Sizing agent raw material composition and sizing agent and method for producing the same

Abstract

The present application relates to the technical field of sizing agent, in particular to a sizing agent raw material composition, a sizing agent and a preparation method thereof; the present application provides a sizing agent raw material composition, which comprises a graphene nanoribbon solution, a non-ionic surfactant, an alkali source and an epoxy resin emulsion; the composition has the advantages of small particle size and good stability when used in the preparation of a sizing agent; after the sizing agent is used for sizing carbon fibers, the interlaminar shear force of the carbon fibers can be improved; the preparation method of the sizing agent is simple in process, mild in conditions and low in cost, and is suitable for industrial production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sizing agent, in particular to a sizing agent raw material composition and a sizing agent and a preparation method thereof. BACKGROUND

[0002] Carbon fiber reinforced composites have the advantages of light weight, high strength, impact resistance, fatigue resistance and corrosion resistance, and are widely used in aerospace, weapon equipment, sports facilities, automobiles and energy industries. In recent years, the production capacity of domestic carbon fiber has steadily increased, and high-performance carbon fiber composites have gradually replaced metal parts. However, carbon fibers are prone to hair and single fiber breakage during production and processing under the action of friction, thereby reducing the strength of the carbon fibers, and the interface properties between the carbon fibers and the matrix are also crucial to the performance of the composites.

[0003] The use of sizing agent for sizing treatment on the surface of carbon fibers forms an organic film on the surface of carbon fibers, which not only reduces wear and tear during processing and avoids the formation of hair, but also protects the clean and active surface after surface treatment and prevents the adsorption of dust and moisture in the air. The emulsion type sizing agent is the most widely used sizing agent due to its safety and environmental protection, but the stability of the emulsion type sizing agent is not enough, and the film formed on the surface of the sizing agent is easily affected by environmental temperature and humidity, affecting the bonding between carbon fibers and resin, and the application in some high-performance carbon fiber fields is limited. Developing high-performance sizing agent has become an important part of the carbon fiber industry chain.

[0004] Graphene nanoribbons are one-dimensional nanoribbon-shaped graphene materials that combine the advantages of carbon nanotubes and graphene, with good dispersion performance, excellent electrical conductivity, ultra-large specific surface area and excellent strength. Introducing graphene nanoribbons to the surface of carbon fibers through sizing agent can improve the surface performance of carbon fibers, thereby further enhancing the interface performance of the composites.

[0005] Therefore, it is necessary to seek a simple method for preparing a graphene nanoribbon modified composite emulsion sizing agent, which is conducive to in-depth research and popularization and application. SUMMARY

[0006] The present application relates to the technical field of sizing agent, in particular to a sizing agent raw material composition and a sizing agent and a preparation method thereof.

[0007] To achieve the above objectives, the first aspect of the present invention provides a sizing agent raw material composition comprising a graphene nanoribbon solution, a nonionic surfactant, an alkali source, and an epoxy resin emulsion.

[0008] The second aspect of the present invention provides a method for preparing a sizing agent, which is prepared using the formulation of the raw material composition described in the present invention. The method includes: (1) adding a nonionic surfactant and an alkali source to a graphene nanoribbon solution and mixing them to obtain solution I; (2) adding solution I to an epoxy resin emulsion and mixing them.

[0009] The third aspect of the present invention provides a sizing agent prepared by the preparation method described in the present invention, wherein the sizing agent has a particle size of 100-300 nm, does not break emulsion or separate into layers after standing for more than 30 days, and does not break emulsion or separate into layers after centrifugation at 3000 rpm for 1 minute.

[0010] Through the above technical solution, the present invention has the following beneficial effects:

[0011] This invention proposes for the first time a sizing agent raw material composition comprising a graphene nanoribbon solution, a nonionic surfactant, an alkali source, and an epoxy resin emulsion. This composition has advantages such as small particle size and good stability when used to prepare sizing agents. After sizing carbon fibers, it can effectively improve the interlaminar shear force of carbon fibers. Furthermore, the preparation method of this invention has the advantages of simple preparation process, mild conditions, and low cost, making it suitable for industrial production. Attached Figure Description

[0012] Figure 1 This is a scanning electron microscope image of the graphene nanoribbons synthesized in Example 1;

[0013] Figure 2 This is an XPS image of the graphene nanoribbons synthesized in Example 1;

[0014] Figure 3 This is an optical image of the graphene nanoribbon composite emulsion sizing agent synthesized in Example 1. Detailed Implementation

[0015] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0016] This invention provides a sizing agent raw material composition comprising a graphene nanoribbon solution, a nonionic surfactant, an alkali source, and an epoxy resin emulsion.

