A polyphenylene ether and a method for producing the same
By controlling the structure and molecular weight distribution of phenolic hydroxyl groups, polyphenylene ether with high phenolic hydroxyl content was prepared, solving the problems of heat resistance and compatibility of polyphenylene ether and achieving good blending performance with other polymers.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- DALIAN ZHONGMU CHEM CO LTD
- Filing Date
- 2023-09-22
- Publication Date
- 2026-07-21
AI Technical Summary
In existing polyphenylene ethers, the phenolic hydroxyl groups are concentrated in the low molecular weight fraction, which leads to decreased heat resistance and prevents the ethers from achieving the advantage of improved compatibility. Furthermore, the molecular weight distribution is uneven.
Polyphenylene ether was prepared by using substituted hydroquinone and substituted phenol as reactants, and a catalyst of copper salt and zinc salt mixed in a certain proportion to form chelates with tertiary amines, through oxidative coupling polymerization. The structure and molecular weight distribution of phenolic hydroxyl groups were controlled.
A polyphenylene ether with high phenolic hydroxyl content was prepared, exhibiting a narrow molecular weight distribution, good compatibility and heat resistance, and excellent mechanical properties.
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Abstract
Description
Technical Field
[0001] This invention relates to a polyphenylene ether with high phenolic hydroxyl content and its manufacturing method. Background Technology
[0002] Polyphenylene oxide (MPPO) is a general-purpose engineering plastic. It possesses excellent comprehensive properties, most notably its excellent dimensional stability and outstanding electrical insulation under long-term load, and it has a wide operating temperature range. It is self-extinguishing. It exhibits excellent water and steam resistance, and finished products have high tensile and impact strength, as well as good creep resistance. Furthermore, it has good abrasion resistance and electrical properties. It is often blended with other polymers to produce MPPO (modified polyphenylene oxide), such as polystyrene, polyamide, polyester, and polyolefins.
[0003] Polyphenylene ether is usually obtained by reacting xylenol with oxygen in an organic solvent in an oxidative coupling reaction using metal salts and amines as catalysts, as shown in CN108017791B.
[0004] Phenolic compounds form biphenylquinone as a byproduct during oxidation. During oxidative polymerization or equilibrium, biphenylquinone reacts with polyphenylene ether (PPE), coupling the biphenyl structure into the PPE molecule. This leads to chain breakage and the formation of low-molecular-weight polymers, broadening the molecular weight distribution and causing problems such as easy oxidation and decreased physical properties of PPE. US4140675 utilizes a rearrangement reaction between biphenylquinone and PPE to obtain PPE containing a biphenyl structure. However, the proportion of phenolic hydroxyl groups in this structure is uncertain, and the high nitrogen content is unfavorable for extrusion processing. The structure and molecular weight of the product obtained from the above rearrangement reaction are uncontrollable.
[0005] A molecular structure with a higher content of phenolic hydroxyl groups in polyphenylene ether can improve the compatibility of polyphenylene ether with other polymers, and also facilitate the chemical modification of the end groups of polyphenylene ether by utilizing the reactivity of phenolic hydroxyl groups. Summary of the Invention
[0006] The problem that the invention aims to solve As mentioned above, the phenolic hydroxyl groups in polyphenylene ethers obtained using the technologies disclosed to date are concentrated in the low molecular weight polyphenylene ether portion, leading to decreased heat resistance and failing to leverage the advantages of phenolic hydroxyl groups in improving compatibility. Currently, no polyphenylene ethers with both high molecular weight and high phenolic hydroxyl content have been found in publicly available data.
[0007] Therefore, the purpose of this invention is to provide a polyphenylene ether with a high phenolic hydroxyl content and an extremely narrow molecular weight distribution, and good compatibility with other polymers.
[0008] Methods for solving problems The inventors conducted in-depth research on the above problems and found that during the polymerization of polyphenylene ether, substituted hydroquinone and substituted phenol are used as reactants, and copper salt and zinc salt are mixed in a certain proportion and chelated with one or more tertiary amines to form a catalyst. Polyphenylene ether is obtained through oxidative coupling polymerization.
