High-performance carbon fiber prepreg and preparation method thereof

Abstract

The invention belongs to the technical field of high polymer materials, and particularly relates to a high-performance carbon fiber prepreg and a preparation method thereof. The high-performance carbon fiber prepreg is prepared from a resin composition and carbon fibers, wherein the resin composition is prepared from the following raw materials in parts by weight: 60 to 70 parts of epoxy resin, 5 to 10 parts of modified carbon nanotubes, 0.5 to 1 part of 2, 2, 4-trimethyl-1, 3-pentanediol monoisobutyrate, 10 to 20 parts of a curing agent, 5 to 10 parts of epoxy triglyceride, 0.05 to 0.1 part of an antioxidant and 1 to 5 parts of functional filler. After the carbon fiber prepreg is subjected to hot pressing and curing, the components are fully crosslinked, and a carbon fiber composite material which is high in strength, resistant to high temperature and good in heat conduction capacity is formed. The carbon fiber prepreg is widely applied to the fields of aerospace, high-speed railways and the like.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of high polymer materials, and particularly relates to a high-performance carbon fiber prepreg and a preparation method thereof. BACKGROUND

[0002] Carbon fiber composite materials have been widely used in the fields of aerospace, high-speed railway, wind power generation, automobile manufacturing, etc. due to their excellent specific strength, specific modulus, fatigue resistance and designability. Carbon fiber composite materials are prepared by hot pressing of prepregs. Therefore, the performance of carbon fiber prepregs determines the final quality and performance of carbon fiber composite materials.

[0003] Carbon fiber prepregs are intermediate materials prepared by pre-impregnation and partial curing of continuous carbon fibers or fabrics and thermosetting or thermoplastic resin matrix under strict control conditions, and have the characteristics of high fiber volume fraction, low porosity, excellent mechanical properties and good process controllability. With the development of new generation aircraft and high-speed trains towards higher speed, longer life and lower energy consumption, more stringent standards are required for the strength, heat resistance, thermal conductivity and interface stability of carbon fiber composite materials. Although traditional epoxy resin-based prepregs have mature technology, they still face the defects of insufficient heat resistance of resin matrix, poor interface shear strength, poor thermal conductivity and poor mechanical properties in extreme environmental conditions, which limit their application range.

[0004] To solve the above problems, researchers have developed high-toughness epoxy, bismaleimide, polyimide, cyanate ester and other high-performance matrix systems, and introduced functional materials such as carbon nanotubes, graphene and boron nitride to modify the resin. However, there are still some defects in the direct addition of carbon nanotubes (CNTs). CNTs are prone to agglomeration and entanglement in the resin due to their high specific surface area and van der Waals force, which leads to stress concentration and increased porosity, thereby weakening the interlaminar performance of the composite material. At the same time, the chemical inertness of CNTs makes the interface wetting and chemical bonding with the epoxy resin insufficient, resulting in low interface thermal resistance and mechanical stress transfer efficiency, and failing to fully utilize the potential of CNTs for reinforcement, toughening and thermal conductivity. Therefore, how to achieve uniform dispersion of CNTs in the resin matrix and strong and tough coupling with the resin / fiber interface while maintaining the excellent mechanical and thermal conductivity properties of CNTs has become a core problem in current research. If boron nitride is directly added to the carbon fiber prepreg, it will not only fail to utilize its high thermal conductivity advantage, but also weaken the overall performance of the carbon fiber prepreg due to problems such as agglomeration and weak interfacial bonding.

[0005] In summary, the existing carbon fiber prepreg technology still has deficiencies in terms of high strength, heat resistance and thermal conductivity, and there is an urgent need for a composite material that can simultaneously achieve high strength, high temperature resistance and good thermal conductivity to provide more reliable technical support for aerospace, high-speed railway and other fields. SUMMARY

[0006] The first object of the present application is to provide a high-performance carbon fiber prepreg. The prepreg is heat-pressed and cured to make the components fully cross-linked, forming a carbon fiber composite material with high strength, high temperature resistance and good heat conduction capacity. Currently, carbon fiber prepreg is widely used in the fields of aerospace, high-speed railway and the like.

