CN113353927B - Heat-conducting composite graphite film and preparation method thereof - Google Patents
Heat-conducting composite graphite film and preparation method thereof Download PDFInfo
- Publication number
- CN113353927B CN113353927B CN202110793326.4A CN202110793326A CN113353927B CN 113353927 B CN113353927 B CN 113353927B CN 202110793326 A CN202110793326 A CN 202110793326A CN 113353927 B CN113353927 B CN 113353927B
- Authority
- CN
- China
- Prior art keywords
- graphite film
- composite graphite
- fibers
- chopped
- treatment
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/20—Graphite
- C01B32/205—Preparation
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/20—Graphite
- C01B32/21—After-treatment
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B14/00—Use of inorganic materials as fillers, e.g. pigments, for mortars, concrete or artificial stone; Treatment of inorganic materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone
- C04B14/38—Fibrous materials; Whiskers
- C04B14/386—Carbon
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B20/00—Use of materials as fillers for mortars, concrete or artificial stone according to more than one of groups C04B14/00 - C04B18/00 and characterised by shape or grain distribution; Treatment of materials according to more than one of the groups C04B14/00 - C04B18/00 specially adapted to enhance their filling properties in mortars, concrete or artificial stone; Expanding or defibrillating materials
- C04B20/02—Treatment
- C04B20/023—Chemical treatment
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B30/00—Compositions for artificial stone, not containing binders
- C04B30/02—Compositions for artificial stone, not containing binders containing fibrous materials
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- D01F9/00—Artificial filaments or the like of other substances; Manufacture thereof; Apparatus specially adapted for the manufacture of carbon filaments
- D01F9/08—Artificial filaments or the like of other substances; Manufacture thereof; Apparatus specially adapted for the manufacture of carbon filaments of inorganic material
- D01F9/12—Carbon filaments; Apparatus specially adapted for the manufacture thereof
- D01F9/14—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments
- D01F9/145—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from pitch or distillation residues
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Organic Chemistry (AREA)
- Ceramic Engineering (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Inorganic Chemistry (AREA)
- Textile Engineering (AREA)
- Nanotechnology (AREA)
- Civil Engineering (AREA)
- Carbon And Carbon Compounds (AREA)
Abstract
The invention provides a heat-conducting composite graphite film, which comprises chopped fibers, wherein the average diameter of the chopped fibers is 9-12 microns, and the length of the chopped fibers is within the range of 1.5-6 mm; the chopped fiber is mesophase pitch-based carbon fiber after surface modification treatment, the mesophase pitch-based carbon fiber is obtained by spinning mesophase pitch raw material with a mesophase content value of 100% and then graphitizing at 2800 ℃ and 3200 ℃, and the grain size La of the mesophase pitch-based carbon fiber is larger than 22.4 nm. The preparation method comprises the following steps: surface treatment of the chopped fibers; mixing and reacting the chopped fibers with a dianhydride monomer, a diamine monomer and a solvent pair; imidization, carbonization and high-temperature graphitization. The heat-conducting composite graphite film has the advantages of good heat-conducting property, good bending resistance and the like.
Description
Technical Field
The invention relates to the technical field of graphite films, in particular to a heat-conducting composite graphite film and a preparation method thereof.
Background
With the rapid development of electronics and information industries, electronic products tend to be integrated and miniaturized, and the service life of the products can be seriously shortened due to the heating problem caused by the long-time work of high-power electronic terminals.
At present, the medium materials for heat dissipation are mainly metal and graphiteCompared with aluminum (the thermal conductivity is 200W/(m.K)) and copper (the thermal conductivity is 380W/(m.K)), the graphite has the comprehensive thermal conductivity of 300-1900W/(m.K) and the density of only 0.7-2.1g/cm 3 And is an excellent material for heat dissipation solution.
The high-thermal-conductivity graphite film is used as a novel thermal conductive material, and the carbon atoms of the high-thermal-conductivity graphite film have a grain orientation structure which can enable heat to be uniformly and rapidly transferred along the a-b plane of the film; the surface of the film can be combined with other materials such as metal, plastic and the like; the composite material has the advantages of low density, high temperature resistance, corrosion resistance, high in-plane thermal conductivity, low thermal expansion coefficient and the like, and can be widely applied to the heat dissipation fields of mobile phones, computers and the like and the military fields of aerospace and the like.
In the current research, the following directions are mainly used for the research on the heat-conducting graphite film material: the first route is to use an expanded graphite calendering method, the process is simple and the cost is low, but the film product has low tensile strength and low thermal conductivity, and the thermal conductivity is only 300-; the second route is to prepare graphene by using an oxidation method, and prepare graphene films from the graphene by processes such as a vacuum filtration method, a spraying method and a spin-coating method, but the graphene films prepared by the methods at the present stage are high in cost and have a large amount of waste liquid pollution; the third route is to prepare a graphite film by using a Chemical Vapor Deposition (CVD) method, wherein the graphite film has excellent performance, but the process has high cost and still stays in a laboratory stage at present; the fourth route is that the Polyimide (PI) film is carbonized and graphitized at high temperature, the thermal conductivity of the obtained PI graphite film can reach 1400W/(m.K), but the in-plane thermal conductivity of the graphite film is far less than the theoretical thermal conductivity (2100W/(m.K)) of the graphite single crystal. Compared with the other three types of materials, the PI graphite film has more advantages in graphite crystallization and orientation.