[0009] The present invention is as follows: [1] A polyphenylene ether, characterized in that it contains polyphenylene ethers with structures as shown in I, II and III, wherein the proportion of X-terminated groups is greater than 45%, the proportion of Y-terminated groups is less than 5%, and the content of Z-structure is less than 0.3% by total mass: (I) (II) (III) Where R1, R2, and R3 are H and C, respectively. 1-8 Alkyl groups, haloalkyl groups, but R1 and R3 are not both hydrogen; X is... ; Y is ; Z is ; Where R1, R2, R3, R4, R5, R6, and R7 are H and C, respectively. 1-8 Alkyl groups, haloalkyl groups, but R1 and R3 are not both hydrogen, R 4-7 They are not both hydrogen; m and n are natural numbers, m = 10 - 500, n = 10 - 500; p and q are natural numbers, p = 0 - 499, q = 0 - 499, p + q = 10 - 500.
[0010] [2] The polyphenylene ether is characterized in that the total nitrogen content is less than 60 ppm as determined by a nitrogen analyzer.
[0011] [3] The polyphenylene ether is characterized in that its molecular weight distribution is 1.2-1.6 as determined by sol-gel chromatography.
[0012] [4] The polyphenylene ether is characterized in that the preparation method includes: Polymerization process: Monomers containing substituted hydroquinone and substituted phenol are dissolved in a good solvent of polyphenylene ether, mixed with a chelate solution containing copper salt and zinc salt and amine, and oxygen-containing gas is introduced into the reactor to carry out an oxidative coupling polymerization reaction. After the target degree of polymerization is reached, the oxygen is stopped. Curing process: Add aminocarboxylic acid compound to the mixture and heat it under nitrogen protection at a temperature of 45-79℃. Precipitation process: After aging, the liquid-liquid separation is performed to remove the water layer, and the oil phase containing polyphenylene ether is precipitated using a poor solvent of polyphenylene ether. Filtration process: Filtrating liquid-solid mixtures; Drying process: The wet polyphenylene ether containing organic solvent obtained by filtration is dried to obtain polyphenylene ether powder.
[0013] [5] The polyphenylene ether is characterized in that, in the polymerization step of the polyphenylene ether manufacturing method, the hydroquinone is replaced by a structure as shown in (IV): (IV) Among them, R 4-7 For H, C 1-8 Alkyl groups, haloalkyl groups, not both hydrogen.
[0014] [6] The polyphenylene ether is characterized in that, in the polymerization process of the polyphenylene ether, the phenol is replaced by a structure as shown in (V): (V) Among them, R 1-3 For H, C 1-8 Alkyl groups, haloalkyl groups, not both hydrogen.
[0015] [7] The polyphenylene ether is characterized in that, in the polyphenylene ether manufacturing method, the molar ratio of substituted hydroquinone to substituted phenol in the polymerization step is 1:1000 to 1:8.
[0016] [8] The polyphenylene ether is characterized in that, in the method of manufacturing the polyphenylene ether, the molar ratio of the catalyst copper salt and zinc salt is M(Cu) / M(Zn) = 4.2-6.6.
[0017] [9] The polyphenylene ether is characterized in that, in the method of manufacturing the polyphenylene ether, the catalyst amine is a monotertiary amine, a ditertiary amine, a polytertiary amine or a mixture of the above tertiary amines.
[0018] The effects of the invention 1. The present invention can provide a polyphenylene ether with high phenolic hydroxyl content, wherein the proportion of X structure end capping is greater than 45%, the proportion of Y structure end capping is less than 5%, the mass content of Z structure is less than 0.3%, the molecular weight distribution is 1.2-1.6, the nitrogen content is extremely low, less than 100ppm, and it has good temperature resistance.
[0019] 2. The polyphenylene ether provided by the present invention has good compatibility with polyamide, and the blend has good heat resistance and excellent mechanical properties. Implementation
[0020] The following is a detailed description of the method for implementing the present invention (hereinafter referred to as "this embodiment"). This embodiment is an example used to illustrate the present invention; the present invention is not limited to this embodiment, and can be implemented with appropriate modifications within the scope of its key points.
