A high-thermal-conductivity carbon fiber film suitable for a spacecraft structure and a method for manufacturing the same

Abstract

This invention relates to a high thermal conductivity carbon fiber film suitable for spacecraft structures and its preparation method. First, the sizing agent on the surface of pitch-based carbon fibers is removed by heating. The treated carbon fiber bundles are then immersed in an electrolyte containing dispersed GNPs and thermally conductive fillers. Using the carbon fiber bundles as the anode and a copper rod as the cathode, GNPs and thermally conductive fillers are electrophoretically deposited on the carbon fiber surface. Subsequently, the surface-electrophoretically deposited carbon fibers are washed, dried, and radially cut into short carbon fibers. The short carbon fibers are then added to deionized water, along with anionic polyacrylamide (APAM) and polyurethane (PU) composite dispersant, and a surfactant. After ultrasonic dispersion, the mixture is filtered, rinsed, and dried. Finally, the resulting film is hot-pressed to obtain the film material. This invention solves the problem of low out-of-plane thermal conductivity in carbon fiber film materials, producing carbon fiber composite materials with high out-of-plane and in-plane thermal conductivity.

Description

Technical Field

[0001] This invention belongs to the field of composite materials, specifically relating to a high thermal conductivity thin film suitable for spacecraft structures and its preparation method, especially the application requirements of composite materials with high thermal conductivity. Background Technology

[0002] In recent years, as my country's aerospace technology has continuously developed towards miniaturization, integration, lightweighting, and multifunctionality, the integration level, operating frequency, and power density of satellite platforms have been continuously increasing. Excessive power density can lead to heat accumulation in small areas, causing device temperatures to deviate from their normal operating temperatures. In satellite antennas and electronic systems, non-uniform temperature distribution can cause severe thermal deformation, resulting in instability in payload operation. Severe uneven heating can even lead to structural damage to materials, thereby affecting the satellite platform's detection missions and service life. Therefore, continuously improving the thermal conductivity of materials and structures is an urgent requirement for the ongoing development of the aerospace field.

[0003] To improve the thermal conductivity of polymer materials, high thermal conductivity fillers have become a focus of research. However, besides the interfacial modification and arrangement of the fillers, the intrinsic thermal conductivity, shape, size, and loading of the fillers all significantly affect the thermal conductivity of polymer composites. Carbon-based fillers and their hybrids possess high intrinsic thermal conductivity, especially chopped carbon fibers, carbon nanotubes, and graphene, which have high aspect ratios and are easily functionalized, allowing for large-scale distributions from nanometer to micrometer scales. Various fillers form thermally conductive network structures through the synergistic effect of cross-linked networks, effectively improving thermal conductivity. Therefore, techniques such as magnetic fields, electric fields, and stress fields are used to study the orientation of fillers in specific directions to improve out-of-plane thermal conductivity.

[0004] This invention proposes a high thermal conductivity carbon fiber thin film suitable for spacecraft structures and its preparation process. The method involves electrophoretically depositing graphene nanosheets (GNPs) and aluminum oxide (Al₂O₃) thin film materials on the surface of chopped carbon fibers. A three-dimensional thermally conductive network structure is constructed between the layers using GNPs@high thermal conductivity inorganic fillers as the thermally conductive layer. The chopped carbon fiber thin film substrate serves as the framework structure to enhance interlayer interactions, aiming to simultaneously improve the thermal conductivity and interlayer mechanical properties of the composite material in the thickness direction. Summary of the Invention

[0005] The purpose of this invention is to address the problems existing in the prior art by providing a high thermal conductivity carbon fiber film suitable for spacecraft structures and its preparation method.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides a high thermal conductivity carbon fiber film suitable for spacecraft structures. The high thermal conductivity carbon fiber film is prepared by cutting and hot pressing carbon fiber yarns with graphene sheets and high thermal conductivity inorganic fillers deposited on the surface.