However, although the PI graphite film prepared by the conventional method has good heat conductivity, the heat conductivity and the bending resistance are reduced after the film thickness is increased, so that the in-plane thermal conductivity is greatly reduced once the film surface has defects caused by bending or external force impact, and the method is limited in practical application, so that the preparation of the heat-conducting PI graphite film which is suitable for more complicated environmental conditions and has insufficient crack resistance and bending resistance is particularly important.
Disclosure of Invention
Based on the current situations of low heat conduction performance, poor bending resistance and the like when the thickness of a graphite film is too large in the prior art, the invention aims to provide a heat-conducting composite graphite film and a preparation method thereof. Then, a carbon fiber surface modification method is used for introducing chemical functional groups for modifying the surface of the mesophase pitch-based carbon fiber so as to enhance the interface bonding force between the carbon fiber and a polyamide acid (PAA) solution. Mixing short-cut heat-conducting carbon fibers into a precursor PAA solution in the process of producing the PI graphite film, mechanically and uniformly mixing, and then carrying out thermal imidization, high-temperature carbonization and graphitization treatment to obtain the PI-based composite graphite film. On the same hand, the folding resistance of the graphite film product is improved, and the heat-conducting property of the graphite film is also improved.
The invention provides a heat-conducting composite graphite film, which comprises chopped fibers, wherein the average diameter of the chopped fibers is 9-12 microns, and the length of the chopped fibers is within the range of 1.5-6 mm; the chopped fibers are mesophase pitch-based carbon fibers subjected to surface modification treatment.
Further, the mesophase pitch-based carbon fiber is obtained by spinning a mesophase pitch raw material with a mesophase content value of 100% and then graphitizing the spun mesophase pitch raw material at 2800-; the grain size La of the mesophase pitch-based carbon fiber is larger than 22.4 nm.
One of the main raw materials for the industrial production of the heat-conducting carbon fiber is mesophase pitch-based carbon fiber, and leftover materials in the industrial process of the heat-conducting carbon fiber are cut and treated to be used as the raw materials of the invention, so that the purposes of waste utilization and resource saving can be achieved. The graphite lamina in the mesophase pitch-based carbon fiber with the mesophase content of 100 percent has high axial orientation, belongs to easily graphitized carbon, and is beneficial to the axial conduction of heat along the fiber. The fibers with proper diameters and grain sizes are beneficial to improving the heat-conducting property of the heat-conducting film; in addition, the short-cut fibers with the appropriate length-diameter ratio are beneficial to improving the bending resistance of the heat-conducting film.
According to the invention, chopped carbon fibers with a certain size range and a predetermined content, especially mesophase pitch-based carbon fibers are added into a graphite film, and the mesophase pitch-based carbon fibers have a series of excellent performances such as high specific modulus, high specific strength, good heat conductivity, corrosion resistance, creep resistance, low thermal expansion coefficient, high temperature resistance, electromagnetic shielding and the like, wherein the most outstanding performances are high modulus and high thermal conductivity, the elastic modulus can reach more than 800GPa, and the thermal conductivity can reach more than 800W/m.K, even more than 1000W/m.K. The chopped fibers are uniformly distributed in the film, and once the surface of the film has crease or crack defects caused by folding or external force impact, the continuity of the fibers ensures that the thermal conductivity of the film is not obviously influenced, so that the film has long-term stable heat conduction and heat dissipation performance.
The invention also provides a preparation method of the high-thermal-conductivity composite graphite film, which comprises the following steps:
s1, adding the chopped fibers into a reaction kettle added with a dianhydride monomer, a diamine monomer and a solvent for reaction to obtain PAA containing the chopped fibers;
s2, carrying out tape casting, drying and imidization treatment on PAA containing chopped fibers in sequence to obtain a PI-based composite membrane;
and S3, sequentially carrying out carbonization and high-temperature graphitization treatment on the PI-based composite film to obtain the PI-based composite graphite film.
Further, in step S1, the method includes: the addition amount of the chopped fiber is 16-18% of the total mass of the dianhydride monomer, the diamine monomer and the chopped fiber. When the content of the chopped fibers is too low, the fibers cannot be uniformly distributed in the PI matrix, and a uniform isotropic film structure cannot be formed after graphitization treatment; when the chopped fiber content is too much, the PAA matrix does not wet the fibers well.
Further, the reaction conditions in the step S1 are as follows: reacting for 20-40 minutes at 40-80 ℃.
Further, the chopped carbon fibers are subjected to surface modification by an air oxidation method before step S1.
Furthermore, the air oxidation method is to carry out heat treatment on the chopped fibers in air, wherein the treatment temperature is 320-700 ℃, and the treatment time is 1-20 minutes. If the temperature is too low or the treatment time is too short, the surface modification effect of the chopped fibers is not obvious; too much etching on the surface of the chopped fiber can reduce the heat-conducting property of the fiber when the temperature is too high or the processing time is too long.
