Carbon fiber reinforced composite material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of composite materials, and particularly relates to a carbon fiber reinforced composite material and a preparation method and application thereof. According to the invention, benzoic acid forms a hydrogen bond cross-linked hydrophobic phase region to enhance the mechanical properties and environmental stability of the polyvinyl alcohol material, so that the polyvinyl alcohol-based carbon fiber reinforced composite material has high strength and excellent water resistance; through reversibility of hydrogen bonds, the carbon fiber reinforced composite material has good recoverability and recyclability. The carbon fiber reinforced composite material provided by the invention is high in tensile strength and excellent in water resistance and solvent resistance, can be recycled, has controllable depolymerization performance, can realize efficient and closed-loop material recovery, and is environment-friendly. The carbon fiber reinforced composite material provided by the invention can be effectively recycled and reprocessed under the assistance of an organic solvent, and the strength and modulus are not obviously reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of composite materials, and particularly relates to a carbon fiber reinforced composite material and a preparation method and application thereof. BACKGROUND

[0002] Carbon fiber reinforced composites (CFRCs) have high specific strength, excellent chemical corrosion resistance and thermal stability, and are widely used in high-end manufacturing fields such as aerospace, automobile manufacturing, wind power generation and high-performance sports equipment.

[0003] Existing CFRCs usually use epoxy resin, polyether ether ketone (PEEK) and other thermosetting or high-melting-point thermoplastic polymers as bonding matrix materials. Such matrix materials form strong interfacial bonding with carbon fibers, making the overall composite material structure stable but irreversible. The carbon fibers in the matrix material are difficult to recycle effectively after the end of the service life, resulting in waste of carbon fibers.

[0004] At present, some researches have attempted to decompose the matrix material in the CFRCs by catalytic pyrolysis or solvent degradation, so as to recycle the carbon fibers. However, the above-mentioned methods have harsh operating conditions and usually need to be carried out in a high-temperature or strong acid and alkali environment, which is easy to cause structural damage to the recycled carbon fibers. SUMMARY

[0005] The purpose of the present application is to provide a carbon fiber reinforced composite material and a preparation method and application thereof. The carbon fiber reinforced composite material provided by the present application can be recycled without structural damage.

[0006] In order to achieve the above-mentioned purpose, the present application provides the following technical scheme:

[0007] The present application provides a carbon fiber reinforced composite material, comprising a carbon fiber substrate and a functional layer covering the surface of the carbon fiber substrate; the functional layer comprises benzoic acid grafted polyvinyl alcohol; the number of layers of the functional layer is 3 or more.

[0008] Preferably, the grafting rate of the benzoic acid grafted polyvinyl alcohol is 30-70%.

[0009] Preferably, the mass ratio of the functional layer to the carbon fiber substrate is not more than 7:10.

[0010] The present application also provides a preparation method of the carbon fiber reinforced composite material described in the above-mentioned scheme, comprising the following steps:

[0011] The polyvinyl alcohol, the p-formaldehyde benzoic acid, the catalyst and the organic solvent are mixed to carry out an acetal reaction, so as to obtain the benzoic acid grafted polyvinyl alcohol;

[0012] After the benzoic acid grafted polyvinyl alcohol is coated on the surface of the carbon fiber substrate, the solvent is removed to obtain the carbon fiber reinforced composite material.

[0013] Preferably, the number average molecular weight of the polyvinyl alcohol is 74000-140000.

[0014] Preferably, the mass ratio of the polyvinyl alcohol and the p-formaldehyde benzoic acid is 30:(15-26).

[0015] Preferably, the mass ratio of the polyvinyl alcohol and the organic solvent is (6-10):100.

[0016] Preferably, the temperature of the acetal reaction is 75-80℃, and the holding time is 20-72 hours.

[0017] Preferably, the solvent removal is heating; the temperature of the solvent removal is 40-60℃, and the holding time is 48-72 hours.

[0018] The application also provides the use of the carbon fiber reinforced composite material prepared by the method in the fields of aerospace, automobile manufacturing, wind power generation, or sports equipment.