[0008] This invention deposits graphene sheets and high thermal conductivity inorganic fillers, enabling the vertical arrangement of two-dimensional fillers within the matrix, which is an effective strategy for improving the thermal conductivity of composite materials in the thickness direction. Introducing GNP sheet structures into the high thermal conductivity inorganic filler particles effectively hinders the in-plane (parallel to fiber) alignment of the GNP sheets (without high thermal conductivity inorganic fillers, GNP sheets are deposited parallel, affecting heat transfer efficiency). The GNP sheets are covered on the surface of the high thermal conductivity inorganic filler particles, constructing a highly effective longitudinal heat conduction path and fully utilizing the ultra-high thermal conductivity of GNPs. The deposited carbon fiber yarn is then chopped, granulated, vacuum self-assembled, and hot-pressed to prepare a high thermal conductivity carbon fiber film.

[0009] Preferably, the carbon fiber includes one or more of high-modulus carbon fiber, high-strength carbon fiber, and pitch-based carbon fiber.

[0010] Preferably, the high thermal conductivity inorganic particulate material includes one or more of aluminum oxide (Al2O3), boron nitride (BN), aluminum nitride (AlN), beryllium oxide (BeO), and zinc oxide (ZnO).

[0011] Preferably, the graphene sheet has a diameter between 0.5 and 1 μm.

[0012] Preferably, the particle size of the high thermal conductivity inorganic particles is 20 μm.

[0013] Preferably, the length of the chopped carbon fiber obtained after shaving is 2-5 mm; The present invention also provides a method for preparing the aforementioned high thermal conductivity carbon fiber thin film, comprising the following steps: S1. Preparation of short-cut carbon fibers Carbon fiber yarn is immersed in an electrolyte containing graphene sheets (GNPs) and thermally conductive inorganic fillers, and deposited by electrophoretic deposition. The deposited carbon fiber yarn is then cut to obtain the chopped carbon fiber. S2. Preparation of high thermal conductivity carbon fiber films The obtained short-cut carbon fibers are added to deionized water, along with a dispersant and a surfactant. The mixture is then dispersed by ultrasonic vibration, filtered, washed, and dried to obtain a film. Finally, it undergoes thermosetting molding to obtain the high thermal conductivity carbon fiber film.

[0014] Preferably, in step S1, the carbon fiber yarn undergoes pretreatment before deposition, specifically by heat-treating the carbon fiber yarn at a temperature of 400°C-500°C to remove the sizing agent from the carbon fiber surface. The specific steps are as follows: the carbon fiber yarn roll is placed on a conveyor frame, and the drawn yarn is passed sequentially through a traction roller and a muffle furnace, removing the sizing agent from the carbon fiber surface at a temperature of 400°C-500°C.

[0015] Preferably, in step S1, the mass fraction of the thermally conductive inorganic particulate material in the electrolyte is 5%-20% of the deionized water, preferably 8%-12%. The mass fraction of the graphene sheet is 5%-20% of the deionized water, preferably 8%-12%.

[0016] Preferably, in step S1, the electrophoretic deposition method uses carbon fiber bundles as the anode and a copper rod as the cathode to deposit electrophoretically on the surface of the carbon fiber. The deposition time is 0.5-3 minutes.

[0017] Preferably, in step S1, the length of the chopped carbon fibers obtained is 2-5 mm. Unlike conventional continuous fiber composite material preparation, this invention involves electrophoretic deposition on continuous fibers, followed by chopped granulation to prepare carbon fiber films. These films serve as thermally conductive structures and interlayer toughening materials. The length of the chopped carbon fibers in this invention is a result of comprehensive consideration of performance and process feasibility. Excessively long fibers result in poor dispersion and are prone to defects, while excessively short fibers have insufficient interfacial bonding area with the matrix, leading to easy debonding.

[0018] Preferably, in step S2, the dispersant is a compound dispersant of anionic polyacrylamide (APAM) and polyurethane (PU) in a mass ratio of 3-7:2; more preferably 5:2. Compared with a single dispersant, the compound dispersant of the present invention has the best dispersion effect on short fibers deposited on the surface.

[0019] Preferably, in step S2, the surfactant includes one or more of KH-540, KH-550, KH-560, and KH-792.

[0020] The ratio of chopped carbon fiber, deionized water, dispersant, and surfactant is 8-12g:80-120ml:10-20g:5-15g, preferably 10g:100ml:15g:10g.

