Water-soluble modified polyphenyl ether sizing agent, preparation method and application thereof

Abstract

The application relates to the technical field of sizing agents for fibers, and discloses a water-soluble modified polyphenyl ether sizing agent and a preparation method and application thereof. The sizing agent comprises modified polyphenyl ether and water, wherein the modified polyphenyl ether is a polymer obtained by grafting a hydrophilic group on polyphenyl ether after chloromethylation reaction; the modified polyphenyl ether contains one or more of a hydroxymethyl group, an aminomethyl group, a carboxymethyl group, a protonated amine ion salt and an aldehyde group; and the content of the modified polyphenyl ether is 0.1-50% by weight and the content of water is 50-99.9% by weight based on the total weight of the sizing agent. The sizing agent can regulate the functional groups contained in the sizing agent and can improve the interfacial strength of carbon fibers and a resin matrix.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sizing agent for fibers, in particular to a water-soluble modified polyphenyl ether sizing agent and a preparation method and application thereof. BACKGROUND

[0002] Carbon fiber is a new type of material with high specific strength and specific modulus. Due to its brittleness and low elongation, problems such as fuzzing or breaking may occur during production and subsequent use. In order to avoid such problems, sizing of carbon fiber becomes an essential part of the production process.

[0003] After sizing, the sizing agent can reduce the generation of carbon fiber fuzz, improve the wear resistance, bundling, spreading and other properties of carbon fiber, improve the interfacial properties between carbon fiber and resin, and increase the performance of carbon fiber composite materials.

[0004] Recently, sizing of carbon fiber is mostly carried out by using emulsion type sizing agent. However, there are problems such as instability, complicated preparation process, inability to control the functional groups contained in the sizing agent, low interfacial strength between carbon fiber and resin matrix, and poor mechanical properties of the composite material containing the carbon fiber.

[0005] Therefore, it is of great significance to research and develop a sizing agent. SUMMARY

[0006] The present application aims to overcome the problems of the prior art, such as complicated preparation process of existing water-soluble thermoplastic sizing agent, and the fact that a single type of water-soluble thermoplastic sizing agent does not have active functional groups and cannot flexibly control the required groups according to demand. The present application provides a water-soluble modified polyphenyl ether sizing agent and a preparation method and application thereof. The sizing agent can control the functional groups contained in the sizing agent and improve the interfacial strength between carbon fiber and resin matrix.

[0007] In order to achieve the above-mentioned purpose, the first aspect of the present application provides a water-soluble modified polyphenyl ether sizing agent, wherein the sizing agent comprises modified polyphenyl ether and water, wherein the modified polyphenyl ether is a polymer obtained by grafting a hydrophilic group to polyphenyl ether after chloromethylation reaction, the modified polyphenyl ether contains one or more of hydroxymethyl, aminomethyl, carboxymethyl, protonated amine ion salt and aldehyde group, and the content of the modified polyphenyl ether is 0.1-50 wt% and the content of water is 50-99.9 wt% based on the total weight of the sizing agent.

[0008] The second aspect of the present application provides a preparation method of a water-soluble modified polyphenyl ether sizing agent, wherein the preparation method comprises:

[0009] (1) chloromethylating polyphenyl ether, chloromethylating reagent and catalyst with solvent to carry out chloromethylating reaction, and obtaining mixed solution; then washing, evaporating and drying the mixed solution to obtain chloromethylated polyphenyl ether resin;

[0010] (2) dispersing the chloromethylated polyphenyl ether resin in water and then carrying out substitution reaction with alkali to obtain water-soluble modified polyphenyl ether;

[0011] (3) dissolving the water-soluble modified polyphenyl ether in water to obtain water-soluble modified polyphenyl ether sizing agent.

[0012] The third aspect of the present application provides a water-soluble modified polyphenyl ether sizing agent prepared by the preparation method.

[0013] The fourth aspect of the present application provides an application of the water-soluble modified polyphenyl ether sizing agent to surface modification of fibers.

