Multi-layer carbon fiber composite material with anti-icing function and preparation method thereof

Abstract

The invention discloses a preparation method of a multi-layer carbon fiber composite material with an anti-icing function. The preparation method comprises the following steps: preparing hydrophobic silicon dioxide resin mixed dispersion liquid, and then preparing prepreg; a mold is cleaned, a release agent is sprayed, three layers of carbon fiber / epoxy resin prepreg and one layer of modified carbon fiber / epoxy resin prepreg are sequentially put into the forming mold, the face, coated with the hydrophobic silicon dioxide resin mixed solution, of the first composite material is located on the outermost side, mold pressing curing forming is conducted, and finally the composite material laminated plate is obtained through the demolding procedure. The carbon fiber prepreg and the hydrophobic modified prepreg are subjected to hot-pressing preparation, the problem that an existing composite material is insufficient in binding force is solved by controlling the resin amount and reversely infiltrating a hydrophobic structure through the resin, and the influence of hydrophobic modification on the mechanical property of the material is reduced.

Description

Technical Field

[0001] The present invention relates to a multi-layer carbon fiber composite material with anti-icing function and its preparation method, belonging to the technical field of resin matrix composite material molding. Background Technique

[0002] Resin-based carbon fiber composite materials are widely used in fields such as aerospace, wind power generation, and automotive industry due to their excellent mechanical properties, stable chemical properties, low density, and easy molding characteristics. Due to the chemical properties of the resin on the surface of the composite material, water vapor in it will be adsorbed, resulting in ice formation on the surface in a low-temperature environment. The formation of ice brings serious safety hazards and even causes huge economic losses. On the one hand, the superhydrophobic surface can reduce the heat exchange between the surface and water droplets and delay the ice formation time of the water droplets on the surface; on the other hand, due to the properties of the superhydrophobic surface, the moving water droplets will be bounced off the surface before icing. Since the superhydrophobic surface has good application prospects in anti-icing, it is particularly important to develop a superhydrophobic surface with anti-icing function for carbon fiber composite materials.

[0003] Patent "Plasma and Graphene Electrothermal Composite Anti-icing Device and Method for Superhydrophobic Coating"

[0004] (CN114104299A) designs a multi-layer anti-icing structure of graphene electrothermal film, insulating layer, electrode layer and superhydrophobic layer, and proposes a method for anti-icing based on plasma of superhydrophobic coating and graphene electrothermal composite. Patent "A Propeller Blade with Built-in Electric Heating" (CN214729705U) lays an electrothermal layer on the blade and covers the skin to achieve the function of electrothermal de-icing without changing the aerodynamic shape. Patent "A Superwetting CuS@SiO2 Photothermal Composite Material and Its Preparation Method and Application" (CN118755300A) adds an alkali solution and a hydrolyzable silicon source to the CuS nanosheet dispersion liquid in sequence for stirring reaction to obtain a superhydrophilic CuS@SiO2 photothermal composite material, and a superhydrophobic photothermal composite material is obtained by low surface energy treatment with silanes, which can be used for photothermal de-icing. Patent "A Composite Anti-icing Coating and Its Preparation Method" (CN116493217A) prepares a three-layer structure of polyurethane (PU) coating, cylindrical polytetrafluoroethylene (PTFE), and polyurethane / fiber coating on the material surface, and uses the huge difference in elastic modulus between the three coatings to de-ice.

[0005] Patent "A Molding Method for the Anti-icing Array Structure on the Surface of a Thermosetting Resin-based Composite Material"

[0006] (CN111907090A) proposes an anti-icing array structure for resin matrix composite materials. By designing the anodic aluminum oxide template structure to construct the surface microstructure, a composite material surface with complete structure, stable size, and high structural consistency is obtained. Patent "A Superhydrophobic Fluorinated Resin Coating Liquid, Anti-icing Coating and Preparation Method and Application"