[0021] Preferably, in step S2, the ultrasonic vibration dispersion time is 15-25 min. The drying temperature is 60-80℃, and the time is 2-3 h.

[0022] Preferably, in step S2, the thermosetting temperature is 20-30°C, the pressure is 1.5-2.5 MPa, and the time is 4-8 min.

[0023] Preferably, the thickness of the high thermal conductivity carbon fiber film obtained in step S2 is 50-80 μm.

[0024] The present invention also provides an application of the aforementioned high thermal conductivity carbon fiber film in interlayer toughening of composite materials.

[0025] Short-cut carbon fibers deposited with graphene sheets (GNPs) and thermally conductive inorganic fillers, after being treated with surfactants, have active functional groups of hydroxyl and carboxyl groups on their surface, making them easier to disperse in water or solvents. Furthermore, in the subsequent preparation of composite materials, they react with the resin in the composite material during the curing process to form chemical bonds, increasing the interfacial bonding strength.

[0026] Compared with the prior art, the present invention has the following advantages: By employing fiber arrangement, a three-dimensional network structure, and multi-scale filler blending, continuous and efficient heat transfer channels are constructed, enabling directional heat conduction or isotropic thermal conductivity. Applying this technology between carbon fiber composite layers significantly improves the in-plane and out-of-plane thermal conductivity and interlayer toughness of the composite material, resulting in multifunctionality. Among these, the high thermal conductivity film prepared using pitch-based carbon fiber exhibits the best thermal conductivity, with an out-of-plane thermal conductivity greater than 10 W / (m·K) and an in-plane thermal conductivity greater than 1000 W / (m·K) in any direction. Attached Figure Description

[0027] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a technical roadmap for the high thermal conductivity carbon fiber film of the present invention; Figure 2 The images shown are electron microscope images of the surface morphology of carbon fibers in Example 1; where a is carbon fiber containing sizing agent; b is carbon fiber without sizing agent; and c is carbon fiber after electrophoretic deposition treatment. Figure 3 This diagram illustrates heat transfer paths for different microstructures; where a represents inorganic filler particles (thermally conductive inorganic fillers); b represents GNPs; and c represents both organic filler particles and GNPs. Figure 4 This is a schematic diagram of the layup structure during performance testing; where a represents the layup sequence of the high thermal conductivity carbon fiber composite material; and b represents the layup sequence for interlaminar toughness performance testing. Detailed Implementation

[0028] The present invention will be described in detail below with reference to embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several adjustments and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0029] Example 1 TC-HC-600 High Thermal Conductivity Pitch-Based Carbon Fiber Film: 1) Place the TC-HC-600 high thermal conductivity pitch-based carbon fiber yarn roll on the conveyor frame, and pass the drawn yarn through the traction roller and muffle furnace in sequence. Remove the sizing agent from the surface of the carbon fiber at a temperature of 480°C. The process before and after removing the sizing agent is as follows: Figure 2 As shown in a and 2b; 2) The treated carbon fiber tow was immersed in an electrolyte with a mass composition of deionized water:GNPs:BN = 100:10:10. Using the carbon fiber tow as the anode and a copper rod as the cathode, GNPs (particle size between 0.5 and 1 μm) and BN (particle size 20 μm) were electrophoretically deposited on the carbon fiber surface for 2 minutes. The resulting fibers are shown in the figure. Figure 2 As shown in c; 3) The carbon fibers after surface electrophoretic deposition are cleaned, dried, and radially cut into 2 mm short carbon fibers; 4) Add 10g of short-cut carbon fibers to 100ml of deionized water, add 15g of anionic polyacrylamide (APAM) and polyurethane (PU) compound dispersant (APAM:PU ratio of 5:2), and 10g of KH-550 surfactant. After ultrasonic vibration dispersion for 20min, filter the solution through filter paper and rinse it three times with deionized water. Dry it at 80°C for 2h. 5) The obtained film was hot-pressed at 25°C and 2.5 MPa for 5 min to obtain a film material with a thickness of 50 μm (CF / GNPs@BN).

[0030] The thermal conductivity of the TC-HC-600 high thermal conductivity pitch-based carbon fiber film material prepared in this embodiment was determined according to GB / T 22588-2008 "Measuring thermal diffusivity or thermal conductivity by flash method", and the properties are shown in Table 1.

