Process for the endcapping of polyvinyl ethers and use thereof

Abstract

The application relates to the technical field of organic synthesis, and provides a polyvinyl ether end-grouping method and application. The method comprises the following steps: dissolving polyvinyl ether and compound A in a second solvent under the protection of an inert gas to generate a second reactant through a second reaction; and dissolving the second reactant, compound B and optional compound C in a third solvent under the protection of an inert gas to generate a polyvinyl ether end-grouping polymer through a third reaction. The polyvinyl ether end-grouping method provided by the application is simple to operate, and can be used to prepare polyvinyl ether products with various end groups. The polyvinyl ether end-grouping method provided by the application can also be carried out in a microreactor, so that the problems of low synthesis efficiency, insufficient conversion rate and easy occurrence of side reactions in the traditional preparation method are effectively solved.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, and more specifically, to a method and application of polyvinyl ether end-grouping. Background Technology

[0002] In recent years, with the development of polymer materials, the design and preparation of polymer structures with special structures and properties have been widely applied in electronics, aerospace, transportation, packaging, food and other fields. Commonly used polymer synthesis methods mainly include free radical polymerization, reversible addition-fragmentation chain transfer polymerization, atom transfer radical polymerization, ring-opening polymerization, and condensation polymerization. Different polymerization methods have specific requirements on the types of monomers and determine the types of terminal groups of the polymer chain, making it difficult to synthesize polymers with special end-group structures.

[0003] Polymer end-grouping not only effectively terminates reactions and stabilizes polymer chain structures, but also allows for the introduction of different functional groups to prepare materials with specific properties. For example, introducing siloxane groups at the polymer chain ends can improve the antifouling effect of products, introducing quinoline groups can improve the photosensitivity of materials, introducing thiol groups can enable click chemistry reactions, and introducing hydrophilic / hydrophobic groups can prepare spherical, vesicle-shaped, and other morphologies of nanoparticles. However, traditional preparation methods face problems such as low synthesis efficiency, insufficient conversion rate, and susceptibility to side reactions. Summary of the Invention

[0004] The purpose of this invention is to provide a method and application for polyvinyl ether end-grouping, in order to solve the technical problems in the prior art that require hydrogenation to remove polymer end groups, the end groups have single functions, and the operation steps are cumbersome.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] In a first aspect, the present invention provides a method for polyvinyl ether end-grouping, comprising:

[0007] Polyvinyl ether and compound A are dissolved in a second solvent under an inert gas atmosphere to undergo a second reaction and obtain a second reactant.

[0008] The second reactant, compound B, and optional compound C are dissolved in a third solvent under an inert gas atmosphere to undergo a third reaction, thereby preparing a polyvinyl ether-terminated polymer.

[0009] Wherein, compound A includes at least one of sodium methoxide, sodium ethoxide, and sodium tert-butoxide;

[0010] Compound B includes at least one of 3-isopropylbenzoic acid, mercapto alcohol, and N-acetyl-L-cysteine;

[0011] Compound C includes benzoin dimethyl ether and / or trimethylamine.

[0012] As a preferred embodiment of the polyvinyl ether end-grouping method provided by the present invention, compound B is 3-isopropylbenzoic acid; or compound B is mercaptool and compound C is benzoin dimethyl ether; or compound B is N-acetyl-L-cysteine ​​and compound C is trimethylamine.

[0013] As another preferred embodiment of the polyvinyl ether end-grouping method provided by the present invention, the molar ratio of the polyvinyl ether to compound A is 1:(3-10);

[0014] And / or, the molar ratio of the polyvinyl ether to compound B is 1:(1-10);

[0015] And / or, the molar ratio of the polyvinyl ether to compound C is 1:(1-10);

[0016] And / or, the concentration of compound A in the second solvent is 0.005–0.5 mol / L;

[0017] And / or, the reaction temperature of the second reaction is 60–110°C; the reaction time is 2–12 h;

[0018] And / or, the reaction temperature of the third reaction is 25–200°C; the reaction time is 30 min–4 h;

[0019] And / or, the molar volume ratio of polyvinyl ether to the third solvent is 0.05 to 1 mol / L.

