Carbon fiber sizing agent as well as preparation method and application thereof

Abstract

The invention discloses a carbon fiber sizing agent and a preparation method and application thereof, particularly relates to the technical field of carbon fiber sizing agents, and is characterized in that the carbon fiber sizing agent is prepared from epoxy resin and auxiliaries, the epoxy resin is at least one of bisphenol A epoxy resin or phenolic aldehyde modified epoxy resin, and the auxiliaries are epoxy resin. The auxiliaries comprise a flexibilizer, a soaking agent, a softening agent, a moisture absorbent and an emulsifier, the flexibilizer is one or more of polyether polyol or hydroxyl-terminated polybutadiene, the soaking agent is a nonionic surfactant, the softening agent is one or more of fatty acid ester or fatty acid amide, and the moisture absorbent is one or more of polyisobutylene or polyisobutylene. The moisture absorbent is one or more of glycerol or sorbitol, the emulsifier is a nonionic surfactant, the concentration of the sizing agent is easy to control, the binding force between the sizing agent and the carbon fiber surface is strong, and the compatibility between the sizing agent and a resin matrix is good.

Description

Technical Field

[0001] This invention relates to the field of carbon fiber sizing agents, and more specifically, to carbon fiber sizing agents, their preparation methods, and applications. Background Technology

[0002] Carbon fiber has excellent mechanical properties and corrosion resistance, and is widely used in aerospace, defense and military industries. However, carbon fiber has a smooth surface and strong hydrophobicity, resulting in poor interfacial bonding with the resin matrix, which limits its full performance. Therefore, sizing treatment of carbon fiber to improve its interfacial bonding with the resin matrix has become a key step in the preparation of carbon fiber composite materials.

[0003] Currently, carbon fiber sizing agents mainly use epoxy resin and bismaleimide resin as the main components, with the addition of toughening agents, impregnating agents, and other additives. However, existing sizing agents have some shortcomings, such as: difficulty in controlling the sizing agent concentration: too high a concentration will affect the fiber opening performance of carbon fibers, while too low a concentration will affect their bundling and abrasion resistance. Insufficient bonding force between the sizing agent and the carbon fiber surface: this leads to easy fiber breakage and fuzzing, affecting its appearance and processing performance. Poor compatibility between the sizing agent and the resin matrix: this results in weak interfacial bonding and low interlaminar shear strength in the composite material.

[0004] Therefore, carbon fiber sizing agents, their preparation methods, and applications are proposed to address the above-mentioned problems. Summary of the Invention

[0005] In order to overcome the above-mentioned defects of the prior art, the present invention provides a carbon fiber sizing agent, its preparation method and application, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a carbon fiber sizing agent, characterized in that it is prepared from the following components: epoxy resin and additives, wherein the epoxy resin is at least one of bisphenol A type epoxy resin or phenolic modified epoxy resin, and the additives include toughening agents, impregnating agents, softeners, hygroscopic agents and emulsifiers, wherein the toughening agent is one or more of polyether polyols or hydroxyl-terminated polybutadiene, the impregnating agent is a nonionic surfactant, the softener is one or more of fatty acid esters or fatty acid amides, the hygroscopic agent is one or more of glycerol or sorbitol, and the emulsifier is a nonionic surfactant.

[0007] As a further preferred embodiment of the present invention, the carbon fiber sizing agent is prepared from the following components in parts by weight: 40-60 parts by weight of epoxy resin, 10-20 parts by weight of toughening agent, 5-10 parts by weight of softener, 5-10 parts by weight of impregnating agent, 1-5 parts by weight of hygroscopic agent, and 0.5-1 parts by weight of emulsifier.

[0008] As a further preferred embodiment of the present invention, the carbon fiber sizing agent is prepared from the following components in parts by weight: 30-80 parts by weight of epoxy resin, 5-30 parts by weight of toughening agent, 2-15 parts by weight of softener, 2-15 parts by weight of impregnating agent, 0.5-10 parts by weight of hygroscopic agent, and 0.2-1.5 parts by weight of emulsifier.

[0009] A method for preparing a carbon fiber sizing agent, characterized in that the preparation method includes: Step 1, Mixing process: The epoxy resin, toughening agent, impregnating agent, softener and hygroscopic agent are mixed evenly to prepare a base resin solution; Step 2, emulsifier dissolution: Dissolve the emulsifier in water to prepare an emulsifier solution; Step 3, Emulsification: Slowly add the base resin solution to the emulsifier solution while stirring continuously until a uniform emulsion is formed; Step 4, Pulping: Sizing carbon fiber is prepared by impregnating carbon fiber in an emulsion and then drying and curing it.