[0007] (CN117903641A) After two fluororesins are evenly mixed according to a specific particle size matching scheme and then coated and sintered in a single layer, a superhydrophobic anti-icing coating can be obtained. The patent "A Superhydrophobic Anti-Icing Coating and Its Preparation Method and Application" (CN117487455A) uses ultraviolet light to cure a slurry mixed with a binder, a solvent, a photoinitiator, nano-silica, and thermochromic microcapsules to obtain a superhydrophobic anti-icing coating. The patent "An Aircraft Epoxy Composite Anti-Icing Coating and Its Construction Method" (CN115093593A) forms a three-dimensional hydrophobic dendritic structure on the surface of epoxy resin through steps such as mixing, dispersing, spraying, and curing a mixed coating of PTFE and nanoparticles to achieve the anti-icing effect. The patent "A Method for Preparing Superhydrophobic Carbon Fiber / Epoxy Resin Composites Using a Sieve as a Template" proposes to construct a micro-nano hierarchical superhydrophobic structure using a sieve as a template to achieve the anti-icing function.

[0008] The technologies described in the above patents have all proposed corresponding solutions for ice formation on the surface of composite materials. For the composite material anti-icing strategy based on electrothermal and photothermal, during the repeated de-icing process of the material, its thermal effect will damage the resin substrate of the material, and the difference in material modulus will also occur, and it may cause the problem of ice melting and re-condensation. For another type, the use of superhydrophobic coating experimental materials for delayed icing and anti-icing functions, the preparation of superhydrophobic coatings focuses on the surface structure and ignores the bonding between the coating and the resin substrate. At the same time, due to the preparation of the micro-structure on the surface of superhydrophobic materials, the durability of the materials is insufficient, which limits the application of superhydrophobic surfaces. In addition, there are technologies that attempt to modify fibers and substrates with hydrophobic materials, but this method has not verified its impact on the mechanical properties of the materials and is not suitable for the preparation of superhydrophobic dynamic anti-icing composite materials. Summary of the Invention

[0009] The technical problems to be solved by the present invention are: the problem of insufficient bonding force of existing composite materials, and how to reduce the impact of hydrophobic modification on the mechanical properties of materials.

[0010] To solve the above problems, the present invention provides a method for preparing a multi-layer carbon fiber composite material with anti-icing function, including the following steps:

[0011] Step 1): Prepare a hydrophobic silica resin mixed dispersion liquid: After diluting epoxy resin, add hydrophobic silica, and after dispersing evenly with ultrasonic dispersion and a magnetic stirrer, add a curing agent to obtain a hydrophobic silica resin mixed liquid; Mix epoxy resin and the curing agent evenly, and obtain a resin glue after defoaming;

[0012] Step 2): Prepare prepreg: Evenly coat the resin glue on the reverse side of the carbon fiber cloth, and evenly coat the hydrophobic silica resin mixture on the front side of the carbon fiber cloth. Place the coated carbon fiber cloth into a vacuum drying oven, heat to volatilize the excess dispersion liquid. When the epoxy resin cures into a gel state, take it out and cool to make the modified carbon fiber / epoxy prepreg, that is, Composite Material I; Evenly coat the resin glue on the front and reverse sides of the carbon fiber cloth, place it into a vacuum drying oven to make the carbon fiber / epoxy prepreg, that is, Composite Material II;

[0013] Step 3) Clean the mold, spray the release agent, sequentially place three layers of Composite Material II and one layer of Composite Material I into the forming mold. The side of Composite Material I coated with the hydrophobic silica resin mixture is on the outermost side, and perform compression molding and curing. Finally, obtain the composite laminate through the demolding process.

[0014] Preferably, in the said Step 1), the epoxy resin includes E51 and a curing agent, and anhydrous ethanol is used for dilution. The mass ratio of E51 to the curing agent is 2.8 - 3:1.

[0015] Preferably, in the said Step 1), the hydrophobic silica is gas-phase silica particles of perfluorodecyltrimethoxysilane, which are dispersed in the dispersion liquid by magnetic stirring and ultrasonic dispersion. The magnetic stirring speed is 100 rpm, the stirring time is 2 h, the ultrasonic dispersion frequency is 40 kHz, and the ultrasonic dispersion time is 0.5 h; The mass ratio of the epoxy resin to the hydrophobic silica is 100:30 - 50.

