Preparation method of emulsion type aramid fiber sizing agent

Abstract

A preparation method of an emulsion type aramid fiber sizing agent belongs to the technical field of fiber surface treatment, and the specific scheme is as follows: preparing aromatic polyamide from corresponding diamine and acyl chloride, then reacting with epoxy resin to prepare modified epoxy resin, and preparing the emulsion type aramid fiber sizing agent under the action of a compound emulsifier. The preparation method disclosed by the invention is simple and relatively low in cost, better interface bonding can be formed between the aramid fiber and the epoxy resin after sizing by the sizing agent, and particularly, the interlayer shear strength of the aramid fiber / epoxy resin composite material is relatively well improved; the preparation method has important significance in improving the use performance and stability of the aramid fiber composite material and expanding the application of the aramid fiber.

Description

Technical Field

[0001] The present invention belongs to the technical field of fiber surface treatment, and particularly relates to a preparation method of an emulsion-type sizing agent for aramid fibers. Background Art

[0002] Aramid fiber is a kind of high-performance polymer fiber. Its molecular structure consists of benzene rings and amide bonds, and it has the advantages of high strength, high modulus, corrosion resistance, acid and alkali resistance, high temperature resistance and light weight. Its strength is 5-6 times that of steel wire, the modulus is 2-3 times that of steel wire or glass fiber, the toughness is 2 times that of steel wire, and the weight is only about 1 / 5 of that of steel wire. It has good insulation and anti-aging properties and has a long life cycle. According to different molecular structures and arrangements, production processes, etc., aramid fiber products mainly include para-aramid fiber (poly-p-phenylene terephthalamide fiber), meta-aramid fiber (poly-m-phenylene isophthalamide fiber) and aramid III fiber (heterocyclic aromatic polyamide fiber). The composite materials prepared with para-aramid fiber as the reinforcement are widely used in the fields of aerospace, transportation, sports equipment, electronic equipment and national defense industry. However, the surface of aramid fiber is smooth and chemically inert, and its interfacial bonding ability with the resin matrix is poor, which affects the performance of the composite material. Therefore, it is necessary to perform surface treatment on aramid fiber to improve its surface and interfacial properties of the composite material.

[0003] Fiber surface treatment methods include physical modification methods such as heat treatment, cold treatment, sizing treatment, and gamma-ray irradiation, and chemical modification methods such as chemical surface etching, surface chemical grafting, and surface chemical deposition. Among them, sizing treatment can effectively play the role of bundling, lubrication, and wetting, and has the advantages of simple and easy process and no effect on the strength of the fiber body, so it is quite popular. Fiber sizing agent is one of the key factors in sizing treatment technology, which has an important influence on the sizing effect and the interface performance of composite materials. According to the dispersion medium used, sizing agents can be divided into two categories: solvent-based sizing agents and water-soluble sizing agents. Solution-based sizing agents are easy to volatilize during use, which has safety hazards and pollutes the environment, and are gradually being eliminated; water-soluble (including emulsion-based) sizing agents use water as a dispersion medium, which is safe and pollution-free, and is the main development direction of fiber sizing agents. Chinese invention patents ZL 202010724401.7 and ZL 202110638084.1 respectively provide methods for preparing water-soluble epoxy resin sizing agents for aramid fibers. The main feature is that isocyanates are used to form chemical bonds between poly(p-phenylene terephthalamide) oligomers, epoxy resins, and polyethylene glycols through chemical reactions. The prepared sizing agent has a certain degree of improvement on the surface properties of aramid fibers and the interface properties of composite materials, but the effect still needs to be improved. Moreover, the preparation process uses hazardous chemicals such as isocyanates (class III hazardous materials according to international and Chinese standards) and high-temperature vacuum distillation and other operations. The preparation steps are complicated. The introduced isocyanates mainly play a role in chemical linking, and polyethylene glycol plays a role in improving water solubility. Its contribution to the interface of the composite material is unknown. Summary of the invention

[0004] In order to solve the problem of development demand of aramid fiber sizing agent, the present invention provides a method for preparing emulsion type aramid fiber sizing agent without using hazardous chemical isocyanate.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for preparing an emulsion type aramid fiber sizing agent, the method comprising the following steps:

[0007] Step 1, preparation of carboxyl-terminated polyaromatic amide: using aromatic diformyl chloride and aromatic diamine as monomers to carry out solution polymerization, using a neutralizer to neutralize the generated HCl, and controlling the excess amount of aromatic diformyl chloride monomer to obtain carboxyl-terminated polyaromatic amide;

[0008] Step 2, preparation of modified epoxy resin containing aromatic amide groups: under high temperature and catalyst, the carboxyl group of the carboxyl-terminated polyaromatic amide obtained in step 1 reacts with the epoxy group of the epoxy resin to introduce the aromatic amide group into the epoxy resin structure to obtain modified epoxy resin containing aromatic amide groups.