[0007] The second object of the present application is to provide a preparation method of the high-performance carbon fiber prepreg. The method is simple and efficient, conducive to large-scale production, and has important significance in industrial practical application.

[0008] To achieve the above objects, the technical scheme adopted by the present application is as follows:

[0009] A high-performance carbon fiber prepreg comprises a resin composition and carbon fibers, wherein the resin composition comprises the following raw materials in parts by weight: epoxy resin 60-70 parts, modified carbon nanotubes 5-10 parts, dodecanol ester 0.5-1 part, curing agent 10-20 parts, epoxy glyceride 5-10 parts, antioxidant 0.05-0.1 part, and functional filler 1-5 parts.

[0010] The preparation process of the modified carbon nanotubes is as follows:

[0011] (1) carbon nanotubes are added to a solvent, a surfactant is added, and stirring is performed at room temperature to obtain activated carbon nanotubes;

[0012] (2) the activated carbon nanotubes obtained in step (1) are added to water, polyethylene glycol methacrylate phosphate, an emulsifier and an initiator are added, and heating reaction is performed to obtain modified carbon nanotubes.

[0013] Further, in step (1), the mass ratio of the carbon nanotubes, the surfactant and the solvent is 1:(0.2-0.8):(20-50); the solvent is ethanol, and the surfactant is sodium dodecyl benzene sulfonate; the stirring time is 1-3h.

[0014] Further, in step (2), the mass ratio of the activated carbon nanotubes, polyethylene glycol methacrylate phosphate, the emulsifier, the initiator and water is 1:(15-30):(0.2-0.4):(0.3-0.6):(90-100).

[0015] Further, in step (2), the emulsifier is styrene maleic anhydride, and the initiator is azobisisobutyronitrile; the heating reaction temperature is 70-80℃, and the time is 2-4h.

[0016] Further, the functional filler is prepared as follows: boron nitride is added into an aqueous solution of ethanol, then gamma-trifluoropropyltrimethoxysilane is added, after stirring, sodium alginate is added, and the functional filler is obtained after reflux reaction.

[0017] Further, the boron nitride, gamma-trifluoropropyltrimethoxysilane, sodium alginate and aqueous solution of ethanol are used in a ratio of 1:(0.1-0.3):(0.5-0.8):(40-60).

[0018] Further, the reflux reaction is carried out at a temperature of 60-70℃ for 3-5h.

[0019] Further, the epoxy resin is bisphenol A type epoxy resin; the curing agent is 4,4'-diamino diphenyl sulfone; and the antioxidant is antioxidant 168.

[0020] The application further provides a preparation method of the high-performance carbon fiber prepreg, comprising the following steps:

[0021] S1. The epoxy resin, modified carbon nanotube, dodecanol ester, curing agent, epoxy glyceride, antioxidant and functional filler are mixed according to the weight parts to obtain a resin mixture;

[0022] S2. The sizing agent on the surface of the carbon fiber is removed, and the carbon fiber is immersed in the resin mixture to obtain a carbon fiber prepreg.

[0023] Further, the treatment temperature for removing the sizing agent on the surface of the carbon fiber is 280-400℃, and the treatment time is 0.5-2min; and the mass ratio of the carbon fiber and the resin mixture is (4-5):(1-3).

[0024] The application has the following beneficial technical effects:

[0025] 1. The present application provides a kind of high-performance carbon fiber prepreg, the prepreg is heated and pressed, and after curing, it makes the components fully crosslinking, form a carbon fiber composite material which has both high strength, high temperature resistance, and also has good heat conduction capacity.Currently carbon fiber prepreg is widely used in aerospace, high-speed railway and other fields.Among them, (1) the modified carbon nanotube added in the present application is first activated with a surfactant, the alkyl chain is adsorbed on the surface of carbon nanotube by hydrophobic interaction, and the sulfonic acid group forms a negatively charged interface layer, providing an electrostatic attraction site for the phosphate group in polyethylene glycol methacrylate phosphate.Ethylene glycol methacrylate phosphate is subjected to free radical polymerization on the surface of carbon nanotube under the action of initiator.The modified carbon nanotube, on the one hand, avoids the agglomeration of carbon nanotube, improves the compatibility with epoxy resin;On the other hand, through the interaction with epoxy resin, the interfacial bonding performance of resin and carbon fiber is effectively improved, and the carbon fiber composite material prepared has high strength, high temperature resistance and other properties.(2) The functional filler prepared in the present application has good thermal conductivity, which can improve the structural uniformity of carbon fiber composite material and improve the mechanical properties of the material.