[0019] The application provides a carbon fiber reinforced composite material. The application enhances the mechanical properties and environmental stability of polyvinyl alcohol materials by forming hydrogen bond cross-linked hydrophobic phase regions with benzoic acid, so that the carbon fiber reinforced composite material has high strength and excellent water resistance. The application makes the carbon fiber reinforced composite material have good recyclability and cyclic usability by the reversibility of hydrogen bonds. The carbon fiber reinforced composite material provided by the application has high tensile strength, excellent water resistance and solvent resistance, and can be recycled and used cyclically. The carbon fiber reinforced composite material has controllable depolymerization performance, can realize efficient and closed-loop material recycling, and is environmentally friendly. The results of the examples show that the strength and modulus of the carbon fiber reinforced composite material provided by the application remain unchanged after being soaked in an aqueous solution or an organic solvent for 24 hours. The carbon fiber reinforced composite material can be effectively recycled and reprocessed with the assistance of an organic solvent, and the strength and modulus will not decrease significantly.

[0020] The application also provides a method for preparing the carbon fiber reinforced composite material. The preparation method provided by the application is simple, easy to operate, and low in cost, and is conducive to large-scale preparation.

[0021] The application also provides the use of the carbon fiber reinforced composite material prepared by the method in the fields of aerospace, automobile manufacturing, wind power generation, or sports equipment. The carbon fiber reinforced composite material provided by the application has excellent comprehensive performance, can be recycled without structural damage, and is suitable for high-end manufacturing, such as aerospace, automobile manufacturing, wind power generation, or sports equipment. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a synthetic route diagram for preparing carbon fiber reinforced composite materials in Example 1;

[0024] Figure 2 SEM image of the carbon fiber reinforced composite material prepared in Example 1;

[0025] Figure 3 The figure shows the flexibility test results of the carbon fiber reinforced composite material prepared in Example 1;

[0026] Figure 4 The nuclear magnetic resonance spectrum of the carbon fiber reinforced composite material prepared in Example 1;

[0027] Figure 5 The graph shows the strength test results of the benzoic acid-grafted polyvinyl alcohol and carbon fiber reinforced composite material prepared in Example 1.

[0028] Figure 6 The graph shows the solvent resistance test results of the carbon fiber reinforced composite material prepared in Example 1.

[0029] Figure 7 The graph shows the test results of the recyclability of the carbon fiber reinforced composite material prepared in Example 1.

[0030] Figure 8 The figures show the tensile strength test results of the carbon fiber reinforced composite materials prepared in Examples 1-3. Detailed Implementation

[0031] The present invention provides a carbon fiber reinforced composite material, comprising a carbon fiber substrate and a functional layer covering the surface of the carbon fiber substrate; the functional layer comprises benzoic acid grafted polyvinyl alcohol; the number of functional layers is three or more.

[0032] The carbon fiber reinforced composite material provided by the present invention includes a carbon fiber substrate; the carbon fiber substrate may be a carbon fiber cloth; the carbon fiber cloth may be a T700 plain weave carbon fiber cloth.

[0033] The carbon fiber reinforced composite material provided by the application comprises a functional layer covering the surface of the carbon fiber substrate; in the functional layer, the grafting rate of the benzoic acid grafted polyvinyl alcohol can be 30-70%, and can be 32%, 40%, 50% or 66% in particular.

[0034] In the application, the number of layers of the functional layer is 3 or more, and can be 4, 5 or 6 in particular.

[0035] In the application, the thickness of a single layer of the functional layer can be 0.21-0.26 mm, and can be 0.24 mm in particular.

[0036] In the application, the mass ratio of the functional layer to the carbon fiber substrate can be no more than 7:10, and can be 6:10, 6.5:10 or 6.8:10 in particular.

[0037] The application further provides a preparation method of the carbon fiber reinforced composite material described in the above scheme, comprising the following steps:

[0038] The polyvinyl alcohol, the p-aldehyde benzoic acid, the catalyst and the organic solvent are mixed to perform an acetal reaction to obtain the benzoic acid grafted polyvinyl alcohol;

[0039] After the benzoic acid grafted polyvinyl alcohol is covered on the surface of the carbon fiber substrate, the solvent is removed to obtain the carbon fiber reinforced composite material.

[0040] The polyvinyl alcohol (PVA), the p-aldehyde benzoic acid (CBA), the catalyst and the organic solvent are mixed to perform an acetal reaction to obtain the benzoic acid grafted polyvinyl alcohol (PCA-CBA). In the application, the number average molecular weight of the polyvinyl alcohol can be 74,000-140,000, and can be 80,000, 100,000 or 120,000 in particular.

