CN105968718A - Preparation method of carbon fiber/graphene/epoxy resin prepreg and carbon fiber composite material - Google Patents

Abstract

A carbon fiber/graphene/epoxy resin prepreg and a method for preparing a carbon fiber composite material belong to the field of carbon fiber composite material preparation. The present invention modifies the surface of the graphene prepared by the improved Hummers method, grafts ‑NH ₂ on the surface or edge of the graphene, improves its dispersibility in the resin matrix, and can effectively increase the concentration of micron carbon fiber and epoxy resin at the same time. The interfacial adhesion between the resin matrix can reduce the existence of void defects, thereby improving the mechanical properties of epoxy resin matrix composites. The carbon fiber/graphene/epoxy resin composite material provided by the present invention has the best mechanical properties when the addition of graphene is 0.5wt%, the bending strength reaches 1525.4MPa, and the interlaminar shear strength reaches 91.14MPa, compared with the carbon fiber reinforced ring Oxygen resin composites improved by 15.41% and 14.14%, respectively. The invention has the characteristics of simple process, low solvent toxicity, suitability for industrialized production and the like.

Description

A kind of preparation method of carbon fiber/graphene/epoxy resin prepreg and carbon fiber composite material

technical field

The invention relates to a method for preparing a composite material, in particular to a method for preparing a unidirectional carbon fiber/graphene/epoxy resin prepreg and a carbon fiber composite material.

Background technique

Carbon fiber reinforced resin composites (CFRP) have excellent specific strength, specific stiffness, corrosion resistance, fatigue resistance and high service temperature, and are widely used in aerospace, sports equipment and national defense industries. Epoxy resin is the most widely used matrix in carbon fiber reinforced resin composite materials. Epoxy resin has a series of advantages such as good adhesion, heat resistance, chemical corrosion resistance, high strength and convenient processing, but the elongation at break of the material It is relatively low and brittle, and the combination of its cured product and fibers is also poor, which seriously affects its application in aerospace.

Prepreg is used to manufacture resin-based composite materials impregnated resin system fibers or their fabrics after drying or pre-polymerized intermediates, and is the main intermediate material for manufacturing composite structural parts. The raw materials of prepreg include reinforcement and matrix. The main auxiliary materials are release paper and embossed polyethylene film, etc. The reinforcement commonly used in prepreg is mainly carbon fiber, aramid fiber, glass fiber and their fabrics. The resin matrix for materials includes two categories: thermosetting resins and thermoplastic resins. At present, most of the actual use of carbon fiber is realized by the way of carbon fiber prepreg. In order to give full play to the ultra-high strength performance of carbon fiber, it is basically necessary to make carbon fiber into a prepreg of unidirectional fiber with only radial distribution and no weft distribution. Dipping material. The quality of the prepreg directly affects the overall performance of the composite material. The performance of the prepreg can be improved by optimizing the processing technology and adding different types of reinforcements.

In addition to surface modification of carbon fiber itself, multi-scale reinforcement is a more commonly used method, that is, adding one or more other nanostructure materials to carbon fiber composites, such as fumed silica, nanoclay, carbon nanotubes, etc. , graphene, etc. Graphene is a single-layer carbon material with a honeycomb lattice structure formed by the accumulation of sp ² hybridized carbon atoms. Promising reinforcement materials, especially for toughening reinforced epoxy composites. The addition of epoxy resin to rubber can increase the viscosity of the system, improve the impact resistance of the prepared composite material, and achieve the effect of toughening.

In traditional composite materials, graphene, as a reinforcement of composite materials, has the disadvantages of poor dispersion in the polymer matrix and poor interfacial bonding with the polymer matrix, while carbon fiber, as a reinforcement, has the disadvantages of surface active functional groups. Less, poor bonding with matrix resin wettability and different degrees of defects, resulting in low interface bonding strength and poor mechanical properties of graphene or carbon fiber reinforced resin matrix composites. In addition, the traditional single-dimensional reinforced epoxy Resin composites sometimes improve some properties while degrading others.