[0031] Example 2 TC-HC-600 High Thermal Conductivity Pitch-Based Carbon Fiber Film: 1) Place the TC-HC-600 type high thermal conductivity pitch-based carbon fiber yarn roll on the conveyor yarn rack, and pass the drawn yarn through the traction roller and muffle furnace in sequence to remove the sizing agent on the surface of the carbon fiber at a temperature of 480°C. 2) The treated carbon fiber bundles were immersed in an electrolyte with a mass composition of deionized water: GNPs: Al2O3 = 100:10:10. Using the carbon fiber bundles as the anode and a copper rod as the cathode, GNPs (particle size between 0.5 and 1 μm) and Al2O3 (particle size 20 μm) were electrophoretically deposited on the carbon fiber surface for 2 min. 3) The carbon fibers after surface electrophoretic deposition are cleaned, dried, and radially cut into 2 mm short carbon fibers; 4) Add 10g of short-cut carbon fibers to 100ml of deionized water, add 15g of anionic polyacrylamide (APAM) and polyurethane (PU) compound dispersant (APAM:PU ratio of 5:2), and 5g of KH-550 surfactant. After ultrasonic vibration dispersion for 20min, filter the solution through filter paper and rinse it three times with deionized water. Dry it at 80°C for 2h. 5) The obtained film was hot-pressed at 25°C and 2.5 MPa for 5 min to obtain a film material with a thickness of 50 μm (CF / GNPs@Al2O3).

[0032] The thermal conductivity of the TC-HC-600 high thermal conductivity pitch-based carbon fiber film material prepared in this embodiment was determined according to GB / T 22588-2008 "Measuring thermal diffusivity or thermal conductivity by flash method", and the properties are shown in Table 1.

[0033] Example 3 M40JB type high thermal conductivity, high modulus carbon fiber film: 1) Place the M40JB type high thermal conductivity pitch-based carbon fiber yarn roll on the conveyor yarn rack, and pass the drawn yarn through the traction roller and muffle furnace in sequence to remove the sizing agent on the surface of the carbon fiber at a temperature of 480°C. 2) The carbon fiber bundles treated above were immersed in an electrolyte solution with a mass composition of deionized water: GNPs: BN = 100: 10: 10. The carbon fiber bundles were used as the anode and the copper rods were used as the cathode. GNPs (particle size between 0.5 and 1 μm) and BN (particle size 20 μm) were electrophoretically deposited on the carbon fiber surface for 2 min. 3) The carbon fibers after surface electrophoretic deposition are cleaned, dried, and radially cut into 2 mm short carbon fibers; 4) Add 10g of short-cut carbon fibers to 100ml of deionized water, add 15g of anionic polyacrylamide (APAM) and polyurethane (PU) compound dispersant (APAM:PU ratio of 5:2), and 5g of KH-550 surfactant. After ultrasonic vibration dispersion for 20min, filter the solution through filter paper and rinse it three times with deionized water. Dry it at 80°C for 2h. 5) The obtained film was hot-pressed at 25°C and 2.5 MPa for 5 min to obtain a film material with a thickness of 50 μm (CF / GNPs@ BN).

[0034] The thermal conductivity of the M40JB type high thermal conductivity pitch-based carbon fiber film material prepared in this embodiment was determined according to GB / T 22588-2008 "Measuring thermal diffusivity or thermal conductivity by flash method", and the properties are shown in Table 1.

[0035] Example 4 T800H type high thermal conductivity, high modulus carbon fiber film: 1) Place the T800H type high thermal conductivity pitch-based carbon fiber yarn roll on the conveyor yarn rack, and pass the drawn yarn through the traction roller and muffle furnace in sequence to remove the sizing agent on the surface of the carbon fiber at a temperature of 480°C. 2) The treated carbon fiber tow was immersed in an electrolyte solution with a mass composition of deionized water:GNPs:Al2O3 = 100:10:10. Using the carbon fiber tow as the anode and a copper rod as the cathode, GNPs (particle size between 0.5 and 1 μm) and Al2O3 (particle size 20 μm) were electrophoretically deposited on the carbon fiber surface for 2 minutes. 3) The carbon fibers after surface electrophoretic deposition are cleaned, dried, and radially cut into 2 mm short carbon fibers; 4) Add 10g of short-cut carbon fibers to 100ml of deionized water, add 15g of anionic polyacrylamide (APAM) and polyurethane (PU) compound dispersant (APAM:PU ratio of 5:2), and 10g of KH-550 surfactant. After ultrasonic vibration dispersion for 20min, filter the solution through filter paper and rinse it three times with deionized water. Dry it at 80°C for 2h. 5) The obtained film was hot-pressed at 25°C and 2.5 MPa for 5 min to obtain a film material with a thickness of 50 μm (CF / GNPs@Al2O3).

