A low halogen content functionalized polyphenylene ether and a method of making the same

Abstract

This invention belongs to the field of polymer science, specifically relating to a low-halogen-content functionalized polyphenylene ether and its preparation method. The method for preparing the functionalized polyphenylene ether of this invention includes the following steps: (1) mixing polyphenylene ether, a solvent, and an alkaline catalyst, then adding a modifier dropwise to react and obtain a functionalized polyphenylene ether solution; (2) mixing the functionalized polyphenylene ether solution with a first precipitant, and sequentially performing homogenization dispersion and filtration treatments to obtain functionalized polyphenylene ether powder; (3) mixing the functionalized polyphenylene ether powder, a second precipitant, and a washing aid, and sequentially performing washing and filtration treatments to obtain a filter cake; (4) mixing the filter cake with a third precipitant, and sequentially performing washing, filtration, and drying treatments to obtain the functionalized polyphenylene ether product. The method of this invention is simple to operate, has low solvent and time costs, high production efficiency, and good versatility, which is beneficial for obtaining functionalized polyphenylene ethers with low halogen content.

Description

Technical Field

[0001] This invention belongs to the field of polymers, and specifically relates to a low-halogen-content functionalized polyphenylene ether and its preparation method. Background Technology

[0002] To minimize signal transmission loss, integrated circuit boards used in high-frequency communication require substrate materials with low dielectric constants and dissipation factors. Among numerous polymer materials, polyphenylene ether (PPE) and its derivatives are widely studied and used in the field of high-frequency circuit boards due to their low water absorption, high glass transition temperature (Tg), high tensile strength, low thermal expansion, low polarity, low dielectric constant, and low dissipation factor. In particular, some low molecular weight PPEs have been developed for the preparation of copper-clad laminates via impregnation to overcome the disadvantages of high molecular weight PPEs, such as high melting point, high viscosity, and low solubility. Simultaneously, to compensate for the loss of thermal and mechanical properties due to low molecular weight, low molecular weight PPEs with curing capabilities after end-group functionalization have also been developed.

[0003] Chemical modification of low molecular weight polyphenylene ethers (PPEs) often involves reacting halogen-containing small organic molecules with their terminal hydroxyl groups to generate modified products with curable groups at both ends, such as methyl methacrylate or vinyl benzyl ether. However, during the reaction, excess small organic molecules and impurities such as halogen salts are difficult to remove from the product, which significantly reduces the electrical properties of the modified product and hinders its application in related electronic and electrical fields. Therefore, reducing the impurity content, especially free chlorine and total chlorine content, in functionalized PPEs has become one of the key issues that urgently needs to be addressed.

[0004] Patent document JP2023132166A reduces the halogen content by adding a terminal-modified low molecular weight polyphenylene ether solution dropwise to a poor solvent, precipitating and recovering the product, and then repeatedly dissolving and reprecipitating. However, the repeated dissolution and precipitation process for dechlorination undoubtedly increases solvent and time costs and inevitably reduces the overall yield. Patent document JP2022161266A adsorbents with certain pore sizes, such as silica gel, alumina, molecular sieves, and activated carbon, are added to the terminal-modified low molecular weight polyphenylene ether solution to adsorb halogen impurities. The mixture is then filtered to remove the adsorbents, and the product with a lower halogen content is recovered by precipitation. Because the adsorbents with certain pore sizes used for halogen removal lack specificity for halogen ions and halogen-containing raw materials, the amount of adsorbent used is very large. In its embodiment, the adsorbent accounts for more than 20 wt% of the modified solution mass. At the same time, indiscriminate adsorption also leads to a decrease in the yield of functionalized polyphenylene ether. Patent document CN104072751A treats the end-modified low molecular weight polyphenylene ether reaction solution with an aqueous solution of alkali metal hydroxide and removes excess vinyl benzyl halides in the reaction through extraction and washing. However, this method is only suitable for removing benzyl chloride or benzyl bromide raw materials, and the aqueous solution heat treatment process of alkali metal hydroxide requires at least 5 hours, which greatly reduces production efficiency. Patent document JP2023054651A removes the remaining acyl chloride compounds by adding an alcohol solution to quench them and then filtering the solution. Although this process does not require hot alkali solution treatment, it is only suitable for removing acyl chloride modifiers. Patent document JP2023135421A reports the effective removal of the remaining acyl chloride compounds in the product through a two-stage heating and drying process. However, physical methods such as heating and drying or high vacuum drying are only suitable for removing low-boiling-point chlorine-containing raw materials and cannot remove high-boiling-point raw materials such as chloromethylstyrene (boiling point 229-240℃) and the generated halide ions.

[0005] In summary, current methods for removing impurities from functionalized low molecular weight polyphenylene ethers suffer from problems such as high residual halogen content, high solvent and time costs, complex operation, low yield, or poor method versatility.

[0006] Therefore, there is an urgent need to develop a method for preparing functionalized polyphenylene ethers that has low halogen content, low solvent and time costs, simple operation, high yield, and strong versatility. Summary of the Invention

[0007] To address the problems existing in the prior art, this invention provides a low-halogen-content functionalized polyphenylene ether and its preparation method. The preparation method of this invention features low solvent and time costs, simple operation, high yield, and strong versatility, resulting in functionalized polyphenylene ethers with low halogen and small organic molecule content.

[0008] Specifically, the present invention provides a method for preparing functionalized polyphenylene ether, the method comprising the steps of:

[0009] (1) Mix polyphenylene ether, solvent and alkaline catalyst, and then add modifier dropwise to react and obtain functionalized polyphenylene ether solution;

[0010] (2) The functionalized polyphenylene ether solution and the first precipitant are mixed and homogenized to obtain a functionalized polyphenylene ether suspension, which is then filtered to obtain functionalized polyphenylene ether powder; or

[0011] The functionalized polyphenylene ether solution and the first precipitant are mixed and filtered to obtain functionalized polyphenylene ether particles. These particles are then processed into functionalized polyphenylene ether powder using a material refining device; or...

[0012] The functionalized polyphenylene ether solution and the first precipitant are mixed and then spray-dried or freeze-dried to obtain functionalized polyphenylene ether powder.

[0013] (3) The functionalized polyphenylene ether powder, the second precipitant and the washing aid are mixed and then washed and filtered in sequence to obtain filter cake;

[0014] (4) The filter cake and the third precipitant are mixed and then washed, filtered and dried in sequence to obtain the functionalized polyphenylene ether product.

[0015] In one or more embodiments, the end groups of the functionalized polyphenylene ether contain carbon-carbon double bonds.

[0016] In one or more embodiments, the polyphenylene ether has the structure shown in Formula I:

[0017]

[0018] In Formula I, R1-R8 are each independently selected from hydrogen atoms and C1-C5 alkyl groups, A is a covalent bond or a C1-C10 alkylene group, m and n are each independent integers from 0 to 30, and at least one of m and n is not 0.

[0019] In one or more embodiments, the polyphenylene ether has a number-average molecular weight of 1000-3000 g / mol.

[0020] In one or more embodiments, the solvent is selected from one or more of toluene, dichloromethane, chloroform, tetrahydrofuran, acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, acetone, and 1,3-dimethyl-2-imidazolinone.

