Polyphenyl ether resin as well as preparation method and application thereof

Abstract

The invention provides polyphenyl ether resin and a preparation method thereof, the polyphenyl ether resin comprises structures shown in a formula (I) and a formula (II) and is prepared through an oxidative polymerization method, the content of the structure shown in the formula (II) in a polymer chain structure is controlled to be 100-10000 ppm, and the heat resistance of the polyphenyl ether resin can be obviously improved; meanwhile, after blending modification with high impact polystyrene (PS), the mechanical property of the alloy resin can be improved. # imgabs0 #

Description

Technical Field

[0001] The invention relates to the technical field of polyphenylene ether resin manufacturing, and in particular to a high-temperature resistant polyphenylene ether resin, a preparation method thereof and application thereof. Background Art

[0002] Polyphenylene ether is an engineering plastic with a high symmetry of molecular chain and low polarity, so it has a low dielectric constant. At the same time, because the molecular chain contains a large number of rigid benzene rings, it has good heat resistance; there is no hydrolyzable group, so it has good hydrolysis resistance and can be immersed in water for a long time without obvious deformation. In addition, the resin itself has the advantages of self-flame retardancy and low density. However, due to the large number of rigid structures, the processing performance is poor. It is improved by blending and modification with other plastics to improve fluidity. It is mainly used in photovoltaic, automobile, water treatment, home appliances and other fields.

[0003] However, during the synthesis of polyphenylene ether resin, by-products in the reaction solution will participate in the polymerization reaction, causing the polymer chain structure and terminal hydroxyl content to change, further leading to changes in the heat resistance and mechanical properties of the resin.

[0004] Chinese patent CN102432864B describes a method for preparing polyphenylene ether resin by precipitation, in which a solvent is added to wash the polyphenylene ether wet material to reduce the content of diphenylquinone, but only the by-products on the surface are removed, and some by-products and small molecules wrapped in the wet material are not fully removed, and the heat resistance and mechanical properties are not mentioned.

[0005] Chinese patent CN117143330 A describes a method for preparing polyphenylene ether resin by a solution process, in which the generation of diphenylquinone is reduced by replacing residual oxygen with nitrogen during the aging process. However, in the actual production process, the solution viscosity is relatively high, the nitrogen replacement efficiency is relatively low, and the entire aging process is relatively long, which affects the production efficiency. From the results of the examples, the heat resistance and mechanical properties of the alloy are not significantly improved.

[0006] Therefore, how to further improve the heat resistance and mechanical properties of polyphenylene ether resin is of great significance. Summary of the invention

[0007] In order to solve the problems existing in the prior art, one of the purposes of the present invention is to provide a polyphenylene ether resin, which has good heat resistance and excellent mechanical properties.

[0008] The inventors have found that polyphenylene ether will inevitably produce a byproduct, diphenylquinone (3,3',5,5'-tetramethyl-4,4'-diphenylquinone), during the polymerization process. Under normal circumstances, this byproduct will participate in the reaction during the later aging process, and part of it will enter the polymer main chain in the form of formula (II). The presence of this structure will cause the content of terminal hydroxyl groups in the polymer to change, affecting the heat resistance. At the same time, when blended and modified with other plastics, the degree of crosslinking inside the alloy will change, affecting the mechanical properties of the product. Therefore, controlling the content of the structure of formula (II) in the polymer is conducive to improving the heat resistance of the polymer and the mechanical properties of the product.

[0009]

[0010] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solution:

[0011] A polyphenylene ether resin comprises structures of formula (I) and formula (II), wherein in the polymer chain, the mass content of the polyphenylene ether of the structure of formula (I) is more than 90%, preferably 98.0-99.99%, and the content of the structure of formula (II) is 100-10000 ppm, preferably 1000-5000 ppm.