[0036] The thermal conductivity of the T800H type high thermal conductivity pitch-based carbon fiber film material prepared in this embodiment was determined according to GB / T 22588-2008 "Measuring thermal diffusivity or thermal conductivity by flash method", and the performance is shown in Table 1.

[0037] Blank group TC-HC-600 High Thermal Conductivity Pitch-Based Carbon Fiber Film: 1) Place the TC-HC-600 type high thermal conductivity pitch-based carbon fiber yarn roll on the conveyor yarn rack, and pass the drawn yarn through the traction roller and muffle furnace in sequence to remove the sizing agent on the surface of the carbon fiber at a temperature of 480°C. 2) The above carbon fibers are cleaned, dried, and radially cut into 2 mm short carbon fibers; 4) Add 10g of short-cut carbon fibers to 100ml of deionized water, add 15g of anionic polyacrylamide (APAM) and polyurethane (PU) compound dispersant (APAM:PU ratio of 5:2), and 5g of KH-550 surfactant. After ultrasonic vibration dispersion for 20min, filter the solution through filter paper and rinse it three times with deionized water. Dry it at 80°C for 2h. 5) The obtained film was hot-pressed at 25°C and 2.5 MPa for 5 min to obtain a film material (s-CF) with a thickness of 50 μm.

[0038] The thermal conductivity of the TC-HC-600 high thermal conductivity pitch-based carbon fiber film material prepared in this embodiment was determined according to GB / T 22588-2008 "Measuring thermal diffusivity or thermal conductivity by flash method", and the properties are shown in Table 1.

[0039] Comparative Example 1 This comparative example provides a high thermal conductivity pitch-based carbon fiber film, which has the same composition and preparation method as Example 1, except that the mass ratio of deionized water:GNPs:BN in the electrolyte is 100:20:0.

[0040] Comparative Example 2 This comparative example provides a high thermal conductivity pitch-based carbon fiber film, which has the same composition and preparation method as Example 1, except that the mass ratio of deionized water:GNPs:BN in the electrolyte is 100:0:20.

[0041] Comparative Example 3 This comparative example provides a high thermal conductivity pitch-based carbon fiber film. The composition and preparation method are basically the same as in Example 1, except that: after cutting the carbon fiber yarn into 2 mm short carbon fibers, it is directly mixed with equal amounts of GNPs and BN and added to deionized water, followed by the addition of a dispersant and surfactant. Direct mixing results in uneven dispersion and generally poor performance.

[0042] Comparative Example 4 This comparative example provides a high thermal conductivity pitch-based carbon fiber film, which has the same composition and preparation method as Example 1, except that the carbon fiber yarns are not cut after deposition.

[0043] Comparative Example 5 This comparative example provides a high thermal conductivity pitch-based carbon fiber film, with the composition and preparation method being basically the same as in Example 1, except that the dispersant is a single dispersant, 15g of anionic polyacrylamide (APAM).

[0044] Comparative Example 6 This comparative example provides a high thermal conductivity pitch-based carbon fiber film, with the composition and preparation method being basically the same as in Example 1, except that the dispersant is a single dispersant, 15g of polyurethane (PU).

[0045] Application Example: High thermal conductivity pitch-based carbon fiber film material is used as an interlayer thermal conductive and toughening material to prepare a composite material.

[0046] (1) First, a 0.08 mm thick TC-HC-600 reinforced epoxy resin prepreg with a fiber content of 62±3% was prepared by wet winding, and then cut into 300 mm * 300 mm squares. Based on... Figure 4 As shown in Figure a, thermally conductive films of the embodiments and comparative examples were prepared during the layup process, and finally cured in an autoclave. A blank control sample without a thermally conductive film was also prepared. The results are shown in Table 1.