[0026] 2. The present application also provides a preparation method of the above-mentioned high-performance carbon fiber prepreg, which is simple and efficient, conducive to large-scale production, and has important significance in industrial practical application. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The electron microscope graph of the modified carbon nanotube obtained in Example 1 of the present application;

[0028] Figure 2 The electron microscope graph of the functional filler obtained in Example 1 of the present application. DETAILED DESCRIPTION

[0029] The following is a further detailed description of the present application in conjunction with specific preferred embodiments, which cannot be deemed to limit the specific implementation of the present application to these descriptions. For ordinary skilled persons in the technical field to which the present application belongs, without departing from the concept of the present application, a number of simple deductions or substitutions can also be made, which should be regarded as falling within the protection scope of the present application. The specific conditions not mentioned in the examples are carried out according to conventional conditions or manufacturer's recommended conditions. The reagents or instruments used, such as no special instructions, are conventional products obtained through market channels.

[0030] The carbon fiber of the present application is 12K T700 industrial grade unidirectional carbon fiber filament; the diameter of carbon nanotube is 10-50 nm, and the length is 0.5-50 μm; the epoxy resin is bisphenol A type epoxy resin; the curing agent is 4,4'-diamino diphenyl sulfone; and the antioxidant is antioxidant 168.

[0031] Example 1

[0032] The embodiment provides a high-performance carbon fiber prepreg, comprising a resin composition and carbon fibers, the resin composition is composed of raw materials in the following weight parts: 65 parts of epoxy resin, 9 parts of modified carbon nanotubes, 0.8 parts of dodecanol ester, 15 parts of curing agent, 8 parts of epoxy triglyceride, 0.08 parts of antioxidant, and 3 parts of functional filler;

[0033] The preparation process of the modified carbon nanotubes is as follows:

[0034] (1) carbon nanotubes are taken and added into anhydrous ethanol, and sodium dodecyl benzene sulfonate is further added, wherein the mass ratio of the carbon nanotubes, the sodium dodecyl benzene sulfonate and the anhydrous ethanol is 1:0.5:40, stirring is carried out at room temperature for 2 hours, and then filtration and drying treatment are carried out to obtain activated carbon nanotubes;

[0035] (2) the activated carbon nanotubes obtained in step (1) are added into water, and polyethylene glycol methacrylate phosphate, styrene maleic anhydride and azobisisobutyronitrile are further added, wherein the mass ratio of the activated carbon nanotubes, the polyethylene glycol methacrylate phosphate, the styrene maleic anhydride, the azobisisobutyronitrile and the water is 1:25:0.3:0.5:95; heating reaction is carried out at 75 DEG C for 3 hours, after the reaction is completed, the reaction liquid is cooled to room temperature, and then filtration and drying are carried out to obtain the modified carbon nanotubes. The electron microscope image of the modified carbon nanotubes is shown in Figure 1 .

[0036] The preparation process of the functional filler is as follows: anhydrous ethanol and water are mixed uniformly in a volume ratio of 1:3 to obtain an aqueous solution of ethanol; boron nitride is taken and added into the aqueous solution of ethanol, and then gamma-trifluoropropyltrimethoxysilane and sodium alginate are added after stirring, wherein the dosage ratio of the boron nitride, the gamma-trifluoropropyltrimethoxysilane, the sodium alginate and the aqueous solution of ethanol is 1:0.2:0.7:50; reflux reaction is carried out at 65 DEG C for 4 hours; after the reaction is completed, the reaction liquid is subjected to suction filtration, washed with anhydrous ethanol for 5 times, and then dried to obtain the functional filler. The electron microscope image of the functional filler is shown in Figure 2 .

[0037] The embodiment also provides a preparation method of the high-performance carbon fiber prepreg.