[0020] As another preferred embodiment of the polyvinyl ether end-grouping method provided by the present invention, the second solvent and the third solvent may be the same or different, and each is independently selected from at least one of ethyl acetate, n-hexane, 1,4-dioxane, tetrahydrofuran, toluene, xylene, dichloromethane, dichloroethane, diphenyl ether, N,N-dimethylacetamide, N,N-dimethylformamide, and dimethyl sulfoxide.

[0021] As another preferred embodiment of the polyvinyl ether end-grouping method provided by the present invention, the method is carried out in a microreactor;

[0022] Preferably, the method includes:

[0023] Polyvinyl ether and compound A are dissolved in a second solvent under an inert gas atmosphere to obtain a second mixture. The second mixture is then pumped into a microreactor to undergo a second reaction to obtain a second reactant.

[0024] At least one of compound B and compound C, along with a second reactant, are dissolved in a third solvent under an inert gas atmosphere to obtain a third mixture. The third mixture is then pumped into a microreactor to undergo a third reaction, yielding a polyvinyl ether-terminated polymer.

[0025] As another preferred embodiment of the polyvinyl ether end-grouping method provided by the present invention, the method for preparing the polyvinyl ether includes: dissolving an ethylene ether monomer, an initiator and a catalyst in a first solvent under an inert gas protective environment, and undergoing a first reaction to obtain a polyvinyl ether.

[0026] Preferably, the preparation method of the polyvinyl ether is carried out in a microreactor;

[0027] More preferably, the method for preparing the polyvinyl ether includes: dissolving an ethylene ether monomer, an initiator, and a catalyst in a first solvent under an inert gas atmosphere, mixing them to obtain a first mixture, and pumping the first mixture into a microreactor to undergo a first reaction to obtain the polyvinyl ether.

[0028] As another preferred embodiment of the polyvinyl ether end-grouping method provided by the present invention, the vinyl ether monomer includes at least one of polyvinyl methyl ether, polyvinyl ethyl ether, polyvinyl n-butyl ether, and polyvinyl isobutyl ether;

[0029] And / or, the initiator includes at least one of 1,1,1-tris(2-bromoisobutyryloxymethyl)ethane, ethyl 2-bromopropionate, ethyl bromoisobutyrate, and ethyl α-bromophenylacetate;

[0030] And / or, the catalyst comprises manganese decacarbonyl;

[0031] And / or, the first solvent comprises at least one of ethyl acetate, n-hexane, 1,4-dioxane, tetrahydrofuran, toluene, xylene, dichloromethane, dichloroethane, diphenyl ether, N,N-dimethylacetamide, N,N-dimethylformamide, and dimethyl sulfoxide.

[0032] And / or, the molar ratio of the vinyl ether monomer to the initiator is 10 to 500:1;

[0033] And / or, the molar ratio of the ethylene ether monomer to the catalyst is 50 to 1000:1;

[0034] And / or, the concentration of the vinyl ether monomer in the first solvent is 0.5 to 5 mol / L.

[0035] As another preferred embodiment of the polyvinyl ether end-grouping method provided by the present invention, the reaction temperature of the first reaction is -50 to 40°C and the reaction time is 10s to 30min.

[0036] Secondly, the present invention provides a polyvinyl ether-terminated polymer prepared by the above-described polyvinyl ether-terminated polymer method.

[0037] As a preferred embodiment of the polyvinyl ether-terminated polymer provided by the present invention, the structure of the polyvinyl ether-terminated polymer is shown in Formula I:

[0038]

[0039] As another preferred embodiment of the polyvinyl ether-terminated polymer provided by the present invention, the structure of the polyvinyl ether-terminated polymer is shown in Formula II:

[0040]

[0041] As another preferred embodiment of the polyvinyl ether-terminated polymer provided by the present invention, the structure of the polyvinyl ether-terminated polymer is shown in Formula III:

[0042]

[0043] Thirdly, the present invention provides the application of the above-mentioned polyvinyl ether end-grouping method in the end-grouping treatment of polyvinyl ether.

[0044] The beneficial effects of this invention are at least as follows:

[0045] The method for terminal grouping of polyvinyl ethers provided by this invention is simple to operate and can prepare polyvinyl ether products with a variety of terminal groups.

