Interface-enhanced carbon fiber sizing agent as well as preparation method and application method thereof

Abstract

The invention relates to an interface-enhanced carbon fiber sizing agent as well as a preparation method and an application method thereof, and belongs to the technical field of sizing agents. The interface enhanced carbon fiber sizing agent is prepared from the following components in parts by weight: 90 to 100 parts of epoxy resin, 5 to 10 parts of dicyandiamide and 30 to 50 parts of nonionic surfactant, wherein the epoxy value of the epoxy resin is not less than 0.4 mol / 100g; the nonionic surfactant comprises at least one of alkylphenol polyoxyethylene ether, fatty acid polyoxyethylene ether, polyethylene glycol and polypropylene glycol. The bonding capacity between the sizing agent and carbon fibers and matrix resin can be effectively enhanced, so that the interface performance of the carbon fiber composite material is effectively improved.

Description

Technical Field

[0001] The present application relates to the technical field of sizing agents, and in particular to an interface-enhanced carbon fiber sizing agent and a preparation method and an application method thereof. Background Art

[0002] Carbon fiber sizing agent plays a vital role in the appearance and process performance of carbon fiber and the comprehensive performance of carbon fiber composite materials. A polymer film will be formed on the surface of the fiber body after sizing treatment, which effectively controls the bundle shaping of the fiber, reduces the friction damage of the fiber during the production process, reduces the amount of lint, protects the surface of the fiber body and improves the processability and weaving performance.

[0003] Currently, after the fiber surface is treated with a sizing agent, it is then impregnated with a matrix resin to produce a carbon fiber composite material. However, the bonding ability between ordinary sizing agents and carbon fibers and matrix resins is not particularly strong, so that the interface performance of carbon fiber composite materials is not particularly high. Summary of the invention

[0004] In view of the deficiencies of the prior art, the purpose of the embodiments of the present application includes providing an interface-enhanced carbon fiber sizing agent and a preparation method and application method thereof, which can effectively enhance the bonding ability between the sizing agent and the carbon fiber and the matrix resin, thereby effectively improving the interface performance of the carbon fiber composite material.

[0005] In the first aspect, an embodiment of the present application provides an interface-enhanced carbon fiber sizing agent, comprising the following components in parts by weight: 90-100 parts of an epoxy resin, 5-10 parts of dicyandiamide, and 30-50 parts of a non-ionic surfactant; wherein the epoxy value of the epoxy resin is not less than 0.4 mol / 100 g; and the non-ionic surfactant comprises at least one of alkylphenol polyoxyethylene ether, fatty acid polyoxyethylene ether, polyethylene glycol, and polypropylene glycol.

[0006] The present application adopts an epoxy resin with an epoxy value of not less than 0.4 mol / 100g and dicyandiamide in a suitable weight combination to improve the reactivity of the sizing agent and enhance the bonding ability between the sizing agent and the carbon fiber and the matrix resin; and then combines a suitable weight of a non-ionic surfactant including at least one of alkylphenol polyoxyethylene ether, fatty acid polyoxyethylene ether, polyethylene glycol, and polypropylene glycol to enhance the compatibility between the epoxy resin and dicyandiamide, so that the epoxy resin and dicyandiamide can be evenly dispersed, and the stability and adhesion of the sizing agent are improved, so that it can be widely used to improve the interface performance of carbon fiber composite materials.

[0007] In some embodiments of the present application, the epoxy resin includes at least one of epoxy resin AG80, epoxy resin E51, and epoxy resin E44.

[0008] The present application adopts at least one of the above-mentioned epoxy resins, the epoxy value of which is not less than 0.4 mol / 100g, which can synergize with dicyandiamide to effectively improve the reactivity of the sizing agent and enhance the bonding ability between the sizing agent and the carbon fiber and the matrix resin.

[0009] In some embodiments of the present application, the alkylphenol polyoxyethylene ether includes at least one of NP-10, OP-8, OP-9, and OP-10.

[0010] In some embodiments of the present application, the fatty acid polyoxyethylene ether includes at least one of LAE-9, SG-50, and SG-6.