[0038] S1. the epoxy resin, the modified carbon nanotubes, the dodecanol ester, the curing agent, the epoxy triglyceride, the antioxidant and the functional filler are mixed uniformly according to the weight parts to obtain a resin mixture;

[0039] S2. the sizing agent on the surface of the carbon fibers is removed at a treatment temperature of 350 DEG C for 1 minute; the carbon fibers are immersed into the resin mixture, and the mass ratio of the carbon fibers and the resin mixture is 4.5:2; and then a carbon fiber prepreg is obtained.

[0040] Example 2

[0041] The embodiment provides a high-performance carbon fiber prepreg, comprising a resin composition and carbon fibers, the resin composition being composed of raw materials in the following weight parts: 60 parts of epoxy resin, 5 parts of modified carbon nanotubes, 0.5 parts of dodecanol ester, 10 parts of curing agent, 5 parts of epoxy triglyceride, 0.05 parts of antioxidant, and 1 part of functional filler;

[0042] The preparation process of the modified carbon nanotubes is as follows:

[0043] (1) carbon nanotubes are taken and added into anhydrous ethanol, and then sodium dodecyl benzene sulfonate is added, wherein the mass ratio of the carbon nanotubes, the sodium dodecyl benzene sulfonate and the anhydrous ethanol is 1:0.2:20, stirring is carried out at room temperature for 1h, and then filtration and drying treatment are carried out to obtain activated carbon nanotubes;

[0044] (2) the activated carbon nanotubes obtained in step (1) are added into water, and then polyethylene glycol methyl acrylate phosphate, styrene maleic anhydride and azobisisobutyronitrile are added, wherein the mass ratio of the activated carbon nanotubes, the polyethylene glycol methyl acrylate phosphate, the styrene maleic anhydride, the azobisisobutyronitrile and the water is 1:15:0.2:0.3:90; heating reaction is carried out at 70℃ for 4h, after the reaction is completed, the reaction liquid is cooled to room temperature, and then filtration and drying are carried out on the reaction liquid to obtain the modified carbon nanotubes.

[0045] The preparation process of the functional filler is as follows: anhydrous ethanol and water are mixed uniformly in a volume ratio of 1:3 to obtain an aqueous solution of ethanol; boron nitride is taken and added into the aqueous solution of ethanol, and then γ-trifluoropropyl trimethoxysilane is added, stirring is uniformly carried out, and then sodium alginate is added, wherein the dosage ratio of the boron nitride, the γ-trifluoropropyl trimethoxysilane, the sodium alginate and the aqueous solution of ethanol is 1:0.1:0.5:40; reflux reaction is carried out at 70℃ for 3h, after the reaction is completed, the reaction liquid is subjected to suction filtration, washed with anhydrous ethanol for 5 times, and then dried to obtain the functional filler.

[0046] The embodiment also provides a preparation method of the high-performance carbon fiber prepreg.

[0047] S1. the epoxy resin, the modified carbon nanotubes, the dodecanol ester, the curing agent, the epoxy triglyceride, the antioxidant and the functional filler are uniformly mixed in the weight parts to obtain a resin mixture;

[0048] S2. the sizing agent on the surface of the carbon fibers is removed at a treatment temperature of 400℃ for 0.5min; the carbon fibers are immersed into the resin mixture, and the mass ratio of the carbon fibers and the resin mixture is 4:1; and then a carbon fiber prepreg is obtained.

[0049] Example 3

[0050] The embodiment provides a high-performance carbon fiber prepreg, comprising a resin composition and carbon fibers, the resin composition being composed of raw materials in the following weight parts: 70 parts of epoxy resin, 10 parts of modified carbon nanotubes, 1 part of dodecanol ester, 20 parts of curing agent, 10 parts of epoxy triglyceride, 0.1 part of antioxidant, and 5 parts of functional filler.

