, the reactor pressure was allowed to drop to 0 MPa and maintained at this pressure for 1-2 hours, at which point the reaction was considered complete. The properties and yield of the polyether product D1 are listed in Table 1.

[0149] Comparative Example 2

[0150] Polyether product D2 was prepared using the method of Example 4, the only difference being that all propylene oxide was added to the reaction vessel using an injection pump, and simultaneously reacted with potassium hydroxide and 4-nonylphenol. The property parameters and yield of polyether product D2 are listed in Table 1.

[0151] Comparative Example 3

[0152] Polyether product D3 was prepared using the method of Example 4, the only difference being that the propylene oxide used in the prepolymerization reaction accounted for 60% of the total mass fraction of propylene oxide. The property parameters and yield of polyether product D3 are listed in Table 1.

[0153] Comparative Example 4

[0154] Polyether product D4 was prepared using the method of Example 4, the only difference being that another portion of propylene oxide was added directly instead of being added in a continuous feeding manner. The property parameters and yield of polyether product D4 are listed in Table 1.

[0155] Table 1

[0156]

[0157] Comparison of data from Comparative Examples 1-4 and Example 4 shows that the polyether product prepared using the method of this application, which uses phenol or alcohol as an initiator and epoxy monomer as a polymerization monomer, and adds the epoxy monomer in two parts with the latter being added in a continuous feeding manner, has a higher product yield, lower product dispersion and unsaturation, and better product quality.

[0158] Furthermore, data from the embodiments shows that the method of this application, whether homopolymerization or copolymerization, can obtain polyether products with high yields, low dispersibility and unsaturation, and high product quality. Data from Examples 1 and 6 shows that the preferred post-processing method of this application can result in lower water and potassium ion content in the polyether product, leading to better product quality. Data from Examples 7 and 8 compared to Example 4 shows that when the prepolymerization reaction temperature and polymerization reaction temperature are within the preferred range (100-110°C), or when the catalyst dosage is within the preferred range (1.5-4.0% relative to the mass of the initiator), a higher product yield can be obtained while maintaining low dispersion. A comparison of data from Examples 9 and 10 compared to Example 4 shows that when the molar ratio of the initiator to the epoxy monomer is within the preferred range (1:(1-60), and more preferably within the range of 1:(1-50), a higher product yield and a polyether product with a relative molecular mass closer to the theoretical design can be obtained.

[0159] The preferred embodiments of this disclosure have been described in detail above. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0160] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0161] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A method for preparing polyether, characterized in that, The method includes: S1 involves contacting a portion of the epoxy monomers with the catalyst and initiator to carry out a prepolymerization reaction; S2. Another portion of the epoxy monomer is added to the mixture obtained in step S1 in a continuous feeding manner to carry out a polymerization reaction; The initiator is an alcohol or a phenol; In step S1, the epoxy monomers account for 4-50% of the total mass fraction of all epoxy monomers. When there are two or more types of epoxy monomers, the epoxy monomers are added one by one to carry out the prepolymerization reaction of S1 and the polymerization reaction of S2. After the reaction of one type of epoxy monomer is completed, the next type of epoxy monomer is added. The method further includes: post-processing the reaction product obtained in step S2 to obtain the polyether; The post-processing includes the following steps: A. Cool the temperature of the reaction product to below 50°C, then adjust the pH to 5-7 and stir. B. Filter the mixture obtained in step A using a magnesium silicate filter cake; C. The filtrate obtained in step B is subjected to vacuum distillation to obtain the polyether.

2. The method according to claim 1, wherein, The molar ratio of the initiator to all the epoxy monomers is 1:(1-60). The portion of epoxy monomers mentioned in step S1 has a mass fraction of 5-40% of all epoxy monomers.

3. The method according to claim 1, wherein, The amount of catalyst used is 0.5-6.0% relative to the mass of the initiator; The catalyst is selected from one or more alkali metals and strong bases.

4. The method according to claim 1, wherein, The catalyst is selected from one or more of potassium hydroxide, sodium hydroxide, magnesium hydroxide, calcium hydroxide, and elemental sodium.

5. The method according to claim 1, wherein, The initiator has the structure shown in Formula 1; Formula 1; R0 is selected from one of C1-C15 alkyl groups and C7-C26 alkyl-substituted phenyl groups.

6. The method according to claim 1, wherein, The initiator is selected from one of 4-pentylphenol, 4-nonylphenol, dodecylphenol, pentadecylphenol, dodecyl alcohol, and n-butanol.

7. The method according to claim 1, wherein, The epoxy monomer has the structure shown in Formula 2: Formula 2; R1 and R2 may be the same or different, and are each independently selected from hydrogen and C1-C3 alkyl groups.

8. The method according to claim 1, wherein, The epoxy monomer is selected from one or more of ethylene oxide, propylene oxide, and butane oxide.

9. The method according to claim 1, wherein, The epoxy monomer includes a first epoxy monomer and a second epoxy monomer, and the method includes: (1) A portion of the first epoxy monomer is contacted with the catalyst and the initiator to carry out a first prepolymerization reaction; (2) Add another portion of the first epoxy monomer to the first mixture obtained in step (1) in a continuous feeding manner to carry out the first polymerization reaction; (3) A portion of the second epoxy monomer is brought into contact with the second mixture obtained in step (2) to carry out a second prepolymerization reaction; (4) Add another portion of the second epoxy monomer to the third mixture obtained in step (3) in a continuous feeding manner to carry out the second polymerization reaction; The ring-opening activity of the second epoxy monomer is higher than that of the first epoxy monomer.

10. The method according to claim 1, wherein, The prepolymerization reaction is carried out at a temperature of 90-120℃, a pressure of 0.1-0.6MPa, and a time of 0.5-2h. The polymerization reaction is carried out at a temperature of 90-120℃ and a pressure of 0.1-0.6MPa. The continuous feeding rate is 2-8 mL / min.

11. The method according to claim 1, wherein, The method further includes: pretreating the catalyst and the initiator before step S1, the pretreatment comprising the following steps: a. The catalyst is dried under vacuum for 10-15 hours; b. Mix the dried catalyst with the initiator and dehydrate it under vacuum for 1-2 hours at a temperature of 80-120°C.

12. A polyether prepared by the method according to any one of claims 1-11, wherein the polyether has a dispersion of 1.05-1.

20.

13. The polyether according to claim 12, wherein, The polyether comprises polymer molecules having the structure shown in Formula 3: Formula 3; Among them, R3, R4, R5 and R6 may be the same or different, and are independently selected from hydrogen and C1-C3 alkyl groups; R0 is selected from one of C1-C15 alkyl groups and C7-C26 alkyl-substituted phenyl groups; x and y may be the same or different, and each is an independent integer from 0 to 50, and x and y are not both 0 at the same time.

14. The polyether according to claim 12, wherein, The number average molecular weight of the polyether is 600-5000.

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