[0011] In some embodiments of the present application, the polyethylene glycol includes at least one of PEG-200, PEG-400, and PEG-600.

[0012] In some embodiments of the present application, the polypropylene glycol includes at least one of PPG-200, PPG-400, and PPG-600.

[0013] The present application adopts the above-mentioned alkylphenol polyoxyethylene ether, fatty acid polyoxyethylene ether, polyethylene glycol, and polypropylene glycol, which is beneficial to enhance the compatibility between epoxy resin and dicyandiamide, so that the epoxy resin and dicyandiamide can be evenly dispersed, effectively improve the stability and adhesion of the sizing agent, and make it widely applicable to improve the interface performance of carbon fiber composite materials.

[0014] In some embodiments of the present application, the sizing agent includes the following components in parts by weight: 95-100 parts of epoxy resin, 8-10 parts of dicyandiamide, and 30-40 parts of non-ionic surfactant.

[0015] The present application further adjusts the epoxy resin, dicyandiamide, and nonionic surfactant to a more appropriate weight ratio for synergy, which can further enhance the bonding ability between the sizing agent and the carbon fiber and the matrix resin, thereby further effectively improving the interface performance of the carbon fiber composite material.

[0016] In a second aspect, the present application embodiment provides a method for preparing an interface-enhanced carbon fiber sizing agent as provided in the first aspect, comprising:

[0017] (1) mixing epoxy resin, dicyandiamide and nonionic surfactant according to the above weight proportions to form a mixed solution;

[0018] (2) Adding water to the mixed solution to perform emulsification and phase inversion to form an interface-enhanced carbon fiber sizing agent.

[0019] The present application adopts the method of first mixing epoxy resin, dicyandiamide and nonionic surfactant into a mixed liquid, then adding water to the mixed liquid for emulsification and phase transition, so that the epoxy resin and dicyandiamide can be evenly dispersed with good compatibility, and a sizing agent with high stability and adhesion can be prepared.

[0020] In some embodiments of the present application, the preparation method includes stirring at 20-40° C. and 500-1000 rpm for mixing and emulsification.

[0021] The present application adopts suitable temperature and stirring speed for mixing and emulsification, which is conducive to uniform dispersion of epoxy resin and dicyandiamide, so as to prepare a sizing agent with high stability and adhesion.

[0022] In some embodiments of the present application, the particle size of the interface enhanced carbon fiber sizing agent is 200-500 nm.

[0023] The present application controls the particle size of the sizing agent emulsion within the range of 200-500 nm, so that the sizing agent can be more evenly dispersed, has better stability and adhesion, and improves the sizing effect on carbon fiber.

[0024] In a third aspect, the present application provides an application method of the interface-enhanced carbon fiber sizing agent provided in the first aspect, comprising:

[0025] (1) dipping the carbon fiber in an interface-enhanced carbon fiber sizing agent, and drying after sizing;

[0026] (2) Mixing a resin and a curing agent to form a resin mixture, impregnating the sizing carbon fiber with the resin mixture, and curing and molding the mixture to obtain a carbon fiber composite material; wherein the resin includes epoxy resin.

[0027] The present application applies the interface-enhanced carbon fiber sizing agent through the above method, which can be effectively adapted to the epoxy resin and has a high bonding ability. The obtained carbon fiber composite material has high interface performance.

[0028] In some embodiments of the present application, the content of the interface-enhanced carbon fiber sizing agent on the carbon fiber after sizing is 0.5%-1.0%.

[0029] The present application sets the content of the sizing agent on the carbon fiber after sizing to 0.5%-1.0%, thereby adjusting the hardness, fuzz, etc. of the carbon fiber and achieving a balance between the process performance and the interface performance of the carbon fiber.

[0030] In some embodiments of the present application, the interlaminar shear strength of the carbon fiber composite material is greater than 100 MPa.