[0012]

[0013] Among them, R 1 , R 2 , R 3 , R 4 R are independently selected from H, halogen, C1-C10 alkyl, C5-C6 cycloalkyl, C6-C10 aryl; 5 , R 5 '、R 6 , R 6 '、R 7 , R 7 '、R 8 , R 8 'are independently selected from H, halogen, C1-C10 alkyl, C5-C6 cycloalkyl, C6-C10 aryl;

[0014] The average repeating unit of the structure of formula (I) is 5≤n≤500, and the average repeating unit of the structure of formula (II) is 0≤m≤10.

[0015] In one embodiment of the present invention, the polyphenylene ether of formula (I) is:

[0016]

[0017] The compound of formula (II) is

[0018] The average repeating unit of the structure of formula (III) is 5≤n≤500, and the average repeating unit of the structure of formula (IV) is 0≤m≤10.

[0019] In one embodiment of the present invention, the glass transition temperature of the polyphenylene ether resin is 210-230°C; and the maximum thermal weight loss rate temperature in air atmosphere is 450-470°C.

[0020] The heat resistance and mechanical properties of the polyphenylene ether resin can be improved by controlling the content of the structure of formula (II). When the content of the structure of formula (II) is high, the content of terminal hydroxyl groups increases, which leads to a decrease in heat resistance. If the content of the structure of formula (II) is controlled at a lower level, there will be fewer crosslinking points during the extrusion process, which affects the mechanical properties of the alloy. Therefore, it is necessary to control the content of the structure of formula (II) within a certain range, so as to improve the heat resistance without affecting the mechanical properties of the alloy.

[0021] In one embodiment of the present invention, after the polyphenylene ether resin and high impact polystyrene (PS) are blended and modified in a mass ratio of 1:1, the tensile strength is 60-70 MPa, the tensile strain is 80-90%, the flexural strength is 95-110 MPa, the flexural modulus is 2300-2400 MPa; and the dielectric constant at 50 Hz is 2.7-2.8.

[0022] In one embodiment of the present invention, the intrinsic viscosity of the polyphenylene ether resin is 0.2 to 0.8 dL / g.

[0023] In order to obtain the polyphenylene ether resin described in the present invention, the degree of reaction between the by-product and the polymer can be controlled by adjusting the temperature of the polymerization reaction, the solid content of the solution during the reaction, the reaction time, etc., so that the structure of formula (II) in the polymer chain is within a certain proportion range, thereby improving the heat resistance and mechanical properties of the alloy.

[0024] The present invention also provides a method for preparing the polyphenylene ether resin, comprising the following steps:

[0025] S1: adding a phenolic compound, an organic amine compound, an acid solution, a metal oxide, and a good solvent of polyphenylene ether into a reaction kettle, introducing an oxidizing gas, and controlling the reaction temperature to perform an oxidative polymerization reaction;

[0026] S2: adding a ligand compound of a metal ion and an optional good solvent of polyphenylene ether to the reaction solution obtained in S1, stirring the mixture sufficiently, performing water-oil separation, and collecting the oil phase solution;

[0027] Polyphenylene ether is isolated.

[0028] Preferably, the separation method of the polyphenylene ether includes: static stratification, centrifugal stratification and filtration stratification.

[0029] S3: fully mixing the oil phase solution obtained in S2 with a poor solvent for polyphenylene ether, and obtaining a wet material of polyphenylene ether resin by filtering equipment;

[0030] S4: removing volatiles from the polyphenylene ether wet material obtained in S3 to obtain polyphenylene ether resin.

[0031] In one embodiment of the present invention, the phenolic compound in S1 has the following general formula,

[0032]

[0033] In one embodiment of the present invention, R 1 , R 2 , R 3 , R 4 They are independently selected from H, halogen, C1-C10 alkyl, C5-C6 cycloalkyl, C6-C10 aryl; preferably, the phenolic compound is selected from 2,6-dimethylphenol, 2,6-diethylphenol, 2,6-diphenylphenol, 2,3,6-trimethylphenol, 2,5-dimethylphenol; the above phenolic compounds can be used alone or in combination of two or more, and their mixing ratio can be selected arbitrarily.