[0041] In the application, the mass ratio of the polyvinyl alcohol to the p-aldehyde benzoic acid can be 30:15-26, and can be 30:16, 30:18, 30:20, 30:22 or 30:24 in particular. The p-aldehyde benzoic acid is added as a crosslinking agent in the application.

[0042] In the application, the catalyst can be an acid; the acid can be hydrochloric acid; the concentration of the hydrochloric acid can be 1 mol / L; and the mass ratio of the p-aldehyde benzoic acid to the catalyst can be (15-26) g:5 mmol, and can be 18 g:5 mmol in particular. -1

[0043] In the application, the organic solvent can comprise one or more of a sulfone type solvent and an amide type solvent; the sulfone type solvent can be dimethyl sulfoxide (DMSO); and the amide type solvent can be N,N-dimethylformamide (DMF).​

[0044] In the present application, the mass ratio of the polyvinyl alcohol and the organic solvent can be 6-10:100, and specifically can be 6:100, 8:100 or 10:100.

[0045] In the present application, the temperature of the acetal reaction can be 75-80℃, and specifically can be 75℃, 77℃ or 79℃, and the holding time can be 20-72 hours, and specifically can be 30 hours, 48 hours, 55 hours, 60 hours, 65 hours or 70 hours.

[0046] After obtaining the benzoic acid grafted polyvinyl alcohol, the present application coats the benzoic acid grafted polyvinyl alcohol on the surface of the carbon fiber substrate and removes the solvent to obtain the carbon fiber reinforced composite material. In the present application, the coating of the benzoic acid grafted polyvinyl alcohol on the surface of the carbon fiber substrate can include the following steps: pouring the solution of the benzoic acid grafted polyvinyl alcohol on the carbon fiber substrate.

[0047] In the present application, the solvent removal can be heating; the temperature of the solvent removal can be 40-60℃, and specifically can be 45℃, 50℃ or 55℃, and the holding time can be 48-72 hours, and specifically can be 48 hours, 52 hours, 56 hours, 60 hours, 66 hours or 72 hours.

[0048] The present application also provides the use of the carbon fiber reinforced composite material prepared by the above-mentioned method or the carbon fiber reinforced composite material prepared by the above-mentioned method in the fields of aerospace, automobile manufacturing, wind power generation or sports equipment.

[0049] The carbon fiber reinforced composite material provided by the present application has excellent comprehensive performance and can be recycled without structural damage, and is suitable for high-end manufacturing, such as aerospace, automobile manufacturing, wind power generation or sports equipment.

[0050] In order to further illustrate the present application, the schemes of the present application are described in detail below in combination with the drawings and examples, but they should not be understood as limiting the scope of protection of the present application.

[0051] Example 1

[0052] In this embodiment, a carbon fiber reinforced composite material is prepared, and the synthesis route is as shown in Figure 1 The specific steps are as follows:

[0053] (1) At 80℃, 30 grams of polyvinyl alcohol is stirred and dissolved in 470 grams of dimethyl sulfoxide for 12 hours to obtain a premix solution; then 25.59 grams of p-formaldehyde benzoic acid and 5 milliliters of 1 mol / L sodium hydroxide solution are added to the premix solution. -1The hydrochloric acid is subjected to acetal reaction at 75℃ for 20h, the grafting rate of the aldehyde group benzoic acid is 50%, and a reaction solution of benzoic acid grafted polyvinyl alcohol (denoted as PVA-CBA 50％ ) is obtained.

[0054] (2) The reaction solution is poured on the carbon fiber cloth, heated to 60℃ to remove dimethyl sulfoxide, step (2) is repeated twice, the total mass ratio of PVA-CBA to the mass of the carbon fiber cloth is 3:7, and a carbon fiber reinforced composite material, denoted as PVA-CBA 50％ carbon fiber reinforced composite material is obtained.

[0055] Example 2

[0056] A carbon fiber reinforced composite material is prepared in this example, and the specific steps are as follows:

[0057] (1) 30g of polyvinyl alcohol is stirred and dissolved in 470g of dimethyl sulfoxide at 80℃ for 12h to obtain a premix solution; then 15.35g of p-aldehyde benzoic acid and 5ml of 1mol / L -1 hydrochloric acid are added to the premix solution, and acetal reaction is carried out at 75℃ for 20h, the grafting rate of the aldehyde group benzoic acid is 30%, and a reaction solution of benzoic acid grafted polyvinyl alcohol (denoted as PVA-CBA 30％ ) is obtained.