[0017] In the present application, the amount of the alkali source is used to make the prepared sizing agent have a pH value of 9-13, preferably 9-10.

[0018] In the present application, the amount of the graphene nanoribbon solution can be selected in a wide range, and the following exemplary description is provided, but the present application is not limited in this regard. For the present application, the weight ratio of the graphene nanoribbon solution to the epoxy resin emulsion is preferably 0.1-10:1, preferably 0.1-1:1, and more preferably 0.5-1:1.

[0019] In the present application, the amount of the non-ionic surfactant can be selected in a wide range. For the present application, the amount is preferably 1-20 mg / mL of the graphene nanoribbon solution, and more preferably 5-9 mg / mL of the graphene nanoribbon solution.

[0020] In the present application, the graphene nanoribbon solution has no special requirements. According to a preferred embodiment of the present application, the graphene nanoribbon solution contains graphene nanoribbons at a content of 0.5-2 wt%, and the rest is a solvent, which has no special requirements, such as water.

[0021] According to a preferred embodiment of the present application, the graphene nanoribbon solution contains modified graphene nanoribbons and deionized water, and the modified graphene nanoribbons are at least one of oxygen-containing functional group graphene nanoribbons, nitrogen-containing functional group graphene nanoribbons, and sulfur-containing functional group graphene nanoribbons, and are preferably oxygen-containing functional group graphene nanoribbons.

[0022] According to a preferred embodiment of the present application, the oxygen-containing functional groups preferably include hydroxyl groups and / or carboxyl groups.

[0023] By using the foregoing preferred embodiments, the stability of the sizing agent can be further improved.

[0024] In the present application, the non-ionic surfactant has no special requirements. According to a preferred embodiment of the present application, the non-ionic surfactant is selected from at least one of Triton X-100, Triton X-114, Triton X-305, and Triton X-405. In the present application, Triton X-100 is used as an exemplary description in the examples, but the present application is not limited in this regard. By using the foregoing preferred embodiments, the stability of the sizing agent can be further improved.

[0025] In the present application, the alkali source has no special requirements. According to a preferred embodiment of the present application, the alkali solution is selected from at least one of ammonia, potassium hydroxide, and sodium hydroxide. In the present application, an ammonia solution is used as an exemplary description in the examples, but the present application is not limited in this regard.

[0026] In the present application, the solid content of the epoxy resin emulsion has no special requirements, according to a preferred embodiment of the present application, the solid content of the epoxy resin emulsion is 30-50wt%. By adopting the preferred embodiment, the stability of the sizing agent can be further improved.

[0027] In the present application, the source of the epoxy resin emulsion has no special requirements, according to a preferred embodiment of the present application, the epoxy resin emulsion comprises: bisphenol A epoxy resin, emulsifier, deionized water. By adopting the preferred embodiment, the stability of the sizing agent can be further improved.

[0028] According to a preferred embodiment of the present application, the epoxy resin emulsion comprises bisphenol A type epoxy resin 30-50wt%, emulsifier 1-10wt%, water 40-70wt%.

[0029] In the present application, the type of emulsifier has a wide range of options, for the present application, preferably, the emulsifier is at least one selected from triton X-100, triton X-114, triton X-305 and triton X-405, preferably X-100.

[0030] The present application provides a preparation method of sizing agent, which is prepared by using the raw material composition formula of the present application, the method comprises: (1) adding nonionic surfactant and alkali source into the graphene nanobelt solution and mixing to obtain solution I; (2) adding solution I into the epoxy resin emulsion and mixing.

[0031] According to a preferred embodiment of the present application, the preparation step of the graphene nanobelt solution comprises: mixing carbon nanotubes with acidic solution first, mixing with oxidant a second, mixing with oxidant b third, first centrifugation, washing, second centrifugation, dialysis treatment of the centrifugal liquid, and using deionized water to concentrate to 0.1-2wt%.

[0032] In the present application, the solvent for washing is selected from deionized water, and the amount can be adjusted according to actual operation.