Further, in step S1, the method includes: the acid dianhydride monomer is one or a mixture of 1,2,4, 5-pyromellitic dianhydride, 3 ', 4, 4' -benzophenone tetracarboxylic dianhydride and 3,3 ', 4, 4' -biphenyl tetracarboxylic dianhydride; the acid diamine monomer is one or more of p-phenylenediamine, 4' -diaminodiphenyl ether, 1, 3-diaminobenzene and 1, 2-diaminobenzene; the acid dianhydride monomer and the acid diamine monomer are in the same amount; the solvent is a polar solvent, and the mass of the solvent is the same as that of the added acid diamine monomer. Preferably, the acid dianhydride monomer in step S1 is 1,2,4, 5-pyromellitic dianhydride; the acid diamine monomer is p-phenylenediamine and the solvent is N, N-dimethylacetamide.
Further, the temperature of the imidization treatment in the step S2 is: 260 ℃ to 330 ℃;
the temperature of the carbonization treatment in the step S3 is 900-1600 ℃; the temperature of the high-temperature graphitization treatment is 2500-3200 ℃.
Compared with the prior art, the invention has the advantages that:
1) according to the invention, a certain amount of short carbon fibers, especially mesophase pitch-based carbon fibers, are added into the raw material formula of the composite film, so that on one hand, adverse effects caused by crease defects of the obtained graphite film can be improved, and on the other hand, the overall thermal conductivity of the graphite film can be improved.
2) The chopped carbon fibers are waste materials generated in the production process of the heat-conducting carbon fibers, and are cut to obtain the chopped mesophase pitch-based carbon fibers, and compared with polyacrylonitrile carbon fibers, the mesophase pitch-based carbon fibers have high heat conductivity; compared with plant fibers, the mesophase pitch-based carbon fibers have good heat conductivity and high mechanical properties.
3) According to the invention, the chopped fiber is subjected to surface modification treatment, and a carbon fiber surface modification method is adopted to introduce chemical functional groups for modifying the surface of the carbon fiber so as to enhance the interface bonding force between the carbon fiber and polyamide acid (PAA), so that the overall heat-conducting property of the composite graphite film is enhanced. The air oxidation method of the invention not only can remove impurities on the surface of the carbon fiber, but also can introduce chemical functional groups for modifying the surface of the carbon fiber.
Therefore, the invention provides the heat-conducting composite graphite film, the high-heat-conducting chopped carbon fibers in the structure are present, the in-plane heat-conducting performance and the bending resistance of the film are still good even if the thickness of the graphite film is large, and the preparation method is simple to operate.
Drawings
These and/or other aspects and advantages of the present invention will become more apparent and more readily appreciated from the following detailed description of the embodiments of the invention, taken in conjunction with the accompanying drawings of which:
FIG. 1 is an SEM image of the arrangement of fibers in the plane of the heat-conducting composite graphite film obtained by the embodiment of the invention;
fig. 2 is an in-plane XRD pattern of the composite film with a heat-conductive composite graphite film surface obtained in the embodiment of the present invention.
Detailed Description
In order that those skilled in the art will better understand the present invention, the following detailed description of the invention is provided in conjunction with the accompanying drawings and the detailed description of the invention.
In each embodiment of the invention, the obtained product is tested for the in-plane room temperature thermal conductivity of the defective graphite film by adopting a laser flash method (LFA), and the specific method is as follows: the test sample is a 25.2mm graphite film wafer, and the average value of the thermal conductivities at a plurality of flash points of a plurality of area samples of the same batch number is taken as the room-temperature in-plane thermal conductivity of the graphite film.
Example 1:
s1, cutting the thermal-conductive mesophase pitch-based carbon fiber leftover materials into short fibers with a certain length, wherein the average diameter of the cut carbon fibers is 9 mu m, and the length of the fibers is 1.5 mm;
s2: then, treating the cut carbon fibers by adopting an air oxidation method, wherein the treatment temperature is 380 ℃, and the treatment time is 10 minutes, so as to obtain modified chopped fibers;
s3: putting 63g of 1,2,4, 5-pyromellitic dianhydride, 21g of p-phenylenediamine and 16g of modified chopped fibers into a reaction kettle, filling 21g N, N-dimethylacetamide solvent into the reaction kettle, and carrying out polymerization reaction for 25 minutes at 60 ℃ to obtain PAA solution containing the chopped fibers;
S4: then respectively obtaining a PI-based composite graphite film by tape casting film forming and a thermal imidization process at 300 ℃;
s5: heating to 1000 ℃ at a heating rate of 5 ℃/min under the protection of argon atmosphere, and preserving heat at 1000 ℃ for 10 minutes to finish carbonization treatment; then heating to 3000 ℃ at the heating rate of 10 ℃/min under the protection of argon atmosphere, and preserving heat at 3000 ℃ for 10 minutes to finish graphitization treatment; and finally, naturally cooling to obtain the composite graphite film.