[0021] [Polyphenylene ether] The polyphenylene ether of this embodiment is characterized in that it contains polyphenylene ethers with structures as shown in I, II, and III, wherein the proportion of X-terminated groups is greater than 45%, the proportion of Y-terminated groups is less than 5%, and the Z-structure content is less than 0.3% by total mass. (I) (II) (III) Where R1, R2, and R3 are H and C, respectively. 1-8 Alkyl groups, haloalkyl groups, but R1 and R3 are not both hydrogen; X is... ; Y is ; Z is ; Where R1, R2, R3, R4, R5, R6, and R7 are H and C, respectively. 1-8 Alkyl groups, haloalkyl groups, but R1 and R3 are not both hydrogen, R 4-7 They are not both hydrogen; m and n are natural numbers, m = 10 - 500, n = 10 - 500; p and q are natural numbers, p = 0 - 499, q = 0 - 499, p + q = 10 - 500.
[0022] The polyphenylene ether of this embodiment has a molecular weight distribution in the range of 1.2-1.6 as determined by sol-gel chromatography (GPC).
[0023] The polyphenylene ether in this embodiment has a total nitrogen content of less than 60 ppm as determined by a nitrogen analyzer.
[0024] [Manufacturing Method] The method for manufacturing polyphenylene ether according to this embodiment includes the following steps: polymerization, maturation, precipitation, filtration and drying.
[0025] Polymerization process: Monomers containing substituted hydroquinone and substituted phenol are dissolved in a good solvent of polyphenylene ether, mixed with a chelate solution containing copper salt and zinc salt and tertiary amine, and oxygen-containing gas is introduced into the reactor to carry out an oxidative coupling polymerization reaction. After the target degree of polymerization is reached, the oxygen is stopped. Curing process: Add aminocarboxylic acid compound to the mixture and heat it under nitrogen protection at a temperature of 81-85℃. Precipitation process: After aging, the liquid-liquid separation is performed to remove the water layer, and the oil phase containing polyphenylene ether is precipitated using a poor solvent of polyphenylene ether. Filtration process: Filtrating liquid-solid mixtures; Drying process: The wet polyphenylene ether containing organic solvent obtained by filtration is dried to obtain polyphenylene ether powder.
[0026] The substituted hydroquinones in this embodiment have structures such as (IV), such as o-methylhydroquinone, o-chlorohydroquinone, 2,6-dimethylhydroquinone, etc., but are not limited to the above compounds.
[0027] (IV) Among them, R 4-7 For H, C 1-8 Alkyl groups, haloalkyl groups, not both hydrogen.
[0028] The substituted phenols in this embodiment have structures like (V), such as 2,6-dimethylphenol, 2,5-dimethylphenol, 2,3,6-trimethylphenol, 2,6-diethylphenol, o-cresol, etc., but are not limited to the above compounds.
[0029] (V) Among them, R 1-3 For H, C 1-8 Alkyl groups, haloalkyl groups, not both hydrogen.
[0030] In this embodiment, the molar ratio of substituted hydroquinone to substituted phenol is 1:1000 to 1:8, preferably 1:200 to 1:20.
[0031] In this embodiment, the metal salt refers to a mixture of copper salt and zinc salt. The copper salt refers to one or more of copper chloride, copper bromide, cuprous chloride, cuprous bromide, copper nitrate, copper sulfate, etc.; the zinc salt refers to zinc chloride, zinc bromide, zinc nitrate, zinc sulfate, etc.
[0032] In this embodiment, the molar ratio of copper salt to zinc salt, M(Cu) / M(Zn), is 4.2-6.6, preferably M(Cu) / M(Zn) = 0.75-0.83.
[0033] Tertiary amines refer to monotertiary amines, such as trimethylamine, triethylamine, tripropylamine, tributylamine, triheptylamine, dimethylbutylamine, monomethyldibutylamine, etc., but not limited to the above compounds; ditertiary amines, such as tetramethylethylenediamine, tetramethylpropylenediamine, tetramethylbutyldiamine, tetramethylpentanediamine, tetramethylheptanediamine, etc., but not limited to the above compounds; and polytertiary amines, such as 1,1,4,7,10,10-hexamethyltriethylenetetramine, but not limited to the above compounds. A tertiary amine or a mixture of tertiary amines forms a catalyst with a metal salt.