[0031] The carbon fiber composite material prepared by using the interface-enhanced carbon fiber sizing agent provided in the present application has an interlaminar shear strength greater than 100 MPa and has high interface performance. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0033] An embodiment of the present application provides an interface-enhanced carbon fiber sizing agent, comprising the following components in parts by weight: 90-100 parts of epoxy resin, 5-10 parts of dicyandiamide, and 30-50 parts of non-ionic surfactant; wherein the epoxy value of the epoxy resin is not less than 0.4 mol / 100g; and the non-ionic surfactant comprises at least one of alkylphenol polyoxyethylene ether, fatty acid polyoxyethylene ether, polyethylene glycol, and polypropylene glycol.

[0034] The sizing agent adopts epoxy resin with an epoxy value of not less than 0.4 mol / 100g and dicyandiamide in appropriate weights to improve the reaction ability of the sizing agent and enhance the bonding ability between the sizing agent and the carbon fiber and the matrix resin; and is further combined with an appropriate weight of a nonionic surfactant including at least one of alkylphenol polyoxyethylene ether, fatty acid polyoxyethylene ether, polyethylene glycol, and polypropylene glycol to enhance the compatibility between the epoxy resin and dicyandiamide, so that the epoxy resin and dicyandiamide can be evenly dispersed, the stability and adhesion of the sizing agent are improved, and the sizing agent can be widely applicable to improve the interface performance of carbon fiber composite materials.

[0035] As an example, the weight of epoxy resin can be, but not limited to, 90, 92, 95, 98, or 100 parts. The weight of dicyandiamide can be, but not limited to, 5, 6, 7, 8, 9, or 10 parts. The weight of nonionic surfactant can be, but not limited to, 30, 32, 35, 38, 40, 42, 45, 48, or 50 parts.

[0036] In some embodiments of the present application, the epoxy resin includes at least one of epoxy resin AG80, epoxy resin E51, and epoxy resin E44. The at least one epoxy resin mentioned above, whose epoxy value is not less than 0.4 mol / 100 g, can synergize with dicyandiamide to effectively improve the reactivity of the sizing agent and enhance the bonding ability between the sizing agent and the carbon fiber and the matrix resin.

[0037] As an example, the alkylphenol polyoxyethylene ether includes at least one of NP-10, OP-8, OP-9, and OP-10. The fatty acid polyoxyethylene ether includes at least one of LAE-9, SG-50, and SG-6. Polyethylene glycol includes at least one of PEG-200, PEG-400, and PEG-600. Polypropylene glycol includes at least one of PPG-200, PPG-400, and PPG-600. The use of the above-mentioned alkylphenol polyoxyethylene ether, fatty acid polyoxyethylene ether, polyethylene glycol, and polypropylene glycol is conducive to enhancing the compatibility between epoxy resin and dicyandiamide, so that epoxy resin and dicyandiamide can be evenly dispersed, effectively improving the stability and adhesion of the sizing agent, so that it can be widely used to improve the interface performance of carbon fiber composite materials.

[0038] Further, the sizing agent includes the following components in parts by weight: 95-100 parts of epoxy resin, 8-10 parts of dicyandiamide, and 30-40 parts of nonionic surfactant. Further adjusting the epoxy resin, dicyandiamide, and nonionic surfactant to more suitable weight parts for coordination can further enhance the bonding ability between the sizing agent and the carbon fiber and the matrix resin, thereby further effectively improving the interface performance of the carbon fiber composite material.

[0039] The present application embodiment provides a method for preparing an interface-enhanced carbon fiber sizing agent as provided in the first aspect, comprising:

[0040] (1) mixing epoxy resin, dicyandiamide and nonionic surfactant according to the above weight proportions to form a mixed solution;

[0041] (2) Adding water to the mixed solution to perform emulsification and phase inversion to form an interface-enhanced carbon fiber sizing agent.

[0042] According to the above method, epoxy resin, dicyandiamide and nonionic surfactant are first mixed into a mixed liquid, and then water is added to the mixed liquid for emulsification and phase inversion, so that the epoxy resin and dicyandiamide are evenly dispersed and have good compatibility, thereby obtaining a sizing agent with high stability and adhesion.