[0016] Preferably, in the said Step 2), the carbon fiber cloth is a T300 / 3K plain woven cloth.

[0017] Preferably, in the said Step 2), in order to reduce the mutual influence of the mechanical properties of the modified functional layer and the base layer of the material, control the amount of the coated resin. Use a coater for coating. The coating thickness of the resin glue is 80 μm, and the coating thickness of the hydrophobic silica resin mixture is 100 μm.

[0018] Preferably, in the said Step 2), on the side of Composite Material I coated with the hydrophobic silica resin mixture, since the resin can wet the particles and the particle content in the surface spraying material is very high, the uncured resin will continue to wet the surface particles upward to obtain a firm surface texture with a rough structure.

[0019] Preferably, in the said Step 2), the forming mold is composed of an outer mold and an inner mold, and the materials are both 304 stainless steel; Among them, the inner mold is a smooth flat plate with dimensions of 120 mm × 160 mm × 4.5 mm, and the outer mold is a metal plate with a rectangular through-hole and a plate thickness of 10 mm.

[0020] Preferably, in the step 3), the process parameters for compression molding and curing are: pressure 1.5 - 2 Mpa, temperature 90 - 120 °C, and time 2 h.

[0021] The present invention also provides a multi-layer carbon fiber composite material with anti-icing function prepared by the above preparation method.

[0022] Preferably, the multi-layer carbon fiber composite material with anti-icing function has superhydrophobicity on its surface, the contact angle with water is 157° ± 2°, the rolling angle is about 2°, and the hydrophobicity of the surface is controlled by adjusting the content of hydrophobic particles. The hydrophobic particles can also be replaced by PTFE, modified metal particles, etc.

[0023] The present invention is prepared by hot pressing carbon fiber prepreg and hydrophobic modified prepreg. By controlling the resin amount and the reverse infiltration of resin into the hydrophobic structure, the problem of insufficient bonding force of existing composite materials is solved, and the influence of hydrophobic modification on the mechanical properties of the material is reduced.

[0024] Compared with the prior art, the present invention has the following excellent effects:

[0025] The present invention fills epoxy resin with nano-scale hydrophobic silica particles, modifies its hydrophobicity, and based on this, prepares modified carbon fiber prepreg. Through compression molding, the modified carbon fiber prepreg and the prepreg are bonded and formed into a multi-layer carbon fiber composite material with anti-icing function. By controlling the resin amount and the reverse infiltration of resin into the hydrophobic structure, the problem of insufficient bonding force of existing composite materials is solved, and the influence of hydrophobic modification on the mechanical properties of the material is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is the structure of the multi-layer carbon fiber composite material with anti-icing function;

[0027] Figure 2 It shows the three-dimensional morphology diagram of the conventional composite material in (a), and the SEM diagrams of the conventional composite material at different magnification ratios in (a1 - a3). The surface is overall regular and smooth, and there is no obvious undulation in the 3D contour structure; Figure 2 (b) shows the three-dimensional morphology diagram of the anti-icing composite material, and (b1 - b3) show the SEM diagrams of the anti-icing composite material at different magnification ratios. The F-SiO2 particles added during the preparation process are pressed out and combined with the resin to form cluster particles. The surface is attached with uniform F-SiO2 particles, and the sample surface has a high contact angle;

[0028] Figure 3 It is the water droplet contact state and contact angle of the ordinary surface and the superhydrophobic surface;

[0029] Figure 4 It is the icing process and time of the water droplets on the ordinary surface (a) and the superhydrophobic surface (b) at -20 °C;

[0030] Figure 5 Temperature change during the ice formation process of water droplets on a common surface (a) and a superhydrophobic surface (b) at -20°C.

[0031] Figure 6 Morphological changes of the impact surface of water droplets on a common surface (a) and a superhydrophobic surface (b) at -20°C. Detailed implementation manners

[0032] To make the present invention more obvious and understandable, preferred embodiments are hereby described in detail in conjunction with the accompanying drawings as follows.