Contents of the invention

The invention provides a carbon fiber/graphene/epoxy resin prepreg and a preparation method of the carbon fiber composite material, which can effectively solve the application defects of graphene and carbon fiber in the composite material. Graphene prepared by graphite oxide-thermal expansion reduction-ultrasonic exfoliation often contains some hydroxyl functional groups on its basal plane and edge, and these groups can be used as active sites to react with silane coupling agents, and then on the surface of graphene. Grafting amino groups, graphene modified by ammonia can significantly improve the interfacial adhesion between graphene and epoxy resin matrix, and improve the dispersion of graphene in resin matrix. Both graphene and carbon fiber are carbon materials. The latter has high compatibility, and the combination of nano-scale graphene and micron-scale carbon fiber can significantly improve the performance of resin-based composite materials.

To achieve the above object, the present invention adopts the following technical solutions:

A kind of preparation method of carbon fiber/graphene/epoxy resin prepreg comprises the following steps successively:

(1) Preparation of graphene

Preferably: weigh the NaNO3 solid and dissolve it in 98% concentrated sulfuric _acid , place the mixed solution in an ice-water bath while stirring to fully dissolve the NaNO3 solid _; weigh graphite and add it to the above mixed solution, and stir evenly; then, slowly Add excess potassium permanganate for oxidation, control the reaction temperature not to exceed 20°C during the addition process, stir evenly, adjust the temperature to 30-40°C and continue to stir the reaction; then add deionized water to the mixture to dilute and add H ₂ O ₂ to turn the solution into bright yellow; filter and wash with 5% hydrochloric acid solution while filtering; dilute the filter cake obtained after filtration with deionized water, and then perform ultrasonic and centrifugation; after centrifugation Add hydrochloric acid solution to the obtained supernatant, stir well and centrifuge again; dry the viscous solid in the lower layer obtained after centrifugation to obtain a graphite oxide sample; take the obtained graphite oxide and quickly put it into a muffle furnace preheated to 1050°C keep in the medium for 30s to obtain expanded graphene; take the expanded graphene and add it to absolute ethanol, ultrasonically peel it for no more than 15h, and vacuum-dry to obtain graphene;

(2) Disperse graphene and N,N'-dicyclohexylcarboimide (DCC) in the aminosilane coupling agent solution, ultrasonicate the mixture for 1-3 hours, and heat the black homogeneous mixture to 60- Stir at 80°C for 12 to 20 hours, then centrifuge and wash with deionized water, and dry the resultant in a vacuum oven to obtain ammonia-modified graphene;

(3) Add the ammonia-modified graphene obtained in step (2) to epoxy resin, polyurethane modified liquid rubber and curing agent composition system, mechanically stir and ultrasonically react for 4-8h, add accelerator (DMP- 30), and continue the ultrasonic reaction for 1 to 2 hours; then, place the reaction solution in a vacuum oven for degassing (such as degassing for 1 to 2 hours in a vacuum oven at 50°C); obtain a graphene/epoxy resin slurry;

(4) The graphene/epoxy resin slurry obtained above is poured into the dipping tank, and an ultrasonic generator is placed in the dipping tank, and then the carbon fiber tow is immersed in the dipping tank, and the tow after the dipping Use the scraping roller to remove the excess resin glue, and the tow after dipping will be wound by winding through the wire discharge machine, and then wound repeatedly, preferably with 2 to 4 layers of repeated winding, and dried at 100 to 120°C for 1 ~4h to obtain unidirectional carbon fiber/graphene/epoxy resin prepreg.

The prepreg is pressed and solidified by a flat-plate hot press to prepare a laminate, which is post-cured in an oven and cooled to room temperature to obtain a carbon fiber composite material.

Preferably, the graphite described in the above step (1) is natural flake graphite, and the graphene is single-layer or multi-layer graphene.

Preferably, the aminosilane coupling agent described in the above step (2) is 3-aminopropyltriethoxysilane, and the dispersion concentration of graphene in 3-aminopropyltriethoxysilane is 0.5-2mg /ml.

Preferably, the mass ratio of graphene and dehydrating agent N,N'-dicyclohexylcarboimide (DCC) in the above step (2) is 10:3-5.

Preferably, the epoxy resin composition component described in above-mentioned step (3) comprises epoxy resin, polyurethane modified liquid rubber and curing agent, and curing agent is diaminodiphenylmethane or methyltetrahydrophthalic anhydride, accelerator For 2,4,6-tris(dimethylaminomethyl)phenol.