The results show that: the thickness of the composite graphite film added with the chopped asphalt-based carbon fibers with the mass fraction of 16 percent is 150 mu m, the in-plane thermal conductivity is 1391W/(m.K), and the composite graphite film is increased by 15 percent compared with the common PI graphite film.
In the embodiments of the invention, the bending resistance of the obtained composite graphite film is tested and contrastively analyzed, the test method is to repeatedly bend the obtained graphite film for many times, test the bending times and the thermal conductivity value of the film, and take the bending times when the film cannot meet the use requirements (failure such as breakage, cracking and the like occurs) as the bending life. The following examples are the same.
The graphite film obtained in this example has a bending life of 28438 times.
Example 2:
s1, cutting the thermal-conductive mesophase pitch-based carbon fiber leftover materials into short fibers with a certain length, wherein the average diameter of the fibers is 9 mu m, and the length of the fibers is 3 mm;
S2: then, processing the carbon fiber in the last step by adopting an air oxidation method, wherein the processing temperature is 400 ℃, and the processing time is 10 minutes to obtain modified chopped fiber;
s3: putting 63g of 1,2,4, 5-pyromellitic dianhydride, 21g of p-phenylenediamine and 16g of the modified chopped fibers in the previous step into a reaction kettle with a proper amount of solvent, filling 21g of N, N-dimethylacetamide solvent into the reaction kettle, and carrying out polymerization reaction for 25 minutes at 60 ℃ to obtain a PAA solution containing the chopped fibers;
s4: then respectively obtaining a PI-based composite graphite film by tape casting film forming and a thermal imidization process at 300 ℃;
s5: heating to 1000 ℃ at a heating rate of 5 ℃/min under the protection of argon atmosphere, and preserving heat at 1000 ℃ for 10 minutes to finish carbonization treatment; then heating to 3000 ℃ at the heating rate of 10 ℃/min under the protection of argon atmosphere, and preserving heat at 3000 ℃ for 10 minutes to finish graphitization treatment; and finally, naturally cooling to obtain the composite graphite film.
The results show that: the thickness of the composite graphite film added with the chopped asphalt-based carbon fibers with the mass fraction of 16 percent is 150 mu m, the in-plane thermal conductivity is 1597W/(m.K), and the composite graphite film is increased by 32 percent compared with the common PI graphite film.
The graphite film obtained in this example had a bending life result of 27631 times.
Example 3:
S1, cutting the high-thermal-conductivity mesophase pitch-based carbon fiber leftover materials into chopped fibers with a certain length, wherein the average diameter of the fibers is 12 mu m, and the length of the fibers is 6 mm;
s2: then, processing the carbon fiber in the last step by adopting an air oxidation method, wherein the processing temperature is 400 ℃, and the processing time is 10 minutes to obtain modified chopped fiber;
s3: putting 60g of 1,2,4, 5-pyromellitic dianhydride, 22g of p-phenylenediamine and 18g of the modified chopped fibers in the previous step into a reaction kettle with a proper amount of solvent, wherein 22g of N, N-dimethylacetamide solvent is filled in the reaction kettle, and carrying out polymerization reaction for 25 minutes at 60 ℃ to obtain a PAA solution containing the chopped fibers;
s4: then respectively obtaining a PI-based composite graphite film by tape casting film forming and a thermal imidization process at 300 ℃;
s5: heating to 1000 ℃ at a heating rate of 5 ℃/min under the protection of argon atmosphere, and preserving heat at 1000 ℃ for 10 minutes to finish carbonization treatment; then heating to 3000 ℃ at the heating rate of 10 ℃/min under the protection of argon atmosphere, and preserving heat at 3000 ℃ for 10 minutes to finish graphitization treatment; and finally, naturally cooling to obtain the composite graphite film.
The results show that: the thickness of the composite graphite film added with the chopped asphalt-based carbon fibers with the mass fraction of 18 percent is 150 mu m, the in-plane thermal conductivity is 1549W/(m.K), and the composite graphite film is increased by 28 percent compared with the common PI graphite film.
The graphite film obtained in this example had a bending life result of 23159 times.
An SEM image of the in-plane fiber arrangement of the thermally conductive composite graphite film obtained in this example is shown in fig. 1, and it can be seen that the chopped mesophase pitch-based carbon fibers are randomly distributed on the surface of the graphite film.
The XRA pattern in the composite film surface of the heat-conducting composite graphite film obtained in the embodiment is shown in figure 2, which shows that the graphite crystal in the composite graphite film has good orientation and the structure presents anisotropy, and indicates that the heat-conducting property is excellent.