[0034] In one embodiment of the present invention, the organic amine compound described in S1 includes one or more of a diamine compound, a monotertiary amine compound, and a monosecondary amine compound, wherein the diamine compound is selected from one or more compounds having the general structural formula of formula (VI);

[0035]

[0036] In one embodiment of the present invention, R 9 , R 10 , R 11 , R 13 R is independently selected from H, C1-C6 straight chain alkyl or branched chain alkyl, and cannot be all H at the same time; 13 A straight chain alkyl group or a branched chain alkyl group selected from C2 to C5.

[0037] In one embodiment of the present invention, the amount of the organic amine compound added is 0.1 to 10% of the molar amount of the phenolic compound.

[0038] In one embodiment of the present invention, the acid solution described in S1 includes one or more mixtures of hydrofluoric acid aqueous solution, hydrochloric acid aqueous solution, hydrobromic acid aqueous solution, hydroiodic acid aqueous solution, sulfuric acid aqueous solution, acetic acid aqueous solution, etc., and the amount of acid added is 0.1 to 5% of the molar amount of the phenolic compound added.

[0039] In one embodiment of the present invention, the metal oxide described in S1 includes one or more mixtures of transition metal oxides such as copper, manganese, cobalt, etc., specifically one or more mixtures of cuprous oxide, cupric oxide, manganese oxide, cobalt oxide, etc., and the added amount of the metal oxide is 0.01 to 1% of the molar addition amount of the phenolic compound.

[0040] In one embodiment of the present invention, the polyphenylene ether good solvent described in S1 includes one or more mixed solvents of chloroform, toluene, xylene, chlorobenzene, tetrahydrofuran, and mixtures of these solvents with methanol, ethanol, propanol, isopropanol, butanol, and acetone.

[0041] In one embodiment of the present invention, the oxygen content in the oxidizing gas described in S1 is 10-100 v / v%.

[0042] In one embodiment of the present invention, the reaction pressure in S1 is normal pressure, and the reaction temperature in S1 is 20 to 35°C, preferably 25 to 30°C.

[0043] In one embodiment of the present invention, the excess rate of oxygen in the oxidizing gas in S1 is 5-200%. The excess rate of oxygen refers to the ratio of the actual amount of oxygen introduced to the theoretical amount of oxygen required for the reaction.

[0044] In one embodiment of the present invention, the reaction is terminated in S2 by adding a ligand compound of a metal ion, wherein the ligand compound of the metal ion is a metal chelator, including one or more alkali metal chelators such as EDTA, EDTA-2Na, EDTA-3Na, EDTA-4Na, NTA (trisodium nitrilotriacetate), citric acid, etc., and the amount of the ligand compound of the metal ion added is 0.001 to 3% of the molar amount of the phenolic compound.

[0045] In one embodiment of the present invention, the addition ratio of the polyphenylene ether good solvent in S2 is 5-20% of the mass of the reaction solution in S1, preferably 15-18%.

[0046] In one embodiment of the present invention, the temperature of the mixed solution in S2 is 30-60°C, preferably 35-45°C.

[0047] In one embodiment of the present invention, the mixing time in S2 is 1 to 60 min, preferably 25 to 30 min°C.

[0048] In one embodiment of the present invention, the poor solvent for the polyphenylene ether described in S3 includes one or more mixed solvents of alcohol solvents such as methanol, ethanol, propanol, isopropanol, butanol or acetone.

[0049] Another object of the present invention is to provide a use of polyphenylene ether resin.

[0050] A use of a polyphenylene ether resin, wherein the resin is the resin of the present invention, or is a resin prepared by the preparation method of the present invention, and the resin is used for blending and modifying with other plastics, preferably with one or more of PS, PA, PP, ABS, PPS, and PC;

[0051] The polyphenylene ether resin of the present invention is preferably used for processing PPO injection molded products, and more preferably used for injection molding of photovoltaic junction box housings, automobile fenders, water pump impellers, battery PACKs and other fields.