Preferably, the mass ratio of each component in the composition system described in the above step (3) is 100:5～15:25～40, or Epoxy resin: polyurethane modified liquid rubber: the ratio of curing agent methyl tetrahydrophthalic anhydride is 100:5-15:60-70, and the amount of accelerator added per 100 parts of epoxy resin is 1ml.

Preferably, the mass of the ammonia-modified graphene described in the above step (3) is 0.05-1% of the mass of the epoxy resin.

The above-mentioned epoxy resin is preferably epoxy resin E51.

Preferably, the curing process of the composite material is curing at 90°C for 1-2 hours, then curing at 130°C for 2-4 hours, and finally curing at 150°C for 2-4 hours.

A carbon fiber/graphene/epoxy resin prepreg is a unidirectional prepreg, which is obtained by winding and arranging wires through a wire arranging machine after impregnating carbon fiber tow.

Compared with the prior art, the technical solution provided by the invention has the following excellent effects:

1. The technical solution provided by the present invention adopts the ammonia-modified graphene of nanometer scale to improve the disadvantages of easy agglomeration of graphene, and improves the dispersion of graphene in the resin matrix through the chemical bond between the amino group and the resin matrix , and have better interfacial interaction with the matrix. In carbon fiber/graphene/epoxy resin composites, an appropriate amount of ammonia-modified graphene can not only play a good role in cross-linking between the fiber and the matrix, but also reduce the generation of void defects, and its good dispersion can help Uniform transfer of applied loads.

2. The strength of the resin matrix is greatly improved after adding ammonia-modified graphene, which delays the generation of cracks in the material under the action of external load. At the same time, the strong bonding between carbon fiber and resin matrix prevents the further development of cracks. Ammonia-modified graphene significantly improves the mechanical properties of carbon fiber composites.

3. The process is simple, has no pollution to the environment, and is suitable for industrial production.

4. The carbon fiber/graphene/epoxy resin composite material prepared by the present invention has the best mechanical properties when the addition of graphene is 0.5wt%, the bending strength reaches 1525.4MPa, and the interlaminar shear strength reaches 91.14MPa, compared with carbon fiber Reinforced epoxy resin composites improved by 15.41% and 14.14%, respectively.

detailed description

The present invention will be described in further detail below in conjunction with the examples, but the present invention is not limited to the following examples. The following examples generally correspond to 1.5g NaNO ₃ solid, 1.5g graphite, and 9g potassium permanganate per 100ml concentrated sulfuric acid, and the consumption can also be adjusted.

Example 1

Weigh the NaNO ₃ solid and dissolve it in 98% concentrated sulfuric acid, place the mixed solution in an ice-water bath while stirring to fully dissolve the NaNO ₃ solid; weigh a small amount of graphite and add it to the above mixed solution, and stir evenly; then, slowly add Excess potassium permanganate is oxidized. During the addition process, control the reaction temperature not to exceed 20°C, stir evenly, adjust the temperature to 30°C and continue to stir the reaction; then add deionized water to the mixture to dilute and add H ₂ O ₂ dropwise , to make the solution turn bright yellow; filter and wash with 5% hydrochloric acid solution while filtering; dilute the filter cake obtained after filtration with deionized water, and then perform ultrasonic and centrifugation; the upper layer obtained after centrifugation Add hydrochloric acid solution to the clear liquid, stir well and centrifuge again; dry the viscous solid in the lower layer obtained after centrifugation to obtain a graphite oxide sample; take the obtained graphite oxide and quickly put it into a muffle furnace preheated to 1050°C for 30s Obtaining expanded graphene; adding a certain amount of expanded graphene to absolute ethanol, and vacuum drying to obtain graphene.

Graphene and N,N'-dicyclohexylcarboimide (DCC) were dispersed in the aminosilane coupling agent 3-aminopropyltriethoxysilane solution, and graphene was dispersed in 3-aminopropyltriethoxy The dispersion concentration in base silane is 0.5mg/ml, and the mass ratio of graphene and N,N'-dicyclohexylcarboimide (DCC) is 10:3. Ultrasonic the mixed solution for 1 hour, heat the black homogeneous mixture to 60°C, stir for 12 hours, then centrifuge and wash with deionized water, and place the resultant in a vacuum oven at 65°C for 12 hours to obtain ammonia-modified graphene; Mix epoxy resin, polyurethane modified liquid rubber, curing agent diaminodiphenylmethane and amino-modified graphene according to the mass ratio of 100:5:25:0.1, mechanically stir and ultrasonically react for 4h, every 100 parts of ring The amount of accelerator (DMP-30) added to the oxygen resin was 1ml, and the ultrasonic reaction was continued for 1h. Then, the reaction solution was placed in a vacuum oven at 50°C for degassing for 1 h;