[0046] The polyvinyl ether end-grouping method provided by this invention can also be carried out in a microreactor. By relying on the enhancement of mass and heat transfer through microfluidic field technology and its continuous flow without backmixing, it effectively improves the problems of low synthesis efficiency, insufficient conversion rate and easy occurrence of side reactions in traditional preparation methods. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the microreactor reaction apparatus used in the polyvinyl ether end-grouping method of the present invention.

[0048] Figure 2 The image shows the 1H NMR spectrum of the mercaptoethanol-terminated polyvinyl ether of Example 7 of this invention.

[0049] Among them, 1-injector, 2-microreactor, 3-heating stirrer, 4-material receiving device. Detailed Implementation

[0050] To make the technical problem to be solved, the technical solution, and the beneficial effects of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely for illustrating this patent and do not limit the scope of protection of this invention in any way.

[0051] The method for polyvinyl ether end-grouping proposed in this invention includes:

[0052] S1. Ethylene ether monomers, initiators, and catalysts are dissolved in a first solvent under an inert gas protective environment to undergo a first reaction and obtain polyvinyl ether;

[0053] S2. Polyvinyl ether and compound A are dissolved in a second solvent under an inert gas atmosphere to undergo a second reaction and obtain a second reactant;

[0054] S3. Dissolve at least one of compound B and compound C, along with the second reactant, in a third solvent under an inert gas atmosphere to undergo a third reaction, thereby obtaining a polyvinyl ether-terminated polymer.

[0055] Compound A includes at least one of sodium methoxide, sodium ethoxide, and sodium tert-butoxide.

[0056] Compound B includes at least one of 3-isopropylbenzoic acid, mercapto alcohol, and N-acetyl-L-cysteine;

[0057] Compound C includes benzoin dimethyl ether and / or trimethylamine.

[0058] The polyvinyl ether end-grouping method proposed in this invention can also be adopted. Figure 1 The microreactor reaction apparatus shown is prepared by means of:

[0059] S1. Ethylene ether monomers, initiators and catalysts are dissolved in a first solvent under an inert gas protection environment, and the mixture is then used to obtain a first mixture. The first mixture is then transferred to syringe 1 and pumped into microreactor 2 at a controlled flow rate to produce a first reaction and obtain polyvinyl ether.

[0060] S2. Polyvinyl ether and compound A are dissolved in a second solvent under an inert gas protection environment, and the mixture is mixed to obtain a second mixture. The second mixture is transferred to syringe 1 and pumped into microreactor 2 at a controlled flow rate to obtain a second reactant.

[0061] S3. Dissolve at least one of compound B and compound C, along with the second reactant, in a third solvent under an inert gas atmosphere. After mixing, obtain a third mixture. Transfer the third mixture to syringe 1 and pump it into microreactor 2 at a controlled flow rate to carry out the third reaction, thereby obtaining a polyvinyl ether-terminated polymer.

[0062] According to some embodiments of the present invention, compound B is 3-isopropylbenzoic acid; or compound B is mercaptool and compound C is benzoin dimethyl ether; or compound B is N-acetyl-L-cysteine ​​and compound C is trimethylamine.

[0063] According to some embodiments of the present invention, the molar ratio of polyvinyl ether to compound A is 1:(3 to 10), for example, it can be 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, etc.

[0064] According to some embodiments of the present invention, the molar ratio of polyvinyl ether to compound B is 1:(1 to 10), for example, it can be 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, etc.

[0065] According to some embodiments of the present invention, the molar ratio of polyvinyl ether to compound C is 1:(1 to 10), for example, it can be 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, etc.

[0066] According to some embodiments of the present invention, the concentration of compound A in the second solvent is 0.005 to 0.5 mol / L.

[0067] According to some embodiments of the present invention, the reaction temperature of the second reaction is 60–110°C; the reaction time is 2–12 h. For example, the reaction temperature of the second reaction can be selected from 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, etc., and the reaction time can be selected from 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, 11 h, 12 h, etc.

[0068] According to some embodiments of the present invention, the reaction temperature of the third reaction is 25–200°C; the reaction time is 30 min–4 h. For example, the reaction temperature of the third reaction can be selected from 25°C, 35°C, 50°C, 70°C, 80°C, 100°C, 120°C, 150°C, 180°C, 200°C, etc., and the reaction time can be selected from 30 min, 45 min, 1 h, 2 h, 3 h, 4 h, etc.