[0010] As a further preferred embodiment of the present invention, in step 1: the epoxy resin, toughening agent, impregnating agent, softener and hygroscopic agent are mixed in a mixer at a speed of 200-280 r / min and stirred for 3-5 min.

[0011] As a further preferred embodiment of the present invention, in step 3: emulsification is performed for 30 to 120 minutes at a temperature of 15 to 35°C using an emulsifier at a speed of 8000 to 12000 rpm.

[0012] As a further preferred embodiment of the present invention, in step 4: the drying temperature is 130~160℃, the drying time is 30~60s, and the heating and curing temperature is 180~220℃, the heating time is 30~60s.

[0013] The application of carbon fiber sizing agents involves prepreg processes such as layup and curing to produce composite materials.

[0014] The application of carbon fiber sizing agents involves mixing sized carbon fibers with a resin matrix to produce composite prepreg.

[0015] The technical effects and advantages of this invention are as follows: 1. Compared with existing technologies, the carbon fiber sizing agent, its preparation method and application, the concentration of the sizing agent is easy to control. By adjusting the proportion of each component, sizing agents of different concentrations can be prepared to meet different application requirements.

[0016] 2. Compared with existing technologies, this carbon fiber sizing agent, its preparation method and application have a strong bonding force between the sizing agent and the carbon fiber surface: the toughening agent and the impregnating agent can improve the bonding force between the sizing agent and the carbon fiber surface and reduce the phenomenon of fiber breakage and fuzzing.

[0017] 3. Compared with existing technologies, this carbon fiber sizing agent, its preparation method and application have good compatibility with the resin matrix: the epoxy resin and the resin matrix have good compatibility, which can improve the interfacial bonding force of the composite material and enhance the interlaminar shear strength. Attached Figure Description

[0018] Figure 1 A schematic flowchart of the preparation method of carbon fiber sizing agent is provided for embodiments of the present invention. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Example 1 Carbon fiber sizing agent is prepared from the following components: epoxy resin and additives, wherein the epoxy resin is at least one of bisphenol A type epoxy resin or phenolic modified epoxy resin, and the additives include toughening agent, impregnating agent, softener, hygroscopic agent and emulsifier, wherein the toughening agent is one or more of polyether polyol or hydroxyl-terminated polybutadiene, the impregnating agent is a nonionic surfactant, the softener is one or more of fatty acid ester or fatty acid amide, the hygroscopic agent is one or more of glycerol or sorbitol, and the emulsifier is a nonionic surfactant; the toughening agent can improve the softness and flexibility of the resin, reduce brittleness, and enhance cold resistance and elongation at break; the impregnating agent has strong penetration, wetting, dispersion and certain refining auxiliary effects, and can reduce the surface tension of the liquid, making the solid material easier to impregnate; the softener can replenish the natural oils lost by the natural fibers during processing, and improve smoothness and strength; the hygroscopic agent can control humidity and prevent moisture.

[0021] The carbon fiber sizing agent is prepared from the following components in parts by weight: 40 parts by weight of epoxy resin, 10 parts by weight of toughening agent, 5 parts by weight of softener, 5 parts by weight of impregnating agent, 1 part by weight of hygroscopic agent, and 0.5 parts by weight of emulsifier.

[0022] A method for preparing a carbon fiber sizing agent, characterized in that the preparation method includes: Step 1, Mixing process: The epoxy resin, toughening agent, impregnating agent, softener and hygroscopic agent are mixed evenly to prepare a base resin solution; Step 2, emulsifier dissolution: Dissolve the emulsifier in water to prepare an emulsifier solution; Step 3, Emulsification: Slowly add the base resin solution to the emulsifier solution while stirring continuously until a uniform emulsion is formed; Step 4, Pulping: Sizing carbon fiber is prepared by impregnating carbon fiber in an emulsion and then drying and curing it.

[0023] In step 1: the epoxy resin, toughening agent, impregnating agent, softener and hygroscopic agent are mixed in a mixer at a speed of 200 r / min and stirred for 3 min.

[0024] In step 3: Emulsify the product at 15°C for 30 minutes using an emulsifier at 8000 rpm.

[0025] In step 4: the drying temperature is 130~160℃, the drying time is 30s, and the heating curing temperature is 180℃, the heating time is 30s.