[0034] The oxygen in this embodiment is oxygen with a purity greater than 95%, preferably greater than 98%.
[0035] Aminocarboxylic acid compounds used to terminate the reaction, such as EDTA and its sodium salt.
[0036] The method for manufacturing polyphenylene ether of the present invention is not limited to the method for manufacturing polyphenylene ether powder of the present embodiment described above. The order and number of specific operations in the polymerization process and post-processing steps can be appropriately adjusted. Example
[0037] The following specific embodiments and comparative examples illustrate this implementation method in detail, but this implementation method is not limited to the following embodiments.
[0038] The methods for determining physical properties and characteristics used in the examples and comparative examples are shown below.
[0039] (1) Determination of intrinsic viscosity The test was conducted using an Ubbelohde viscometer, with toluene as the solvent, at a temperature of 30°C.
[0040] (2) Determination of molecular weight and molecular weight distribution The determination was performed using a Shimadzu LC-20ADXR sol-gel permeation chromatography (GPC) system, with standard polystyrene samples as the standard, chloroform as the mobile phase, and 25°C.
[0041] (3) Determination of end-group structure The measurements were performed using a Vrian Unity Inova 400MHz nuclear magnetic resonance spectrometer from Varian, USA. 1 H-NMR, d6-chloroform.
[0042] (4) Nitrogen content determination The Jinan Alwa KN680 fully automatic Kjeldahl nitrogen analyzer was used.
[0043] (5) Mechanical property determination The blending and granulation were carried out using an LTE26 / 40 twin-screw extruder from LABTECH, Switzerland.
[0044] Linear strips were prepared using a Ningbo Plastics Machinery SZ-800NB-A injection molding machine.
[0045] Mechanical properties were tested using the Z010 universal electronic tensile testing machine from Zwick GmbH, Germany. Example 1
[0046] In a 4L double-walled glass reactor, 1900g of toluene, 12g of triethylamine, 2g of tetramethylethylenediamine, 0.33g of copper chloride, and 0.06g of zinc chloride were added and stirred until dissolved. Then, 190g of 2,6-dimethylphenol and 0.85g of o-methylhydroquinone were added, and the material temperature was adjusted to 30℃. Under stirring, oxygen (98.5% purity) was introduced from the bottom of the reactor at a rate of 300mL / min to initiate polymerization. The material temperature was controlled between 40-43℃ by the reactor jacket. After 60 minutes of polymerization, the oxygen was stopped, and the polymerization was completed. 2.6g of EDTA-2Na was added to the reactor, and the temperature was raised to 82℃ under nitrogen protection and held for 20 minutes to obtain an organic mixture containing polyphenylene ether.
[0047] The above mixture was added to 100 mL of distilled water and stirred vigorously for 2 min, then allowed to stand for 15 min to remove the colored aqueous layer. The pale yellow oil phase was slowly added to 3000 mL of methanol while stirring vigorously, causing polyphenylene ether to precipitate as a white precipitate. The precipitate was then filtered to obtain a wet filter cake of polyphenylene ether. The filter cake was heated at 120 °C under nitrogen for 3 h to obtain a white polyphenylene ether powder.
[0048] The obtained polyphenylene ether was subjected to 1 H-NMR measurements were performed to calibrate the specific structure.