Example 4:
s1, cutting the thermal-conductive mesophase pitch-based carbon fiber leftover materials into short fibers with a certain length, wherein the average diameter of the fibers is 9 mu m, and the length of the fibers is 3 mm;
s2: then, processing the carbon fiber in the last step by adopting an air oxidation method, wherein the processing temperature is 700 ℃, and the processing time is 10 minutes to obtain modified chopped fiber;
s3: putting 60g of 1,2,4, 5-pyromellitic dianhydride, 22g of p-phenylenediamine and 18g of the modified chopped fibers in the previous step into a reaction kettle with a proper amount of solvent, wherein 22g of N, N-dimethylacetamide solvent is filled in the reaction kettle, and carrying out polymerization reaction for 25 minutes at 60 ℃ to obtain a PAA solution containing the chopped fibers;
s4: then respectively obtaining a PI-based composite graphite film by tape casting film forming and a thermal imidization process at 300 ℃;
S5: heating to 1000 ℃ at a heating rate of 5 ℃/min under the protection of argon atmosphere, and preserving heat at 1000 ℃ for 10 minutes to finish carbonization treatment; then heating to 3000 ℃ at the heating rate of 10 ℃/min under the protection of argon atmosphere, and preserving heat at 3000 ℃ for 10 minutes to finish graphitization treatment; and finally, naturally cooling to obtain the composite graphite film.
The results show that: the thickness of the composite graphite film added with the chopped asphalt-based carbon fibers with the mass fraction of 18 percent is 150 mu m, the in-plane thermal conductivity is 1271W/(m.K), and the composite graphite film is increased by 5 percent compared with the common PI graphite film.
The graphite film obtained in this example had a bending life result of 25157 times.
Example 5:
s1, cutting the thermal conduction mesophase pitch-based carbon fiber leftover materials into chopped fibers with certain length, wherein the average diameter of the fibers is 12 mu m, and the length of the fibers is 3 mm;
s2: then, processing the carbon fiber in the last step by adopting an air oxidation method, wherein the processing temperature is 400 ℃, and the processing time is 5 minutes to obtain modified chopped fiber;
s3: putting 60g of 1,2,4, 5-pyromellitic dianhydride, 22g of p-phenylenediamine and 18g of the chopped fibers subjected to the one-step modification into a reaction kettle with a proper amount of solvent, wherein 22g of N, N-dimethylacetamide solvent is filled in the reaction kettle, and performing polymerization reaction at 60 ℃ for 25 minutes to obtain a PAA solution containing the chopped fibers;
S4: then respectively obtaining a PI-based composite graphite film by tape casting film forming and a thermal imidization process at 300 ℃;
s5: heating to 1000 ℃ at a heating rate of 5 ℃/min under the protection of argon atmosphere, and preserving heat at 1000 ℃ for 10 minutes to complete carbonization treatment; then heating to 3000 ℃ at the heating rate of 10 ℃/min under the protection of argon atmosphere, and preserving heat at 3000 ℃ for 10 minutes to finish graphitization treatment; and finally, naturally cooling to obtain the composite graphite film.
The results show that: the thickness of the composite graphite film added with the chopped asphalt-based carbon fiber with the mass fraction of 18 percent is 150 mu m, the in-plane thermal conductivity is 1464W/(m.K), and the composite graphite film is increased by 21 percent compared with the common PI graphite film.
The graphite film obtained in this example had a bending life result of 24385 times.
Comparative example 1:
s1, cutting the thermal-conductive mesophase pitch-based carbon fiber leftover materials into chopped fibers with a certain length, wherein the average diameter of the fibers is 12 mu m, and the length of the fibers is 3 mm;
s2: then, processing the carbon fiber in the last step by adopting an air oxidation method, wherein the processing temperature is 400 ℃, and the processing time is 10 minutes to obtain modified chopped fiber;
s3: putting 69g of 1,2,4, 5-pyromellitic dianhydride, 26g of p-phenylenediamine and 5g of the modified chopped fibers in the previous step into a reaction kettle with a proper amount of solvent, filling 26g N, N-dimethylacetamide solvent into the reaction kettle, and carrying out polymerization reaction for 25 minutes at 60 ℃ to obtain PAA solution containing the chopped fibers;
S4: then respectively obtaining a PI-based composite graphite film by tape casting film forming and a thermal imidization process at 300 ℃;
s5: heating to 1000 ℃ at a heating rate of 5 ℃/min under the protection of argon atmosphere, and preserving heat at 1000 ℃ for 10 minutes to finish carbonization treatment; then heating to 3000 ℃ at the heating rate of 10 ℃/min under the protection of argon atmosphere, and preserving heat at 3000 ℃ for 10 minutes to finish graphitization treatment; and finally, naturally cooling to obtain the composite graphite film.
The results show that: the thickness of the composite graphite film added with the chopped asphalt-based carbon fiber with the mass fraction of 5 percent is 150 mu m, the in-plane thermal conductivity is 1217W/(m.K), and the composite graphite film is increased by 0.6 percent compared with the common PI graphite film; the graphite film obtained had a bending life result of 20624 times.