[0009] Step 3: Take 30 - 60 parts by weight of deionized water, 1 - 10 parts of modified epoxy resin containing aromatic amide groups, and 1 - 2 parts of emulsifier, mix them, stir at 50 - 80°C for 10 - 60 min, and the stirring speed is 800 - 5000 r / min to obtain an emulsion-type sizing agent for aramid fibers. The solid content of the sizing agent is 1.5% - 24%. Before use, the sizing agent is diluted with deionized water to a solid content of 0.5 - 5%.

[0010] Further, Step 1 is specifically as follows: Take aromatic dicarbonyl chloride monomers and aromatic diamine monomers in a molar ratio of (1.1 - 1.3):1, dissolve them in reaction solvent A, the molar concentration of the aromatic diamine monomer is 0.5 - 1 mol / L, add a neutralizing agent equimolar to the aromatic diamine monomer, react at -5 - 5°C for 30 - 60 min under nitrogen conditions. After the reaction, pour the reaction solution into deionized water, stir and precipitate, the stirring time is 5 - 30 min, filter and wash thoroughly with deionized water, and vacuum dry at 50 - 80°C for 24 - 48 h to obtain carboxyl-terminated polyaramide.

[0011] Further, Step 2 is specifically as follows: Weigh 1 - 4 parts by weight of carboxyl-terminated polyaramide, 10 - 40 parts of epoxy resin, and 0.1 - 0.4 parts of catalyst, add them to 30 - 60 parts of reaction solvent B, carry out a modification reaction under nitrogen conditions, the reaction temperature is 110 - 160°C, the reaction time is 12 - 24 h, and after the reaction, remove low-boiling substances by rotary evaporation to obtain modified epoxy resin containing aromatic amide groups.

[0012] Further, the emulsifier is one or a combination of more of a non-ionic emulsifier and an anionic emulsifier. Among them, the non-ionic emulsifier is preferably tw-80, op-10, sp-80, sp-20, and the anionic emulsifier is preferably sodium dodecylbenzenesulfonate.

[0013] Further, in Step 1, the aromatic dicarbonyl chloride monomers include one or a combination of two of terephthaloyl chloride and isophthaloyl chloride; the aromatic diamine monomers include one or a combination of more of p-phenylenediamine, m-phenylenediamine, 4,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 4,4'-diaminodiphenyl ether, and 3,3'-diaminodiphenyl ether; the reaction solvent A is one of N-methylpyrrolidone, dimethylformamide, and dimethylacetamide; the neutralizing agent is one or a combination of two of anhydrous calcium chloride and pyridine.

[0014] Furthermore, in step two, the epoxy resin is a difunctional epoxy resin, preferably a difunctional glycidyl ether epoxy resin, more preferably one of bisphenol A diglycidyl ether epoxy resins E51 and E44; the reaction solvent B is one of propylene glycol methyl ether and acetone; the catalyst is a triphenylphosphine-tetrabutylammonium bromide catalytic system with a weight ratio of 1:1.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] In the present invention, the epoxy resin is modified by synthesizing carboxyl-terminated polyarylamide to prepare a modified epoxy resin containing arylamide groups, and an emulsification technique is used to prepare a modified epoxy resin emulsion as a sizing agent for aramid fibers. The introduction of arylamide groups in the sizing agent makes the arylamide groups have similarity with the structure of aramid fibers, so they have good affinity with aramid fibers. After sizing and drying treatments, the sizing agent, aramid fibers, and epoxy resin can form strong bonds through hydrogen bonds; the introduction of epoxy groups in the sizing agent enables it to have good wettability and compatibility with the matrix resin and participate in the curing process of the resin. Therefore, this sizing agent can form a strong interfacial bond between aramid fibers and the matrix resin, effectively improving the interfacial properties of the composite material. This sizing agent is an aqueous emulsion without organic solvents and is pollution-free to the environment during use. Compared with the prior art, its preparation raw material components are simplified, the hazardous chemical isocyanate is not used, the preparation method is simple and easy to implement, and the improvement of the interfacial properties of the composite material is significant. Therefore, this sizing agent can solve the problem that the comprehensive properties of the composite material cannot be fully exerted due to poor interfacial properties, and is especially suitable for aramid fiber-reinforced epoxy resin composites with large demand. The emulsion-type sizing agent for aramid fibers of the present invention not only has good interfacial synergistic effect, but also has a simple and easy preparation process and is pollution-free to the environment during application, having good application prospects. In summary, the emulsion-type sizing agent for aramid fibers of the present invention can improve the surface properties of aramid fibers and the interfacial properties of their composite materials, which is of great significance for improving the use performance and stability of aramid fiber composites and expanding the application of aramid fibers. Description of the Drawings