[0069] According to some embodiments of the present invention, the molar volume ratio of polyvinyl ether to the third solvent is 0.05 to 1 mol / L.

[0070] According to some embodiments of the present invention, the second solvent is selected from at least one of ethyl acetate, n-hexane, 1,4-dioxane, tetrahydrofuran, toluene, xylene, dichloromethane, dichloroethane, diphenyl ether, N,N-dimethylacetamide, N,N-dimethylformamide, and dimethyl sulfoxide.

[0071] According to some embodiments of the present invention, the third solvent is selected from at least one of ethyl acetate, n-hexane, 1,4-dioxane, tetrahydrofuran, toluene, xylene, dichloromethane, dichloroethane, diphenyl ether, N,N-dimethylacetamide, N,N-dimethylformamide, and dimethyl sulfoxide.

[0072] According to some embodiments of the present invention, the vinyl ether monomers include at least one of polyvinyl methyl ether, polyvinyl ethyl ether, polyvinyl n-butyl ether, and polyvinyl isobutyl ether.

[0073] According to some embodiments of the present invention, the initiator includes at least one selected from 1,1,1-tris(2-bromoisobutyryloxymethyl)ethane, ethyl 2-bromopropionate, ethyl bromoisobutyrate, and ethyl α-bromophenylacetate.

[0074] According to some embodiments of the present invention, the catalyst comprises manganese decacarbonyl.

[0075] According to some embodiments of the present invention, the first solvent includes at least one selected from ethyl acetate, n-hexane, 1,4-dioxane, tetrahydrofuran, toluene, xylene, dichloromethane, dichloroethane, diphenyl ether, N,N-dimethylacetamide, N,N-dimethylformamide, and dimethyl sulfoxide.

[0076] According to some embodiments of the present invention, the molar ratio of ethylene ether monomers to initiators is 10 to 500:1, for example, it can be 10:1, 100:1, 150:1, 200:1, 250:1, 300:1, 400:1, 500:1, etc.

[0077] According to some embodiments of the present invention, the molar ratio of ethylene ether monomers to catalyst is 50 to 1000:1, for example, it can be 50:1, 100:1, 200:1, 400:1, 500:1, 700:1, 900:1, 1000:1, etc.

[0078] According to some embodiments of the present invention, the concentration of the vinyl ether monomer in the first solvent is 0.5 to 5 mol / L, for example, it can be 0.5 mol / L, 0.8 mol / L, 0.9 mol / L, 1 mol / L, 1.2 mol / L, 1.5 mol / L, 2 mol / L, 3 mol / L, 4 mol / L, 5 mol / L, etc.

[0079] According to some embodiments of the present invention, the reaction temperature of the first reaction is -50 to 40°C, and the reaction time is 10 seconds to 30 minutes. For example, the reaction temperature of the first reaction can be -50°C, -40°C, -30°C, -20°C, -10°C, 0°C, 10°C, 20°C, 30°C, 40°C, etc.; the reaction time of the first reaction can be 10 seconds, 20 seconds, 30 seconds, 1 minute, 5 minutes, 10 minutes, 20 minutes, 30 minutes, etc.

[0080] The method for polyvinyl ether end-grouping provided by the present invention will be described in detail below with reference to specific embodiments.

[0081] Unless otherwise defined, the technical terms used in the following embodiments have the same meaning as commonly understood by those skilled in the art. Unless otherwise specified, the reagents used in the following embodiments are conventional biochemical reagents; the raw materials, instruments, and equipment used in the following embodiments can all be obtained commercially or by existing methods; unless otherwise specified, the reagent dosages are those used in conventional experimental operations; unless otherwise specified, the experimental methods are conventional methods.

[0082] In the various embodiments and comparative examples of this invention, the number-average molecular weight (Mn) and molecular weight distribution index (PDI) of the polymers were determined using gel permeation chromatography (GPC). Specifically, a Shimadzu LC-20AD gel permeation chromatograph was used, with tetrahydrofuran as the mobile phase, narrow-distribution polystyrene as the standard, and the mobile phase flow rate was 1.0 mL / min.