Pour the resin slurry into the dipping tank, and place an ultrasonic generator in the dipping tank. The power is controlled at 150W. The T300 grade 3K carbon fiber tow from Weihai Kaizhan Fiber Co., Ltd. enters the dipping tank, and the dipping time is controlled as For 10 seconds, the tension of the tow is 150 grams. The tow after dipping is removed by a scraping roller to remove excess resin glue. Dry at 100° C. for 1 hour to obtain a unidirectional prepreg, and the carbon fiber mass fraction in the prepreg is 60%. The prepreg was pressed and cured by a flat hot press to prepare a laminate, and post-cured in an oven. The curing process was 1 hour at 90°C, then 2 hours at 130°C, and finally 2 hours at 150°C. Cool to room temperature to obtain the carbon fiber/graphene/epoxy resin-based composite material of the present invention.

Example 2

Weigh the NaNO ₃ solid and dissolve it in 98% concentrated sulfuric acid, place the mixed solution in an ice-water bath while stirring to fully dissolve the NaNO ₃ solid; weigh a small amount of graphite and add it to the above mixed solution, and stir evenly; then, slowly add Excess potassium permanganate is oxidized. During the addition process, control the reaction temperature not to exceed 20°C, stir evenly, adjust the temperature to 40°C and continue to stir the reaction; then add deionized water to the mixture to dilute and add H ₂ O ₂ dropwise , to make the solution turn bright yellow; filter and wash with 5% hydrochloric acid solution while filtering; dilute the filter cake obtained after filtration with deionized water, and then perform ultrasonic and centrifugation; the upper layer obtained after centrifugation Add hydrochloric acid solution to the clear liquid, stir well and centrifuge again; dry the viscous solid in the lower layer obtained after centrifugation to obtain a graphite oxide sample; take the obtained graphite oxide and quickly put it into a muffle furnace preheated to 1050°C for 30s Obtaining expanded graphene; adding a certain amount of expanded graphene to absolute ethanol, ultrasonicating for 5 hours, and vacuum drying to obtain graphene.

Dispersion of Graphene and N,N'-Dicyclohexylcarboimide (DCC) in 3-Aminopropyltriethoxysilane Solution, Dispersion of Graphene in 3-Aminopropyltriethoxysilane The concentration is 2mg/ml, and the mass ratio of graphene and N,N'-dicyclohexylcarboimide (DCC) is 2:1. Ultrasonic the mixture for 3 hours, heat the black homogeneous mixture to 80°C, stir for 20 hours, then centrifuge and wash with deionized water, and place the resultant in a vacuum oven at 65°C for 12 hours to obtain ammonia-modified graphene; Mix epoxy resin, polyurethane modified liquid rubber, curing agent methyl tetrahydrophthalic anhydride and amino-modified graphene according to the mass ratio of 100:15:60:0.1, mechanically stir and ultrasonically react for 8h, every 100 parts of ring The amount of accelerator (DMP-30) added to the oxygen resin was 1ml, and the ultrasonic reaction was continued for 2h. Then, the reaction solution was placed in a vacuum oven at 50°C for 2 hours to debubble;

Pour the resin slurry into the dipping tank, and place an ultrasonic generator in the dipping tank. The power is controlled at 200W. The T300 grade 3K carbon fiber tow from Weihai Kaizhan Fiber Co., Ltd. enters the dipping tank, and the dipping time is controlled as For 20 seconds, the tension of the tow is 200 grams. The tow after dipping is removed by a scraping roller to remove excess resin glue. Dry at 120° C. for 4 hours to obtain a unidirectional prepreg, and the carbon fiber mass fraction in the prepreg is 60%. The prepreg was pressed and cured by a flat hot press to prepare a laminate, and post-cured in an oven. The curing process was 2 hours at 90°C, 4 hours at 130°C, and 4 hours at 150°C. Cool to room temperature to obtain the carbon fiber/graphene/epoxy resin-based composite material of the present invention.