[0017] Figure 1 is the infrared spectrum diagram of the modified epoxy resin containing arylamide groups in Example 1 of the present invention;

[0018] Figure 2 is the distribution diagram of the average particle size of the emulsion in Example 2 of the present invention. Detailed Embodiments

[0019] The technical solutions in the present invention will be clearly and completely described below in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are only a part of the embodiments of the invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without any creative work belong to the scope of protection of the present invention.

[0020] The preparation method of the present invention is simple, with low cost, and has no pollution to the environment during the application process. The aromatic amide groups contained in the sizing agent can form hydrogen bonds with aramid fibers, increasing the binding force with the fiber surface; the epoxy groups contained in the sizing agent have good wettability and compatibility with the resin matrix and can participate in the resin curing process, thereby forming a strong bond with the resin matrix, which is of great significance for improving the performance and application of aramid fiber composites.

[0021] Example 1

[0022] A preparation method of an emulsion-type aramid fiber sizing agent, the method comprising the following steps:

[0023] Preparation of carboxyl-terminated polyaramide: Take terephthaloyl chloride and p-phenylenediamine monomers in a molar ratio of 1.15:1, dissolve them in the reaction solvent N-methylpyrrolidone, the molar concentration of p-phenylenediamine monomer is 0.6 mol / L, add anhydrous calcium chloride equimolar to the p-phenylenediamine monomer, react at -5 °C for 30 min under nitrogen conditions, after the reaction is completed, pour the reaction solution into deionized water for stirring precipitation, the stirring time is 15 min, filter and wash thoroughly with deionized water, and vacuum dry at 60 °C for 48 h to obtain carboxyl-terminated polyaramide.

[0024] Preparation of modified epoxy resin containing aromatic amide groups: Weigh 1.5 parts of carboxyl-terminated polyaramide, 15 parts of epoxy resin E-51, and 0.2 parts of a catalyst of triphenylphosphine-tetrabutylammonium bromide with a weight ratio of 1:1, add them to 40 parts of the reaction solvent propylene glycol monomethyl ether, carry out a modification reaction under nitrogen conditions, the reaction temperature is 120 °C, the reaction time is 24 h, after the reaction is completed, remove the low-boiling substances by rotary evaporation treatment to obtain a modified epoxy resin containing aromatic amide groups. The structure of the modified epoxy resin containing aromatic amide groups is:

[0025]

[0026] The structure of R in the above structural formula is:

[0027]

[0028] Among them, 25 ≤ n ≤ 30, 1.5 ≤ m ≤ 2.5.

[0029] Preparation of sizing agent emulsion: Take 45 parts of deionized water, 5 parts of modified epoxy resin containing aromatic amide groups, and 1 part of compound emulsifier (OP-10 and SP-80 are compounded according to the weight ratio of 4:1) by weight, mix them, stir at 60 °C for 30 min, and the stirring speed is 2000 r / min to obtain an emulsion-type aramid fiber sizing agent with a solid content of 10%. The particle size of the sizing agent emulsion is analyzed by a laser particle size analyzer, and its average particle size is 465 nm.

[0030] Preparation of composite material: Dilute the above sizing agent with deionized water to a sizing agent emulsion with a solid content of 2.5%. After treating the aramid fiber, uniformly coat the epoxy resin on the aramid fiber tow, and then lay it flat in a hot pressing mold for hot pressing. The hot pressing process is as follows: First, pre-cure at 140 °C for 30 min, keep the pressure at 5 MPa, and then raise the temperature to 160 °C and keep it at a pressure of 10 MPa for 2 h for hot pressing and curing.

[0031] Figure 1 It is the infrared spectrogram of the modified epoxy resin containing aromatic amide groups in Example 1. As shown in the figure, the absorption peak near 3400 cm-1 is for the N-H group, the absorption peak near 1620 cm-1 is for C=O, and the absorption peak near 915 cm-1 is for the epoxy group.