[0014] Compared with the emulsion type sizing agent commonly used for carbon fibers, the water-soluble sizing agent has better stability, and compared with the water-soluble polyimide sizing agent commonly used in thermoplastic systems, the preparation process of the sizing agent is more flexible, the functional groups contained in the sizing agent can be controlled, the interfacial strength of carbon fibers and resin matrix can be improved, and the mechanical properties of the composite material are improved. DETAILED DESCRIPTION

[0015] The endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The ranges or values should be construed to be approximations that allow for significant variation. Various ranges of values that are stated herein are considered to be approximate values that can vary by a small amount. Endpoints of various ranges of values, endpoints of various ranges of values and individual point values, and individual point values can be combined with each other to form one or more new ranges of values, which should be considered to be specifically disclosed herein.

[0016] As described above, the first aspect of the present application provides a water-soluble modified polyphenyl ether sizing agent, wherein the sizing agent comprises modified polyphenyl ether and water, wherein the modified polyphenyl ether is a polymer obtained by grafting hydrophilic groups to polyphenyl ether after chloromethylation reaction, the modified polyphenyl ether comprises one or more of hydroxymethyl, aminomethyl, carboxymethyl, protonated amine ion salt and aldehyde group, and the content of the modified polyphenyl ether is 0.1-50 wt% and the content of water is 50-99.9 wt% based on the total weight of the sizing agent.

[0017] The inventors of the present application have unexpectedly found that the present application can form modified polyphenyl ether containing amino, hydroxyl, modified polyphenyl ether, which can improve the interfacial strength of carbon fiber and resin matrix, and improve the mechanical properties of the composite material; in addition, the preparation method is more flexible, and the functional groups contained in the sizing agent can be controlled.

[0018] According to the present application, preferably, the content of the modified polyphenyl ether is 1-10% by weight, and the content of water is 99-90% by weight, based on the total weight of the sizing agent. In the present application, the content of the modified polyphenyl ether and water is limited within the aforementioned range, which can make the sizing uniform and have good bunching.

[0019] According to the present application, the modified polyphenyl ether has a structure represented by formula (1):

[0020]

[0021] wherein the molar ratio of x, y and z is (17-52):(0-27):(48-83); preferably, the molar ratio of x:y:z is (17-47):(0-27):(53-83); more preferably, the molar ratio of x:y:z is (17-47):0:(53-83).

[0022] wherein R1 is selected from one or more of H, CH3, C2H5, C3H8, COOH, ph, OH and NH2;

[0023] wherein R2 is selected from one or more of Cl, CHO, COOH, OH, NH2 and protonated amine ion salt, wherein the cation of the amine ion salt is one or more of protonated triethylamine, diethylamine, n-propylamine, n-butylamine, cyclohexylamine, ethylenediamine, benzylamine, aniline, N-toluidine, N,N'-dimethyl aniline, diphenylamine, triphenylamine, o-toluidine, m-toluidine and p-toluidine cation, and the anion of the amine ion salt is one or more of chloride ion, bromide ion and iodide ion.

[0024] wherein R3 is selected from one or more of CHO, COOH, OH, NH2 and protonated amine ion salt, wherein the cation of the amine ion salt is one or more of protonated triethylamine, diethylamine, n-propylamine, n-butylamine, cyclohexylamine, ethylenediamine, benzylamine, aniline, N-toluidine, N,N'-dimethyl aniline, diphenylamine, triphenylamine, o-toluidine, m-toluidine and p-toluidine cation, and the anion of the amine ion salt is one or more of chloride ion, bromide ion and iodide ion.

[0025] The second aspect of the present application provides a preparation method of a water-soluble modified polyphenyl ether sizing agent, wherein the preparation method comprises:

[0026] (1) contacting a polyphenylene ether, a chloromethylation reagent, and a catalyst with a solvent to perform a chloromethylation reaction, to obtain a mixed solution; and then washing, evaporating, and drying the mixed solution to obtain a chloromethylation polyphenylene ether resin;

[0027] (2) dispersing the chloromethylation polyphenylene ether resin in water and then contacting with a base to perform a substitution reaction, to obtain a water-soluble modified polyphenylene ether;

[0028] (3) dissolving the water-soluble modified polyphenylene ether in water to obtain a water-soluble modified polyphenylene ether sizing agent. According to the present application, the solvent is n-hexane and / or chloroform.

[0029] According to the present application, the chloromethylation reagent is selected from one or more of trioxane-hydrogen chloride, paraformaldehyde-hydrogen chloride, formaldehyde dimethyl acetal-hydrogen chloride, methyl chloride, chloromethyl ether, dichloromethyl ether, and chloromethyl alkyl ether.