[0051] The preparation process of the modified carbon nanotubes is as follows:

[0052] (1) carbon nanotubes are taken and added into anhydrous ethanol, and sodium dodecyl benzene sulfonate is added, wherein the mass ratio of the carbon nanotubes, the sodium dodecyl benzene sulfonate and the anhydrous ethanol is 1:0.8:50, stirring is carried out at room temperature for 3h, and then filtration and drying treatment are carried out to obtain activated carbon nanotubes;

[0053] (2) the activated carbon nanotubes obtained in step (1) are added into water, and polyethylene glycol methacrylate phosphate, styrene maleic anhydride and azobisisobutyronitrile are added, wherein the mass ratio of the activated carbon nanotubes, the polyethylene glycol methacrylate phosphate, the styrene maleic anhydride, the azobisisobutyronitrile and the water is 1:30:0.4:0.6:100; heating reaction is carried out at 80℃ for 2h, after the reaction is completed, the reaction liquid is cooled to room temperature, and then filtration and drying are carried out to obtain the modified carbon nanotubes.

[0054] The preparation process of the functional filler is as follows: anhydrous ethanol and water are mixed uniformly in a volume ratio of 1:3 to obtain an aqueous solution of ethanol; boron nitride is taken and added into the aqueous solution of ethanol, and then γ-trifluoropropyl trimethoxysilane is added, stirring is uniformly carried out, and then sodium alginate is added, wherein the dosage ratio of the boron nitride, the γ-trifluoropropyl trimethoxysilane, the sodium alginate and the aqueous solution of ethanol is 1:0.3:0.8:60; reflux reaction is carried out at 60℃ for 5h, after the reaction is completed, the reaction liquid is subjected to suction filtration, washed with anhydrous ethanol for 5 times, and then dried to obtain the functional filler.

[0055] The embodiment also provides a preparation method of the high-performance carbon fiber prepreg.

[0056] S1. the epoxy resin, the modified carbon nanotubes, the dodecanol ester, the curing agent, the epoxy triglyceride, the antioxidant and the functional filler are uniformly mixed in the weight parts to obtain a resin mixture;

[0057] S2. the sizing agent on the surface of the carbon fibers is removed at a treatment temperature of 280℃ for 2min; the carbon fibers are immersed into the resin mixture, and the mass ratio of the carbon fibers and the resin mixture is 5:3; and then a carbon fiber prepreg is obtained.

[0058] Comparative Example 1

[0059] The comparative example 1 and the example 1 are basically the same, the difference lies in: the modified carbon nanotube is replaced by the carbon nanotube; the others are consistent with the example 1.

[0060] Comparative example 2

[0061] The comparative example 2 and the example 1 are basically the same, the difference lies in: the modified carbon nanotube is replaced by the activated carbon nanotube, the others are consistent with the example 1.

[0062] Comparative example 3

[0063] The comparative example 3 and the example 1 are basically the same, the difference lies in: the functional filler is replaced by the boron nitride, the others are consistent with the example 1.

[0064] Application example

[0065] The carbon fiber prepreg obtained in the example 1 is parallelly laid, and a hot press tank forming process is used for processing, the forming pressure is controlled to be 1 MPa, first from room temperature to 85 DEG C, the heating rate is 1.5 DEG C / min, at the temperature, curing for 30 min, continue to heat to 130 DEG C curing 2h, heating to 180 DEG C curing 2h, the carbon fiber composite material with a thickness of about 1mm is prepared.

[0066] The examples 2-3 and the comparative examples 1-3 are all prepared by the above method to obtain the carbon fiber composite material.

[0067] Test example

[0068] The carbon fiber composite materials obtained in the examples 1-3 and the comparative examples 1-3 of the application are tested for performance at 25 DEG C, and after being placed at 240 DEG C for 5h, the specific performance test is as follows:

[0069] Tensile properties of the material: refer to the test standard ASTM D3039; interlaminar shear strength: refer to the test standard ASTM D2344; thermal conductivity: refer to the test standard GB / T10297-2015; the above experimental results are recorded in table 1 and table 2.

[0070] Table 1

[0071]

[0072] Table 2

[0073]

[0074]

[0075] From the test results of Table 1 and Table 2, it can be seen that the tensile strength, interlaminar shear strength, and thermal conductivity of the carbon fiber composite materials prepared in Examples 1-3 are all superior to those of Comparative Examples 1-3. The comprehensive performance of Example 1 is the best. Compared with Example 1, in Comparative Example 1, the modified carbon nanotubes are replaced by carbon nanotubes; in Comparative Example 2, the modified carbon nanotubes are replaced by activated carbon nanotubes; and in Comparative Example 3, the functional filler is replaced by boron nitride; the tensile strength and interlaminar shear strength of the composite materials all decrease.