[0033] In the present application, the dialysis operation is dialysis in deionized water for 3 days, and the deionized water is changed every day, and the concentration of the graphene nanobelt solution after dialysis is 0.5-2wt% by adding water.

[0034] In the present application, the acidic solution has no special requirements, according to a preferred embodiment of the present application, the acidic solution is at least one selected from concentrated sulfuric acid, concentrated nitric acid and concentrated hydrochloric acid, in the present application, the example is exemplarily described by using concentrated sulfuric acid, but the present application is not limited to this range. By adopting the preferred embodiment, the dispersibility of the carbon nanotube can be further improved.

[0035] In the present application, the oxidizing agent a has no special requirements, according to a preferred embodiment of the present application, the oxidizing agent a is selected from at least one of potassium permanganate, potassium chlorate and sodium permanganate, in the present application, potassium permanganate is exemplarily illustrated in the examples, but the present application is not limited to this range. By adopting the foregoing preferred embodiment, the yield of graphene nanoribbons can be further improved.

[0036] In the present application, the oxidizing agent b has no special requirements, according to a preferred embodiment of the present application, the oxidizing agent b is selected from hydrogen peroxide aqueous solution.

[0037] In the present application, the solid content of the graphene nanoribbon solution has no special requirements, according to a preferred embodiment of the present application, the solid content of the graphene nanoribbon solution is 0.01%-2wt%. By adopting the foregoing preferred embodiment, the dispersibility of graphene nanoribbons can be further improved.

[0038] In the present application, the mass and volume ratio of the carbon nanotube and the acidic solution has no special requirements, according to a preferred embodiment of the present application, the mass and volume ratio of the carbon nanotube and the acidic solution is 1g:(100-500mL). By adopting the foregoing preferred embodiment, the dispersibility of carbon nanotubes can be further improved.

[0039] In the present application, the mass and volume ratio of the carbon nanotube and the oxidizing agent a has no special requirements, according to a preferred embodiment of the present application, the mass and volume ratio of the carbon nanotube and the oxidizing agent a is 1g:(3-15g). By adopting the foregoing preferred embodiment, the yield of graphene nanoribbons can be further improved.

[0040] In the present application, the mass and volume ratio of the carbon nanotube and the oxidizing agent b has no special requirements, according to a preferred embodiment of the present application, the mass and volume ratio of the carbon nanotube and the oxidizing agent b is 1g:(1-20mL).

[0041] The present application has no special requirements for carbon nanotubes, and commonly used carbon nanotubes can be applied to the present application.

[0042] In the present application, the mixing conditions are all carried out under stirring conditions, and the rotation speed can be adjusted by personnel in the art according to actual operation.

[0043] In the present application, in step (1), the first mixing condition has no special requirements.

[0044] According to a preferred embodiment of the present application, the first mixing is ultrasonic mixing, and the time of the ultrasonic mixing has no special requirements, as long as the solution is uniformly dispersed.

[0045] According to a preferred embodiment of the present application, the first mixing temperature is 10-30℃.

[0046] According to a preferred embodiment of the present application, the first mixing time is 30-120min.

[0047] In the present application, the second mixing condition in step (1) has no special requirements.

[0048] According to a preferred embodiment of the present application, the second mixing temperature is 10-120℃, preferably 50-80℃.

[0049] According to a preferred embodiment of the present application, the second mixing time is 60-300min.

[0050] In the present application, the third mixing condition in step (1) has no special requirements.

[0051] According to a preferred embodiment of the present application, the third mixing temperature is 0-30℃.

[0052] According to a preferred embodiment of the present application, the third mixing time is 5-20min.

[0053] In the present application, the first centrifugation condition in step (1) has no special requirements.

[0054] According to a preferred embodiment of the present application, the first centrifugation temperature is 10-30℃.

[0055] According to a preferred embodiment of the present application, the first centrifugation time is 5-20min.

[0056] According to a preferred embodiment of the present application, the first centrifugation speed is 6000-10000rpm.

[0057] In the present application, the second centrifugation condition in step (1) has no special requirements.

[0058] According to a preferred embodiment of the present application, the second centrifugation temperature is 10-30℃.

[0059] According to a preferred embodiment of the present application, the second centrifugation time is 20-60min.

[0060] According to a preferred embodiment of the present application, the second centrifugation speed is 4000-8000rpm.