Comparative example 2:
s1, cutting the thermal-conductive mesophase pitch-based carbon fiber leftover materials into chopped fibers with a certain length, wherein the average diameter of the fibers is 12 mu m, and the length of the fibers is 3 mm;
s2: the chopped fibers are not subjected to any treatment;
s3: putting 60g of 1,2,4, 5-pyromellitic dianhydride, 22g of p-phenylenediamine and 18g of the modified chopped fibers in the previous step into a reaction kettle with a proper amount of solvent, wherein 22g of N, N-dimethylacetamide solvent is filled in the reaction kettle, and carrying out polymerization reaction for 25 minutes at 60 ℃ to obtain a PAA solution containing the chopped fibers;
S4: then respectively obtaining a PI-based composite graphite film by tape casting film forming and thermal imidization process at 300 ℃;
s5: heating to 1000 ℃ at a heating rate of 5 ℃/min under the protection of argon atmosphere, and preserving heat at 1000 ℃ for 10 minutes to finish carbonization treatment; then heating to 3000 ℃ at the heating rate of 10 ℃/min under the protection of argon atmosphere, and preserving heat at 3000 ℃ for 10 minutes to finish graphitization treatment; and finally, naturally cooling to obtain the composite graphite film.
The results show that: the thickness of the composite graphite film added with the chopped asphalt-based carbon fiber with the mass fraction of 18 percent is 150 mu m, the in-plane thermal conductivity is 1440W/(m.K), and the composite graphite film is increased by 19 percent compared with a common PI graphite film; the bending life of the obtained graphite film was 19718 times.
Comparative example 3:
s1, cutting the plant fiber into chopped fiber with a certain length, wherein the fiber length is 3 mm;
s2: then, processing the carbon fiber in the last step by adopting an air oxidation method, wherein the processing temperature is 400 ℃, and the processing time is 10 minutes to obtain modified chopped fiber;
s3: putting 60g of 1,2,4, 5-pyromellitic dianhydride, 22g of p-phenylenediamine and 18g of the modified chopped fibers in the previous step into a reaction kettle with a proper amount of solvent, wherein 22g of N, N-dimethylacetamide solvent is filled in the reaction kettle, and carrying out polymerization reaction for 25 minutes at 60 ℃ to obtain a PAA solution containing the chopped fibers;
S4: then respectively obtaining a PI-based composite graphite film by tape casting film forming and a thermal imidization process at 300 ℃;
s5: heating to 1000 ℃ at a heating rate of 5 ℃/min under the protection of argon atmosphere, and preserving heat at 1000 ℃ for 10 minutes to finish carbonization treatment; then heating to 3000 ℃ at the heating rate of 10 ℃/min under the protection of argon atmosphere, and preserving heat at 3000 ℃ for 10 minutes to finish graphitization treatment; and finally, naturally cooling to obtain the composite graphite film.
The results show that: the thickness of the composite graphite film added with 18% of plant fiber is 150 μm, the in-plane thermal conductivity is 1217W/(m.K), which is 0.6% more than that of the common PI graphite film; the bending life of the obtained graphite film was 20611 times.
Comparative example 4:
s1, cutting the polyacrylonitrile carbon fiber into chopped fibers with a certain length, wherein the average diameter of the fibers is 12 mu m, and the length of the fibers is 3 mm;
s2: then, processing the carbon fiber in the last step by adopting an air oxidation method, wherein the processing temperature is 400 ℃, and the processing time is 10 minutes to obtain modified chopped fiber;
s3: putting 60g of 1,2,4, 5-pyromellitic dianhydride, 22g of p-phenylenediamine and 18g of the modified chopped fibers in the previous step into a reaction kettle with a proper amount of solvent, wherein 20g of N, N-dimethylacetamide solvent is filled in the reaction kettle, and carrying out polymerization reaction for 25 minutes at 60 ℃ to obtain a PAA solution containing the chopped fibers;
S4: then respectively obtaining a PI-based composite graphite film by tape casting film forming and a thermal imidization process at 300 ℃;
s5: heating to 1000 ℃ at a heating rate of 5 ℃/min under the protection of argon atmosphere, and preserving heat at 1000 ℃ for 10 minutes to finish carbonization treatment; then heating to 3000 ℃ at the heating rate of 10 ℃/min under the protection of argon atmosphere, and preserving heat at 3000 ℃ for 10 minutes to finish graphitization treatment; and finally, naturally cooling to obtain the composite graphite film.
The results show that: the thickness of the composite graphite film added with the polyacrylonitrile carbon fiber with the mass fraction of 18 percent is 150 mu m, the in-plane thermal conductivity is 765W/(m.K), and the composite graphite film is reduced by 37 percent compared with the common PI graphite film; the resulting graphite film had a bending life of 23159 times.
Comparative example 5:
s1: putting 60g of 1,2,4, 5-pyromellitic dianhydride and 22g of p-phenylenediamine into a reaction kettle with a proper amount of solvent, wherein the reaction kettle is filled with 22g N, N-dimethylacetamide solvent, and carrying out polymerization reaction for 25 minutes at 60 ℃ to obtain PAA solution;
s2: then respectively obtaining a PI-based composite graphite film by tape casting film forming and a thermal imidization process at 300 ℃;
s3: heating to 1000 ℃ at a heating rate of 5 ℃/min under the protection of argon atmosphere, and preserving heat at 1000 ℃ for 10 minutes to complete carbonization treatment; then heating to 3000 ℃ at the heating rate of 10 ℃/min under the protection of argon atmosphere, and preserving heat at 3000 ℃ for 10 minutes to complete graphitization treatment; and finally, naturally cooling to obtain the composite graphite film.