[0021] In one or more embodiments, the alkaline catalyst is an inorganic base and / or an organic base.

[0022] In one or more embodiments, the inorganic base is selected from one or more of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, and potassium carbonate.

[0023] In one or more embodiments, the organic base is selected from one or more of triethylamine, diisopropylamine, N-methylmorpholine, 4-dimethylaminopyridine, 2,6-dimethylpyridine, sodium methoxide, sodium ethoxide, potassium ethoxide, and potassium tert-butoxide.

[0024] In one or more embodiments, the modifier is an acyl halide compound of Formula II and / or a benzyl halide compound of Formula III:

[0025]

[0026] In Formula II, R9 is a covalent bond, a C1-C10 alkylene or phenylene; R10-R12 are each independently selected from hydrogen atoms and C1-C5 alkyl groups, and X is a chlorine atom or a bromine atom; in Formula III, Y is a chlorine atom or a bromine atom, and the vinyl group on the benzene ring is located at the ortho, meta, or para position of the chloromethyl or bromomethyl group.

[0027] In one or more embodiments, the acyl halide compound is selected from one or more of methacryloyl chloride, acryloyl chloride, and butenoyl chloride.

[0028] In one or more embodiments, the benzyl halide compound is selected from one or more of 4-chloromethylstyrene, 3-chloromethylstyrene, and 1-(bromomethyl)-4-vinylbenzene.

[0029] In one or more embodiments, the mass ratio of the polyphenylene ether to the solvent is 1:(0.2-20).

[0030] In one or more embodiments, the molar ratio of the polyphenylene ether to the basic catalyst is 1:(2-4).

[0031] In one or more embodiments, the mixing time of the polyphenylene ether, the solvent and the alkaline catalyst is 0.5-4 h.

[0032] In one or more embodiments, the mixing temperature of the polyphenylene ether, the solvent, and the alkaline catalyst is 0-100°C.

[0033] In one or more embodiments, the molar ratio of the polyphenylene ether to the modifier is 1:(2-4).

[0034] In one or more embodiments, the modifier is added over a period of 0.5-1 hour.

[0035] In one or more embodiments, the temperature of the reaction is 0-100°C.

[0036] In one or more embodiments, the reaction time is 2-10 hours.

[0037] In one or more embodiments, the modifier is an acyl halide compound of formula II, and the solvent is selected from one or more of toluene, dichloromethane, chloroform, and tetrahydrofuran.

[0038] In one or more embodiments, the modifier is an acyl halide compound of formula II, and the organic base is selected from one or more of triethylamine, diisopropylamine, N-methylmorpholine, 4-dimethylaminopyridine and 2,6-dimethylpyridine.

[0039] In one or more embodiments, the modifier is an acyl halide compound of formula II, and the mixing time of the polyphenylene ether, the solvent and the alkaline catalyst is 0.5-4 h.

[0040] In one or more embodiments, the modifier is an acyl halide compound of formula II, and the mixing temperature of the polyphenylene ether, the solvent and the basic catalyst is 0-5°C.

[0041] In one or more embodiments, the modifier is an acyl halide compound of formula II. After the modifier is added dropwise, the temperature is raised to the reaction temperature in 1-2 hours, and the reaction temperature is 0-30°C.

[0042] In one or more embodiments, the modifier is an acyl halide compound of formula II, and the reaction time is 2-4 hours.

[0043] In one or more embodiments, the modifier is an acyl halide compound of formula II, and step (1) further includes quenching the residual raw material with a quenching agent after the reaction is completed, filtering, and obtaining a functionalized polyphenylene ether solution.

[0044] In one or more embodiments, the modifier is an acyl halide compound of formula II, and the quencher is water and / or methanol.

[0045] In one or more embodiments, the modifier is an acyl halide compound of formula II, and the molar ratio of the quencher to the acyl halide compound is 1:(1-2).

[0046] In one or more embodiments, the modifier is an acyl halide compound of formula II, and the quenching time is 3-10 min.

[0047] In one or more embodiments, the modifier is a benzyl halide compound of Formula III, and the solvent is selected from one or more of toluene, acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, acetone, and 1,3-dimethyl-2-imidazolinone.

[0048] In one or more embodiments, the modifier is a benzyl halide compound of formula III, and the organic base is selected from one or more of sodium methoxide, sodium ethoxide, potassium ethoxide, and potassium tert-butoxide.

[0049] In one or more embodiments, the modifier is a benzyl halide compound of formula III, and the mixing time of the polyphenylene ether, the solvent, and the alkaline catalyst is 1-4 hours.

[0050] In one or more embodiments, the modifier is a benzyl halide compound of formula III, and the mixing temperature of the polyphenylene ether, the solvent and the alkaline catalyst is 30-100°C.

[0051] In one or more embodiments, the modifier is a benzyl halide compound of formula III, and the reaction temperature is 30-100°C.

[0052] In one or more embodiments, the modifier is a benzyl halide compound of formula III, and the reaction time is 4-10 h.

[0053] In one or more embodiments, the first precipitant is water and / or methanol; preferably, the first precipitant is water or a mixture of water and methanol in a mass ratio of (1-10):1.

[0054] In one or more embodiments, the mass ratio of the functionalized polyphenylene ether solution to the first precipitant is 1:(1-10).

[0055] In one or more embodiments, the temperature of the first precipitant is 20-60°C.

[0056] In one or more embodiments, the homogenization dispersion process takes 3-60 minutes.

[0057] In one or more embodiments, the homogenization and dispersion process is performed using a homogenizer, an ultrasonic extractor, an ultrasonic homogenizer, or an ultrasonic emulsifier.

[0058] In one or more embodiments, the particle size D50 of the functionalized polyphenylene ether powder is 10-200 μm. In one or more embodiments, the second precipitant is water and / or methanol; preferably, the second precipitant is a mixture of water and methanol in a mass ratio of (1-10):1.

[0059] In one or more embodiments, the mass ratio of the functionalized polyphenylene ether solution obtained in step (1) to the second precipitant added in step (3) is 1:(1-10).

[0060] In one or more embodiments, the temperature of the second precipitant is 20-60°C.

[0061] In one or more embodiments, the detergent additive is a small organic molecule containing an OH bond or an NH bond; the detergent additive is preferably one or more selected from thiourea, N,N-diethylthiourea, 1,3-diethylurea, benzoylurea, diethanolamine and isopropanolamine.

[0062] In one or more embodiments, the mass ratio of the functionalized polyphenylene ether solution to the detergent additive is 1:(0.001-0.03).

[0063] In one or more embodiments, the temperature of the washing process in step (3) is 20-60°C.

[0064] In one or more embodiments, the washing speed in step (3) is 100-400 rpm.

[0065] In one or more embodiments, the washing process in step (3) takes 0.5-2 hours.

[0066] In one or more embodiments, the third precipitant is water and / or methanol; preferably, the third precipitant is methanol or a mixture of water and methanol in a mass ratio of 1:(1-10).

[0067] In one or more embodiments, the mass ratio of the functionalized polyphenylene ether solution obtained in step (1) to the third precipitant added in step (4) is 1:(1-10).