[0030] According to the present application, the catalyst is selected from one or more of hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, zinc chloride, aluminum trichloride, ferric sesquioxide, tin tetrachloride, and tin dichloride.

[0031] According to the present application, the base is selected from one or more of sodium hydroxide, potassium hydroxide, triethylamine, diethylamine, n-propylamine, n-butylamine, cyclohexylamine, ethylenediamine, benzylamine, aniline, N-methylaniline, N,N'-dimethylaniline, diphenylamine, triphenylamine, o-toluidine, m-toluidine, and p-toluidine.

[0032] According to the present application, in step (1), the chloromethylation reaction is performed under conditions including a temperature of 10-130°C and a time of 0.5-50h; preferably, the temperature is 40-90°C and the time is 4-25h.

[0033] According to the present application, in step (1), the weight ratio of the polyphenylene ether, the chloromethylation reagent, the catalyst, and the solvent is 1:(0.1-20): (0.1-20):(1-500); preferably, the weight ratio of the polyphenylene ether, the chloromethylation reagent, the catalyst, and the solvent is 1:(0.5-10):(0.5-10):(4-400).

[0034] According to the present application, in step (2), the substitution reaction is performed under conditions including a temperature of 40-90°C and a time of 0.5-50h; preferably, the temperature is 50-80°C and the time is 4-25h.

[0035] According to the present application, the weight ratio of the amount of chloromethylated polyphenyl ether resin, water and alkali is 1:(1-500):(0.1-20); preferably, the weight ratio of the amount of chloromethylated polyphenyl ether resin, water and alkali is 1:(5-400):(2-10).

[0036] According to the present application, in step (3), the weight ratio of the amount of water-soluble modified polyphenyl ether and water is (0.1-50):(50-99.9); preferably, the weight ratio of the amount of water-soluble modified polyphenyl ether and water is (1-10):(99-90).

[0037] According to the present application, in step (3), the conditions for dissolving the water-soluble modified polyphenyl ether in water include a temperature of 10-80°C, preferably 40-70°C.

[0038] According to the present application, in step (3), the conditions for dissolving the water-soluble modified polyphenyl ether in water include a temperature of 10-80°C, preferably 40-70°C. In the present application, preferably, the process is carried out under stirring at a stirring rate of 10-400 rpm.

[0039] According to a preferred embodiment of the present application, the preparation method of the water-soluble modified polyphenyl ether sizing agent comprises:

[0040] (1) Put polyphenyl ether resin into a flask, add solvent, then add a certain amount of chloromethylation reagent and catalyst, stir, and keep the reaction solution at 40-90°C for 4-25 h. After the reaction is completed, add water to the obtained product, transfer to a separatory funnel, wash with water until neutral, evaporate the solvent of the organic layer, and repeatedly wash with ethanol, dry, to obtain chloromethylated polyphenyl ether resin; wherein the weight ratio of the amount of polyphenyl ether, chloromethylation reagent, catalyst and solvent is 1:(0.5-10):(0.5-10):(4-400);

[0041] (2) Disperse chloromethylated polyphenyl ether resin in water, then add a certain amount of alkali solution, heat and stir to dissolve the chloromethylated polyphenyl ether resin, filter the insoluble matter, collect the filtrate, and dry at low temperature to obtain water-soluble polyphenyl ether resin. The heating temperature is 50-80°C, the reaction time is 4-25 h, the drying temperature is 40°C-90°C, and the drying time is 0.5-50 h; wherein the weight ratio of the amount of chloromethylated polyphenyl ether resin, water and alkali is 1:(5-400):(2-10);

[0042] (3) dissolving the water-soluble polyphenyl ether resin in water, stirring uniformly under the condition that the temperature is 40-70℃ and the stirring rate is 10-400rpm, wherein the weight ratio of the water-soluble modified polyphenyl ether and the water is (1-10):(99-90); obtaining the water-soluble polyphenyl ether sizing agent.

[0043] According to a particularly preferred embodiment of the present application, in the present application, the reaction synthesis route of the water-soluble modified polyphenyl ether sizing agent is as follows:

[0044]

[0045] According to another particularly preferred embodiment of the present application, in the present application, the reaction synthesis route of the water-soluble modified polyphenyl ether sizing agent is as follows:

[0046]

[0047] The third aspect of the present application provides a water-soluble modified polyphenyl ether sizing agent prepared by the preparation method as described above.