[0058] (2) The reaction solution is poured on the carbon fiber cloth, heated to 60℃ to remove dimethyl sulfoxide, step (2) is repeated twice, the total mass ratio of PVA-CBA to the mass of the carbon fiber cloth is 3:7, and a carbon fiber reinforced composite material, denoted as PVA-CBA 30％ carbon fiber reinforced composite material is obtained.

[0059] Example 3

[0060] A carbon fiber reinforced composite material is prepared in this example, and the specific steps are as follows:

[0061] (1) 30g of polyvinyl alcohol is stirred and dissolved in 470g of dimethyl sulfoxide at 80℃ for 12h to obtain a premix solution; then 18.94g of p-aldehyde benzoic acid and 5ml of 1mol / L -1 hydrochloric acid are added to the premix solution, and acetal reaction is carried out at 75℃ for 20h, the grafting rate of the aldehyde group benzoic acid is 37%, and a reaction solution of benzoic acid grafted polyvinyl alcohol (denoted as PVA-CBA 37％ ) is obtained.

[0062] (2) The reaction solution is poured on the carbon fiber cloth, heated to 60℃ to remove dimethyl sulfoxide, step (2) is repeated twice, the total mass ratio of PVA-CBA to the mass of the carbon fiber cloth is 3:7, and a carbon fiber reinforced composite material, denoted as PVA-CBA37％ Carbon fiber reinforced composite material.

[0063] Test Example 1

[0064] SEM test was performed on the carbon fiber cloth of Example 1, the carbon fiber reinforced composite material with 1 functional layer, the carbon fiber reinforced composite material with 2 functional layers and the carbon fiber reinforced composite material with 3 functional layers, and the results are shown in Figure 2 .

[0065] According to Figure 2 It can be seen that the fiber bundles of the pure carbon fiber cloth are relatively loose, and there are obvious gaps between the fiber bundles. In contrast, in the carbon fiber reinforced composite material with functional layer, all the fiber bundles are tightly covered by PUU plastic, and there is no gap in the multi-layer carbon fiber reinforced composite material.

[0066] Test Example 2

[0067] Flexibility test was performed on the carbon fiber reinforced composite material prepared in Example 1, and the results are shown in Figure 3 .

[0068] According to Figure 3 It can be seen that the carbon fiber composite material prepared in Example 1 has high flexibility, can be molded into various shapes (as shown in ii, iii, iv), and can quickly recover to the original shape (as shown in i) after the external force is removed.

[0069] Test Example 3

[0070] NMR test was performed on the carbon fiber reinforced composite material prepared in Example 1, and the results are shown in Figure 4 .

[0071] According to Figure 4 It can be seen that the successful synthesis of PVA-CBA 50％ is proved.

[0072] Test Example 4

[0073] Tensile strength test was performed on the PVA-CBA 50％ of Example 1, the carbon fiber reinforced composite material with 1 functional layer, the carbon fiber reinforced composite material with 2 functional layers and the carbon fiber reinforced composite material, and the results are shown in Figure 5 .

[0074] According to Figure 5 It can be seen that in Example 1, the PVA-CBA 50％The strength of the carbon fiber reinforced composite material is 104.6 MPa, the strength of the carbon fiber reinforced composite material is 815.4 MPa, and the modulus is 30.6 GPa; the bending strength of the carbon fiber reinforced composite material with 1 layer of functional layer is 75.2 MPa, and the modulus is 12.5 GPa; the bending strength of the carbon fiber reinforced composite material with 2 layers of functional layer is 75.2 MPa, and the modulus is 22.4 GPa; the bending strength of the carbon fiber reinforced composite material is 237.8 MPa, and the modulus is 26.8 GPa.

[0075] Test Example 5

[0076] The solvent resistance of the carbon fiber reinforced composite material prepared in Example 1 was detected, and the test method was as follows: the carbon fiber reinforced composite material was soaked in water, acid solution (1 mol·L -1 of hydrochloric acid solution), salt solution (saturated sodium chloride solution) or organic solvent for 24 h, and its tensile strength was tested, and the results are shown in Figure 6

[0077] According to Figure 6 it can be seen that after the carbon fiber reinforced composite material is soaked in water, 1 mol·L -1 of hydrochloric acid solution or saturated sodium chloride solution for 24 h, its tensile strength is almost the same as that of the original carbon fiber reinforced composite material, indicating that the carbon fiber reinforced composite material has excellent water resistance; the carbon fiber reinforced composite material can maintain its structure after being soaked in acetone (Ace), 1,4-dioxane (Diox), dichloromethane (DCM), ethyl acetate (EA), n-hexane (n-Hex), petroleum ether (PE), trichloromethane (TCM), tetrahydrofuran (THF), acetonitrile (ACN) or ethanol for 24 h, and can restore its original mechanical strength after drying.