[0052] Compared with the prior art, the technical solution of the present application has the following beneficial effects: by controlling the content of formula (II), the terminal hydroxyl content is within a certain proportion range, which is beneficial to reducing the proportion of oligomers and improving heat resistance; in addition, when blending modification is carried out, the necessary structure of formula (II) is beneficial to provide cross-linking points and improve the mechanical properties of the alloy resin. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 The NMR spectrum of the compound of formula (IV) obtained in the example. DETAILED DESCRIPTION

[0054] In order to better understand the technical solution of the present invention, the following examples will further illustrate the method provided by the present invention, but the present invention is not limited to the listed examples, and should also include any other known changes within the scope of the claims of the present invention.

[0055] The present invention is further explained below by more specific examples, but does not constitute any limitation.

[0056] The sources of raw materials used in the following examples and comparative examples are as follows:

[0057] 2,6-Dimethylphenol, Shanghai MacLean Biochemical Technology Co., Ltd., purity >99%;

[0058] 2,3,6-Trimethylphenol, Beijing Bailingwei Technology Co., Ltd., purity>99%;

[0059] N,N-diisopropylethylenediamine, Shanghai MacLean Biochemical Technology Co., Ltd., purity >98%;

[0060] Di(4-tert-butylphenyl)amine, Shanghai MacLean Biochemical Technology Co., Ltd., purity >98%;

[0061] N,N-dimethylbutylamine, Shanghai MacLean Biochemical Technology Co., Ltd., purity >98%;

[0062] Cuprous oxide, Shanghai MacLean Biochemical Technology Co., Ltd., purity >98%;

[0063] Toluene, Wanhua Chemical Group Co., Ltd., purity >99%;

[0064] Methanol, Shanghai Aladdin Biochemical Technology Co., Ltd., purity >99%;

[0065] 40% HBr, Shanghai Aladdin Biochemical Technology Co., Ltd.

[0066] EDTA·4Na, Shanghai Aladdin Biochemical Technology Co., Ltd., purity>98%.

[0067] The prepared polyphenylene ether resin was tested for relevant properties using the following methods:

[0068] The content of the structure of formula (II) was tested by hydrogen nuclear magnetic spectrum.

[0069] The intrinsic viscosity is tested by Ubbelohde viscometer, instrument manufacturer: Hangzhou Zhuoxiang Technology Co., Ltd., instrument model: AVM-4.

[0070] The glass transition temperature was measured by differential scanning calorimetry (DSC), and the maximum thermal decomposition temperature was measured by thermogravimetric analyzer (TGA).

[0071] The tensile strength, tensile strain, flexural strength and flexural modulus were tested by a universal testing machine, referring to ISO527-1 / 2 and ISO178 standards respectively.

[0072] The dielectric constant is tested by a dielectric constant meter, with reference to the ASTM D 150 standard.

[0073] The content of the structure of formula (II) can be tested by nuclear magnetic resonance C spectrum, instrument manufacturer: Bruker, model: AVANCENeo 600. Test conditions: The sample is dissolved in deuterated chloroform, and the molar ratio of tertiary carbon atoms is tested (see attached Figure 1 ).

[0074] Example 1

[0075] This embodiment provides a method for preparing a polyphenylene ether resin, comprising the following steps:

[0076] S1: 300 g (2.46 mol) of 2,6-dimethylphenol, 3.61 g (0.025 mol) of N,N-diisopropylethylenediamine, 3.518 g (0.0125 mol) of di(4-tert-butylphenyl)amine, 2.53 g (0.025 mol) of N,N-dimethylbutylamine, and 1185 g of toluene were added to a 3 L reactor in sequence, and then a mixture of 0.35 g (0.0025 mol) of cuprous oxide and 4.98 g (0.025 mol) of a 40% HBr aqueous solution was added, and after being fully stirred, oxygen was introduced to carry out polymerization reaction at a rate of 1.5 L / min for 50 min to obtain a reaction solution of polyphenylene ether;