[0033] Example 1

[0034] (1) Prepare a hydrophobic silica resin mixed dispersion. After diluting 6 g of epoxy resin with 50 ml of absolute ethanol, add 4 g of hydrophobic silica. After dispersing evenly by ultrasonic dispersion and magnetic stirrer, add 3 g of curing agent to obtain a hydrophobic silica resin mixture; mix 12 g of epoxy resin and 4 g of curing agent evenly, and let it stand to defoam to obtain a resin glue.

[0035] (2) Prepare prepregs. Use a coater to evenly coat 80 μm on the reverse side of the carbon fiber woven fabric with the resin glue in step (1), and evenly coat 100 μm of the hydrophobic modified epoxy resin mixture on the front side of the carbon fiber fabric. Put the carbon fiber fabric evenly coated with resin into a vacuum drying oven, heat it to 80°C to volatilize the dispersion liquid therein, and take it out and cool it when the epoxy resin cures into a gel state to make a modified carbon fiber / epoxy resin prepreg; coat 80 μm of the resin glue on both the front and back sides of the carbon fiber fabric in the same way to make a carbon fiber / epoxy resin prepreg.

[0036] (3) Use ultrasonic to clean the mold, spray a release agent on the mold surface, put three layers of carbon fiber prepregs and one layer of hydrophobic modified prepreg into the molding mold in sequence, and close the mold and apply pressure according to a pressure of 1.5 Mpa - 2 Mpa and a temperature of 90°C - 120°C for 2 h. Finally, obtain an ice-proof composite laminate through the demolding process.

[0037] Example 2

[0038] Use 4 layers of carbon fiber prepregs and prepare the initial composite by molding according to the above process;

[0039] As a control group, verify the ice-proof property and hydrophobicity.

[0040] Example 3

[0041] Use 4 layers of modified carbon fiber prepregs and prepare the ice-proof composite by molding according to the above process; verify the improvement of the mechanical properties by this method.

[0042] Experiment 1: Observe the surface structure of the material using a super-depth-of-field microscope and an electron microscope.

[0043] Experiment 2: Place the sample on a -20°C semiconductor cooling table, drop a 5 μL water droplet on the sample, observe the freezing process, and record the freezing delay time and temperature change.

[0044] Experiment 3: Measure the tensile strength and shear strength of the material using a universal testing machine.

[0045] Figure 1 It is a multi-layer carbon fiber composite material structure with anti-icing function.

[0046] Figure 2 (a) shows the three-dimensional morphology diagram of the anti-icing composite material in Example 1, and (a1-a3) show the SEM diagrams of the anti-icing composite material at different magnifications. The F-SiO2 particles added during the preparation process are pressed out and combined with the resin to form cluster particles, and uniform F-SiO2 particles are attached to the surface, with a high contact angle on the sample surface; Figure 2 (b) shows the three-dimensional morphology diagram of the surface of the sample in Example 2, and (b1-b3) show the SEM diagrams of the conventional composite material at different magnifications. The surface is overall regular and smooth, and there are no obvious undulations in the 3D contour structure.

[0047] Figure 3 It is the water droplet contact state and contact angle of the (a) superhydrophobic surface of Example 1 and the (b) surface of Example 2.

[0048] Figure 4 It is the freezing process and time of the water droplets on the (a) superhydrophobic surface of Example 1 and the (b) surface of Example 2 at -20°C.

[0049] Figure 5 It is the temperature change during the freezing process of the water droplets on the (a) superhydrophobic surface of Example 1 and the (b) surface of Example 2 at -20°C.

[0050] Figure 6 It is the morphological change of the water droplets hitting the surface of the (a) superhydrophobic surface of Example 1 and the (b) surface of Example 2 at -20°C.

[0051] The tensile strength and shear strength data of the above-prepared material are shown in Table 1.