[0048] The fourth aspect of the present application provides an application of the water-soluble modified polyphenyl ether sizing agent as described above to surface modification of fibers.

[0049] According to the present application, the fibers include carbon fibers and / or graphite fibers, preferably carbon fibers.

[0050] According to a preferred embodiment of the present application, the method for surface modification of carbon fibers by using the water-soluble modified polyphenyl ether sizing agent includes:

[0051] The water-soluble modified polyphenyl ether sizing agent is put into a sizing tank, the unsized carbon fibers are immersed in the sizing agent and pass through the sizing tank at a speed of 0.1m / min-1m / min, the sizing time is 30s-2.5min, the excess sizing agent of the carbon fibers out of the tank is squeezed out, and then the sized carbon fibers are dried at 100-260℃, preferably, the sized carbon fibers are dried at a gradient temperature of 100℃, 130℃, 160℃, 180℃, 200℃, 220℃ and 260℃.

[0052] The sized carbon fibers can be used to prepare thermoplastic composites at high temperature, which improves the compatibility of the carbon fiber / resin interface and improves the toughness, strength and ductility of the composites.

[0053] According to the present application, the amount of the fibers is 10-5000g, preferably 100-1000g, relative to 100mL of the sizing agent.

[0054] The present application will be described in detail by way of examples as follows.

[0055] The following examples and comparative examples are:

[0056] The thermal stability parameter is measured by a thermal gravimetric method, wherein the atmosphere is N2, the temperature rising rate is 10℃ / min, and the temperature range is 100-800℃.

[0057] The interlaminar shear strength test method is as follows: a single fiber is fixed on a self-made glass mold, a small amount of polyetherimide powder is dipped with a needle point to coat on the fiber to form a point, a microbead is spontaneously formed by heating and melting at 300℃ on a flat plate vulcanizing machine, the interface strength is tested according to the micro-detaching method, the microbead coating length is observed by a microscope, the fiber with a coating length of 100-170μm is selected, and the fiber is passed through a self-made clamp with micro-holes to fix the microbead in the micro-holes of the clamp, and the clamp is placed on a single fiber strength tester, and the length is set to 10mm and the stretching speed is set to 2mm / min.

[0058] The polyphenyl ether raw material is a commercially available product with a trade name of LXN025 from Bluestar Chemical New Materials Co., Ltd.

[0059] Example 1

[0060] This example is to illustrate the sizing agent prepared by the method of the present application.

[0061] (1) 2g of polyphenyl ether and 100mL of n-hexane are mixed, 16g of trioxane and 5mL of hydrochloric acid are added, and then 20g of zinc chloride is added, and the mixture is stirred and sealed, heated to 60℃ and kept for 6 hours. After the reaction is completed, 200mL of hot water is added, the organic phase is transferred to a separatory funnel and washed with hot water until the washed water is neutral, the organic phase is dried at 40℃, the obtained solid is washed with ethanol and dried at 80℃ for 12h to obtain a chloromethylated polyphenyl ether product;

[0062] (2) 2g of the chloromethylated polyphenyl ether is dispersed in 45g of water, stirred, 20g of sodium hydroxide is added, heated to 80℃ and kept for 4h, the obtained solution is dried at 90℃, the obtained solid is washed with ethanol, the washing liquid is collected and dried at 90℃ to obtain a hydroxymethylated polyphenyl ether 1;

[0063] (3) 2g of the alcoholized polyphenyl ether 1 is dissolved in 40g of water to obtain a water-soluble polyphenyl ether sizing agent 1.

[0064] In addition, the obtained sizing agent is used for sizing the non-sizing carbon fiber, the sizing time is 30s, and the drying temperature is 130℃.

[0065] The content of the modified polyphenyl ether is 5wt% and the content of water is 95wt% based on the total weight of the sizing agent.

[0066] In addition, the structural formula of the prepared modified polyphenyl ether is as follows:

[0067]

[0068] wherein x:y = 17:83.

[0069] Example 2

[0070] This example is directed to illustrate the sizing agent prepared by the method of the present application.