[0077] S2: Add 152g of EDTA·4Na aqueous solution (concentration 2.5wt%) to the reaction solution in S1, stir thoroughly, then add 75g of toluene solution (5wt% relative to the mass of the reaction solution), maintain the temperature of the reaction solution at 40°C, continue stirring for 20min, stop stirring, let stand to separate and collect the oil phase, then add pure water for washing until the conductivity of the water phase is less than 300μs / cm;

[0078] S3: adding the washed oil phase solution in S2 to a methanol solution for precipitation, the mass ratio of the two being 1:2, and after being fully mixed, filtering the mixed solution using a filtering device to obtain a wet material of polyphenylene ether resin;

[0079] S4: The wet polyphenylene ether obtained in S3 is placed in a vacuum oven for drying to obtain a qualified polyphenylene ether resin product A1 (polyphenylene ether content of formula (III) is 99.8wt%), wherein the content of the structure of formula (IV) is 1580ppm, and the characteristic viscosity is 0.71dL / g.

[0080] Example 2

[0081] The polymerization experiment was carried out according to the method of Example 1. The difference from Example 1 is that the ratio of organic amines was adjusted, namely 2.888g (0.02mol) N,N-diisopropylethylenediamine, 4.362g (0.0155mol) di(4-tert-butylphenyl)amine, and 2.024g (0.02mol) N,N-dimethylbutylamine. At the same time, the amount of toluene added in step S2 was 150g (10% of the mass of the reaction solution), the reaction temperature was 45°C, and the reaction time was 30min, to obtain polyphenylene ether resin A2 (polyphenylene ether content of formula (III) 99.5wt%), the structure content of formula (IV) was 3580ppm, and the intrinsic viscosity was 0.58dL / g.

[0082] Example 3

[0083] The polymerization experiment was carried out according to the method of Example 1, except that the amount of cuprous oxide and 40% HBr aqueous solution was adjusted, and 0.42 g (0.003 mol) of cuprous oxide and 5.976 g (0.03 mol) of 40% HBr aqueous solution were added. Meanwhile, the amount of toluene added in step S2 was 225 g (15% of the mass of the reaction solution), the reaction temperature was 50° C., and the reaction time was 40 min, to obtain polyphenylene ether resin A3 (99.5 wt% of polyphenylene ether of formula (III)), the content of structure of formula (IV) was 4260 ppm, and the intrinsic viscosity was 0.45 dL / g.

[0084] Example 4

[0085] The polymerization experiment was carried out according to the method of Example 1, except that the oxygen introduction rate was adjusted to 2 L / min. At the same time, the amount of toluene added in step S2 was 300 g (20% of the mass of the reaction solution), the reaction temperature was 60° C., and the reaction time was 50 min, to obtain polyphenylene ether resin A4 (polyphenylene ether content of formula (III) 99.2 wt%), the structure content of formula (IV) was 6680 ppm, and the intrinsic viscosity was 0.31 dL / g.

[0086] Example 5

[0087] The polymerization experiment was carried out according to the method of Example 1, except that the amount of EDTA·4Na aqueous solution (concentration 2.5wt%) added was adjusted to 304g. At the same time, 2,6-dimethylphenol was replaced with 2,3,6-trimethylphenol to obtain polyphenylene ether resin A5, with a polyphenylene ether content of formula (III) of 99.5wt%, a structure content of formula (IV) of 4432ppm, and an intrinsic viscosity of 0.65dL / g.

[0088] Example 6

[0089] A polymerization experiment was carried out according to the method of Example 1. The difference from Example 1 is that di(4-tert-butylphenyl)amine is replaced by dibutylamine to obtain polyphenylene ether resin A6, with a polyphenylene ether content of formula (III) of 99.7wt%, a structure content of formula (IV) of 2221ppm, and a characteristic viscosity of 0.68dL / g.

[0090] Example 7

[0091] A polymerization experiment was carried out according to the method of Example 1. The difference from Example 1 is that di(4-tert-butylphenyl)amine is replaced by N,N-diethylbutylamine to obtain polyphenylene ether resin A7, with a polyphenylene ether content of formula (III) of 99.8wt%, a structure content of formula (IV) of 886ppm, and an intrinsic viscosity of 0.75dL / g.