[0068] In one or more embodiments, the temperature of the third precipitant is 20-60°C.

[0069] In one or more embodiments, the drying temperature is 90-120°C.

[0070] In one or more embodiments, the drying time is 2-8 hours.

[0071] In one or more embodiments, the drying is carried out in a vacuum environment.

[0072] The present invention provides a functionalized polyphenylene ether, wherein the chlorine content of the functionalized polyphenylene ether is ≤50ppm.

[0073] In one or more embodiments, the end groups of the functionalized polyphenylene ether contain carbon-carbon double bonds; preferably, the functionalized polyphenylene ether is formed by reacting polyphenylene ether with a modifier, wherein the polyphenylene ether and the modifier are preferably as defined in any embodiment herein.

[0074] In one or more embodiments, the content of the functionalized polyphenylene ether with organic small molecules is ≤40ppm, and the organic small molecules are the modifiers described in any of the embodiments herein.

[0075] In one or more embodiments, the functionalized polyphenylene ether is prepared using the method described in any of the embodiments herein.

[0076] Compared with the prior art, the present invention has the following beneficial effects:

[0077] (1) The present invention is simple to operate, has low solvent and time costs, high production efficiency, and good versatility;

[0078] (2) The present invention homogenizes and refines large polyphenylene ether solid particles through homogenization and dispersion, which reduces the difficulty of washing operation. It has a good washing ability for inorganic halogen ions and organic halogen-containing compounds. Moreover, the homogenization and dispersion + washing process can be adapted to different types of chemical modification processes.

[0079] (3) By adding detergent additives, the content of halogen ions in this invention is reduced to below 50 ppm. Detailed Implementation

[0080] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0081] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0082] In this document, the terms “contains,” “includes,” “containing,” and similar terms encompass the meanings of “basically composed of” and “composed of.” For example, when this document discloses “A contains B and C,” “A is basically composed of B and C” and “A is composed of B and C” should be considered as having been disclosed in this document.

[0083] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0084] Unless otherwise specified, percentages refer to mass percentages and proportions refer to mass ratios in this article.

[0085] In this document, when describing embodiments or examples, it should be understood that it is not intended to limit the invention to those embodiments or examples. Rather, all alternatives, modifications, and equivalents of the methods and materials described herein are covered within the scope defined by the claims.

[0086] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0087] In this document, "alkyl" refers to a straight-chain or branched monovalent saturated hydrocarbon group having a specified number of carbon atoms. Alkyl groups can be those having 1 to 10 carbon atoms (C1-C10 alkyl). Alkyl groups typically contain 1-8 carbon atoms (C1-C8 alkyl), preferably 1-6 carbon atoms (C1-C6 alkyl), and more preferably 1-4 carbon atoms (C1-C4 alkyl). Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, etc.

[0088] In this document, "alkylene" refers to a divalent saturated hydrocarbon group formed by the loss of a hydrogen atom from an alkyl group. Alkylenes can be those having 1 to 10 carbon atoms (C1-C10 alkylenes). Alkylenes typically contain 1 to 8 carbon atoms (C1-C8 alkylenes), preferably 1 to 6 carbon atoms (C1-C6 alkylenes), and more preferably 1 to 4 carbon atoms (C1-C4 alkylenes).

[0089] In this article, "phenylene" refers to a divalent saturated hydrocarbon group formed by benzene losing two hydrogen atoms, wherein the two lost hydrogen atoms can be located in the ortho, meta, or para position of the benzene ring.

[0090] In this invention, functionalized polyphenylene ether refers to polyphenylene ether whose end groups are modified with reactive functional groups. In some embodiments, functionalized polyphenylene ether refers to polyphenylene ether with carbon-carbon double bonds at the end groups. Functionalized polyphenylene ether can be obtained by reacting polyphenylene ether with a modifier. The modifier contains at least two reactive functional groups, one of which (e.g., a halogen) reacts with the terminal hydroxyl group of the polyphenylene ether, and the remaining reactive functional group (e.g., a carbon-carbon double bond) is retained in the functionalized polyphenylene ether.

[0091] In this invention, low molecular weight polyphenylene ether refers to polyphenylene ether with a low molecular weight, particularly a number average molecular weight ≤ 3000 g / mol (e.g., a number average molecular weight of 1000-3000 g / mol). Functionalized polyphenylene ethers obtained by reacting low molecular weight polyphenylene ethers with modifiers are low molecular weight functionalized polyphenylene ethers. The functionalized polyphenylene ethers of this invention are preferably low molecular weight functionalized polyphenylene ethers.

[0092] The method for preparing functionalized polyphenylene ether of the present invention includes the following steps:

[0093] (1) Mix polyphenylene ether, solvent and alkaline catalyst, and then add modifier dropwise to react and obtain functionalized polyphenylene ether solution;

[0094] (2) The functionalized polyphenylene ether solution and the first precipitant are mixed and homogenized to obtain a functionalized polyphenylene ether solution, which is then filtered to obtain functionalized polyphenylene ether powder; or

[0095] The functionalized polyphenylene ether solution and the first precipitant are mixed and filtered to obtain functionalized polyphenylene ether particles. These particles are then processed into functionalized polyphenylene ether powder using a material refining device; or...

[0096] The functionalized polyphenylene ether solution and the first precipitant are mixed and then spray-dried or freeze-dried to obtain functionalized polyphenylene ether powder.

[0097] (3) The functionalized polyphenylene ether powder, the second precipitant and the washing aid are mixed and then washed and filtered in sequence to obtain filter cake;

[0098] (4) The filter cake and the third precipitant are mixed and then washed, filtered and dried in sequence to obtain functionalized polyphenylene ether.

[0099] This invention first prepares a functionalized polyphenylene ether solution using polyphenylene ether, a solvent, an alkaline catalyst, and a modifier. Then, the functionalized polyphenylene ether solution undergoes post-treatment to obtain functionalized polyphenylene ether with low halogen content and low organic small molecule content. The key to the post-treatment process in this invention lies in dispersion treatment and the addition of detergent additives.

[0100] In the preparation of the functionalized polyphenylene ether solution in this invention, the structure of the polyphenylene ether is as shown in Formula I.

[0101]

[0102] In Formula I, R1-R8 are each independently selected from hydrogen atoms and C1-C5 alkyl groups, A is a covalent bond or a C1-C10 alkylene group, and m and n are each independent integers from 0 to 30; at least one of m and n is not 0.

[0103] In this invention, the number-average molecular weight of the polyphenylene ether is preferably 1000-3000 g / mol, for example 1200 g / mol, 1500 g / mol, 1800 g / mol, 2000 g / mol, 2200 g / mol, 2500 g / mol, or 2800 g / mol. The values ​​of m and n in the polyphenylene ether structural formula can be determined based on the number-average molecular weight of the polyphenylene ether and the selection of substituents R1-R8.

[0104] In the process of preparing the functionalized polyphenylene ether solution of the present invention, the solvent can be one or more selected from toluene, dichloromethane, chloroform, tetrahydrofuran, acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, acetone and 1,3-dimethyl-2-imidazolinone.