[0049] The chemical shift of the hydrogen atom in the benzene ring of the (1H) end cap of the (X) methylphenol hydroxyl structure in polyphenylene ether is 6.28 ppm. The chemical shift of the hydrogen atom in the benzene ring of the (Y)-terminated (3H) structure of 2,6-dimethylphenoxy in polyphenylene ether is 7.10 ppm. The chemical shift of the hydrogen atom in the benzene ring of the biphenyl structure (Z) in polyphenylene ether is 7.34 ppm at (4H); The chemical shift of the hydrogen atom in the benzene ring of the hydroxyl-terminated polyphenylene oxide (PPE) is 6.35 ppm at (2H). The chemical shift of the methyl hydrogen in the 2,6-dimethylphenoxy structure of polyphenylene ether is 2.15 ppm at (6H); The calculation method for the X-structure end cap ratio is as follows: (Equation-1) Where A(X) is the integral area at 6.28 ppm, A(Y) is the integral area at 7.10 ppm, and A(P) is the integral area at 6.35 ppm; The calculation method for the Y-structure end cap ratio is as follows: (Equation-2) The method for calculating the mass content of the Z-structure relative to the 2,6-dimethylphenoxy structure is as follows: (Equation 3) Where A(Q) is the integral area at 2.15 ppm. Example 2
[0050] The zinc chloride content was 0.08 g. Other conditions were the same as in Example 1. Example 3
[0051] The amount of o-methylhydroquinone was 1.2 g. Other conditions were the same as in Example 1. Example 4
[0052] The amount of o-methylhydroquinone was 0.6 g. Other conditions were the same as in Example 1. Example 5
[0053] The amount of o-methylhydroquinone was 0.2 g. Other conditions were the same as in Example 1. Example 6
[0054] The amount of o-methylhydroquinone was 3.6 g. Other conditions were the same as in Example 1. Example 7
[0055] The amount of o-methylhydroquinone was 12.8 g. Other conditions were the same as in Example 1.
[0056] Comparative Example 1 The catalyst was 0.39 g of copper chloride, without the addition of zinc chloride. Other conditions were the same as in Example 1.
[0057] Comparative Example 2 0.2 g of o-methylhydroquinone, 0.39 g of copper chloride catalyst, and no zinc chloride were added. Other conditions were the same as in Example 1.
[0058] Comparative Example 3 190g of 2,6-dimethylphenol, without o-methylhydroquinone; 0.39g of copper chloride catalyst, without zinc chloride. Other conditions were the same as in Example 1.
[0059] Comparative Example 4 0.2 g of zinc chloride. Other conditions were the same as in Example 1.
[0060] Comparative Example 5 Add 0.6 g of hydroquinone, but o-methylhydroquinone is not added. Other conditions are the same as in Example 1.
[0061] Comparative Example 6 6g triethylamine, 1g tetramethylethylenediamine, 8g morpholine. Other conditions are the same as in Example 1.
[0062] Preparation of modified polyphenylene ether by blending with polyamide Material proportions are as follows: 33 parts by weight of polyphenylene ether (polyphenylene ether obtained in the examples, comparative examples and commercial products) Polyamide (PA66, EPR27, Shenma Engineering Plastics Co., Ltd.) 60 parts by weight SEBS (G1651, Kraton Company, USA) 5 parts by weight Antioxidant (Irganox 1010, Ciba Specialty Chemicals) 2 parts by weight Polyphenylene ether, polyamide and SEBS were dried at 60°C for 3 hours before use, mixed according to metering, granulated by an extruder, and then test strips were prepared by injection molding.
[0063] Table 1 describes the characteristics of polyphenylene ethers obtained under different conditions in Examples 1-7 and Comparative Examples 1-5. The polyphenylene ethers obtained in Examples 1-6 all exhibited high phenolic hydroxyl content, extremely low Z-structure content, and a very narrow molecular weight distribution. The polyphenylene ethers obtained in the comparative examples did not possess these characteristics.
[0064] Table 2 describes a comparison of the properties of polyphenylene ether obtained in Example 5, Comparative Examples 2 and 6, and commercial polyphenylene ether blended with polyamide. The polyphenylene ether blend obtained in Example 5 has better strength and toughness; the polyphenylene ether blends obtained in Comparative Examples 2 and 6 have lower strength and poorer toughness; commercial ZM050 performs poorly in terms of strength and toughness and has a strong odor.
[0065] It should be understood that this embodiment is for illustrative purposes only and is not intended to limit the scope of the invention. Furthermore, it should be understood that after reading this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms are also within the scope defined by the appended claims.