[0071] (1) 2 g of polyphenylene ether was mixed with 100 mL of n-hexane, 8 g of trioxane and 2.5 mL of hydrochloric acid were added, and then 10 g of zinc chloride was added, and the mixture was stirred and sealed, heated to 90°C and kept for 25 hours. After the reaction was completed, 200 mL of hot water was added, and the obtained organic phase was transferred to a separatory funnel, and the organic phase was washed with hot water until the washed water was neutral, and the organic phase was dried at 40°C, the obtained solid was washed with ethanol, and dried at 80°C for 12 h to obtain a chloromethylated polyphenylene ether product;

[0072] (2) 2 g of the chloromethylated polyphenylene ether was dispersed in 45 g of water, stirred, 3.5 g of n-butylamine was added, heated to 70°C and kept for 25 h, and the obtained solution was dried at 90°C to obtain n-butylamine polyphenylene ether 1;

[0073] (3) 2 g of the n-butylamine polyphenylene ether 1 was dissolved in 40 g of water to obtain a water-soluble polyphenylene ether sizing agent 2.

[0074] In addition, the obtained sizing agent was used to size the non-sizable carbon fiber, the sizing time was 30 s, and the drying temperature was 130°C.

[0075] wherein the content of the modified polyphenylene ether is 5% by weight, and the content of water is 95% by weight, based on the total weight of the sizing agent.

[0076] and the structural formula of the prepared modified polyphenylene ether is:

[0077]

[0078] wherein x:y = 19:81.

[0079] Example 3

[0080] This example is directed to illustrate the sizing agent prepared by the method of the present application.

[0081] (1) 2g of polyphenylene ether and 100mL of n-hexane were mixed, 1.6g of trioxane and 0.5mL of hydrochloric acid were added, then 2g of zinc chloride was added, the mixture was stirred and sealed, heated to 60°C and kept for 6 hours. After the reaction was completed, 200mL of hot water was added, the obtained product was transferred to a separatory funnel, the organic phase was washed with hot water until the washed water was neutral, the organic phase was dried at 40°C, the obtained solid was washed with ethanol and dried at 80°C for 12h to obtain a chloromethylated polyphenylene ether product;

[0082] (2) 2g of chloromethylated polyphenylene ether was dispersed in 45g of water, stirred, 0.5g of sodium hydroxide was added, heated to 50°C and kept for 25h, the obtained solution was dried at 90°C, the obtained solid was washed with ethanol, the washing liquid was collected and dried at 90°C to obtain a hydroxymethylated polyphenylene ether 2;

[0083] (3) 2g of the alcoholized polyphenylene ether 2 was dissolved in 40g of water to obtain a water-soluble polyphenylene ether sizing agent 3.

[0084] The obtained sizing agent was used to size the non-sizable carbon fiber, the sizing time was 30s and the drying temperature was 130°C.

[0085] The content of the modified polyphenylene ether was 5wt% and the content of water was 95wt% based on the total weight of the sizing agent.

[0086] The structural formula of the obtained modified polyphenylene ether was as follows:

[0087]

[0088] x:y = 47:53

[0089] Example 4

[0090] This example is to illustrate the sizing agent prepared by the method of the present application.

[0091] (1) 2g of polyphenylene ether and 100mL of n-hexane were mixed, 0.8g of trioxane and 0.25mL of hydrochloric acid were added, then 1g of zinc chloride was added, the mixture was stirred and sealed, heated to 90°C and kept for 25 hours. After the reaction was completed, 200mL of hot water was added, the obtained product was transferred to a separatory funnel, the organic phase was washed with hot water until the washed water was neutral, the organic phase was dried at 40°C, the obtained solid was washed with ethanol and dried at 80°C for 12h to obtain a chloromethylated polyphenylene ether product;

[0092] (2) 2g of chloromethylated polyphenylene ether was dispersed in 45g of water, stirred, 1.7g of n-butylamine was added, heated to 70°C and kept for 4h, the obtained solution was dried at 90°C to obtain an n-butylamineated polyphenylene ether 2;

[0093] (3) 2 g of the n-butylamine modified polyphenyl ether 2 was dissolved in 40 g of water to obtain a water-soluble polyphenyl ether sizing agent 4.

[0094] In addition, the obtained sizing agent was used to size the non-sizing carbon fiber, the sizing time was 30 s, and the drying temperature was 130 °C.