[0105] In the process of preparing functionalized polyphenylene ether solution according to the present invention, the alkaline catalyst can be an inorganic base and / or an organic base; the inorganic base is preferably selected from one or more of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate and potassium carbonate; the organic base is preferably selected from one or more of triethylamine, diisopropylamine, N-methylmorpholine, 4-dimethylaminopyridine, 2,6-dimethylpyridine, sodium methoxide, sodium ethoxide, potassium ethoxide and potassium tert-butoxide.

[0106] In the process of preparing functionalized polyphenylene ether solution in this invention, the modifier is an acyl halide compound represented by Formula II and / or a benzyl halide compound represented by Formula III;

[0107]

[0108] In Formula II, R9 is a covalent bond, a C1-C10 alkylene or phenylene; R10-R12 are each independently selected from hydrogen atoms and C1-C5 alkyl groups, and X is a chlorine atom or a bromine atom; in Formula III, Y is a chlorine atom or a bromine atom, and the vinyl group on the benzene ring is located at the ortho, meta, or para position of the chloromethyl or bromomethyl group.

[0109] In the preparation of the functionalized polyphenylene ether solution according to this invention, the mass ratio of polyphenylene ether to solvent can be 1:(0.2-20), for example 1:0.5, 1:2, 1:4, 1:6, 1:8, 1:10, 1:12, 1:14, 1:16, 1:18, or 1:20. The molar ratio of polyphenylene ether to alkaline catalyst can be 1:(2-4), for example 1:2, 1:2.5, 1:3, 1:3.5, or 1:4. In the preparation of the functionalized polyphenylene ether solution according to this invention, the mixing time of polyphenylene ether, solvent, and alkaline catalyst can be 0.5-4 h, for example 0.5 h, 0.8 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, or 4 h. In the preparation of the functionalized polyphenylene ether solution according to this invention, the mixing temperature of polyphenylene ether, solvent, and alkaline catalyst can be 0-100℃, for example, 0℃, 10℃, 20℃, 30℃, 40℃, 50℃, 60℃, 70℃, 80℃, 90℃, and 100℃. In the preparation of the functionalized polyphenylene ether solution according to this invention, the molar ratio of polyphenylene ether to modifier can be 1:(2-4), for example, 1:2, 1:2.5, 1:3, 1:3.5, and 1:4. In the preparation of the functionalized polyphenylene ether solution according to this invention, the dropwise addition time of the modifier can be 0.5-1h, for example, 0.5h, 0.6h, 0.7h, 0.8h, 0.9h, and 1h. In the preparation of the functionalized polyphenylene ether solution according to this invention, the reaction temperature can be 0-100℃, for example, 0℃, 10℃, 20℃, 30℃, 40℃, 50℃, 60℃, 70℃, 80℃, 90℃, and 100℃. The reaction time in the preparation of the functionalized polyphenylene ether solution according to this invention can be 2-10 hours, for example, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, and 10 hours.

[0110] In some embodiments, an acyl halide compound of Formula II is used as a modifier, and the solvent may be one or more selected from toluene, dichloromethane, chloroform, and tetrahydrofuran; in some embodiments, an acyl halide compound of Formula II is used as a modifier, and the organic base may be one or more selected from triethylamine, diisopropylamine, N-methylmorpholine, 4-dimethylaminopyridine, and 2,6-dimethylpyridine; in some embodiments, when an acyl halide compound of Formula II is used as a modifier, the mixing time of polyphenylene ether, solvent, and basic catalyst may be 0.5-4 h, for example, 0.5 h, 0.8 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, or 4 h. In some embodiments, when an acyl halide compound of Formula II is used as a modifier, the mixing temperature of polyphenylene ether, solvent, and basic catalyst may be 0-5 °C, for example, 0 °C, 1 °C, 2 °C, 3 °C, 4 °C, or 5 °C. In some embodiments, an acyl halide compound of Formula II is used as a modifier. After the modifier is added dropwise, the temperature is raised to the reaction temperature within 1-2 hours. The reaction temperature can be 0-30°C, for example, 10°C, 20°C, or 30°C. In some embodiments, an acyl halide compound of Formula II is used as a modifier, and the reaction time can be 2-4 hours, for example, 2 hours, 2.5 hours, 3 hours, 3.5 hours, or 4 hours. In some embodiments, the method further includes quenching residual raw materials with a quenching agent after the reaction, filtering, and obtaining a functionalized polyphenylene ether solution. The quenching agent can be water and / or methanol; the molar ratio of the quenching agent to the acyl halide compound can be 1:(1-2), for example, 1:1, 1:1.5, or 1:2. The quenching time can be 3-10 minutes, for example, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, or 9 minutes.

[0111] In some embodiments, a benzyl halide compound of Formula III is used as a modifier, and the solvent may be one or more selected from toluene, acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, acetone, and 1,3-dimethyl-2-imidazolinone. In some embodiments, a benzyl halide compound of Formula III is used as a modifier, and the organic base may be one or more selected from sodium methoxide, sodium ethoxide, potassium ethoxide, and potassium tert-butoxide. In some embodiments, when a benzyl halide compound of Formula III is used as a modifier, the mixing time of the polyphenylene ether, solvent, and alkaline catalyst may be 1-4 h, for example, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, or 4 h. In some embodiments, when a benzyl halide compound of Formula III is used as a modifier, the mixing temperature of the polyphenylene ether, solvent, and alkaline catalyst may be 30-100 °C, for example, 30 °C, 40 °C, 50 °C, 60 °C, 70 °C, 80 °C, 90 °C, or 100 °C. In some embodiments, a benzyl halide compound of Formula III is used as a modifier, and the reaction temperature can be 30-100°C, for example 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, or 100°C. In some embodiments, a benzyl halide compound of Formula III is used as a modifier, and the reaction time can be 4-10 hours, for example 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, or 10 hours.

[0112] In the purification process of the functionalized polyphenylene ether solution of the present invention, the first precipitant can be water and / or methanol; preferably, the first precipitant is a mixture of water and methanol, more preferably, the mass ratio of water to methanol can be (1-10):1, for example 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1. In the purification process of the functionalized polyphenylene ether solution of the present invention, the mass ratio of the functionalized polyphenylene ether solution to the first precipitant can be 1:(1-10), for example 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1. In the purification process of the functionalized polyphenylene ether solution of the present invention, the temperature of the first precipitant can be 20-60℃, for example 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃.

[0113] In the process of removing impurities from functionalized polyphenylene ether solutions, the homogenization and dispersion treatment of this invention can refine the particle size of large suspended particles in the precipitant, resulting in functionalized polyphenylene ether powder with a particle size that meets the requirements of this invention, which is beneficial for subsequent washing. Existing equipment such as homogenizers, ultrasonic extractors, ultrasonic homogenizers, and ultrasonic emulsifiers can be used for homogenization and dispersion treatment.

[0114] In this invention, there are several alternative techniques for homogeneous dispersion processing. For example, large-particle products can be prepared using conventional precipitation techniques, and after filtration and drying, a material refining device can be used to refine the particle size of the large-particle products to the requirements of this invention. The material refining device can be a grinding mill. Alternatively, spray drying or freeze drying techniques can be used to prepare powder products of the target particle size. In this case, it is preferable to completely remove the solvent from the powder product through drying before subsequent washing.