[0083] The preparation processes in the various embodiments and comparative examples of this invention are all in Figure 1 The reaction was carried out in the apparatus shown. A 50mL SEG syringe was used, and the microreactor was a PFA microchannel reactor.

[0084] Example 1

[0085] Preparation of polyvinyl ether

[0086] A PFA pipe with an inner diameter of 1 mm, a length of 2.54 m, and a retention volume of 2 mL was used as a microreactor. The device was connected and the reaction pipe was flushed with ethyl acetate. In a reaction flask after high-temperature dehydration, vinyl methyl ether (0.02 mol, 1.1616 g / 1.56 mL), vinyl ethyl ether (0.02 mol, 1.4422 g / 1.91 mL), vinyl isobutyl ether (0.02 mol, 2.0032 g / 1.60 mL), manganese carbonyl (0.00002 mol, 0.0078 g), and ethyl bromide isobutyrate (0.0001 mol, 0.0195 g / 0.015 mL) were dissolved in 18.44 mL, 18.09 mL, or 18.40 mL of ethyl acetate under nitrogen protection. The solution was stirred thoroughly and transferred to a syringe. The temperature of the low-temperature circulating reaction vessel was adjusted to 0 °C, and the flow rate of the syringe pump was set to 0.4 mL / min. The solution in the syringe was continuously pumped into the microreactor. After 20 min, the reaction solution was collected, 100 mL of methanol was added, the precipitate was collected, filtered, and vacuum dried to obtain polyvinyl ether. The number-average molecular weights of the polymers, as determined by GPC, were 9870 g / mol, 13920 g / mol, and 17610 g / mol, with molecular weight distribution indices of 1.24, 1.27, and 1.26, respectively.

[0087] Example 2

[0088] Preparation of dehalogenated polyvinyl ether

[0089] A PFA tube with an inner diameter of 1 mm, a length of 2.54 m, and a retention volume of 2 mL was used as a microreactor. The apparatus was connected, and the reaction tube was flushed with 1,4-dioxane. In a reaction flask after high-temperature dehydration, under nitrogen protection, polyvinyl ether (0.014 mmol, 0.2 g, Mn = 13920 g / mol) and sodium tert-butoxide (0.14 mmol, 13.81 mmg) were dissolved in 14 mL of 1,4-dioxane, stirred thoroughly, and transferred to a syringe. The oil bath temperature was adjusted to 90 °C, and the flow rate of the syringe pump was adjusted to 6.67 μL / min. The solution in the syringe was continuously pumped into the microreactor. After 5 h, the reaction solution was collected, 50 mL of methanol was added, precipitation was performed, filtered, and vacuum dried to obtain dehalogenated (bromine-atomized) polyvinyl ether. 1 The dehalogenation conversion rate of the polymer was 94% as determined by H NMR.

[0090] Example 3

[0091] Preparation of dehalogenated polyvinyl ether

[0092] The preparation process is the same as in Example 2, except that 0.14 mmol sodium tert-butoxide is replaced with 0.14 mmol sodium methoxide and 0.14 mmol sodium ethoxide.

[0093] through 1 The dehalogenation conversion rate of the polymer was measured to be 76% and 83% by H NMR.

[0094] Example 4

[0095] Preparation of dehalogenated polyvinyl ether

[0096] The preparation process is the same as in Example 2, except that the oil bath temperature is changed from 90°C to 60°C and 110°C.

[0097] through 1 The dehalogenation conversion rate of the polymer was measured to be 61% and 95% by H NMR.

[0098] Example 5

[0099] Preparation of dehalogenated polyvinyl ether

[0100] The preparation process is the same as in Example 2, except that the flow rate of the injection pump is adjusted from 6.67 μL / min to 16.67 μL / min and 2.778 μL / min.

[0101] through 1 The dehalogenation conversion rate of the polymer was measured to be 78% and 94% by ¹H NMR.