[0043] In some embodiments of the present application, the preparation method includes mixing and emulsifying at 20-40° C. and 500-1000 rpm. The use of a suitable temperature and stirring speed for mixing and emulsifying is conducive to uniformly dispersing the epoxy resin and dicyandiamide to obtain a sizing agent with high stability and adhesion.

[0044] In some embodiments of the present application, the particle size of the interface-enhanced carbon fiber sizing agent is 200-500 nm. Controlling the particle size of the sizing agent emulsion within the range of 200-500 nm can make the sizing agent more evenly dispersed, have better stability and adhesion, and improve the sizing effect on the carbon fiber.

[0045] The present application embodiment provides an application method of the interface-enhanced carbon fiber sizing agent provided in the first aspect, comprising:

[0046] (1) dipping the carbon fiber in an interface-enhanced carbon fiber sizing agent, and drying after sizing;

[0047] (2) Mixing a resin and a curing agent to form a resin mixture, impregnating the sizing carbon fiber with the resin mixture, and curing and molding the mixture to obtain a carbon fiber composite material; wherein the resin includes epoxy resin.

[0048] The interface-enhanced carbon fiber sizing agent applied by the above method can be effectively adapted to the epoxy resin and has a high bonding ability, and the obtained carbon fiber composite material has a high interface performance.

[0049] In some embodiments of the present application, the content of the interface-enhanced carbon fiber sizing agent on the sizing carbon fiber is 0.5%-1.0%. As an example, the content of the interface-enhanced carbon fiber sizing agent on the sizing carbon fiber can be, but is not limited to, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%. Setting the content of the sizing agent on the sizing carbon fiber to 0.5%-1.0% can adjust the hardness, hairiness, etc. of the carbon fiber to achieve a balance between the process performance and interface performance of the carbon fiber.

[0050] In some embodiments of the present application, the interlaminar shear strength of the carbon fiber composite material is greater than 100 MPa. The interlaminar shear strength of the carbon fiber composite material prepared by applying the interface-enhanced carbon fiber sizing agent provided in the present application is greater than 100 MPa, and has high interface performance.

[0051] The features and performance of the present application are further described in detail below in conjunction with the embodiments.

[0052] Example 1

[0053] This embodiment provides an interface-enhanced carbon fiber sizing agent, and the preparation method thereof is as follows:

[0054] (1) 100 kg of epoxy resin AG80, 5 kg of dicyandiamide, and 30 kg of alkylphenol polyoxyethylene ether OP-10 were mixed at 30° C. and 600 rpm to form a mixed solution;

[0055] (2) Add water to the mixed solution, and continue to emulsify and invert the phase at 30° C. and 600 rpm to obtain a sizing agent with a particle size of 416 nm.

[0056] Example 2

[0057] This embodiment provides an interface-enhanced carbon fiber sizing agent, and the preparation method thereof is as follows:

[0058] (1) 100 kg of epoxy resin AG80, 10 kg of dicyandiamide, and 30 kg of fatty acid polyoxyethylene ether LAE-9 were mixed at 30° C. and 600 rpm to form a mixed solution;

[0059] (2) Add water to the mixed solution, and continue to emulsify and invert the phase at 30° C. and 600 rpm to obtain a sizing agent with a particle size of 483 nm.

[0060] Example 3

[0061] This embodiment provides an interface-enhanced carbon fiber sizing agent, and the preparation method thereof is as follows:

[0062] (1) 100 kg of epoxy resin E51, 5 kg of dicyandiamide, and 50 kg of polyethylene glycol PEG-400 were mixed at 30° C. and 600 rpm to form a mixed solution;

[0063] (2) Add water to the mixed solution, and continue to emulsify and invert the phase at 30° C. and 600 rpm to obtain a sizing agent with a particle size of 221 nm.