[0115] In the process of removing impurities from functionalized polyphenylene ether solution, the dispersion treatment time can be 3-60 min, for example 5 min, 10 min, 15 min, 20 min, 30 min, 40 min, 50 min, or 60 min.

[0116] In the purification process of functionalized polyphenylene ether solutions according to this invention, the target particle size D50 (also known as particle size D50) of the functionalized polyphenylene ether powder is 10-200 μm, for example, 20 μm, 40 μm, 60 μm, 80 μm, 100 μm, 120 μm, 140 μm, 160 μm, 180 μm, and 200 μm. In some embodiments, the particle size D50 of the functionalized polyphenylene ether powder is 50-150 μm, for example, 80-120 μm. This invention has found that controlling the particle size of the functionalized polyphenylene ether powder within the above range is beneficial for subsequent steps to fully remove halogens and small organic molecules from the functionalized polyphenylene ether, resulting in a functionalized polyphenylene ether product with low halogen content and low small organic molecule content.

[0117] In the purification process of the functionalized polyphenylene ether solution of the present invention, the second precipitant can be water and / or methanol; preferably, the second precipitant is a mixture of water and methanol, more preferably, the mass ratio of water to methanol can be (1-10):1, for example 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1. In the purification process of the functionalized polyphenylene ether solution of the present invention, the mass ratio of the functionalized polyphenylene ether solution to the second precipitant can be 1:(1-10), for example 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10. In the purification process of the functionalized polyphenylene ether solution of the present invention, the temperature of the second precipitant can be 20-60℃, for example 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃.

[0118] In the process of removing impurities from functionalized polyphenylene ether solutions, the detergent can be a small organic molecule containing OH or NH bonds; preferably, the detergent can be one or more selected from thiourea, N,N-diethylthiourea, 1,3-diethylurea, benzoylurea, diethanolamine and isopropanolamine.

[0119] In the purification process of the functionalized polyphenylene ether solution according to this invention, the mass ratio of the functionalized polyphenylene ether solution to the detergent additive can be 1:(0.001-0.03), for example 1:0.001, 1:0.005, 1:0.01, 1:0.015, 1:0.02, 1:0.025, or 1:0.03. In this invention, the detergent additive is a small molecule organic compound capable of coordinating and binding with halide ions.

[0120] In the purification process of the functionalized polyphenylene ether solution of this invention, the washing temperature in step (3) can be 20-60℃, for example 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, or 60℃. In the purification process of the functionalized polyphenylene ether solution of this invention, the washing speed in step (3) can be 100-400 rpm, for example 100 rpm, 200 rpm, 300 rpm, or 400 rpm. In the purification process of the functionalized polyphenylene ether solution of this invention, the washing time in step (3) can be 0.5-2 hours, for example 0.5 hours, 0.8 hours, 1 hour, 1.5 hours, or 1.8 hours.

[0121] In the purification process of the functionalized polyphenylene ether solution of this invention, the third precipitant can be water and / or methanol; preferably, the third precipitant is methanol, or a mixture of water and methanol; more preferably, the mass ratio of water to methanol can be 1:(1-10), for example, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, or 1:10. In the purification process of the functionalized polyphenylene ether solution of this invention, the mass ratio of the functionalized polyphenylene ether solution to the first precipitant can be 1:(1-10), for example, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, or 1:10. In the purification process of the functionalized polyphenylene ether solution of this invention, the temperature of the third precipitant can be 20-60℃, for example, 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, or 60℃.

[0122] In the purification process of the functionalized polyphenylene ether solution of this invention, the drying temperature can be 90-120℃, for example, 90℃, 95℃, 100℃, 105℃, 110℃, 115℃, or 120℃. The drying time in the purification process of the functionalized polyphenylene ether solution of this invention can be 2-8 hours, for example, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, or 8 hours. The drying process of the functionalized polyphenylene ether solution of this invention can be carried out in a vacuum environment.

[0123] This invention provides a functionalized polyphenylene ether, wherein the chlorine content of the functionalized polyphenylene ether is ≤50ppm. The end groups of the functionalized polyphenylene ether of this invention may contain carbon-carbon double bonds. The functionalized polyphenylene ether of this invention can be prepared by reacting polyphenylene ether with a modifier; in some embodiments, the functionalized polyphenylene ether is prepared from the polyphenylene ether of this invention and a modifier.

[0124] In this invention, the content of organic small molecules in the functionalized polyphenylene ether is ≤40ppm, and the organic small molecules are the modifiers described in any embodiment of this invention.

[0125] The present invention will be described below by way of specific embodiments. It should be understood that these embodiments are merely illustrative and are not intended to limit the scope of the invention. The methods, reagents, and materials used in the embodiments are conventional methods, reagents, and materials in the art, unless otherwise stated. The raw material compounds in the embodiments are all commercially available.

[0126] In this invention, the test method for the particle size D50 of functionalized low molecular weight polyphenylene ether powder is as follows: weigh 20.0 mg of functionalized low molecular weight polyphenylene ether suspension obtained by filtration, add 10 g of deionized water, vibrate and mix for 3 min to obtain a mixed solution, take 2 g of the mixed solution, and use a laser particle size analyzer to determine the particle size D50 corresponding to the cumulative particle size distribution percentage of the sample reaching 50%.

[0127] In this invention, the method for calculating / testing the yield of functionalized low molecular weight polyphenylene ether products is as follows: Yield (%) = [mass of functionalized low molecular weight polyphenylene ether products / mass of functionalized low molecular weight polyphenylene ether theoretically generated from the complete reaction of polyphenylene ether raw materials] × 100%.

[0128] In this invention, the test method for the free chlorine content of functionalized low molecular weight polyphenylene ether products is as follows: accurately weigh 3.00g of functionalized low molecular weight polyphenylene ether products, add 40g of butanone, 5g of deionized water and 0.5g of glacial acetic acid to dissolve, and determine the chloride ion content using an automatic potentiometric titrator.

[0129] In this invention, the method for testing the modifier content of functionalized low molecular weight polyphenylene ether products is as follows: gas chromatography is used to determine the content of functionalized low molecular weight polyphenylene ether products.

[0130] Example 1

[0131] This embodiment uses the process of the present invention to prepare functionalized low molecular weight polyphenylene ether, and the specific steps are as follows:

[0132] (1) 120g of solid polyphenylene ether (wherein, the number average molecular weight of polyphenylene ether is 1200, the polyphenylene ether is the polyphenylene ether shown in Formula I of this paper, where R1, R3, R6, and R8 are methyl groups, R2, R4, R5, and R7 are hydrogen atoms, and A is -C(CH3)2-), 30.5g of triethylamine, and 240g of toluene were added to a reaction vessel equipped with a temperature control and stirring device. The mixture was stirred at 0℃ and 200rpm for 2h to fully dissolve the solid polyphenylene ether. Then, 31.5g of methacryloyl chloride was added dropwise at 0℃ over 0.5h. After the reaction solution was heated to 25℃, the reaction was continued for 1.5h. 3g of ultrapure water was added for quenching. After the reaction was completed for 5min, insoluble impurities were removed through a filter to obtain a functionalized low molecular weight polyphenylene ether solution.