[0102] Example 6

[0103] Preparation of 3-isopropylbenzoic acid-terminated polyvinyl ether

[0104] A PFA microreactor with an inner diameter of 1 mm, a length of 2.54 m, and a retention volume of 2 mL was used. The apparatus was connected, and the reaction tubing was flushed with diphenyl ether. In a reaction flask after high-temperature dehydration, under nitrogen protection, 3-isopropylbenzoic acid (0.14 mmol, 0.0230 g) and debrominated polyvinyl ether (0.014 mmol, 0.2 g, Mn = 13920 g / mol) were dissolved in 20 mL of diphenyl ether, stirred thoroughly, and transferred to a syringe. The oil bath temperature was adjusted to 200 °C, and the flow rate of the syringe pump was adjusted to 16.67 μL / min. The solution in the syringe was continuously pumped into the microreactor. After 4 h, the reaction solution was collected, 100 mL of methanol was added, precipitation was achieved, filtered, and vacuum dried to obtain 3-isopropylbenzoic acid-terminated polyvinyl ether. 1 The conversion rate of polymer end groups, as measured by H NMR, was 81%.

[0105] Example 7

[0106] Preparation of mercaptool-terminated polyvinyl ethyl ether

[0107] A PFA microreactor with an inner diameter of 1 mm, a length of 2.54 m, and a retention volume of 2 mL was used. The apparatus was connected, and the reaction tubing was flushed with dimethyl sulfoxide (DMSO). In a reaction flask after high-temperature dehydration, under nitrogen protection, mercaptoethanol (0.14 mmol, 0.0109 g), benzoin dimethyl ether (0.014 mol, 0.0036 g), and debrominated polyvinyl ether (0.014 mmol, 0.2 g, Mn = 13920 g / mol) were dissolved in 20 mL of DMSO, stirred thoroughly, and transferred to a syringe. The oil bath temperature was adjusted to 25 °C or 70 °C, and the flow rate of the syringe pump was adjusted to 66.67 μL / min. The solution was continuously pumped into the microreactor. After 1 h, the reaction solution was collected, 100 mL of methanol was added, precipitation was achieved, filtered, and vacuum dried to obtain mercaptoethanol-terminated polyvinyl ether. 1 The polymer end-group conversion rates were measured to be 87% and 95% by ¹H NMR.

[0108] Example 8

[0109] Preparation of N-acetyl-L-cysteine-terminated polyvinyl ether

[0110] A PFA microreactor with an inner diameter of 1 mm, a length of 2.54 m, and a retention volume of 2 mL was used as the microreactor. The apparatus was connected, and the reaction tubing was flushed with dimethyl sulfoxide. In a reaction flask after high-temperature dehydration, under nitrogen protection, trimethylamine (0.014 mol, 0.0008 g), N-acetyl-L-cysteine ​​(0.14 mmol, 0.0228 g), and debrominated polyvinyl ether (0.014 mmol, 0.2 g, Mn = 13920 g / mol) were dissolved in 20 mL of dimethyl sulfoxide, stirred thoroughly, and transferred into a syringe. The oil bath temperature was adjusted to 35℃, and the flow rate of the syringe pump was adjusted to 200 μL / min or 16.67 μL / min. The solution in the syringe was continuously pumped into the microreactor. After 1 hour, the reaction solution was collected, 100 mL of methanol was added, precipitation was carried out, and the solution was filtered and vacuum dried to obtain pure N-acetyl-L-cysteine-terminated polyvinyl ether. The polymer end-group conversion rate was 67% and 91% as determined by 1H NMR.

[0111] Example 9

[0112] Preparation of mercaptool-terminated polyvinyl ether in a batch reactor

[0113] In a reaction flask dehydrated at high temperature, under nitrogen protection, mercaptoethanol (0.14 mmol, 0.0109 g), benzoin dimethyl ether (0.014 mol, 0.0036 g), and debrominated polyvinyl ether (0.014 mmol, 0.2 g, Mn = 13920 g / mol) were dissolved in 20 mL of dimethyl sulfoxide. The mixture was stirred thoroughly and transferred to a syringe. The oil bath temperature was adjusted to 70 °C, and the reaction was stirred for 30 min. 100 mL of methanol was added, the precipitate was collected, filtered, and dried under vacuum to obtain mercaptoethanol-terminated polyvinyl ether. 1 The polymer end-group conversion rate was 64% as determined by H NMR.

[0114] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications with the same function.