[0061] In the present application, after the first centrifugation operation, the supernatant is discarded, and the step of rinsing with a small amount of deionized water has no special requirements for the number of rinsing times, which can be adjusted by the person skilled in the art according to the actual operation.

[0062] In the present application, after the second centrifugation operation, a dialysis step is further included, and the specific operation is as follows: the graphene nanoribbon solution is poured into a dialysis bag, and the dialysis bag is placed in deionized water for dialysis for 3 days, and the water is changed once a day.

[0063] In the present application, after the dialysis is completed, the concentration of the graphene nanoribbon solution after dialysis needs to be adjusted to 0.5-2wt% by adding water.

[0064] In the present application, the solution I obtained in the step (2) needs to be adjusted to pH=10 by using ammonia water.

[0065] In the present application, the mixing condition of the solution I and the epoxy emulsion in the step (3) has no special requirement, and according to a preferred embodiment of the present application, the mixing condition is as follows: mixing under stirring at 10000r for 20min.

[0066] The present application provides a sizing agent prepared by the preparation method of the sizing agent. The particle size of the sizing agent is 100-300nm, and the sizing agent is not emulsified and not stratified after standing for more than 30 days, and is not emulsified and not stratified after centrifugation at 3000r / min for 1min.

[0067] In the following examples, the type of epoxy resin is E51;

[0068] The emulsifier is triton X-100.

[0069] The tube diameter of the carbon nanotube raw material is 4-6nm.

[0070] Example 1

[0071] (1) 1g of carbon nanotube was added into 150mL of concentrated sulfuric acid (98wt%), and ultrasonic treatment was performed at room temperature (25℃) for 30min to uniformly disperse the carbon nanotube, and the obtained mixture was stirred at room temperature (25℃) for 1h, and then 5g of potassium permanganate was slowly added, and the reaction was continued for 1h, and then the temperature was increased to 70℃ and the reaction was continued for 2h. After the reaction was completed, the obtained graphene nanoribbon solution was carefully poured into 500mL of ice water containing 10mL of hydrogen peroxide (temperature 0℃, time 5min). Centrifugal separation was performed at a centrifugal speed of 8000r / min for 10min, and then the supernatant was discarded, and a small amount of deionized water was used for washing and further centrifugal separation. The centrifugal speed was 5000r / min, and the centrifugal time was 40min. Then the graphene nanoribbon solution after centrifugation was poured into a dialysis bag. Dialysis was performed in deionized water for 3 days, and the water was changed once a day. The concentration of the graphene nanoribbon solution after dialysis was adjusted to 1wt% by adding water;

[0072] (2) 10mL of the graphene nanoribbon aqueous solution was taken, 50mg of triton X-100 was added under stirring, and the solution was adjusted to pH=10 by using ammonia water (25wt%).

[0073] (3) 35% epoxy resin E51 is added into 5% emulsifier Triton X-100 and 60% water, and then stirred at 10000 r for 20 minutes, and then the graphene nanobelt aqueous solution is mixed with the epoxy resin emulsion to obtain the sizing agent, and the weight ratio of the graphene nanobelt solution to the epoxy resin emulsion is 1:9.

[0074] The particle size of the sizing agent is 100-300 nm, and the sizing agent is not emulsified and not stratified after standing for more than 30 days, and is not emulsified and not stratified after centrifugation at 3000 r / min for 1 minute, which indicates that the sizing agent has the advantages of small particle size and high stability.

[0075] Figure 1 is a scanning electron microscope image of the graphene nanobelt synthesized in the embodiment, and the model of the scanning electron microscope is FEI Quanta 450 FEG SEM; from Figure 1 It can be seen that the structure of the graphene nanobelt is a strip-shaped lamellar structure.

[0076] Figure 2 is an X-ray photoelectron spectroscopy (XPS) full spectrum image (a) and C1s spectrum (b) of the graphene nanobelt synthesized in the embodiment, and the model of the XPS is EscaLab 250Xi. From Figure 2 a), it can be seen that the elements in the graphene nanobelt mainly include carbon and oxygen, Figure 2 b) shows that the oxygen-containing functional groups on the graphene nanobelt mainly include hydroxyl and carboxyl. Figure 2 Figure 2

[0077] Figure 3 is an optical picture of the graphene nanobelt composite emulsion sizing agent synthesized in the embodiment; from Figure 3 It can be seen that the graphene nanobelt is stably dispersed in the sizing agent.