[0026] The application of carbon fiber sizing agents involves prepreg processes such as layup and curing to produce composite materials.

[0027] Example 2 Carbon fiber sizing agent is prepared from the following components: epoxy resin and additives, wherein the epoxy resin is at least one of bisphenol A type epoxy resin or phenolic modified epoxy resin, and the additives include toughening agent, impregnating agent, softener, hygroscopic agent and emulsifier, wherein the toughening agent is one or more of polyether polyol or hydroxyl-terminated polybutadiene, the impregnating agent is a nonionic surfactant, the softener is one or more of fatty acid ester or fatty acid amide, the hygroscopic agent is one or more of glycerol or sorbitol, and the emulsifier is a nonionic surfactant; the toughening agent can improve the softness and flexibility of the resin, reduce brittleness, and enhance cold resistance and elongation at break; the impregnating agent has strong penetration, wetting, dispersion and certain refining auxiliary effects, and can reduce the surface tension of the liquid, making the solid material easier to impregnate; the softener can replenish the natural oils lost by the natural fibers during processing, and improve smoothness and strength; the hygroscopic agent can control humidity and prevent moisture.

[0028] The carbon fiber sizing agent is prepared from the following components in parts by weight: 60 parts by weight of epoxy resin, 20 parts by weight of toughening agent, 10 parts by weight of softener, 10 parts by weight of impregnating agent, 5 parts by weight of hygroscopic agent, and 1 part by weight of emulsifier.

[0029] A method for preparing a carbon fiber sizing agent, characterized in that the preparation method includes: Step 1, Mixing process: The epoxy resin, toughening agent, impregnating agent, softener and hygroscopic agent are mixed evenly to prepare a base resin solution; Step 2, emulsifier dissolution: Dissolve the emulsifier in water to prepare an emulsifier solution; Step 3, Emulsification: Slowly add the base resin solution to the emulsifier solution while stirring continuously until a uniform emulsion is formed; Step 4, Pulping: Sizing carbon fiber is prepared by impregnating carbon fiber in an emulsion and then drying and curing it.

[0030] In step 1: the epoxy resin, toughening agent, impregnating agent, softener and hygroscopic agent are mixed in a mixer at a speed of 280 r / min and stirred for 5 min.

[0031] In step 3: Emulsify the product at 35°C for 120 minutes using an emulsifier at 12000 rpm.

[0032] In step 4: the drying temperature is 160℃ and the drying time is 60s, and the heating and curing temperature is 220℃ and the heating time is 60s.

[0033] The application of carbon fiber sizing agents involves prepreg processes such as layup and curing to produce composite materials.

[0034] Example 3 Carbon fiber sizing agent is prepared from the following components: epoxy resin and additives, wherein the epoxy resin is at least one of bisphenol A type epoxy resin or phenolic modified epoxy resin, and the additives include toughening agent, impregnating agent, softener, hygroscopic agent and emulsifier, wherein the toughening agent is one or more of polyether polyol or hydroxyl-terminated polybutadiene, the impregnating agent is a nonionic surfactant, the softener is one or more of fatty acid ester or fatty acid amide, the hygroscopic agent is one or more of glycerol or sorbitol, and the emulsifier is a nonionic surfactant; the toughening agent can improve the softness and flexibility of the resin, reduce brittleness, and enhance cold resistance and elongation at break; the impregnating agent has strong penetration, wetting, dispersion and certain refining auxiliary effects, and can reduce the surface tension of the liquid, making the solid material easier to impregnate; the softener can replenish the natural oils lost by the natural fibers during processing, and improve smoothness and strength; the hygroscopic agent can control humidity and prevent moisture.

[0035] The carbon fiber sizing agent is prepared from the following components in parts by weight: 30 parts by weight of epoxy resin, 5 parts by weight of toughening agent, 2 parts by weight of softener, 2 parts by weight of impregnating agent, 0.5 parts by weight of hygroscopic agent, and 0.2 parts by weight of emulsifier.

[0036] A method for preparing a carbon fiber sizing agent, characterized in that the preparation method includes: Step 1, Mixing process: The epoxy resin, toughening agent, impregnating agent, softener and hygroscopic agent are mixed evenly to prepare a base resin solution; Step 2, emulsifier dissolution: Dissolve the emulsifier in water to prepare an emulsifier solution; Step 3, Emulsification: Slowly add the base resin solution to the emulsifier solution while stirring continuously until a uniform emulsion is formed; Step 4, Pulping: Sizing carbon fiber is prepared by impregnating carbon fiber in an emulsion and then drying and curing it.