[0064] Example 4

[0065] This embodiment provides an interface-enhanced carbon fiber sizing agent, and the preparation method thereof is as follows:

[0066] (1) 100 kg of epoxy resin E44, 5 kg of dicyandiamide, and 30 kg of polypropylene glycol PPG-400 were mixed at 30° C. and 600 rpm to form a mixed solution;

[0067] (2) Add water to the mixed solution, and continue to emulsify and invert the phase at 30° C. and 600 rpm to obtain a sizing agent with a particle size of 403 nm.

[0068] Comparative Example 1

[0069] This comparative example provides a carbon fiber sizing agent, which is different from Example 1 in that no dicyandiamide is added.

[0070] Comparative Example 2

[0071] This comparative example provides a carbon fiber sizing agent, which is different from Example 1 in that the epoxy resin AG80 is replaced by epoxy resin E35.

[0072] Comparative Example 3

[0073] This comparative example provides a carbon fiber sizing agent, which is different from Example 1 in that alkylphenol polyoxyethylene ether OP-10 is replaced by polysorbate 80.

[0074] Comparative Example 4

[0075] This comparative example provides a carbon fiber sizing agent, which is different from Example 1 in that 2 kg of dicyandiamide is taken.

[0076] Comparative Example 5

[0077] This comparative example provides a carbon fiber sizing agent, which is different from Example 1 in that 15 kg of dicyandiamide is taken.

[0078] Comparative Example 6

[0079] This comparative example provides a carbon fiber sizing agent, which is different from Example 1 in that 20 kg of alkylphenol polyoxyethylene ether OP-10 is taken.

[0080] Comparative Example 7

[0081] This comparative example provides a carbon fiber sizing agent, which is different from Example 1 in that 60 kg of alkylphenol polyoxyethylene ether OP-10 is taken.

[0082] Test Example 1

[0083] This test example tests the stability of the sizing agents provided in Examples 1-4 and Comparative Examples 1-7, and the specific method is: take an appropriate amount of diluted sizing agent in a test tube, let it stand at room temperature for 72 hours, and observe whether it is stratified (including no stratification, slight stratification, obvious stratification). The results are shown in Table 1.

[0084] Table 1 Sizing agents provided by Examples 1-4 and Comparative Examples 1-7

[0085]

[0086] As can be seen from the results in Table 1, the sizing agents provided in Examples 1-4 are relatively stable and not stratified. However, after the nonionic surfactant alkylphenol polyoxyethylene ether OP-10 was replaced with polysorbate-80 in Comparative Example 3, the sizing agent was unstable and obvious stratification occurred; the amount of dicyandiamide added was increased in Comparative Example 5, and the sizing agent was unstable and slight stratification occurred; the amount of nonionic surfactant added was reduced in Comparative Example 6, and the sizing agent was unstable and obvious stratification occurred. It is explained that the present application adopts epoxy resin and dicyandiamide to coordinate according to appropriate weights, and then cooperates with an appropriate weight of nonionic surfactant including at least one of alkylphenol polyoxyethylene ether, fatty acid polyoxyethylene ether, polyethylene glycol, and polypropylene glycol, which can enhance the compatibility between epoxy resin and dicyandiamide, so that epoxy resin and dicyandiamide can be evenly dispersed, thereby obtaining a stable sizing agent.

[0087] Test Example 2

[0088] This test example tests the performance of the sizing agents provided in Examples 1-4 and Comparative Examples 1-7. The specific method is: the same carbon fiber is immersed in the sizing agents provided in Examples 1-4 and Comparative Examples 1-7 for testing. The wear resistance is defined as the mass of the remaining hairs of 50m carbon fiber after passing through a certain pressure filter membrane, and the tensile strength is based on GB / T 3362-2017. The results are shown in Table 2.