[0133] (2) Add 100g of functionalized low molecular weight polyphenylene ether solution to the reactor, then add 200g of a mixed solution of methanol and water at 40℃ (methanol and water mass ratio of 1:1), and use a homogenizer to homogenize and disperse for 10min to obtain functionalized low molecular weight polyphenylene ether suspension. Then filter the filtrate using a Buchner funnel to obtain powder (particle size D50 of 80μm).

[0134] (3) Transfer the powder back to the reaction vessel with temperature control and stirring function, add 200g of a mixed solution of methanol and water at 25℃ (methanol and water mass ratio of 1:1) and 1g of 1,3-diethylurea, stir at 25℃ and 200rpm for 0.5 hours, then filter the filtrate using a Buchner funnel to obtain filter cake.

[0135] (4) Wash the filter cake with 100g of methanol at 50℃, transfer the filter cake to a vacuum drying oven, and dry it at 100℃ for 4h to obtain a functionalized low molecular weight polyphenylene ether product with a yield of 92% and a free chlorine content of 30ppm.

[0136] Example 2

[0137] This embodiment uses the process of the present invention to prepare functionalized low molecular weight polyphenylene ether, and the specific steps are as follows:

[0138] (1) Add 200g of solid polyphenylene ether (wherein, the number average molecular weight of polyphenylene ether is 2000, and the polyphenylene ether is the polyphenylene ether shown in Formula I of this paper, where R1, R3, R4, R5, R6, and R8 in Formula I are methyl groups, R2 and R7 are hydrogen atoms, and A is a covalent bond), 20g of sodium hydroxide, and 250g of N,N-dimethylformamide to a reaction vessel equipped with a temperature control and stirring device. Stir at 70℃ and 300rpm for 4h to fully dissolve the solid polyphenylene ether. Then, cool the reaction solution to 55℃ and add 36.5g of 4-chloromethylstyrene dropwise over 0.5h. Continue to react the reaction solution at this temperature for 5h to obtain a functionalized low molecular weight polyphenylene ether solution.

[0139] (2) Add 100g of functionalized low molecular weight polyphenylene ether solution and 100g of water at 60℃ to the reactor. Use an ultrasonic homogenizer to homogenize and disperse for 8 minutes to obtain functionalized low molecular weight polyphenylene ether suspension. Then filter using a Buchner funnel to obtain powder (particle size D50 is 120μm).

[0140] (3) Transfer the powder back to the reaction vessel with temperature control and stirring function, add 200g of a mixed solution of methanol and water at 40℃ (methanol and water mass ratio of 1:3) and 2g of diethanolamine, stir at 40℃ and 200rpm for 0.5 hours, then filter the filtrate using a Buchner funnel to obtain filter cake.

[0141] (4) Wash the filter cake with 100g of methanol at 40℃, transfer the filter cake to a vacuum drying oven, and dry it at 100℃ for 4h to obtain a functionalized low molecular weight polyphenylene ether product with a yield of 91%, a free chlorine content of 50ppm, and a 4-chloromethylstyrene content of 30ppm.

[0142] Example 3

[0143] This embodiment uses the process of the present invention to prepare functionalized low molecular weight polyphenylene ether, and the specific steps are as follows:

[0144] (1) Add 120g of solid polyphenylene ether (wherein, the number average molecular weight of polyphenylene ether is 1200, the polyphenylene ether is the polyphenylene ether shown in Formula I of this paper, where R1, R3, R6, and R8 are methyl groups, R2, R4, R5, and R7 are hydrogen atoms, and A is -C(CH3)2-), 16.2g of sodium methoxide, and 180g of N,N-dimethylacetamide to a reaction vessel equipped with a temperature control and stirring device. Stir at 70℃ and 300rpm for 2h to fully dissolve the solid polyphenylene ether. Then, cool the reaction solution to 60℃ and add 36.5g of 4-chloromethylstyrene dropwise over 0.5h. Continue to react the reaction solution at this temperature for 10h to obtain a functionalized low molecular weight polyphenylene ether solution.

[0145] Steps (2)-(4) are basically the same as in Example 2, except that the detergent additives added are 2g N,N-diethylthiourea and 2g 1,3-diethylurea. The yield of the functionalized low molecular weight polyphenylene ether product is 92%, the free chlorine content is 15ppm, and the 4-chloromethylstyrene content is 40ppm.

[0146] Example 4

[0147] This embodiment uses the process of the present invention to prepare functionalized low molecular weight polyphenylene ether, and the specific steps are as follows:

[0148] (1) Add 120g of solid polyphenylene ether (wherein, the number average molecular weight of polyphenylene ether is 1200, the polyphenylene ether is the polyphenylene ether shown in Formula I of this paper, where R1, R3, R6, and R8 are methyl groups, R2, R4, R5, and R7 are hydrogen atoms, and A is -C(CH3)2-), 16.2g of sodium methoxide, and 180g of N,N-dimethylacetamide to a reaction vessel equipped with a temperature control and stirring device. Stir at 70℃ and 300rpm for 2h to fully dissolve the solid polyphenylene ether. Then, cool the reaction solution to 60℃ and add 36.5g of 4-chloromethylstyrene dropwise over 0.5h. Continue to react the reaction solution at this temperature for 10h to obtain a functionalized low molecular weight polyphenylene ether solution.

[0149] (2) Add 100g of functionalized low molecular weight polyphenylene ether solution and 200g of water at 60℃ to the reactor. Use a homogenizer to homogenize and disperse for 10min to obtain functionalized low molecular weight polyphenylene ether suspension. Then filter using a Buchner funnel to obtain powder (particle size D50 is 120μm).

[0150] (3) Transfer the powder back to the reaction vessel with temperature control and stirring function, add 200g of a mixed solution of methanol and water at 40℃ (methanol and water mass ratio of 1:3), 0.7g of N,N-diethylthiourea and 0.3g of diethanolamine, stir at 40℃ and 200rpm for 0.5 hours, then filter the filtrate using a Buchner funnel to obtain filter cake;

[0151] (4) Wash the filter cake with 100g of methanol at 50℃, transfer the filter cake to a vacuum drying oven, and dry it at 100℃ for 4h to obtain a functionalized low molecular weight polyphenylene ether product with a yield of 92%, a free chlorine content of 20ppm, and a 4-chloromethylstyrene content of 20ppm.

[0152] Example 5

[0153] This embodiment uses the process of the present invention to prepare functionalized low molecular weight polyphenylene ether, and the specific steps are as follows:

[0154] (1) Same as step (1) in Example 4;

[0155] (2) Add 100g of functionalized low molecular weight polyphenylene ether solution and 200g of water at 60°C to the reactor. Then filter the solution using a Buchner funnel and transfer the filter cake to a vacuum drying oven. Dry the cake at 100°C for 4 hours to obtain functionalized blocky functionalized low molecular weight polyphenylene ether solid. Then process the powder using a grinder (material refining device) for 60 minutes to obtain functionalized low molecular weight polyphenylene ether powder (particle size D50 is 180μm).