Example 3

Weigh the NaNO ₃ solid and dissolve it in 98% concentrated sulfuric acid, place the mixed solution in an ice-water bath while stirring to fully dissolve the NaNO ₃ solid; weigh a small amount of graphite and add it to the above mixed solution, and stir evenly; then, slowly add Excess potassium permanganate is oxidized. During the addition process, control the reaction temperature not to exceed 20°C, stir evenly, adjust the temperature to 35°C and continue to stir the reaction; then add deionized water to the mixture to dilute and add H ₂ O ₂ dropwise , to make the solution turn bright yellow; filter and wash with 5% hydrochloric acid solution while filtering; dilute the filter cake obtained after filtration with deionized water, and then perform ultrasonic and centrifugation; the upper layer obtained after centrifugation Add hydrochloric acid solution to the clear liquid, stir well and centrifuge again; dry the viscous solid in the lower layer obtained after centrifugation to obtain a graphite oxide sample; take the obtained graphite oxide and quickly put it into a muffle furnace preheated to 1050°C for 30s To obtain expanded graphene; add a certain amount of expanded graphene to absolute ethanol, ultrasonicate for 15 hours, and vacuum-dry to obtain graphene.

Dispersion of Graphene and N,N'-Dicyclohexylcarboimide (DCC) in 3-Aminopropyltriethoxysilane Solution, Dispersion of Graphene in 3-Aminopropyltriethoxysilane The concentration is 1mg/ml, and the mass ratio of graphene and N,N'-dicyclohexylcarboimide (DCC) is 2:1. Ultrasonic the mixture for 2 hours, heat the black homogeneous mixture to 70°C, stir for 16 hours, then centrifuge and wash with deionized water, and place the resultant in a vacuum oven at 65°C for 12 hours to obtain ammonia-modified graphene; Mix epoxy resin, rubber, curing agent methyl tetrahydrophthalic anhydride and amino-modified graphene according to the mass ratio of 100:10:70:0.5, mechanically stir and ultrasonically react for 6 hours, and add to every 100 parts of epoxy resin The amount of accelerator (DMP-30) was 1ml, and the ultrasonic reaction was continued for 2h. Then, the reaction solution was placed in a vacuum oven at 50°C for degassing for 1 h;

Pour the resin slurry into the dipping tank, and place an ultrasonic generator in the dipping tank. The power is controlled at 180W. The T300 grade 3K carbon fiber tow of Weihai Extension Fiber Co., Ltd. enters the dipping tank, and the dipping time is controlled for 15 second, the tow tension is 180 grams, the tow after dipping is removed excess resin glue by the scraping roller, the tow after dipping is discharged by winding through the wire arrangement machine, and is wound repeatedly for 3 layers, at 110 Dry at ℃ for 3 hours to obtain a unidirectional prepreg, the mass fraction of carbon fiber in the prepreg is 60%. The prepreg was pressed and cured by a flat hot press to prepare a laminate, and post-cured in an oven. The curing process was 1 hour at 90°C, then 2 hours at 130°C, and finally 4 hours at 150°C. Cool to room temperature to obtain the carbon fiber/graphene/epoxy resin-based composite material of the present invention.

Example 4

Weigh the NaNO ₃ solid and dissolve it in 98% concentrated sulfuric acid, place the mixed solution in an ice-water bath while stirring to fully dissolve the NaNO ₃ solid; weigh a small amount of graphite and add it to the above mixed solution, and stir evenly; then, slowly add Excess potassium permanganate is oxidized. During the addition process, control the reaction temperature not to exceed 20°C, stir evenly, adjust the temperature to 35°C and continue to stir the reaction; then add deionized water to the mixture to dilute and add H ₂ O ₂ dropwise , to make the solution turn bright yellow; filter and wash with 5% hydrochloric acid solution while filtering; dilute the filter cake obtained after filtration with deionized water, and then perform ultrasonic and centrifugation; the upper layer obtained after centrifugation Add hydrochloric acid solution to the clear liquid, stir well and centrifuge again; dry the viscous solid in the lower layer obtained after centrifugation to obtain a graphite oxide sample; take the obtained graphite oxide and quickly put it into a muffle furnace preheated to 1050°C for 30s To obtain expanded graphene; add a certain amount of expanded graphene to absolute ethanol, ultrasonicate for 15 hours, and vacuum-dry to obtain graphene.