[0092] Comparative Example 1

[0093] Compared with Example 1, the main difference is that toluene is not added in step S2. The rest is based on Example 1 to synthesize a polyphenylene ether resin, No. 1, with a polyphenylene ether content of formula (III) of 98.2wt%, a structure content of formula (IV) of 15320ppm, and an intrinsic viscosity of 0.70dL / g.

[0094] Comparative Example 2

[0095] Compared with Example 1, the main difference is that in step S2, the temperature is controlled at 70°C and the reaction time is maintained at 120 min. The rest is referenced to Example 1 to synthesize a polyphenylene ether resin, No. 2, with a polyphenylene ether content of formula (III) of 98.0wt%, a structure content of formula (IV) of 18520ppm, and an intrinsic viscosity of 0.19dL / g.

[0096] Comparative Example 3

[0097] Compared with Example 1, the main difference is that the number of washing times in step S2 is increased so that the conductivity of the water phase is less than 50 μs / cm. At the same time, the wet material obtained in step S3 is washed with methanol at least 3 times. The rest is based on Example 1 to synthesize a polyphenylene ether resin, numbered 3, with a polyphenylene ether content of formula (III) of 99.9wt%, a structure content of formula (IV) of 89ppm, and an intrinsic viscosity of 0.85dL / g.

[0098] The relevant test results are shown in Table 1 below.

[0099] Table 1 Resin performance test results and alloy performance test results

[0100]

[0101]

[0102] It can be seen from the table that by controlling step S2 so that the content of the structure of formula (II) is within the preferred range, the performance of the polyphenylene ether resin and its alloys can be significantly improved.

[0103] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as limiting the present invention. Those skilled in the art will appreciate that, under the guidance of this specification, some modifications or adjustments may be made to the present invention. These modifications or adjustments should also be within the scope defined by the claims of the present invention.

Claims

1. A polyphenylene ether resin, characterized in that The polyphenylene ether of formula (I) and formula (II) is included, wherein the mass content of the polyphenylene ether of formula (I) is 90% or more, preferably 98.0 to 99.99%, and the content of the polyphenylene ether of formula (II) is 100 to 10000 ppm, preferably 1000 to 5000 ppm. Wherein, R1, R2, R3, and R4 are independently selected from H, halogen, C1-C10 alkyl, C5-C6 cycloalkyl, and C6-C10 aryl; R5, R5', R6, R6', R7, R7', R8, and R8' are independently selected from H, halogen, C1-C10 alkyl, C5-C6 cycloalkyl, and C6-C10 aryl; The average repeating unit of the structure of formula (I) is 5≤n≤500, and the average repeating unit of the structure of formula (II) is 0≤m≤10.

2. The polyphenylene ether resin according to claim 1, characterized in that The structure of the polyphenylene ether of formula (I) is: The structure of the compound of formula (II) is: The average repeating unit of the structure of formula (III) is 5≤n≤500, and the average repeating unit of the structure of formula (IV) is 0≤m≤10.

3. The polyphenylene ether resin according to claim 1 or 2, characterized in that The glass transition temperature of the polyphenylene ether resin is 210-230° C.; the maximum thermal weight loss rate temperature in air atmosphere is 450-470° C.

4. A method for preparing the polyphenylene ether resin according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1: adding a phenolic compound, an organic amine compound, an acid solution, a metal oxide, and a good solvent of polyphenylene ether into a reaction kettle, introducing an oxidizing gas, and controlling the reaction temperature to perform an oxidative polymerization reaction; S2: adding a ligand compound of a metal ion and an optional good solvent of polyphenylene ether to the reaction solution obtained in S1, stirring the mixture sufficiently, performing water-oil separation, and collecting the oil phase solution; Polyphenylene ether is isolated.