[0089] Table 2 Sizing agent properties

[0090] sample Sizing agent content on carbon fiber (%) Wear resistance(mg) Tensile strength(Mpa) Example 1 0.98 2.2 5138 Example 2 0.90 2.9 5205 Example 3 0.95 3.2 4978 Example 4 0.51 3.1 5056 Comparative Example 1 0.93 2.1 4711 Comparative Example 2 0.98 2.5 4892 Comparative Example 3 0.98 2.8 4780 Comparative Example 4 0.74 3.4 4756 Comparative Example 5 0.98 5.1 4912 Comparative Example 6 0.93 3.5 4863 Comparative Example 7 0.88 5.2 4711

[0091] It can be seen from the results in Table 2 that after the sizing agents provided in Examples 1-4 are applied to carbon fibers, their wear resistance and tensile strength are both high. In Comparative Example 1, after the sizing agent without adding dicyandiamide was applied to the carbon fiber, its tensile strength was greatly reduced; in Comparative Example 2, after the epoxy resin AG80 with an epoxy value of not less than 0.4 mol / 100g was replaced with the sizing agent of epoxy resin E35 and applied to the carbon fiber, its tensile strength was reduced; in Comparative Example 3, after the non-ionic surfactant alkylphenol polyoxyethylene ether OP-10 was replaced with polysorbate-80 and applied to the carbon fiber, its tensile strength was reduced to a certain extent; in Comparative Example 4, after the sizing agent with reduced dicyandiamide addition was applied to the carbon fiber, its wear resistance and tensile strength were reduced to a certain extent; in Comparative Example 5, after the sizing agent with increased dicyandiamide addition was applied to the carbon fiber, its wear resistance was greatly reduced, and the tensile strength was also reduced to a certain extent; in Comparative Example 6, after the sizing agent with reduced non-ionic surfactant addition was applied to the carbon fiber, its wear resistance and tensile strength were reduced; in Comparative Example 7, after the sizing agent with increased non-ionic surfactant addition was applied to the carbon fiber, its wear resistance and tensile strength were greatly reduced.

[0092] It is explained that the present application adopts an epoxy resin with an epoxy value of not less than 0.4 mol / 100g and dicyandiamide in a suitable weight combination to improve the reactivity of the sizing agent and enhance the bonding ability between the sizing agent and the carbon fiber; and then combined with a suitable weight of a non-ionic surfactant including at least one of alkylphenol polyoxyethylene ether, fatty acid polyoxyethylene ether, polyethylene glycol, and polypropylene glycol, the compatibility between the epoxy resin and dicyandiamide can be enhanced, the epoxy resin and dicyandiamide can be evenly dispersed, the stability and adhesion of the sizing agent are improved, and it can improve the interface performance of the carbon fiber.

[0093] Implementation Group 1

[0094] (1) The carbon fibers were respectively impregnated with the sizing agents provided in Examples 1-4 and Comparative Examples 1-7 (see Table 1), and then dried after sizing;

[0095] (2) Epoxy resin E51 and curing agent DDS are mixed to form an epoxy resin mixture, and the sized carbon fibers are impregnated with the epoxy resin mixture, and cured to obtain carbon fiber composite materials. The performance of each carbon fiber composite material is tested according to the national standard GB / T30969-2014, as shown in Table 3.

[0096] Table 3 Sizing agent properties

[0097]

[0098]

[0099] From the results in Table 3, it can be seen that after the sizing agents provided in Examples 1-4 are used to prepare carbon fiber composite materials, the interlaminar shear strength thereof is relatively high, reaching above 100 MPa. In comparative example 1, after the sizing agent without adding dicyandiamide was used to prepare the carbon fiber composite material, its interlaminar shear strength was greatly reduced; in comparative example 2, after the epoxy resin AG80 with an epoxy value of not less than 0.4 mol / 100g was replaced by the sizing agent of epoxy resin E35 and applied to the preparation of the carbon fiber composite material, its interlaminar shear strength was reduced to a certain extent; in comparative example 3, after the non-ionic surfactant alkylphenol polyoxyethylene ether OP-10 was replaced by polysorbate-80 and applied to the preparation of the carbon fiber composite material, its interlaminar shear strength was reduced to a certain extent; in comparative example 4, after the sizing agent with reduced dicyandiamide addition was applied to the preparation of the carbon fiber composite material, its interlaminar shear strength was reduced to a certain extent; in comparative example 5, after the sizing agent with increased dicyandiamide addition was applied to the preparation of the carbon fiber composite material, its interlaminar shear strength was reduced to a certain extent; in comparative example 6, after the sizing agent with reduced nonionic surfactant addition was applied to the preparation of the carbon fiber composite material, its interlaminar shear strength was reduced to a certain extent; in comparative example 7, after the sizing agent with increased nonionic surfactant addition was applied to the preparation of the carbon fiber composite material, its interlaminar shear strength was greatly reduced.