[0052] Table 1

[0053] Serial number Tensile strength (MPa) Shear strength (MPa) Example 1 472.1 425.93 Example 2 463.3 452.96 Example 3 344.6 262.04

Claims

1. A preparation method of a multi-layer carbon fiber composite material with an anti-icing function, characterized in that, It includes the following steps: Step 1): Prepare the hydrophobic silica resin mixed dispersion liquid: Dilute the epoxy resin, add hydrophobic silica, disperse it evenly by ultrasonic dispersion and magnetic stirrer, and then add the curing agent to obtain the hydrophobic silica resin mixed liquid; Mix the epoxy resin and the curing agent evenly, and obtain the resin glue after defoaming; Step 2): Prepare the prepreg: Uniformly coat the resin glue on the reverse side of the carbon fiber cloth, and uniformly coat the hydrophobic silica resin mixed liquid on the front side of the carbon fiber cloth. Put the coated carbon fiber cloth into a vacuum drying oven, heat to volatilize the excess dispersion liquid, and take it out and cool it when the epoxy resin cures into a gel state to make the modified carbon fiber / epoxy prepreg, that is, Composite Material One; Coat the resin glue evenly on the front and reverse sides of the carbon fiber cloth, put it into a vacuum drying oven to make the carbon fiber / epoxy prepreg, that is, Composite Material Two; Step 3): Clean the mold, spray the release agent, put three layers of Composite Material Two and one layer of Composite Material One into the molding mold in sequence, with the side coated with the hydrophobic silica resin mixed liquid of Composite Material One on the outermost side, carry out compression molding and curing, and finally obtain the composite laminate through the demolding process.

2. The preparation method according to claim 1, characterized in that, In the said Step 1), the epoxy resin includes E51 and the curing agent, and the dilution uses absolute ethanol. The mass ratio of E51 to the curing agent is 2.8 - 3:

1.

3. The preparation method according to claim 1, characterized in that, In the said Step 1), the hydrophobic silica is gas-phase silica particles of perfluorodecyltrimethoxysilane, and is dispersed in the dispersion liquid by magnetic stirrer stirring dispersion and ultrasonic dispersion. The magnetic stirring speed is 100 rpm, the stirring time is 2 h, the ultrasonic dispersion frequency is 40 kHz, and the ultrasonic dispersion time is 0.5 h; The mass ratio of the epoxy resin to the hydrophobic silica is 100:30 - 50.

4. The preparation method according to claim 1, characterized in that, In the said Step 2), the carbon fiber cloth is a T300 / 3K plain woven cloth.

5. The preparation method according to claim 1, characterized in that, In the said Step 2), in order to reduce the mutual influence of the mechanical properties of the modified functional layer and the base layer of the material, control the amount of the coated resin, use a coater for coating, the coating thickness of the resin glue is 80 μm, and the coating thickness of the hydrophobic silica resin mixed liquid is 100 μm.

6. The preparation method according to claim 1, characterized in that, In the said Step 2), on the side of Composite Material One coated with the hydrophobic silica resin mixed liquid, since the resin can wet the particles and the particle content in the surface spray is very high, the uncured resin will continue to wet the surface particles upward to obtain a firm surface texture with a rough structure.

7. The preparation method according to claim 1, characterized in that, In the said Step 2), the molding mold is composed of an outer mold and an inner mold, and the materials are both 304 stainless steel; Among them, the inner mold is a smooth flat plate with dimensions of 120 mm × 160 mm × 4.5 mm, and the outer mold is a metal plate with a rectangular through hole, and the plate thickness is 10 mm.

8. The preparation method according to claim 1, characterized in that, In the said Step 3), the process parameters of the compression molding and curing are: pressure 1.5 - 2 Mpa, temperature 90 - 120 °C, and time is 2 h.

9. A multi-layer carbon fiber composite material with anti-icing function prepared by the preparation method according to any one of claims 1 - 8.

10. The multi-layer carbon fiber composite material with an anti-icing function according to claim 9, characterized in that, It has superhydrophobicity on the surface, the contact angle with water is 157° ± 2°, the rolling angle is about 2°, and the hydrophobicity of the surface is controlled by adjusting the content of hydrophobic particles.

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