[0156] (3) Same as step (3) in Example 4;

[0157] (4) Following the same steps as in Example 4, the functionalized low molecular weight polyphenylene ether product was finally obtained, with a yield of 92%, a free chlorine content of 45 ppm, and a 4-chloromethylstyrene content of 40 ppm.

[0158] Comparative Example 1

[0159] This comparative example uses an extraction and washing post-treatment process to prepare functionalized low molecular weight polyphenylene ethers. The specific steps are as follows:

[0160] (1) Add 120g of solid polyphenylene ether (wherein, the number average molecular weight of polyphenylene ether is 1200, the polyphenylene ether is the polyphenylene ether shown in Formula I of this paper, where R1, R3, R6, and R8 are methyl groups, R2, R4, R5, and R7 are hydrogen atoms, and A is -C(CH3)2-), 30.5g of triethylamine, and 240g of toluene to a reaction vessel equipped with a temperature control and stirring device. Stir at 0℃ and 200rpm for 2h to fully dissolve the solid polyphenylene ether. Then, add 31.5g of methacryloyl chloride dropwise over 0.5h at 0℃. After the reaction solution is heated to 25℃, continue the reaction for 1.5h. Add 3g of ultrapure water for quenching. After the reaction is completed for 5min, remove insoluble impurities through a filter to obtain a functionalized low molecular weight polyphenylene ether solution.

[0161] (2) Take 100g of functionalized low molecular weight polyphenylene ether solution and add it to a separatory funnel, and add 100g of toluene for dilution; then add 50g of ultrapure water for extraction. During the process, severe emulsification requires long-term (more than 10 hours) standing and separation; repeat the above extraction operation 3 times. The obtained organic layer is removed from the solvent at 70℃ and 50mmHg vacuum to obtain functionalized polyphenylene ether intermediate liquid with a solid content of 70wt%; use 200g of water for precipitation, and then filter it with a Buchner funnel to obtain a filter cake. Transfer the filter cake to a vacuum drying oven and dry it at 100℃ for 4h to obtain functionalized low molecular weight polyphenylene ether product with a yield of 75% and a free chlorine content of 270ppm.

[0162] Comparative Example 2

[0163] The specific steps for preparing functionalized low molecular weight polyphenylene ether in this comparative example are shown below:

[0164] (1) Same as step (1) in Example 2;

[0165] (2) Add 100g of functionalized low molecular weight polyphenylene ether solution and 100g of water at 60℃ to the reaction vessel. After the functionalized low molecular weight polyphenylene ether precipitates, filter it using a Buchner funnel to obtain the first filter cake.

[0166] (3) Transfer the first filter cake to a reaction vessel with temperature control and stirring function, add 200g of a mixed solution of methanol and water at 40℃ (methanol and water mass ratio of 1:3), stir at 40℃ and 200rpm for 0.5 hours, then filter the filtrate using a Buchner funnel to obtain the second filter cake.

[0167] (4) Wash the second filter cake with 100g of methanol at 40℃, transfer the second filter cake to a vacuum drying oven, and dry it at 100℃ for 4h to obtain a functionalized low molecular weight polyphenylene ether product with a yield of 92%, a free chlorine content of 500ppm, and a 4-chloromethylstyrene content of 340ppm.

[0168] Comparative Example 3

[0169] The specific steps for preparing functionalized low molecular weight polyphenylene ether in this comparative example are shown below:

[0170] (1) Same as step (1) in Example 2;

[0171] (2) Add 100g of functionalized low molecular weight polyphenylene ether solution and 100g of water at 60℃ to the reaction vessel. After the functionalized low molecular weight polyphenylene ether precipitates, filter it using a Buchner funnel to obtain the first filter cake.

[0172] (3) Transfer the first filter cake back to the reaction vessel with temperature control and stirring function, add 200g of a mixed solution of methanol and water at 40℃ (methanol and water mass ratio of 1:3) and 2g of diethanolamine, stir at 40℃ and 200rpm for 0.5 hours, then filter the filtrate using a Buchner funnel to obtain the second filter cake.

[0173] (4) Wash the second filter cake with 100g of methanol at 40℃, transfer the second filter cake to a vacuum drying oven, and dry it at 100℃ for 4h to obtain a functionalized low molecular weight polyphenylene ether product with a yield of 93%, a free chlorine content of 320ppm, and a 4-chloromethylstyrene content of 300ppm.

[0174] Comparative Example 4

[0175] (1) Same as step (1) in Example 2;

[0176] (2) Same as step (2) in Example 2;

[0177] (3) Transfer the powder back to the reaction vessel with temperature control and stirring function, add 200g of a mixed solution of methanol and water at 40℃ (methanol and water mass ratio of 1:3), stir at 40℃ and 200rpm for 0.5 hours, then filter the filtrate using a Buchner funnel to obtain filter cake.

[0178] (4) Wash the filter cake with 100g of methanol at 40℃, transfer the filter cake to a vacuum drying oven, and dry it at 100℃ for 4h to obtain a functionalized low molecular weight polyphenylene ether product with a yield of 91%, a free chlorine content of 200ppm, and a 4-chloromethylstyrene content of 260ppm.

[0179] As can be seen from the content of free chlorine and 4-chloromethylstyrene in the functionalized low molecular weight polyphenylene ether products obtained in Examples 2 and Comparative Examples 2-4, the homogeneous dispersion process and detergent additive process of the present invention are beneficial to reducing the content of free chlorine and small organic molecules in the functionalized polyphenylene ether products.

[0180] Furthermore, the 4-chloromethylstyrene content in the functionalized low molecular weight polyphenylene ether products obtained in Example 2 and Comparative Examples 2-4 was compared: Comparative Example 3 (without homogenization but with added detergent additives) removed 40 ppm more 4-chloromethylstyrene than Comparative Example 2 (without homogenization or detergent additives); Comparative Example 4 (with homogenization but without added detergent additives) removed 80 ppm more 4-chloromethylstyrene than Comparative Example 2 (without homogenization or detergent additives); Example 2 (with homogenization and detergent additives) removed 310 ppm more 4-chloromethylstyrene than Comparative Example 2 (without homogenization or detergent additives). The removal amounts of 4-chloromethylstyrene indicate that there is a synergistic effect between the homogenization process and the detergent additive addition process of this invention, both synergistically enhancing the removal effect of small organic molecules.

Claims

1. A method of making a functionalized polyphenylene ether, characterized by, The method includes the following steps: (1) Mix polyphenylene ether, solvent and alkaline catalyst, and then add modifier dropwise to react and obtain functionalized polyphenylene ether solution; (2) The functionalized polyphenylene ether solution and the first precipitant are mixed and homogenized to obtain a functionalized polyphenylene ether suspension, which is then filtered to obtain functionalized polyphenylene ether powder; or The functionalized polyphenylene ether solution and the first precipitant are mixed and filtered to obtain functionalized polyphenylene ether particles. These particles are then processed into functionalized polyphenylene ether powder using a material refining device; or... The functionalized polyphenylene ether solution and the first precipitant are mixed and then spray-dried or freeze-dried to obtain functionalized polyphenylene ether powder. (3) The functionalized polyphenylene ether powder, the second precipitant and the washing aid are mixed and then washed and filtered in sequence to obtain filter cake; (4) The filter cake and the third precipitant are mixed and then washed, filtered and dried in sequence to obtain the functionalized polyphenylene ether product.