Dispersion of Graphene and N,N'-Dicyclohexylcarboimide (DCC) in 3-Aminopropyltriethoxysilane Solution, Dispersion of Graphene in 3-Aminopropyltriethoxysilane The concentration is 1mg/ml, and the mass ratio of graphene and N,N'-dicyclohexylcarboimide (DCC) is 2:1. Ultrasonic the mixture for 2 hours, heat the black homogeneous mixture to 70°C, stir for 16 hours, then centrifuge and wash with deionized water, and place the resultant in a vacuum oven at 65°C for 12 hours to obtain ammonia-modified graphene; Mix epoxy resin, rubber, curing agent diaminodiphenylmethane and amino-modified graphene according to the mass ratio of 100:10:35:0.5, mechanically stir and ultrasonically react for 6 hours, and add to every 100 parts of epoxy resin The amount of accelerator (DMP-30) was 1ml, and the ultrasonic reaction was continued for 2h. Then, the reaction solution was placed in a vacuum oven at 50°C for degassing for 1 h;

Pour the resin slurry into the dipping tank, and place an ultrasonic generator in the dipping tank. The power is controlled at 180W. The T300 grade 3K carbon fiber tow from Weihai Kaizhan Fiber Co., Ltd. enters the dipping tank, and the dipping time is controlled as 15 seconds, the tow tension is 180 grams, the tow after dipping is removed excess resin glue by the scraping roller, the tow after dipping is discharged by winding through the wire arrangement machine, and is wound repeatedly for 3 layers. Dry at 110° C. for 3 hours to obtain a unidirectional prepreg, and the mass fraction of carbon fibers in the prepreg is 60%. The prepreg was pressed and cured by a flat hot press to prepare a laminate, and post-cured in an oven. The curing process was 1 hour at 90°C, then 2 hours at 130°C, and finally 4 hours at 150°C. Cool to room temperature to obtain the carbon fiber/graphene/epoxy resin-based composite material of the present invention.

Example 5

The difference between this embodiment and Example 1 is that epoxy resin, polyurethane modified liquid rubber rubber, curing agent diaminodiphenylmethane and amino-modified graphene are according to the quality of 100:10:30:0.7 in the resin matrix composition Than mix evenly.

Example 6

The difference between this embodiment and embodiment 1 is that epoxy resin, polyurethane modified liquid rubber rubber, curing agent diaminodiphenylmethane and amino-modified graphene are according to the quality of 100:10:30:1 in the resin matrix composition Than mix evenly.

Example 7

The difference between this embodiment and embodiment 3 is that epoxy resin, polyurethane modified liquid rubber rubber, curing agent methyl tetrahydrophthalic anhydride and amino-modified graphene are according to the quality of 100:10:70:0.7 in the resin matrix composition Than mix evenly.

Example 8

The difference between this embodiment and embodiment 3 is that epoxy resin, polyurethane modified liquid rubber rubber, curing agent methyl tetrahydrophthalic anhydride and amino-modified graphene are according to the quality of 100:10:70:1 in the resin matrix composition Than mix evenly.

Comparative example 1

The T300 grade 3K carbon fiber tows of Weihai Tuanfa Fiber Co., Ltd. enter the dipping tank, and the glue solution is prepared as follows: mix epoxy resin, rubber, and curing agent diaminodiphenylmethane according to the mass ratio of 100:10:35 , mechanically stirred and ultrasonically reacted for 6h, added 1ml accelerator (DMP-30) to every 100 parts of epoxy resin, and continued ultrasonically for 2h, the reaction solution was placed in a vacuum oven at 50°C for 1h to debubble, and the glue Pour into the dipping tank, the power of the ultrasonic generator is controlled to 200W, the dipping time is controlled to be 20 seconds, and the tow tension is 180 grams. The tow after dipping removes excess resin glue by a scraping roller. After dipping The tows are arranged by winding through the wire-discharging machine, wound repeatedly for 2 layers, and dried at 110°C for 3 hours to obtain a unidirectional prepreg with a mass fraction of carbon fiber in the prepreg of 60%. The prepreg was pressed and cured by a flat hot press to prepare a laminate, and post-cured in an oven. The curing process was 1 hour at 90°C, then 2 hours at 130°C, and finally 2 hours at 150°C. Cool to room temperature to obtain the carbon fiber/epoxy resin composite material described in this example.