The results show that: the thickness of the pure graphite film is 150 μm, and the in-plane thermal conductivity is 1210W/(m.K); the resulting graphite film had 19459 fold life results.
Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (7)
1. A heat-conducting composite graphite film is characterized by comprising chopped fibers, wherein the chopped fibers have an average diameter of 9-12 microns and a length of 1.5-6 mm; the chopped fibers are mesophase pitch-based carbon fibers subjected to surface modification treatment;
the surface modification is carried out by an air oxidation method;
the air oxidation method is to carry out heat treatment on the mesophase pitch-based carbon fiber in the air, wherein the treatment temperature is 320-700 ℃, and the treatment time is 1-20 minutes;
the mesophase pitch-based carbon fiber is obtained by spinning a mesophase pitch raw material with a mesophase content value of 100 percent and then graphitizing the spun mesophase pitch raw material at 2800 ℃ and 3200 ℃; the grain size La of the mesophase pitch-based carbon fiber is larger than 22.4 nm.
2. The method for preparing a thermally conductive composite graphite film according to claim 1, comprising the steps of:
s1, adding the chopped fibers into a reaction kettle added with a dianhydride monomer, a diamine monomer and a solvent, and reacting to obtain a PAA solution containing the chopped fibers;
s2, carrying out tape casting, drying and imidization treatment on the PAA solution containing the chopped fibers in sequence to obtain a PI-based composite membrane;
and S3, sequentially carrying out carbonization and high-temperature graphitization treatment on the PI-based composite membrane to obtain the PI-based composite graphite membrane.
3. The method for preparing a thermally conductive composite graphite film according to claim 2, wherein in step S1: the addition amount of the chopped fiber is 16-18% of the total mass of the dianhydride monomer, the diamine monomer and the chopped fiber.
4. The method for preparing a thermally conductive composite graphite film according to claim 2, wherein the reaction conditions in step S1 are as follows: reacting for 20-40 minutes at 40-80 ℃.
5. The method of preparing a thermally conductive composite graphite film according to claim 2,
in the step S1:
the dianhydride monomer is one or more of 1,2,4, 5-pyromellitic dianhydride, 3 ', 4, 4' -benzophenone tetracarboxylic dianhydride and 3,3 ', 4, 4' -biphenyl tetracarboxylic dianhydride;
The diamine monomer is one or more of p-phenylenediamine, 4' -diaminodiphenyl ether, 1, 3-diaminobenzene and 1, 2-diaminobenzene;
the dianhydride monomer and diamine monomer species are in the same amount;
the solvent is a polar solvent, and the mass of the solvent is the same as that of the added diamine monomer.
6. The method of preparing a thermally conductive composite graphite film according to claim 2 or 5, wherein the dianhydride monomer in step S1 is 1,2,4, 5-pyromellitic dianhydride; the diamine monomer is p-phenylenediamine and the solvent is N, N-dimethylacetamide.
7. The method of preparing a thermally conductive composite graphite film according to claim 2,
the temperature of the imidization treatment in step S2 is: 260 ℃ to 330 ℃;
the temperature of the carbonization treatment in the step S3 is 900-1600 ℃; the temperature of the high-temperature graphitization treatment is 2500-3200 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110793326.4A CN113353927B (en) | 2021-07-14 | 2021-07-14 | Heat-conducting composite graphite film and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110793326.4A CN113353927B (en) | 2021-07-14 | 2021-07-14 | Heat-conducting composite graphite film and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113353927A CN113353927A (en) | 2021-09-07 |
| CN113353927B true CN113353927B (en) | 2022-07-29 |
Family
ID=77539300
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110793326.4A Active CN113353927B (en) | 2021-07-14 | 2021-07-14 | Heat-conducting composite graphite film and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113353927B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115626834B (en) * | 2022-09-21 | 2023-08-11 | 安徽国风新材料股份有限公司 | Preparation method of silicon carbide fiber and carbon fiber reinforced polyimide graphite film |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009215404A (en) * | 2008-03-10 | 2009-09-24 | Teijin Ltd | Sheet-shaped thermally conductive molded product |
| WO2010024462A1 (en) * | 2008-09-01 | 2010-03-04 | 帝人株式会社 | Pitch-derived graphitized short fiber and molded object obtained using same |
| JP2010064391A (en) * | 2008-09-11 | 2010-03-25 | Kaneka Corp | Graphite composite film |
| JP2012171986A (en) * | 2011-02-17 | 2012-09-10 | Teijin Ltd | Thermally conductive composition |
| JP2013007124A (en) * | 2011-06-22 | 2013-01-10 | Teijin Ltd | Pitch-based graphitized short fiber coated with polyamide imide |
| CN110304625A (en) * | 2019-06-25 | 2019-10-08 | 浙江福斯特新材料研究院有限公司 | Graphene induces the preparation method of the high thermal conductivity graphite film of orientation of polyimide crystallization |