[0032] Example 2

[0033] A preparation method of an emulsion-type aramid fiber sizing agent, the method comprising the following steps:

[0034] Preparation of carboxyl-terminated polyarylamide: Take terephthaloyl chloride and p-phenylenediamine monomers according to a molar ratio of 1.2:1, dissolve them in the reaction solvent N-methylpyrrolidone, the molar concentration of p-phenylenediamine monomer is 0.8 mol / L, add anhydrous calcium chloride equimolar to the p-phenylenediamine monomer, react at 0 °C for 30 min under nitrogen conditions, pour the reaction solution into deionized water after the reaction is completed for stirring precipitation, the stirring time is 15 min, filter and wash thoroughly with deionized water, and dry in vacuum at 60 °C for 36 h to obtain carboxyl-terminated polyarylamide.

[0035] Preparation of modified epoxy resin containing aromatic amide groups: Weigh 2 parts of carboxyl-terminated polyarylamide, 20 parts of epoxy resin E-51, and 0.25 parts of a catalyst of triphenylphosphine-tetrabutylammonium bromide with a weight ratio of 1:1, add them to 50 parts of the reaction solvent propylene glycol methyl ether, carry out a modification reaction under nitrogen conditions, the reaction temperature is 130 °C, the reaction time is 18 h, and remove the low-boiling substances by rotary evaporation after the reaction is completed to obtain a modified epoxy resin containing aromatic amide groups. The structure of the modified epoxy resin containing aromatic amide groups is:

[0036]

[0037] The structure of R in the said structural formula is as follows:

[0038]

[0039] Among them, 28 ≤ n ≤ 33, 1.5 ≤ m ≤ 2.5.

[0040] Preparation of the sizing agent emulsion: Take 40 parts of deionized water, 9 parts of modified epoxy resin containing arylamide groups, and 1 part of compound emulsifier (TW-80 and SP-80 compounded in a weight ratio of 4:1) by weight, mix them, stir at 60 °C for 30 min, and the stirring speed is 4000 r / min to obtain an emulsion-type aramid fiber sizing agent with a solid content of 18%. Use a laser particle size analyzer to characterize the particle size and its distribution of the sizing agent emulsion. Its average particle size is 279 nm, and the particle size distribution diagram is shown in Figure 2 .

[0041] Preparation of the composite material: Dilute the above sizing agent with deionized water to a sizing agent emulsion with a solid content of 2%. After treating the aramid fiber, evenly coat the epoxy resin on the aramid fiber tow, and then lay it flat in a hot pressing mold for hot pressing molding. The hot pressing process is as follows: First, pre-cure at 140 °C for 30 min, keep the pressure at 5 MPa, and then raise the temperature to 160 °C and keep it at a pressure of 10 MPa for 2 h for hot pressing and curing.

[0042] Example 3:

[0043] A method for preparing an emulsion-type aramid fiber sizing agent, the said method comprising the following steps:

[0044] Preparation of carboxyl-terminated polyaramide: Take isophthaloyl chloride and m-phenylenediamine monomers in a molar ratio of 1.25:1, dissolve them in the reaction solvent N,N-dimethylformamide, the molar concentration of the m-phenylenediamine monomer is 0.8 mol / L, add anhydrous calcium chloride and pyridine equimolar to the m-phenylenediamine monomer, react at -2 °C for 40 min under nitrogen conditions, pour the reaction solution into deionized water after the reaction is completed for stirring precipitation, the stirring time is 15 min, filter and wash thoroughly with deionized water, and dry in vacuum at 60 °C for 30 h to obtain carboxyl-terminated polyaramide.

[0045] Preparation of modified epoxy resin containing aromatic amide group: Weigh 2.2 parts of carboxyl-terminated polyarylamide, 22 parts of epoxy resin E-51, and 0.2 part of a catalyst of triphenylphosphine-tetrabutylammonium bromide with a weight ratio of 1:1, and add them to 40 parts of the reaction solvent propylene glycol monomethyl ether. The modification reaction is carried out under nitrogen conditions, with a reaction temperature of 120 °C and a reaction time of 15 h. After the reaction, low-boiling substances are removed by rotary evaporation to obtain the modified epoxy resin containing aromatic amide group. The structure of the modified epoxy resin containing aromatic amide group is:

[0046]

[0047] In the above structural formula, the structure of R is:

[0048]

[0049] Among them, 30 ≤ n ≤ 35 and 1.5 ≤ m ≤ 2.5.