Comparative example 2

The T300 grade 3K carbon fiber tow of Weihai Tuanfa Fiber Co., Ltd. enters the dipping tank, and the glue solution is prepared according to the following method: mix epoxy resin, rubber, and curing agent methyl tetrahydrophthalic anhydride in a mass ratio of 100:15:70 , mechanically stirred and ultrasonically reacted for 6h, added 1ml accelerator (DMP-30) to every 100 parts of epoxy resin, and continued ultrasonically for 2h, the reaction solution was placed in a vacuum oven at 50°C for 1h to debubble, and the glue Pour into the dipping tank, the power of the ultrasonic generator is controlled to be 180W, the dipping time is controlled to be 15 seconds, and the tow tension is 180 grams. The tow after dipping removes excess resin glue by a scraping roller. After dipping The tows are arranged by winding through the wire-discharging machine, wound repeatedly for 4 layers, and dried at 110°C for 3 hours to obtain a unidirectional prepreg with a mass fraction of carbon fiber in the prepreg of 60%. The prepreg was pressed and cured by a flat hot press to prepare a laminate, and post-cured in an oven. The curing process was 1 hour at 90°C, then 2 hours at 130°C, and finally 2 hours at 150°C. Cool to room temperature to obtain the carbon fiber/epoxy resin composite material described in this example.

The present invention tests the flexural properties of carbon fiber composite materials according to "GB/T 1449-2005 Fiber Reinforced Plastic Bending Performance Test Method", and tests the carbon fiber composite material according to "JC/T 773 Unidirectional Fiber Reinforced The interlaminar shear strength of the material, the test results of the mechanical properties of the carbon fiber composite materials obtained in Examples 1-8 of the present invention and Comparative Examples 1-2 are shown in Table 1.

The mechanical property data of the carbon fiber composite material that table 1 embodiment of the present invention and comparative example obtain

sample Bending strength (MPa) Interlaminar shear strength (MPa) Example 1 1365.5 87.33 Example 2 1433.8 87.11 Example 3 1525.4 91.14 Example 4 1460.1 88.24 Example 5 1420.3 86.06 Example 6 1391.9 86.47 Example 7 1402.6 85.59 Example 8 1396.4 85.38 Comparative example 1 1321.7 79.85 Comparative example 2 1315.2 79.92

As can be seen from Table 1, the flexural strength and the interlaminar shear strength of the carbon fiber/graphene/epoxy resin composite material obtained in the present invention have significantly improved compared to the carbon fiber/epoxy resin composite material, indicating that modified graphite The addition of alkene helps the uniform transmission of the applied load, and the interfacial bonding force between the carbon fiber and the resin matrix is better, which contributes to the improvement of the mechanical properties.

Finally, it should be noted that the above examples are only used to further illustrate the technical solutions of the present invention, but are not limited thereto. After reading the description of the present invention, those skilled in the art can modify the specific implementation of the present invention or equivalent Replacement, any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention are within the protection scope of the pending claims.

Claims (10)

1. the preparation method of carbon fiber/graphite alkene/epoxy prepreg, it is characterised in that comprise the following steps successively:

(1) preparation of Graphene

(2) by Graphene and N, N'-Dicyclohexylcarbodiimide (DCC) is dispersed in amino silicane coupling agent solution, will mixing Ultrasonic 1～3 hour of liquid, is heated to 60～80 DEG C by the homogeneous mixture of black, stirs 12～20 hours, is then centrifuged for separating also Clean with deionized water, gains are placed in vacuum drying oven and are dried, obtain ammonia modified graphene；

(3) the ammonia modified graphene of gained in step (2) is joined epoxy resin, polyurethane-modified liquid rubber and solidification In agent composition system, mechanical agitation ultrasonic reaction 4～8h, add accelerator (DMP-30), and continue ultrasonic reaction 1～2h； Then, de-bubbled in vacuum drying oven is placed reaction liquid into；Obtain Graphene/epoxy resin serosity；

(4) Graphene obtained above/epoxy resin serosity is poured in steeping vat, and in steeping vat, be placed with ultrasound wave send out Raw device, then immerses in steeping vat by carbon fibre tow, and the tow after impregnation removes unnecessary resin adhesive liquid by spreading roller, leaching Tow after glue arranges silk by the way of row's silk machine uses winding, is repeatedly wound around, and is dried 1～4h under the conditions of 100～120 DEG C, Obtain unidirectional carbon/Graphene/epoxy prepreg.