[0078] Test Example 6

[0079] The recycling performance of the PVA-CBA 50％ and carbon fiber reinforced composite material prepared in Example 1 was detected, and the test method was as follows: the carbon fiber reinforced composite material of Example 1 (size of 10x10 cm) was soaked in 200 mL of DMSO, and the PVA-CBA 50％ was recovered by evaporating DMSO, and the PVA-CBA 50％ and carbon fiber cloth were used to prepare carbon fiber reinforced composite material again, and the results are shown in Figure 7

[0080] According to Figure 7 it can be seen that after 3 h of room temperature soaking, the PVA-CBA 50％ is separated from the carbon fiber cloth and can be taken out from the solution; the carbon fiber reinforced composite material and PVA-CBA 50％ ​​With the original carbon fiber reinforced composite and PVA-CBA 50％ The consistent tensile strength indicates that its mechanical properties were not affected.

[0081] Test Example 7

[0082] PVA-CBA prepared in Examples 1-3 30％ PVA-CBA 37％ PVA-CBA 50％ The tensile strength of the carbon fiber reinforced composite was tested, and the results are as follows: Figure 8 As shown.

[0083] according to Figure 8 It can be seen that the PVA-CBA in Example 2 30％ The tensile strength of the first example was 80.8 MPa, the tensile strength of the carbon fiber composite material in Example 2 was 626.1 MPa, and the tensile strength of the PVA-CBA in Example 3 was... 37％ The tensile strength of the first example is 87.6 MPa, and the tensile strength of the carbon fiber reinforced composite material in Example 3 is 688.9 MPa.

[0084] As can be seen from the above embodiments, the carbon fiber reinforced composite material provided by the present invention has high tensile strength, excellent water resistance and solvent resistance, is recyclable, has controllable depolymerization performance, can achieve efficient and closed-loop material recycling, and is environmentally friendly.

[0085] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. Other embodiments can be obtained based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A carbon fiber reinforced composite material, characterized by, The carbon fiber reinforced composite material comprises a carbon fiber substrate and a functional layer coated on the surface of the carbon fiber substrate. The functional layer comprises benzoic acid grafted polyvinyl alcohol. The functional layer has three or more layers.

2. The carbon fiber reinforced composite material according to claim 1, characterized by, The grafting rate of the benzoic acid grafted polyvinyl alcohol is 30-70%.

3. The carbon fiber reinforced composite material according to claim 1 or 2, characterized in that, The mass ratio of the functional layer to the carbon fiber substrate is not more than 7:

10.

4. The method of producing a carbon fiber-reinforced composite material according to any one of claims 1 to 3, characterized by, The method comprises the following steps: The polyvinyl alcohol, p-formaldehyde benzoic acid, a catalyst and an organic solvent are mixed to perform an acetal reaction to obtain benzoic acid grafted polyvinyl alcohol. The benzoic acid grafted polyvinyl alcohol is coated on the surface of the carbon fiber substrate, and then the solvent is removed to obtain the carbon fiber reinforced composite material.

5. The preparation method according to claim 4, characterized in that, The number average molecular weight of the polyvinyl alcohol is 74,000-140,000.

6. The preparation method according to claim 4, characterized in that, The mass ratio of the polyvinyl alcohol to p-formaldehyde benzoic acid is 30:15-26.

7. The preparation method according to claim 4, characterized in that, The mass ratio of the polyvinyl alcohol to the organic solvent is 6-10:

100.

8. The preparation method according to claim 4, characterized in that, The temperature of the acetal reaction is 75-80℃, and the holding time is 20-72 hours.

9. The preparation method according to claim 4, characterized in that, The solvent removal is heating; the temperature of the solvent removal is 40-60℃, and the holding time is 48-72 hours.

10. The carbon fiber reinforced composite material of any one of claims 1-3 or the carbon fiber reinforced composite material obtained by the preparation method of any one of claims 4-9 is applied in the fields of aerospace, automobile manufacturing, wind power generation or sports equipment.

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