Claims

1. A method for polyvinyl ether end-grouping, characterized in that, include: Polyvinyl ether and compound A are dissolved in a second solvent under an inert gas atmosphere to undergo a second reaction and obtain a second reactant. The second reactant, compound B, and optional compound C are dissolved in a third solvent under an inert gas atmosphere to undergo a third reaction, thereby preparing a polyvinyl ether-terminated polymer. Wherein, compound A includes at least one of sodium methoxide, sodium ethoxide, and sodium tert-butoxide; Compound B is 3-isopropylbenzoic acid, and compound C is not added; Alternatively, compound B may be a mercaptool, and compound C may be benzoin dimethyl ether; Alternatively, compound B may be N-acetyl-L-cysteine, and compound C may be trimethylamine.

2. The method according to claim 1, characterized in that, The molar ratio of the polyvinyl ether to compound A is 1:(3~10); And / or, the molar ratio of the polyvinyl ether to compound B is 1:(1~10); And / or, the molar ratio of the polyvinyl ether to compound C is 1:(1~10); And / or, the concentration of compound A in the second solvent is 0.005~0.5 mol / L; And / or, the reaction temperature of the second reaction is 60~110℃; the reaction time is 2~12h; And / or, the reaction temperature of the third reaction is 25~200℃, and the reaction time is 30min~4h; And / or, the molar volume ratio of the polyvinyl ether to the third solvent is 0.05~1 mol / L.

3. The method according to claim 1 or 2, characterized in that, The second solvent and the third solvent may be the same or different, and each is independently selected from at least one of ethyl acetate, n-hexane, 1,4-dioxane, tetrahydrofuran, toluene, xylene, dichloromethane, dichloroethane, diphenyl ether, N,N-dimethylacetamide, N,N-dimethylformamide, and dimethyl sulfoxide.

4. The method according to claim 1 or 2, characterized in that, The method is carried out in a microreactor.

5. The method according to claim 4, characterized in that, The method includes: Polyvinyl ether and compound A are dissolved in a second solvent under an inert gas atmosphere to obtain a second mixture. The second mixture is then pumped into a microreactor to undergo a second reaction to obtain a second reactant. At least one of compound B and compound C, along with a second reactant, are dissolved in a third solvent under an inert gas atmosphere to obtain a third mixture. The third mixture is then pumped into a microreactor to undergo a third reaction, yielding a polyvinyl ether-terminated polymer.

6. The method according to claim 1, characterized in that, The method for preparing the polyvinyl ether includes: dissolving an ethylene ether monomer, an initiator, and a catalyst in a first solvent under an inert gas protective environment, and undergoing a first reaction to obtain the polyvinyl ether.

7. The method according to claim 6, characterized in that, The preparation method of the polyvinyl ether is carried out in a microreactor.

8. The method according to claim 7, characterized in that, The method for preparing the polyvinyl ether includes: dissolving ethylene ether monomers, initiators and catalysts in a first solvent under an inert gas protection environment, mixing them to obtain a first mixture, and pumping the first mixture into a microreactor to undergo a first reaction to obtain polyvinyl ether.

9. The method according to any one of claims 6-8, characterized in that, The vinyl ether monomers include at least one of polyvinyl methyl ether, polyvinyl ethyl ether, polyvinyl n-butyl ether, and polyvinyl isobutyl ether; And / or, the initiator includes at least one of 1,1,1-tris(2-bromoisobutyryloxymethyl)ethane, ethyl 2-bromopropionate, ethyl bromoisobutyrate, and ethyl α-bromophenylacetate; And / or, the catalyst comprises manganese decacarbonyl; And / or, the first solvent includes at least one of ethyl acetate, n-hexane, 1,4-dioxane, tetrahydrofuran, toluene, xylene, dichloromethane, dichloroethane, diphenyl ether, N,N-dimethylacetamide, N,N-dimethylformamide, and dimethyl sulfoxide; And / or, the molar ratio of the vinyl ether monomer to the initiator is 10~500:1; And / or, the molar ratio of the ethylene ether monomer to the catalyst is 50~1000:1; And / or, the concentration of the vinyl ether monomer in the first solvent is 0.5~5 mol / L.

10. The method according to any one of claims 6-8, characterized in that, The reaction temperature of the first reaction is -50~40℃, and the reaction time is 10s~30min.

11. A polyvinyl ether-terminated polymer, prepared by any one of claims 1-10.

12. The application of the method according to any one of claims 1-10 in the end-grouping treatment of polyvinyl ether.

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