[0078] Example 2

[0079] ​​(1) 1g carbon nanotubes were added to 150mL concentrated sulfuric acid (98wt%), and ultrasonic dispersion was performed at room temperature (25℃) for 30min to obtain a uniform dispersion. The obtained mixture was stirred at room temperature (25℃) for 1h, and then 3g potassium permanganate was slowly added. After 1h of reaction, the temperature was increased to 70℃ and the reaction was continued for 2h. After the reaction was completed, the obtained graphene nanoribbon solution was carefully poured into 500mL ice water containing 10mL hydrogen peroxide (temperature 0℃, time 5min). Centrifugal separation was performed at a centrifugal speed of 8000r / min for 10min. After centrifugation, the supernatant was discarded, and the graphene nanoribbon solution was washed with a small amount of deionized water and centrifuged again. The centrifugal speed was 5000r / min, and the centrifugal time was 40min. Then the centrifuged graphene nanoribbon solution was poured into a dialysis bag. Dialysis was performed in deionized water for 3 days, and the water was changed every day. The concentration of the dialyzed graphene nanoribbon solution was adjusted to 1wt% by adding water;

[0080] (2) 10mL of the graphene nanoribbon aqueous solution was taken, and 70mg of triton X-100 was added under stirring, and the solution was adjusted to pH=10 with ammonia water (25wt%);

[0081] (3) 35% epoxy resin was added to 5% emulsifier and 60% water based on the total weight of the epoxy resin emulsion, and stirring was performed at 10000r for 20min. Then the graphene nanoribbon aqueous solution was mixed with the epoxy resin emulsion to obtain a sizing agent, and the weight ratio of the graphene nanoribbon solution to the epoxy resin emulsion was 3:7.

[0082] The particle size of the sizing agent was 100-300nm, and it did not break emulsion or separate after standing for more than 30 days, and it did not break emulsion or separate after centrifugation at 3000r / min for 1min, indicating that the sizing agent of the present application has the advantages of small particle size and high stability.

[0083] Example 3

[0084] (1) 1g carbon nanotubes were added to 150mL concentrated sulfuric acid (98wt%), and ultrasonic dispersion was performed at room temperature (25℃) for 30min to obtain a uniform dispersion. The obtained mixture was stirred at room temperature (25℃) for 1h, and then 3g potassium permanganate was slowly added. After 1h of reaction, the temperature was increased to 70℃ and the reaction was continued for 2h. After the reaction was completed, the obtained graphene nanoribbon solution was carefully poured into 500mL ice water containing 10mL hydrogen peroxide (temperature 0℃, time 5min). Centrifugal separation was performed at a centrifugal speed of 8000r / min for 10min. After centrifugation, the supernatant was discarded, and the graphene nanoribbon solution was washed with a small amount of deionized water and centrifuged again. The centrifugal speed was 5000r / min, and the centrifugal time was 40min. Then the centrifuged graphene nanoribbon solution was poured into a dialysis bag. Dialysis was performed in deionized water for 3 days, and the water was changed every day. The concentration of the dialyzed graphene nanoribbon solution was adjusted to 1wt% by adding water;

[0085] (2) Take 10 mL of graphene nanoribbon aqueous solution, add 90 mg of Triton X-100 under stirring, and adjust the solution to pH=10 with ammonia (25wt%);

[0086] (3) 35% epoxy resin is added to 5% emulsifier and 60% water, and the mixture is stirred at 10000r for 20 minutes to obtain an epoxy resin emulsion, then the graphene nanoribbon aqueous solution is mixed with the epoxy resin emulsion to obtain the sizing agent, and the weight ratio of the graphene nanoribbon solution to the epoxy resin emulsion is 2:8.

[0087] The particle size of the sizing agent is 100-300 nm, and the sizing agent is not emulsified or stratified after standing for more than 30 days or centrifuging at 3000r / min for 1 minute, indicating that the sizing agent has the advantages of small particle size and high stability.

[0088] The preferred embodiments of the application are described in detail above, but the application is not limited thereto. Within the technical concept of the application, various simple modifications can be made to the technical solutions of the 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 application and fall within the protection scope of the application.