[0050] Preparation of the sizing agent emulsion: Take 41 parts of deionized water, 9 parts of the modified epoxy resin containing aromatic amide group, and 1 part of a compound emulsifier (compounded from tw-80 and sp-20 in a weight ratio of 4:1) and mix them. Stir at 60 °C for 30 min at a stirring speed of 3000 r / min to obtain an emulsion-type aramid fiber sizing agent with a solid content of 18%. The particle size of the sizing agent emulsion is analyzed using a laser particle size analyzer, and its average particle size is 579 nm.

[0051] Preparation of the composite material: Dilute the above sizing agent with deionized water to a sizing agent emulsion with a solid content of 1%. After treating the aramid fiber, uniformly coat the epoxy resin on the aramid fiber tow, and then lay it flat in a hot pressing mold for hot pressing. The hot pressing process is as follows: First, pre-cure at 140 °C for 30 min while maintaining a pressure of 5 MPa, and then raise the temperature to 160 °C and maintain it at a pressure of 10 MPa for 2 h for hot pressing and curing.

[0052] Example 4:

[0053] A preparation method of an emulsion-type aramid fiber sizing agent, the method comprising the following steps:

[0054] Preparation of carboxyl-terminated polyarylamide: Take isophthaloyl chloride and m-phenylenediamine monomers in a molar ratio of 1.15:1, dissolve them in the reaction solvent N,N-dimethylformamide, with the molar concentration of m-phenylenediamine monomer being 0.9 mol / L. Add anhydrous calcium chloride and pyridine equimolar to the m-phenylenediamine monomer, and react at -5 °C for 50 min under nitrogen conditions. After the reaction, pour the reaction solution into deionized water for stirring precipitation for 15 min, filter and wash thoroughly with deionized water, and vacuum dry at 60 °C for 42 h to obtain carboxyl-terminated polyarylamide.

[0055] Preparation of modified epoxy resin containing aromatic amide group: Weigh 2.5 parts of carboxyl-terminated polyarylamide, 25 parts of epoxy resin E-51, and 0.15 part of a catalyst of triphenylphosphine-tetrabutylammonium bromide with a weight ratio of 1:1, and add them to 50 parts of the reaction solvent propylene glycol methyl ether. Carry out the modification reaction under nitrogen conditions, with a reaction temperature of 130 °C and a reaction time of 18 h. After the reaction, remove the low-boiling substances by rotary evaporation to obtain the modified epoxy resin containing aromatic amide group. The structure of the modified epoxy resin containing aromatic amide group is:

[0056]

[0057] In the above structural formula, the structure of R is:

[0058]

[0059] Among them, 25 ≤ n ≤ 30 and 1.5 ≤ m ≤ 2.5.

[0060] Preparation of the sizing agent emulsion: Take 39 parts of deionized water, 10 parts of the modified epoxy resin containing aromatic amide group, and 1 part of a compound emulsifier (op-10 and sp-20 are compounded in a weight ratio of 4:1) and mix them. Stir at 60 °C for 60 min with a stirring speed of 2000 r / min to obtain an emulsion-type aramid fiber sizing agent with a solid content of 10%. Analyze the particle size of the sizing agent emulsion using a laser particle size analyzer, and its average particle size is 627 nm.

[0061] Preparation of the composite material: Dilute the above sizing agent with deionized water to a sizing agent emulsion with a solid content of 1.5%. After treating the aramid fiber, uniformly coat the epoxy resin on the aramid fiber tow, and then lay it flat in a hot pressing mold for hot pressing. The hot pressing process is as follows: First, pre-cure at 140 °C for 30 min while maintaining a pressure of 5 MPa, and then raise the temperature to 160 °C and maintain it at a pressure of 10 MPa for 2 h for hot pressing and curing.

[0062] Comparative Example 1:

[0063] In order to further verify the performance of the emulsion-type aramid fiber sizing agent described in the present invention, aramid fiber / epoxy resin composites prepared from aramid fibers untreated with the sizing agent are used as a comparative example to compare the performance of the emulsion-type aramid fiber sizing agents in Examples 1 to 4. The interlaminar shear strength is referred to JC / T 773-2010 "Test Method for Interlaminar Shear Strength of Unidirectional Fiber Reinforced Plastics", and the prepared composite materials are cut into specimens with dimensions of 20 mm × 10 mm × 2 mm.