[0076] After experiencing high temperature, the tensile strength, interlaminar shear strength, and thermal conductivity of Examples 1-3 still remain at a high level, among which the decline trend of each index of Comparative Examples 1 and 2 is more obvious, indicating that the high-temperature resistance performance is poor. The thermal conductivity of Comparative Example 3 decreases more obviously, indicating that the functional filler can improve the thermal conductivity of the carbon fiber composite material.

[0077] Finally, it should be pointed out that the above examples are only used to illustrate the technical solutions of the present application, but not to limit it. The basic principles and main features of the present application have been described above with specific embodiments, and on the basis of the present application, some modifications or replacements can be made, but these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the present application.

Claims

1. A high performance carbon fiber prepreg, characterized by, The resin composition comprises the following raw materials by weight: 60-70 parts of epoxy resin, 5-10 parts of modified carbon nanotube, 0.5-1 part of dodecanol ester, 10-20 parts of curing agent, 5-10 parts of epoxy glyceride, 0.05-0.1 part of antioxidant, and 1-5 parts of functional filler. The preparation process of the modified carbon nanotube is as follows: (1) carbon nanotubes are added to a solvent, a surfactant is added, and stirring is performed at room temperature to obtain activated carbon nanotubes; (2) the activated carbon nanotubes obtained in step (1) are added to water, polyethylene glycol methacrylate phosphate, an emulsifier, and an initiator are added, and heating reaction is performed to obtain modified carbon nanotubes.

2. The high performance carbon fiber prepreg according to claim 1, wherein, In step (1), the mass ratio of the carbon nanotubes, the surfactant, and the solvent is 1:(0.2-0.8):(20-50); the solvent is ethanol, and the surfactant is sodium dodecyl benzene sulfonate; the stirring time is 1-3 h.

3. The high performance carbon fiber prepreg according to claim 1, wherein, In step (2), the mass ratio of the activated carbon nanotubes, polyethylene glycol methacrylate phosphate, the emulsifier, the initiator, and water is 1:(15-30):(0.2-0.4):(0.3-0.6):(90-100).

4. The high performance carbon fiber prepreg of claim 1, wherein, In step (2), the emulsifier is styrene maleic anhydride, and the initiator is azobisisobutyronitrile; the heating reaction temperature is 70-80℃, and the time is 2-4 h.

5. The high performance carbon fiber prepreg of claim 1, wherein, The preparation process of the functional filler is as follows: boron nitride is added to an aqueous solution of ethanol, γ-trifluoropropyltrimethoxysilane is added, sodium alginate is added after uniform stirring, and reflux reaction is performed to obtain the functional filler.

6. The high-performance carbon fiber prepreg according to claim 5, wherein, The use amount ratio of the boron nitride, the γ-trifluoropropyltrimethoxysilane, the sodium alginate, and the aqueous solution of ethanol is 1:(0.1-0.3):(0.5-0.8):(40-60).

7. The high-performance carbon fiber prepreg according to claim 5, wherein, The reflux reaction temperature is 60-70℃, and the time is 3-5 h.

8. The high performance carbon fiber prepreg according to claim 1, wherein, The epoxy resin is bisphenol A type epoxy resin; the curing agent is 4,4'-diamino diphenyl sulfone; and the antioxidant is antioxidant 168.

9. The process for the preparation of a high performance carbon fibre prepreg according to any one of claims 1 to 8, characterised in that, The method comprises the following steps: S1. The epoxy resin, the modified carbon nanotube, the dodecanol ester, the curing agent, the epoxy glyceride, the antioxidant, and the functional filler are mixed uniformly according to the weight parts to obtain a resin mixture; S2. The sizing agent on the surface of the carbon fiber is removed, and the carbon fiber is immersed in the resin mixture to obtain a carbon fiber prepreg.

10. The method for preparing the high-performance carbon fiber prepreg according to claim 9, characterized in that, The treatment temperature for removing the sizing agent on the surface of the carbon fiber is 280-400℃, and the time is 0.5-2 min; and the mass ratio of the carbon fiber to the resin mixture is (4-5):(1-3).

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