2. according to the preparation method of a kind of carbon fiber/graphite alkene/epoxy prepreg described in claim 1, it is characterised in that The preparation of Graphene: weigh NaNO₃Solid is dissolved in the concentrated sulphuric acid of 98%, mixed liquor is placed in ice-water bath stirring simultaneously and makes NaNO₃Solid fully dissolves；Weigh graphite to join in above-mentioned mixed liquor, stir；Subsequently, excess it is slowly added to high Potassium manganate aoxidizes, and controls reaction temperature and is less than 20 DEG C, stir, temperature is transferred to 30-40 DEG C in adition process Continue stirring reaction；Then in mixed liquor, add deionized water dilute and drip H₂O₂, make solution become glassy yellow；Filter, With the hydrochloric acid solution washing of mass concentration 5% while filtering, remove the MnO in solution₂；The filter cake obtained after filtering is used Deionized water dilutes, then carries out ultrasonic and centrifugal treating；The supernatant obtained after centrifugal adds hydrochloric acid solution, fully stirs Mix rear recentrifuge；The lower floor's viscous solid obtained after being centrifuged is dried, and obtains graphite oxide sample；Take gained graphite oxide, Quickly put into and be preheated in the Muffle furnace of 1050 DEG C keep 30s to obtain expanded graphite alkene；Take expanded graphite alkene and add anhydrous second In alcohol, ultrasonic stripping is not higher than 15h, and vacuum drying obtains Graphene.

3. according to the preparation method of a kind of carbon fiber/graphite alkene/epoxy prepreg described in claim 2, it is characterised in that Described in above-mentioned steps (1), graphite is natural flake graphite, and Graphene is single or multiple lift Graphene.

4. according to the preparation method of a kind of carbon fiber/graphite alkene/epoxy prepreg described in claim 1, it is characterised in that Amino silicane coupling agent described in step (2) is 3-aminopropyl triethoxysilane, and Graphene is at 3-aminopropyl-triethoxy Dispersion concentration in silane is 0.5～2mg/ml.

5. according to the preparation method of a kind of carbon fiber/graphite alkene/epoxy prepreg described in claim 1, it is characterised in that Graphene and N, the mass ratio of N'-Dicyclohexylcarbodiimide (DCC) is 10:3～5.

6. according to the preparation method of a kind of carbon fiber/graphite alkene/epoxy prepreg described in claim 1, it is characterised in that In step (3), in composition system, firming agent is MDA or methyl tetrahydro phthalic anhydride, and accelerator is 2,4,6-tri-(two Methylamino methyl) phenol；Each constituent mass ratio epoxy resin in composition system: polyurethane-modified liquid rubber: firming agent two Diaminodiphenylmethane is 100:5～15:25～40, or epoxy resin: polyurethane-modified liquid rubber: firming agent methyl tetrahydro phthalic anhydride For 100:5～15:60～70, the amount adding accelerator in the epoxy resin of every 100 parts is 1ml.

7. according to the preparation method of a kind of carbon fiber/graphite alkene/epoxy prepreg described in claim 1, it is characterised in that Quality is epoxy resin quality 0.05～1% of ammonia modified graphene described in step (3)；Epoxy resin is preferably asphalt mixtures modified by epoxy resin Fat E51.

8. according to the preparation method of a kind of carbon fiber/graphite alkene/epoxy prepreg described in claim 1, it is characterised in that The operating power of step (4) supersonic generator is 150～200 watts, and the control impregnation time is 10～20 seconds, and tow tension is 150～200 grams.

9. utilize the preparation method of carbon fiber/graphite alkene/epoxy prepreg that claim 1-8 any one method prepares The method preparing carbon fibre composite, it is characterised in that prepreg is prepared laminate by flat-bed press press curing, Solidify after carrying out in an oven, be cooled to room temperature, obtain ammonia modified graphene-carbon fiber reinforced epoxy resin-based composite i.e. carbon Fiber/Graphene/epoxy resin composite material.

10. according to the preparation method of claim 8, it is characterised in that solidification process is solidification 1～2 hour at 90 DEG C, then Solidify 2～4 hours at 130 DEG C, solidify 2～4 hours at last 150 DEG C.