[0095] The content of the modified polyphenyl ether was 5% by weight, and the content of water was 95% by weight, based on the total weight of the sizing agent.

[0096] The structural formula of the modified polyphenyl ether prepared is:

[0097]

[0098] x:y = 52:48

[0099] Example 5

[0100] This embodiment is to illustrate the sizing agent prepared by the method of the present application.

[0101] (1) 2 g of polyphenyl ether and 100 mL of n-hexane were mixed, 1.6 g of trioxane and 0.5 mL of hydrochloric acid were added, and then 2 g of zinc chloride was added, stirred, heated to 60 °C and kept for 6 hours. After the reaction was completed, 200 mL of hot water was added, and the obtained material was transferred to a separatory funnel, and the organic phase was washed with hot water until the washed water was neutral, and the organic phase was dried at 40 °C, the obtained solid was washed with ethanol and dried at 80 °C for 12 h to obtain a chloromethylated polyphenyl ether product;

[0102] (2) 2 g of the chloromethylated polyphenyl ether was dispersed in 45 g of water, stirred, 0.25 g of sodium hydroxide was added, heated to 50 °C and kept for 4 h, the obtained solution was dried at 90 °C, the obtained solid was washed with ethanol, the washing liquid was collected and dried at 90 °C to obtain a hydroxymethylated polyphenyl ether 3;

[0103] (3) 2 g of the alcoholized polyphenyl ether 3 was dissolved in 40 g of water to obtain a water-soluble polyphenyl ether sizing agent 3.

[0104] In addition, the obtained sizing agent was used to size the non-sizing carbon fiber, the sizing time was 30 s, and the drying temperature was 130 °C.

[0105] As a result, a water-soluble modified polyphenyl ether sizing agent was prepared.

[0106] The content of the modified polyphenyl ether was 5% by weight, and the content of water was 95% by weight, based on the total weight of the sizing agent.

[0107] The structural formula of the modified polyphenyl ether prepared is:

[0108]

[0109] wherein: x:y:z = 47:26:27

[0110] Comparative Example 1

[0111] LXN025 polyphenyl ether resin was used.

[0112] Comparative Example 2

[0113] The sizing agent was prepared according to the same method as Example 1, except that the "trioxyhexacyclic ring" in Step 1 was replaced by "4.5 g formaldehyde", and chloromethylated polyphenyl ether could not be obtained.

[0114] Comparative Example 3

[0115] The sizing agent was prepared according to the same method as Example 1, except that no heating was performed in Step 1, and chloromethylated polyphenyl ether could not be obtained.

[0116] Test Example 1

[0117] The sizing agent of the above examples was tested for thermal stability and interlayer shear strength with polyphenyl ether resin, and the results are shown in Table 1 below:

[0118] Table 1

[0119] Sample Name T 5％ (°C) Interlaminar Shear Strength (MPa) Example 1 430 70.1 Example 2 410 67.2 Example 3 435 67.0 Example 4 416 63.4 Example 5 398 54.5 Comparative Example 1 440 - Comparative Example 2 - - Comparative Example 3 - -

[0120] Compared with Comparative Example 1, the thermal stability of the water-soluble modified polyphenyl ether sizing agent of the present application is slightly lower, but still higher than the processing temperature of polyphenyl ether, at the same time, the hydroxyl and amino groups in the modification form hydrogen bonds with the oxygen in the polyphenyl ether, increasing the interlayer shear strength of the carbon fiber and the polyphenyl ether resin, and more importantly, the type and amount of the modified functional groups can be easily adjusted to control the interlayer shear strength with the polyphenyl ether matrix resin. Thus, the interface strength between carbon fiber and resin is improved, and the performance of the composite material is improved. In addition, in the present application, it should be noted that the polyphenyl ether is modified to prepare the sizing agent, which is coated on the surface of the fiber, in order to enhance the interfacial bonding performance of the carbon fiber and the resin, and the interlayer shear strength is an index for measuring the interfacial bonding performance. The polyphenyl ether resin was selected as the matrix resin and the sized carbon fiber to test the interlayer shear strength between them.

[0121] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be considered as disclosed by the present application, and all fall within the protection scope of the present application.