Claims

1. A sizing agent raw material composition, characterized by, The composition comprises a graphene nanoribbon solution, a non-ionic surfactant, an alkali source, and an epoxy resin emulsion, wherein the preparation steps of the graphene nanoribbon solution include: mixing carbon nanotubes with an acidic solution, mixing with oxidant a, mixing with oxidant b, first centrifugation, washing, second centrifugation, dialysis treatment of the centrifugal liquid, and concentration of 0.1-2wt% with deionized water; the acidic solution is selected from at least one of concentrated sulfuric acid, concentrated nitric acid and concentrated phosphoric acid; the oxidant a is selected from at least one of potassium permanganate, potassium chlorate and sodium permanganate; the oxidant b is hydrogen peroxide.

2. The composition of claim 1, wherein, The weight ratio of the graphene nanoribbon solution to the epoxy resin emulsion is 0.1-10:1; The amount of non-ionic surfactant is 1-20mg / mL of graphene nanoribbon solution; The graphene nanoribbon solution contains graphene nanoribbons at a content of 0.5-2wt%, and the rest is solvent, and the solvent is water.

3. The composition of claim 2, wherein, The weight ratio of the graphene nanoribbon solution to the epoxy resin emulsion is 0.1-1:1; The amount of non-ionic surfactant is 5-9mg / mL of graphene nanoribbon solution.

4. The composition of claim 3, wherein, The weight ratio of the graphene nanoribbon solution to the epoxy resin emulsion is 0.5-1:

1.

5. The composition of claim 1, wherein, The graphene nanoribbon solution contains modified graphene nanoribbons and deionized water, and the modified graphene nanoribbons are at least one of oxygen-containing functional group graphene nanoribbons, nitrogen-containing functional group graphene nanoribbons and sulfur-containing functional group graphene nanoribbons; And / or The non-ionic surfactant is selected from at least one of Triton X-100, Triton X-114, Triton X-305 and Triton X-405; and / or The alkali source is selected from at least one of ammonia, sodium hydroxide and potassium hydroxide; and / or The epoxy resin emulsion is a bisphenol A type epoxy emulsion; and / or The solid content of the epoxy resin emulsion is 30-50wt%; The epoxy resin emulsion comprises 30-50wt% of bisphenol A type epoxy resin, 1-10wt% of emulsifier and 40-70wt% of water.

6. The composition of claim 5, wherein, The modified graphene nanoribbons are oxygen-containing functional group graphene nanoribbons; The concentration of the modified graphene nanoribbons is 0.5-2wt%; And / or The non-ionic surfactant is selected from Triton X-100; and / or The emulsifier is selected from at least one of Triton X-100, Triton X-114, Triton X-305 and Triton X-405.

7. The composition of claim 6, wherein, The oxygen-containing functional groups include hydroxyl and / or carboxyl; The emulsifier is Triton X-100.

8. The composition of claim 1, wherein, The ratio of the carbon nanotubes to the acidic solution is 1g:(100-500mL); and / or The ratio of the carbon nanotubes to the oxidant a is 1g:(3-15 g); and / or The ratio of the carbon nanotubes to the oxidizing agent b is 1 g: (1-20 mL).

9. The composition of claim 1, wherein, the first mixing condition comprises: a temperature of 10-30℃; and / or a time of 30-120 min; and / or the second mixing condition comprises: a temperature of 50-80℃; and / or a time of 60-300 min; and / or the third mixing condition is: a temperature of 0-30℃; and / or a time of 5-20 min.

10. The composition of claim 1, wherein, the first centrifugation condition comprises: a time of 5-20 min; and / or a speed of 6000-10000 rpm; and / or the second centrifugation condition comprises: a time of 20-60 min; and / or a speed of 4000-8000 rpm.

11. A method for preparing a sizing agent, characterized by, A preparation method of the sizing agent of claim 11, comprising: (1) mixing a non-ionic surfactant and an alkali source in a graphene nanoribbon solution to obtain solution I; (2) mixing solution I into an epoxy resin emulsion.

12. The sizing agent prepared by the preparation method of claim 11, wherein the particle size of the sizing agent is 100-300 nm, the sizing agent does not break emulsion or separate layers after standing for more than 30 days, and the sizing agent does not break emulsion or separate layers after centrifugation at 3000 revolutions per minute for 1 minute.

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