[0064] Table 1 shows the interlaminar shear strength of the composites prepared from the aramid fibers treated with the sizing agent in Examples 1 to 4 and the aramid fibers without sizing agent treatment in Comparative Example 1. It can be seen from Table 1 that after the surface of the aramid fibers is treated with the sizing agent of the present invention, the interlaminar shear strength of its composite material is significantly improved compared with the composite material prepared from the untreated aramid fibers, and the interlaminar shear strength is increased by 54.34% - 96.68%. The fiber sizing of the present invention can effectively improve the interfacial properties of the composite material.

[0065] Table 1 Interlaminar Shear Strength of Composite Material Samples Prepared in Examples 1 to 4 and Comparative Example 1

[0066] Sample Interlaminar Shear Strength (MPa) Example 1 95.75 Example 2 82.37 Example 3 102.31 Example 4 104.97 Comparative Example 1 53.37

[0067] In addition, it should be understood that although this specification is described according to the embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A preparation method of an emulsion-type sizing agent for aramid fibers, characterized in that, It includes the following steps: Step 1, preparation of carboxyl-terminated polyaramide: Using aromatic dicarboxylic acid dichloride and aromatic diamine as monomers for solution polymerization, neutralizing the generated HCl with a neutralizing agent, and obtaining carboxyl-terminated polyaramide by controlling the excess of aromatic dicarboxylic acid dichloride monomer; Step 2, preparation of modified epoxy resin containing arylamide group: Under high temperature and the action of a catalyst, the carboxyl group of the carboxyl-terminated polyaramide prepared in Step 1 reacts with the epoxy group of the epoxy resin, introducing the arylamide group into the epoxy resin structure to obtain a modified epoxy resin containing arylamide group; Step 3, uniformly stirring the modified epoxy resin containing arylamide group, deionized water and an emulsifier to obtain an emulsion-type sizing agent for aramid fiber.

2. The preparation method according to claim 1, wherein: In Step 1, take aromatic dicarboxylic acid dichloride monomer and aromatic diamine monomer in a molar ratio of (1.1 - 1.3):1, dissolve them in reaction solvent A, the molar concentration of the aromatic diamine monomer is 0.5 - 1 mol / L, add a neutralizing agent equimolar to the aromatic diamine monomer, react at -5 to 5 °C for 30 - 60 min under nitrogen conditions, after the reaction, pour the reaction solution into deionized water for stirring precipitation, filter and wash thoroughly with deionized water, and vacuum dry to obtain carboxyl-terminated polyaramide.

3. The preparation method according to claim 1, characterized in that: In Step 2, weigh 1 - 4 parts of carboxyl-terminated polyaramide, 10 - 40 parts of epoxy resin, and 0.1 - 0.4 parts of catalyst according to weight parts, add them to 30 - 60 parts of reaction solvent B, carry out a modification reaction under nitrogen conditions, the reaction temperature is 110 - 160 °C, the reaction time is 12 - 24 h, after the reaction, use rotary evaporation to remove low-boiling substances to obtain a modified epoxy resin containing arylamide group.

4. The preparation method according to claim 1, wherein: In Step 3, the emulsifier is a combination of one or more of a non-ionic emulsifier and an anionic emulsifier.

5. The preparation method according to claim 1 or 2, characterized in that: The aromatic dicarboxylic acid dichloride monomer includes one or a combination of two of terephthaloyl chloride and isophthaloyl chloride; the aromatic diamine monomer includes one or a combination of more of p-phenylenediamine, m-phenylenediamine, 4,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether; the neutralizing agent includes one or a combination of two of anhydrous calcium chloride and pyridine.

6. The preparation method according to claim 2, characterized in that: The reaction solvent A includes one of N-methylpyrrolidone, dimethylformamide, and dimethylacetamide.

7. The preparation method according to claim 1 or 3, characterized in that: The epoxy resin is a difunctional epoxy resin, and the catalyst is a catalytic system of triphenylphosphine and tetrabutylammonium bromide with a weight ratio of 1:

1.

8. The preparation method according to claim 3, characterized in that: The reaction solvent B is one of propylene glycol methyl ether and acetone.

9. The preparation method according to claim 1, characterized in that: In Step 3, the weight parts of the modified epoxy resin containing arylamide group, deionized water and the emulsifier are (1 - 10):(30 - 60):(1 - 2), and the temperature of the stirring reaction is 50 - 80 °C.

10. The preparation method according to claim 2, characterized in that: The temperature of the vacuum drying is 50 - 80 °C, and the time is 24 - 48 h.

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