5. The preparation method according to claim 4, characterized in that: Also includes S3: fully mixing the oil phase solution obtained in S2 with a poor solvent for polyphenylene ether, and obtaining a wet material of polyphenylene ether resin by filtering equipment; S4: removing volatiles from the polyphenylene ether wet material obtained in S3 to obtain polyphenylene ether resin.

6. The preparation method according to claim 4, characterized in that: The phenolic compound in S1 has the following general formula, R1, R2, R3, and R4 are independently selected from H, halogen, C1-C10 alkyl, C5-C6 cycloalkyl, and C6-C10 aryl; preferably, the phenolic compound is selected from 2,6-dimethylphenol, 2,6-diethylphenol, 2,6-diphenylphenol, 2,3,6-trimethylphenol, and 2,5-dimethylphenol.

7. The preparation method according to any one of claims 4 to 6, characterized in that: The organic amine compound described in S1 includes one or more of diamine compounds, monotertiary amine compounds, and monosecondary amine compounds, wherein the diamine compound is selected from one or more compounds having the general structural formula of formula (VI); Among them, R9, R 10 , R 11 , R 13 R is independently selected from H, C1-C6 straight chain alkyl or branched chain alkyl, and cannot be all H at the same time; 13 A straight chain alkyl or branched chain alkyl selected from C2 to C5; Preferably, the amount of the organic amine compound added is 0.1 to 10% of the molar amount of the phenolic compound; Preferably, the acid solution described in S1 comprises a mixture of one or more of a hydrofluoric acid aqueous solution, a hydrochloric acid aqueous solution, a hydrobromic acid aqueous solution, a hydroiodic acid aqueous solution, a sulfuric acid aqueous solution, and an acetic acid aqueous solution; Preferably, the amount of acid added is 0.1 to 5% of the molar amount of phenolic compound added; Preferably, the metal oxide described in S1 comprises one or more mixtures of copper, manganese and cobalt metal oxides, preferably one or more mixtures of cuprous oxide, cupric oxide, manganese oxide and cobalt oxide; Preferably, the amount of the metal oxide added is 0.01 to 1% of the molar amount of the phenolic compound added; Preferably, the polyphenylene ether good solvent described in S1 includes one or more mixed solvents of chloroform, toluene, xylene, chlorobenzene, tetrahydrofuran, and mixtures of these solvents and methanol, ethanol, propanol, isopropanol, butanol, and acetone; Preferably, the oxygen content in the oxidizing gas described in S1 is 10-100 v / v%; Preferably, the reaction pressure in S1 is normal pressure, and the reaction temperature in S1 is 20 to 35° C., preferably 25 to 30° C.; Preferably, the excess rate of oxygen in the oxidizing gas in S1 is 5 to 200%.

8. The preparation method according to any one of claims 4 to 7, characterized in that: In S2, the reaction is terminated by adding a ligand compound of a metal ion, wherein the ligand compound of the metal ion is a metal chelating agent, including one or more of EDTA, EDTA-2Na, EDTA-3Na, EDTA-4Na, trisodium nitrilotriacetate, and citric acid, and the amount of the ligand compound of the metal ion added is 0.001 to 3% of the molar amount of the phenolic compound; Preferably, the addition ratio of the polyphenylene ether good solvent in S2 is 5-20% of the mass of the reaction solution in S1, preferably 15-18%; Preferably, the temperature of the mixed solution in S2 is 30 to 60°C, preferably 35 to 45°C; Preferably, the mixing time described in S2 is 1 to 60 min, preferably 25 to 30 min°C; Preferably, the poor solvent for polyphenylene ether described in S3 includes one or more mixed solvents of methanol, ethanol, propanol, isopropanol, butanol or acetone.

9. Use of the polyphenylene ether resin according to any one of claims 1 to 3 or the polyphenylene ether resin prepared by the preparation method according to any one of claims 4 to 8 for blending and modification with other plastics, preferably with one or more of PS, PA, PP, ABS, PPS, and PC; Preferably, the resin is used for injection molding of photovoltaic junction box housings, automobile fenders, water pump impellers, and battery PACKs.

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