Claims

1. A water-soluble modified polyphenylene ether sizing agent for surface modification of fibers, characterized in that, The fiber includes carbon fiber and / or graphite fiber, and the sizing agent includes modified polyphenylene ether and water, wherein the modified polyphenylene ether is a polymer obtained by grafting hydrophilic groups onto polyphenylene ether after chloromethylation and then reacting it with an alkali, and the content of the modified polyphenylene ether is 0.1-50% by weight and the content of water is 50-99.9% by weight, based on the total weight of the sizing agent; The modified polyphenylene ether has the structure shown in formula (1): The molar ratio of x, y, and z is (17-52):(0-27):(48-83); R1 is selected from one or more of H, CH3, C2H5, C3H8, COOH, ph, OH and NH2; R2 is selected from one or more of Cl, CHO, COOH, OH, NH2 and protonated amine ion salts, wherein the cation in the amine ion salt is one or more of protonated triethylamine, diethylamine, n-propylamine, n-butylamine, cyclohexylamine, ethylenediamine, benzylamine, aniline, N-toluidine, N,N'-dimethylamine, diphenylamine, triphenylamine, o-toluidine, m-toluidine and p-toluidine cations, and the anion in the amine ion salt is one or more of chloride ion, bromide ion and iodide ion; R3 is selected from one or more of CHO, COOH, OH, NH2 and protonated amine ion salts, wherein the cation in the amine ion salt is one or more of protonated triethylamine, diethylamine, n-propylamine, n-butylamine, cyclohexylamine, ethylenediamine, benzylamine, aniline, N-toluidine, N,N'-dimethylamine, diphenylamine, triphenylamine, o-toluidine, m-toluidine and p-toluidine cations, and the anion in the amine ion salt is one or more of chloride ion, bromide ion and iodide ion.

2. The modified polyphenylene ether sizing agent according to claim 1, wherein, The amount of fiber used is 10-5000g relative to 100mL of the sizing agent.

3. A method for preparing the water-soluble modified polyphenylene ether sizing agent according to claim 1 or 2, characterized in that, The preparation method includes: (1) Polyphenylene ether, chloromethylating agent and catalyst are contacted with solvent to carry out chloromethylation reaction to obtain a mixed solution; then the mixed solution is washed, evaporated and dried to obtain chloromethylated polyphenylene ether resin; (2) The chloromethylated polyphenylene ether resin is dispersed in water and then contacted with an alkali to carry out a substitution reaction to obtain water-soluble modified polyphenylene ether; (3) Dissolve the water-soluble modified polyphenylene ether in water to obtain a water-soluble modified polyphenylene ether sizing agent.

4. The method according to claim 3, wherein, The solvent is n-hexane and / or chloroform; And / or, the chloromethylating agent is selected from one or more of paraformaldehyde-hydrogen chloride, paraformaldehyde-hydrogen chloride, formaldehyde dimethyl acetal-hydrogen chloride, methyl chloride, chloromethyl ether, dichloromethyl ether, and chloromethyl alkyl ether; And / or, the catalyst is selected from one or more of hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, zinc chloride, aluminum trichloride, ferric oxide, tin tetrachloride, and tin dichloride; And / or, the base is selected from one or more of sodium hydroxide, potassium hydroxide, triethylamine, diethylamine, n-propylamine, n-butylamine, cyclohexylamine, ethylenediamine, benzylamine, aniline, N-toluidine, N,N'-dimethylamine, diphenylamine, triphenylamine, o-toluidine, m-toluidine, and p-toluidine.

5. The method according to claim 3, wherein, In step (1), the conditions for the chloromethylation reaction include: a temperature of 10-130°C and a time of 0.5-50 h; And / or, in step (1), the weight ratio of the polyphenylene ether, the chloromethylating agent, the catalyst and the solvent is 1:(0.1-20):(0.1-20):(1-500).

6. The method according to claim 3, wherein, In step (2), the conditions for the substitution reaction include: a temperature of 40-90℃ and a time of 0.5-50h; And / or, the weight ratio of the chloromethylated polyphenylene ether resin, water and alkali is 1:(1-500):(0.1-20).

7. The method according to claim 3, wherein, In step (3), the weight ratio of the water-soluble modified polyphenylene ether to water is (0.1-50):(50-99.9); And / or, in step (3), the conditions under which the water-soluble modified polyphenylene ether dissolves in water include a temperature of 10-80°C.

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