[0037] In step 1: the epoxy resin, toughening agent, impregnating agent, softener and hygroscopic agent are mixed in a mixer at a speed of 200 r / min and stirred for 3 min.

[0038] In step 3: Emulsify the product at 15°C for 30 minutes using an emulsifier at 8000 rpm.

[0039] In step 4: the drying temperature is 130℃ and the drying time is 30s, and the heating and curing temperature is 180℃ and the heating time is 30s.

[0040] The application of carbon fiber sizing agents involves mixing sized carbon fibers with a resin matrix to produce composite prepreg.

[0041] Example 4 Carbon fiber sizing agent is prepared from the following components: epoxy resin and additives, wherein the epoxy resin is at least one of bisphenol A type epoxy resin or phenolic modified epoxy resin, and the additives include toughening agent, impregnating agent, softener, hygroscopic agent and emulsifier, wherein the toughening agent is one or more of polyether polyol or hydroxyl-terminated polybutadiene, the impregnating agent is a nonionic surfactant, the softener is one or more of fatty acid ester or fatty acid amide, the hygroscopic agent is one or more of glycerol or sorbitol, and the emulsifier is a nonionic surfactant; the toughening agent can improve the softness and flexibility of the resin, reduce brittleness, and enhance cold resistance and elongation at break; the impregnating agent has strong penetration, wetting, dispersion and certain refining auxiliary effects, and can reduce the surface tension of the liquid, making the solid material easier to impregnate; the softener can replenish the natural oils lost by the natural fibers during processing, and improve smoothness and strength; the hygroscopic agent can control humidity and prevent moisture.

[0042] The carbon fiber sizing agent is prepared from the following components in parts by weight: 80 parts by weight of epoxy resin, 30 parts by weight of toughening agent, 15 parts by weight of softener, 15 parts by weight of impregnating agent, 10 parts by weight of hygroscopic agent, and 1.5 parts by weight of emulsifier.

[0043] A method for preparing a carbon fiber sizing agent, characterized in that the preparation method includes: Step 1, Mixing process: The epoxy resin, toughening agent, impregnating agent, softener and hygroscopic agent are mixed evenly to prepare a base resin solution; Step 2, emulsifier dissolution: Dissolve the emulsifier in water to prepare an emulsifier solution; Step 3, Emulsification: Slowly add the base resin solution to the emulsifier solution while stirring continuously until a uniform emulsion is formed; Step 4, Pulping: Sizing carbon fiber is prepared by impregnating carbon fiber in an emulsion and then drying and curing it.

[0044] In step 1: the epoxy resin, toughening agent, impregnating agent, softener and hygroscopic agent are mixed in a mixer at a speed of 280 r / min and stirred for 5 min.

[0045] In step 3: Emulsify the product at 35°C for 120 minutes using an emulsifier at 12000 rpm.

[0046] In step 4: the drying temperature is 160℃ and the drying time is 60s, and the heating and curing temperature is 220℃ and the heating time is 60s.

[0047] The application of carbon fiber sizing agents involves mixing sized carbon fibers with a resin matrix to produce composite prepreg.

[0048] Among them are bisphenol A type epoxy resin (model E-51, produced by Yueyang Petrochemical) and nonionic surfactant (Pingpingjia O-10).

[0049] Table 1. Performance test results of sizing agents in each example and comparative example. Sizing agent concentration (solid content) test: The solid content of the emulsion was determined using the drying method according to GB / T2793 standard. The results showed that the solid content of the sizing agent prepared by this invention could be controlled between 40% and 50%, and the emulsion had good stability, showing no stratification after standing for 30 days.

[0050] Interfacial bonding strength (interlaminar shear strength ILSS) test: The sized carbon fibers were made into unidirectional composite prepregs, and the interlaminar shear strength (ILSS) was tested according to GB / T3354 standard. The test results showed that the carbon fiber composite treated with the sizing agent of this invention achieved an ILSS value of over 84 MPa, which was approximately 35% higher than the comparative example, indicating good compatibility between the sizing agent and the resin matrix, and significantly enhanced interfacial bonding. Fiber opening / bundling property (fiber breakage rate) test: The surface morphology of carbon fibers after sizing was observed using a laser scanning microscope. The results showed that the carbon fibers treated by this invention had a uniform surface film and good monofilament dispersion (fiber opening). In the weaving process, the average number of fuzzy fibers was less than 2 per meter, and the breakage rate was significantly reduced, demonstrating excellent bundle cohesion and abrasion resistance.