[0100] It is explained that the present application adopts an epoxy resin with an epoxy value of not less than 0.4 mol / 100g and dicyandiamide in a suitable weight combination to improve the reactivity of the sizing agent and enhance the bonding ability between the sizing agent and the carbon fiber and the matrix resin; and then combined with a suitable weight of a non-ionic surfactant including at least one of alkylphenol polyoxyethylene ether, fatty acid polyoxyethylene ether, polyethylene glycol, and polypropylene glycol, the compatibility between the epoxy resin and dicyandiamide can be enhanced, the epoxy resin and dicyandiamide can be evenly dispersed, the stability and adhesion of the sizing agent can be improved, and it can be widely used to improve the interface performance of carbon fiber composite materials.

[0101] The embodiments described above are part of the embodiments of the present application, rather than all of the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

Claims

1. An interface-enhanced carbon fiber sizing agent, characterized in that: The invention comprises the following components in parts by weight: 90-100 parts of epoxy resin, 5-10 parts of dicyandiamide, and 30-50 parts of nonionic surfactant; Wherein, the epoxy value of the epoxy resin is not less than 0.4 mol / 100g; The nonionic surfactant includes at least one of alkylphenol polyoxyethylene ether, fatty acid polyoxyethylene ether, polyethylene glycol, and polypropylene glycol.

2. The interface-enhanced carbon fiber sizing agent according to claim 1, characterized in that: The epoxy resin includes at least one of epoxy resin AG80, epoxy resin E51, and epoxy resin E44.

3. The interface-enhanced carbon fiber sizing agent according to claim 1, characterized in that: The alkylphenol polyoxyethylene ether includes at least one of NP-10, OP-8, OP-9 and OP-10; And / or, the fatty acid polyoxyethylene ether includes at least one of LAE-9, SG-50, and SG-6; And / or, the polyethylene glycol includes at least one of PEG-200, PEG-400, and PEG-600; And / or, the polypropylene glycol includes at least one of PPG-200, PPG-400, and PPG-600.

4. The interface-enhanced carbon fiber sizing agent according to claim 1, characterized in that: The sizing agent comprises the following components in parts by weight: 95-100 parts of epoxy resin, 8-10 parts of dicyandiamide, and 30-40 parts of nonionic surfactant.

5. A method for preparing an interface-enhanced carbon fiber sizing agent according to any one of claims 1 to 4, characterized in that: include: (1) mixing the epoxy resin, the dicyandiamide, and the nonionic surfactant according to the above weight proportions to form a mixed liquid; (2) adding water to the mixed solution to perform emulsification and phase inversion to form the interface-enhanced carbon fiber sizing agent.

6. The preparation method according to claim 5, characterized in that: The preparation method comprises stirring at 20-40° C. and 500-1000 rpm for mixing and emulsification.

7. The preparation method according to claim 5, characterized in that: The particle size of the interface-enhanced carbon fiber sizing agent is 200-500 nm.

8. A method for applying the interface-enhanced carbon fiber sizing agent according to any one of claims 1 to 4, characterized in that: include: (1) dipping the carbon fiber into the interface-enhanced carbon fiber sizing agent, and drying after sizing; (2) mixing a resin and a curing agent to form a resin mixture, impregnating the sized carbon fiber with the resin mixture, and curing and molding the carbon fiber composite material; Wherein, the resin includes epoxy resin.

9. The application method according to claim 8, characterized in that: The content of the interface-enhanced carbon fiber sizing agent on the carbon fiber after sizing is 0.5%-1.0%.

10. The application method according to claim 8 or 9, characterized in that: The interlaminar shear strength of the carbon fiber composite material is greater than 100 MPa.

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