[0047] Table 1 Properties of high thermal conductivity composite materials

[0048] As can be seen from Examples 1-4, the in-plane thermal conductivity of the high thermal conductivity carbon fiber composite film prepared by the present invention is 597-1091 W / (m·K), and the surface thermal conductivity is 4.7-10.3 W / (m·K). The heat transfer path of the present invention is as follows: Figure 3 As shown in c, the heat transfer paths of comparative examples 1 and 2 are as follows: Figure 3 As shown in a and b, the high thermal conductivity carbon fiber composite material prepared by the present invention also has excellent thermal conductivity and can be used in spacecraft structural / functional components.

[0049] (2) Based on Figure 4 As shown in b, the layup was performed using the same material method. The thermal conductivity of the resulting composite material was characterized using a laser flash test instrument (NanoFlash, LFA 467, Netzsch) according to GB / T 22588-2008 "Measurement of Thermal Diffusion Coefficient or Thermal Conductivity by Flash Method". Interlaminar fracture toughness tests were conducted on a universal testing machine. Five samples were tested in each group. Mode I testing followed ASTM D5528 standard. The results are shown in Table 2.

[0050] Table 2 Composite Material Properties in Application Examples

[0051] As can be seen from Application Example 1, the high thermal conductivity carbon fiber composite film prepared by the present invention provides dual-functionality and improves the in-plane and out-of-plane thermal conductivity and interlayer toughness of the pitch-based carbon fiber laminate.

[0052] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A high thermal conductivity carbon fiber film suitable for spacecraft structures, characterized in that, The high thermal conductivity carbon fiber film is prepared by cutting and hot pressing carbon fiber yarns with graphene sheets and high thermal conductivity inorganic fillers deposited on the surface.

2. The high thermal conductivity carbon fiber film according to claim 1, characterized in that, The carbon fiber includes one or more of high-modulus carbon fiber, high-strength carbon fiber, and pitch-based carbon fiber.

3. The high thermal conductivity carbon fiber film according to claim 1, characterized in that, The high thermal conductivity inorganic particulate material includes one or more of aluminum oxide, boron nitride, aluminum nitride, beryllium oxide, and zinc oxide.

4. The high thermal conductivity carbon fiber film according to claim 1, characterized in that, The length of the chopped carbon fiber is 2-5 mm.

5. A method for preparing a high thermal conductivity carbon fiber thin film as described in claim 1, characterized in that, Includes the following steps: S1. Preparation of short-cut carbon fibers Carbon fiber yarn is immersed in an electrolyte containing graphene sheets and thermally conductive inorganic fillers, and deposited by electrophoretic deposition. The deposited carbon fiber yarn is then cut to obtain the chopped carbon fiber. S2. Preparation of high thermal conductivity carbon fiber films The obtained short-cut carbon fibers are added to deionized water, along with a dispersant and a surfactant. The mixture is then dispersed by ultrasonic vibration, filtered, washed, and dried to obtain a film. Finally, it undergoes thermosetting molding to obtain the high thermal conductivity carbon fiber film.

6. The preparation method according to claim 1, characterized in that, In step S1, the mass fraction of the thermally conductive inorganic particulate material in the electrolyte is 5%-20% of the deionized water; the mass fraction of the graphene sheet is 5%-20% of the deionized water.

7. The preparation method according to claim 1, characterized in that, In step S2, the dispersant is a compound dispersant of anionic polyacrylamide and polyurethane, with a mass ratio of 3-7:

2.

8. The preparation method according to claim 1, characterized in that, In step S2, the ratio of chopped carbon fiber, deionized water, dispersant, and surfactant is 8-12g: 80-120ml: 10-20g: 5-15g.

9. The preparation method according to claim 1, characterized in that, In step S2, the thermosetting temperature is 20-30°C, the pressure is 1.5-2.5 MPa, and the time is 4-8 min.

10. The application of the high thermal conductivity carbon fiber film as described in claim 1 in interlayer toughening of composite materials.

Images