[0066]
[0067]
Claims
1. A polyphenylene ether, characterized in that, Polyphenylene ethers containing structures as shown in I, II, and III, wherein the proportion of X-terminated groups is greater than 45%, the proportion of Y-terminated groups is less than 5%, and the Z-structure content is less than 0.3% by total mass. （I） (II) (III) Where R1, R2, and R3 are H and C, respectively. 1-8 Alkyl groups, but R1 and R3 are both hydrogen; X is... ； Y is ； Z is ； Where R1, R2, R3, R4, R5, R6, and R7 are H and C, respectively. 1-8 Alkyl groups, but R1 and R3 are hydrogen at the same time, R 4-7 They are not both hydrogen; m and n are natural numbers, m = 10 - 500, n = 10 - 500; p and q are natural numbers, p = 0 - 499, q = 0 - 499, p + q = 10 - 500; The polyphenylene ether is 1 H-NMR determination of the specific structure showed that the chemical shift of the hydrogen atom in the benzene ring of the (X) end cap of the o-methylphenol hydroxyl structure in polyphenylene ether was 6.28 ppm in (1H). The chemical shift of the hydrogen atom in the benzene ring of the (Y)-terminated (3H) structure of 2,6-dimethylphenoxy in polyphenylene ether is 7.10 ppm. The chemical shift of the hydrogen atom in the benzene ring of the biphenyl structure (Z) in polyphenylene ether is 7.34 ppm at (4H); The chemical shift of the hydrogen atom in the benzene ring of the hydroxyl-terminated polyphenylene oxide (PPE) is 6.35 ppm at (2H). The chemical shift of the methyl hydrogen in the 2,6-dimethylphenoxy structure of polyphenylene ether is 2.15 ppm at (6H); The calculation method for the X-structure end cap ratio is as follows: (Equation-1) Where A(X) is the integral area at 6.28 ppm, A(Y) is the integral area at 7.10 ppm, and A(P) is the integral area at 6.35 ppm; The calculation method for the Y-structure end cap ratio is as follows: (Equation-2) The method for calculating the mass content of the Z-structure relative to the 2,6-dimethylphenoxy structure is as follows: (Equation 3) Where A(Q) is the integral area at 2.15 ppm.
2. The polyphenylene ether according to claim 1, characterized in that, The total nitrogen content, as determined by a nitrogen analyzer, was less than 60 ppm.
3. The polyphenylene ether according to claim 1, characterized in that, The molecular weight distribution was determined to be 1.2-1.6 by sol-gel chromatography.
4. The polyphenylene ether according to claim 1, characterized in that, Preparation methods include: Polymerization process: Monomers containing substituted hydroquinone and substituted phenol are dissolved in a good solvent of polyphenylene ether, mixed with a chelate solution containing copper salt and zinc salt and amine, and oxygen-containing gas is introduced into the reactor to carry out an oxidative coupling polymerization reaction. After the target degree of polymerization is reached, the oxygen is stopped. Curing process: Add aminocarboxylic acid compound to the mixture and heat it under nitrogen protection at a temperature of 45-79℃. Precipitation process: After aging, the liquid-liquid separation is performed to remove the water layer, and the oil phase containing polyphenylene ether is precipitated using a poor solvent of polyphenylene ether. Filtration process: Filtrating liquid-solid mixtures; Drying process: The wet polyphenylene ether containing organic solvent obtained by filtration is dried to obtain polyphenylene ether powder. The substituted hydroquinone has the structure shown in (IV): (IV) Among them, R 4-7 For H, C 1-8 Alkyl groups, not all of which are hydrogen; The substituted phenol has the structure shown in (V): （V） Among them, R 1-3 For H, C 1-8 Alkyl groups, not all of which are hydrogen.
5. The polyphenylene ether according to claim 4, characterized in that, In the polyphenylene ether manufacturing method, the molar ratio of substituted hydroquinone to substituted phenol in the polymerization step is 1:1000 to 1:
8.
6. The polyphenylene ether according to claim 4, characterized in that, In the polyphenylene ether manufacturing method, the molar ratio of the catalyst copper salt to zinc salt is M(Cu) / M(Zn) = 4.2-6.
6.
7. The polyphenylene ether according to claim 4, characterized in that, In the method for manufacturing polyphenylene ether, the catalyst amine is a monotertiary amine, a ditertiary amine, a polytertiary amine, or a mixture of the above tertiary amines.