[0051] Wetting (contact angle) test: The contact angle of the sizing agent emulsion on the carbon fiber surface was tested using a contact angle meter. The contact angle of Example 1 was 45.5°, while that of the comparative example was 68.0°. The lower contact angle indicates that the impregnating agent added in this invention effectively reduces surface tension and significantly improves the wetting performance of the sizing agent on the carbon fiber.

[0052] The working process of this invention is as follows: Epoxy resin, toughening agent, impregnating agent, softener, and hygroscopic agent are mixed in a mixer at a speed of 200-280 r / min for 3-5 minutes to prepare a base resin solution. An emulsifier is dissolved in water to prepare an emulsifier solution. The base resin solution is slowly added to the emulsifier solution while continuously stirring until a uniform emulsion is formed. The emulsification process is carried out at a temperature of 15-35°C using an emulsifier at a speed of 8000-12000 rpm for 30-120 minutes. Carbon fibers are then impregnated in the emulsion and subjected to drying and curing steps to obtain sized carbon fibers. The drying temperature is 130-160°C, and the drying time is 30-60 seconds. The curing temperature is 180-220°C, and the curing time is 30-60 seconds. The above describes the working principle of this carbon fiber sizing agent, its preparation method, and its application.

Claims

1. A carbon fiber sizing agent, characterized in that, It is prepared from the following components: epoxy resin and additives, wherein the epoxy resin is at least one of bisphenol A type epoxy resin or phenolic modified epoxy resin, and the additives include toughening agents, penetrating agents, softeners, hygroscopic agents and emulsifiers, wherein the toughening agent is one or more of polyether polyols or hydroxyl-terminated polybutadiene, the penetrating agent is a nonionic surfactant, the softener is one or more of fatty acid esters or fatty acid amides, the hygroscopic agent is one or more of glycerol or sorbitol, and the emulsifier is a nonionic surfactant.

2. The carbon fiber sizing agent according to claim 1, characterized in that, The carbon fiber sizing agent is prepared from the following components in parts by weight: 40-60 parts by weight of epoxy resin, 10-20 parts by weight of toughening agent, 5-10 parts by weight of softener, 5-10 parts by weight of impregnating agent, 1-5 parts by weight of hygroscopic agent, and 0.5-1 parts by weight of emulsifier.

3. The carbon fiber sizing agent according to claim 1, characterized in that, The carbon fiber sizing agent is prepared from the following components in parts by weight: 30-80 parts by weight of epoxy resin, 5-30 parts by weight of toughening agent, 2-15 parts by weight of softener, 2-15 parts by weight of impregnating agent, 0.5-10 parts by weight of hygroscopic agent, and 0.2-1.5 parts by weight of emulsifier.

4. The method for preparing the carbon fiber sizing agent according to any one of claims 1, characterized in that, The preparation method includes: Step 1, Mixing process: The epoxy resin, toughening agent, impregnating agent, softener and hygroscopic agent are mixed evenly to prepare a base resin solution; Step 2, emulsifier dissolution: Dissolve the emulsifier in water to prepare an emulsifier solution; Step 3, Emulsification: Slowly add the base resin solution to the emulsifier solution while stirring continuously until a uniform emulsion is formed; Step 4, Pulping: Sizing carbon fiber is prepared by impregnating carbon fiber in an emulsion and then drying and curing it.

5. The method for preparing the carbon fiber sizing agent according to claim 4, characterized in that, In step 1: the epoxy resin, toughening agent, impregnating agent, softener and hygroscopic agent are mixed in a mixer at a speed of 200-280 r / min for 3-5 minutes.

6. The method for preparing the carbon fiber sizing agent according to claim 4, characterized in that, In step 3: at a temperature of 15~35℃, emulsify the product using an emulsifier at a speed of 8000~12000rpm for 30~120min.

7. The method for preparing the carbon fiber sizing agent according to claim 4, characterized in that, In step 4: the drying temperature is 130~160℃, the drying time is 30~60s, and the heating curing temperature is 180~220℃, the heating time is 30~60s.

8. The application of the carbon fiber sizing agent according to any one of claims 1-7, characterized in that, Prepregs are layered and cured to produce composite materials.

9. The application of the carbon fiber sizing agent according to claim 8, characterized in that, Sizing carbon fibers are mixed with a resin matrix to produce a composite prepreg.

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