| CN110629326A (en) * | 2019-10-29 | 2019-12-31 | 北京化工大学 | Preparation method of high-thermal-conductivity mesophase pitch-based carbon fiber |
| CN112266260A (en) * | 2020-10-21 | 2021-01-26 | 安徽国风塑业股份有限公司 | Preparation method of polyimide graphite film |
-
2021
- 2021-07-14 CN CN202110793326.4A patent/CN113353927B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009215404A (en) * | 2008-03-10 | 2009-09-24 | Teijin Ltd | Sheet-shaped thermally conductive molded product |
| WO2010024462A1 (en) * | 2008-09-01 | 2010-03-04 | 帝人株式会社 | Pitch-derived graphitized short fiber and molded object obtained using same |
| JP2010064391A (en) * | 2008-09-11 | 2010-03-25 | Kaneka Corp | Graphite composite film |
| JP2012171986A (en) * | 2011-02-17 | 2012-09-10 | Teijin Ltd | Thermally conductive composition |
| JP2013007124A (en) * | 2011-06-22 | 2013-01-10 | Teijin Ltd | Pitch-based graphitized short fiber coated with polyamide imide |
| CN110304625A (en) * | 2019-06-25 | 2019-10-08 | 浙江福斯特新材料研究院有限公司 | Graphene induces the preparation method of the high thermal conductivity graphite film of orientation of polyimide crystallization |
| CN110629326A (en) * | 2019-10-29 | 2019-12-31 | 北京化工大学 | Preparation method of high-thermal-conductivity mesophase pitch-based carbon fiber |
| CN112266260A (en) * | 2020-10-21 | 2021-01-26 | 安徽国风塑业股份有限公司 | Preparation method of polyimide graphite film |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113353927A (en) | 2021-09-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| AU2020102143A4 (en) | Preparation method of graphene polyimide composite sponge precursor-based thermal-conductive film | |
| CN110872193B (en) | Preparation method of high-thermal-conductivity graphene/chopped carbon fiber composite material | |
| CN107304490B (en) | Preparation method of graphene/polyimide composite carbon fiber | |
| CN109650892B (en) | High-thermal-conductivity graphene film and preparation method thereof | |
| CN109956466B (en) | Graphene-based composite film with high thermal conductivity in-plane direction and thickness direction and preparation method thereof | |
| CN108329495B (en) | Graphene-cellulose nanocrystalline composite heat-conducting film with bionic structure and preparation thereof | |
| CN102534858B (en) | Method for preparing graphene/polyimide composite fibers | |
| CN111777841B (en) | Lamellar anisotropy-based graphene/epoxy resin composite material and preparation method thereof | |
| CN108997754B (en) | Polyimide high-temperature dielectric composite film and preparation method thereof | |
| CN112574468B (en) | Heat-conducting polymer composite material with multi-layer continuous network structure and preparation method thereof | |
| Zhu et al. | Graphene–carbon composite films as thermal management materials | |
| CN113353927B (en) | Heat-conducting composite graphite film and preparation method thereof | |
| CN105696116A (en) | Preparation method of novel high-heat conduction carbon fibers | |
| CN112694685B (en) | Preparation method of poly 4-methylpentene nanosheet composite film | |
| CN113213935A (en) | Preparation method of polyimide-based graphite film | |
| CN113233453B (en) | High-electric-conductivity heat-conduction graphite material and preparation method thereof | |
| Yang et al. | Chemo-mechanically exfoliated boron nitride nanosheet/poly (vinyl alcohol) composites as efficient heat dissipation components | |
| CN109957962B (en) | Carboxylated carbon nanotube-polyurethane heat-conducting film and preparation method thereof | |
| CN115626834B (en) | Preparation method of silicon carbide fiber and carbon fiber reinforced polyimide graphite film | |
| CN102766990B (en) | Preparation method of high heat conductivity carbon fiber | |
| CN113388249B (en) | Benzoxazole polymer nanofiber-based insulating heat-conducting polymer composite material as well as preparation method and application thereof | |
| CN114956068B (en) | Artificial graphite heat conducting film and preparation method thereof | |
| CN114539783A (en) | High-thermal-conductivity high-insulation gasket and preparation method thereof | |
| CN111621879B (en) | Polybenzazole graphite fiber and preparation method thereof | |
| CN116675888B (en) | Preparation method of imidazole ionic liquid modified graphene/polyimide composite film and polyimide graphite film |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CP01 | Change in the name or title of a patent holder | ||
| CP01 | Change in the name or title of a patent holder |
Address after: 410000 East, 2nd, 7th and 8th floors of building B8, luguyuyuan, No.27 Wenxuan Road, Changsha hi tech Development Zone, Changsha City, Hunan Province Patentee after: Aerospace Science and Industry (Changsha) New Materials Research Institute Co.,Ltd. Address before: 410000 East, 2nd, 7th and 8th floors of building B8, luguyuyuan, No.27 Wenxuan Road, Changsha hi tech Development Zone, Changsha City, Hunan Province Patentee before: CHANGSHA ADVANCED MATERIALS INDUSTRIAL RESEARCH INSTITUTE Co.,Ltd. |