2. The method of claim 1, wherein, The method has one or more of the following characteristics: The end groups of the functionalized polyphenylene ether contain carbon-carbon double bonds; The structure of the polyphenylene ether is shown in Formula I: In Formula I, R1-R8 are each independently selected from hydrogen atoms and C1-C5 alkyl groups, A is a covalent bond or a C1-C10 alkylene group, m and n are each independent integers from 0 to 30, and at least one of m and n is not 0; The number-average molecular weight of the polyphenylene ether is 1000-3000 g / mol; The solvent is selected from one or more of toluene, dichloromethane, chloroform, tetrahydrofuran, acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, acetone, and 1,3-dimethyl-2-imidazolinone; The alkaline catalyst is an inorganic base and / or an organic base; the inorganic base is preferably selected from one or more of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, and potassium carbonate; the organic base is preferably selected from one or more of triethylamine, diisopropylamine, N-methylmorpholine, 4-dimethylaminopyridine, 2,6-dimethylpyridine, sodium methoxide, sodium ethoxide, potassium ethoxide, and potassium tert-butoxide. The modifier is an acyl halide compound represented by Formula II and / or a benzyl halide compound represented by Formula III: In Formula II, R9 is a covalent bond, a C1-C10 alkylene or phenylene; R10-R12 are each independently selected from hydrogen atoms and C1-C5 alkyl groups, and X is a chlorine atom or a bromine atom; in Formula III, Y is a chlorine atom or a bromine atom, and the vinyl group on the benzene ring is located at the ortho, meta, or para position of the chloromethyl or bromomethyl group; preferably, the acyl halide is selected from one or more of methacryloyl chloride, acryloyl chloride, and butenoyl chloride, and the benzyl halide is selected from one or more of 4-chloromethylstyrene, 3-chloromethylstyrene, and 1-(bromomethyl)-4-vinylbenzene; The mass ratio of the polyphenylene ether to the solvent is 1:(0.2-20); The molar ratio of the polyphenylene ether to the alkaline catalyst is 1:(2-4); The mixing time for the polyphenylene ether, the solvent, and the alkaline catalyst is 0.5-4 hours. The mixing temperature of the polyphenylene ether, the solvent, and the alkaline catalyst is 0-100℃; The molar ratio of the polyphenylene ether to the modifier is 1:(2-4); The modifier is added over a period of 0.5-1 hour. The reaction temperature is 0-100℃; The reaction time is 2-10 hours.

3. The method of claim 2, wherein, The modifier is an acyl halide compound represented by Formula II, and the method has one or more of the following characteristics: The solvent is selected from one or more of toluene, dichloromethane, chloroform, and tetrahydrofuran; The organic base is selected from one or more of triethylamine, diisopropylamine, N-methylmorpholine, 4-dimethylaminopyridine, and 2,6-dimethylpyridine; The mixing time for the polyphenylene ether, the solvent, and the alkaline catalyst is 0.5-4 hours. The mixing temperature of the polyphenylene ether, the solvent, and the alkaline catalyst is 0-5°C. After adding the modifier, the temperature is raised to the reaction temperature in 1-2 hours, and the reaction temperature is 0-30℃. The reaction time is 2-4 hours; Step (1) also includes quenching residual raw materials with a quenching agent after the reaction is completed, filtering, and obtaining a functionalized polyphenylene ether solution.

4. The method as described in claim 3, characterized in that, The method has one or more of the following characteristics: The quenching agent is water and / or methanol; The molar ratio of the quencher to the acyl halide compound is 1:(1-2); The quenching time is 3-10 minutes.

5. The method as described in claim 2, characterized in that, The modifier is a benzyl halide compound represented by Formula III, and the method has one or more of the following characteristics: The solvent is selected from one or more of toluene, acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, acetone and 1,3-dimethyl-2-imidazolinone; The organic base is selected from one or more of sodium methoxide, sodium ethoxide, potassium ethoxide, and potassium tert-butoxide; The mixing time for the polyphenylene ether, the solvent, and the alkaline catalyst is 1-4 hours. The mixing temperature of the polyphenylene ether, the solvent and the alkaline catalyst is 30-100℃; The reaction temperature is 30-100℃; The reaction time is 4-10 hours.

6. The method as described in claim 1, characterized in that, The method has one or more of the following characteristics: The first precipitant is water and / or methanol; preferably, the first precipitant is water or a mixture of water and methanol in a mass ratio of (1-10):

1. The mass ratio of the functionalized polyphenylene ether solution to the first precipitant is 1:(1-10); The temperature of the first precipitant is 20-60℃; The homogenization and dispersion treatment time is 3-60 min; The homogenization and dispersion process is performed using a homogenizer, an ultrasonic extractor, an ultrasonic homogenizer, or an ultrasonic emulsifier. The particle size D50 of the functionalized polyphenylene ether powder is 10-200 μm.

7. The method as described in claim 1, characterized in that, The method has one or more of the following characteristics: The second precipitant is water and / or methanol; preferably, the second precipitant is a mixture of water and methanol in a mass ratio of (1-10):

1. The mass ratio of the functionalized polyphenylene ether solution obtained in step (1) to the second precipitant added in step (3) is 1:(1-10); The temperature of the second precipitant is 20-60℃; The detergent additive is a small organic molecule containing OH or NH bonds; the detergent additive is preferably selected from one or more of thiourea, N,N-diethylthiourea, 1,3-diethylurea, benzoylurea, diethanolamine and isopropanolamine; The mass ratio of the functionalized polyphenylene ether solution to the detergent additive is 1:(0.001-0.03); The washing temperature in step (3) is 20-60℃; The washing speed in step (3) is 100-400 rpm; The washing process in step (3) takes 0.5-2 hours.

8. The method as described in claim 1, characterized in that, The method has one or more of the following characteristics: The third precipitant is water and / or methanol; preferably, the third precipitant is methanol or a mixture of water and methanol in a mass ratio of 1:(1-10); The mass ratio of the functionalized polyphenylene ether solution obtained in step (1) to the third precipitant added in step (4) is 1:(1-10); The temperature of the third precipitant is 20-60℃; The drying temperature is 90-120℃; The drying time is 2-8 hours; The drying process is carried out in a vacuum environment.

9. A functionalized polyphenylene ether, characterized in that, The chlorine content of the functionalized polyphenylene ether is ≤50ppm; Preferably, the end groups of the functionalized polyphenylene ether contain carbon-carbon double bonds; preferably, the functionalized polyphenylene ether is formed by reacting polyphenylene ether with a modifier, wherein the polyphenylene ether and the modifier are preferably as defined in claim 2; Preferably, the content of organic small molecules in the functionalized polyphenylene ether is ≤40ppm, and the organic small molecules are the modifiers described in claim 2.

10. The functionalized polyphenylene ether as described in claim 9, characterized in that, The functionalized polyphenylene ether is prepared by any one of claims 1-8.

Images