CN115448747A - Graphite fiber composite foam carbon and preparation method thereof - Google Patents
Graphite fiber composite foam carbon and preparation method thereof Download PDFInfo
- Publication number
- CN115448747A CN115448747A CN202211054652.4A CN202211054652A CN115448747A CN 115448747 A CN115448747 A CN 115448747A CN 202211054652 A CN202211054652 A CN 202211054652A CN 115448747 A CN115448747 A CN 115448747A
- Authority
- CN
- China
- Prior art keywords
- mesophase pitch
- graphite fiber
- carbon
- foam
- fiber composite
- 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.)
- Pending
Links
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 162
- 239000006260 foam Substances 0.000 title claims abstract description 86
- 229910052799 carbon Inorganic materials 0.000 title claims abstract description 85
- 239000010439 graphite Substances 0.000 title claims abstract description 77
- 229910002804 graphite Inorganic materials 0.000 title claims abstract description 77
- 239000000835 fiber Substances 0.000 title claims abstract description 72
- 239000002131 composite material Substances 0.000 title claims abstract description 28
- 238000002360 preparation method Methods 0.000 title abstract description 18
- 239000011302 mesophase pitch Substances 0.000 claims abstract description 58
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims abstract description 53
- 238000005087 graphitization Methods 0.000 claims abstract description 28
- 239000000843 powder Substances 0.000 claims abstract description 27
- 238000003763 carbonization Methods 0.000 claims abstract description 17
- 238000005187 foaming Methods 0.000 claims abstract description 16
- 210000003041 ligament Anatomy 0.000 claims abstract description 13
- 238000007254 oxidation reaction Methods 0.000 claims abstract description 9
- 230000003647 oxidation Effects 0.000 claims abstract description 7
- 238000010438 heat treatment Methods 0.000 claims description 24
- 238000000034 method Methods 0.000 claims description 23
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 claims description 15
- 230000008569 process Effects 0.000 claims description 12
- 239000010426 asphalt Substances 0.000 claims description 8
- 238000010000 carbonizing Methods 0.000 claims description 4
- 239000000126 substance Substances 0.000 claims description 3
- 230000001590 oxidative effect Effects 0.000 claims description 2
- 239000011148 porous material Substances 0.000 abstract description 3
- 230000000052 comparative effect Effects 0.000 description 8
- 238000001878 scanning electron micrograph Methods 0.000 description 7
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 229920000049 Carbon (fiber) Polymers 0.000 description 4
- 239000004917 carbon fiber Substances 0.000 description 4
- 230000006835 compression Effects 0.000 description 4
- 238000007906 compression Methods 0.000 description 4
- 229920002239 polyacrylonitrile Polymers 0.000 description 4
- 238000009826 distribution Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 238000000227 grinding Methods 0.000 description 2
- 239000004620 low density foam Substances 0.000 description 2
- 239000013081 microcrystal Substances 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 239000011295 pitch Substances 0.000 description 2
- 238000007873 sieving Methods 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- 230000008094 contradictory effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- IDGUHHHQCWSQLU-UHFFFAOYSA-N ethanol;hydrate Chemical compound O.CCO IDGUHHHQCWSQLU-UHFFFAOYSA-N 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000012782 phase change material Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 239000002243 precursor Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 150000003254 radicals Chemical class 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000009210 therapy by ultrasound Methods 0.000 description 1
Images
Classifications
-
- 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
- C04B38/00—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof
- C04B38/06—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof by burning-out added substances by burning natural expanding materials or by sublimating or melting out added substances
- C04B38/063—Preparing or treating the raw materials individually or as batches
- C04B38/0635—Compounding ingredients
- C04B38/0645—Burnable, meltable, sublimable materials
- C04B38/067—Macromolecular compounds
-
- 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
- C01B32/05—Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30
-
- 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
- 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
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
- C04B35/52—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbon, e.g. graphite
- C04B35/522—Graphite
-
- 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
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
- C04B35/52—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbon, e.g. graphite
- C04B35/528—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbon, e.g. graphite obtained from carbonaceous particles with or without other non-organic components
- C04B35/532—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbon, e.g. graphite obtained from carbonaceous particles with or without other non-organic components containing a carbonisable binder
-
- 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
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/71—Ceramic products containing macroscopic reinforcing agents
- C04B35/78—Ceramic products containing macroscopic reinforcing agents containing non-metallic materials
- C04B35/80—Fibres, filaments, whiskers, platelets, or the like
-
- 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
- C04B38/00—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/50—Constituents or additives of the starting mixture chosen for their shape or used because of their shape or their physical appearance
- C04B2235/52—Constituents or additives characterised by their shapes
- C04B2235/5208—Fibers
- C04B2235/5216—Inorganic
- C04B2235/524—Non-oxidic, e.g. borides, carbides, silicides or nitrides
- C04B2235/5248—Carbon, e.g. graphite
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
- C04B2235/74—Physical characteristics
- C04B2235/77—Density
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
- C04B2235/96—Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
- C04B2235/96—Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
- C04B2235/9607—Thermal properties, e.g. thermal expansion coefficient
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Organic Chemistry (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Inorganic Chemistry (AREA)
- Geology (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Carbon And Carbon Compounds (AREA)
Abstract
The invention discloses graphite fiber composite foam carbon and a preparation method thereof, wherein in the graphite fiber composite foam carbon, mesophase pitch-based graphite fibers are compounded on ligament parts of the graphite fibers and are oriented and arranged, and the porosity of the foam carbon is more than 77%; the preparation method comprises the following steps: adding high-heat-conductivity mesophase graphite fiber powder into low-softening-point mesophase pitch, performing high-temperature self-foaming to obtain carbon foam, and performing oxidation, carbonization and graphitization to obtain the high-heat-conductivity carbon foam. The foam carbon has uniform pores and high porosity, and the graphite fibers are arranged in the ligament part in an oriented manner and have higher compressive strength and heat conductivity coefficient.
Description
Technical Field
The invention relates to a foam carbon and a preparation method thereof, in particular to a graphite fiber composite foam carbon and a preparation method thereof.
Background
The mesophase pitch-based carbon foam is a porous functional carbon material with a three-dimensional network structure, and after heat treatment, the carbon foam has the characteristics of easy processing and easy forming, and has excellent chemical and physical properties of low density, high conductivity, high thermal conductivity, low thermal expansion coefficient, high temperature resistance, acid and alkali resistance, wave absorption performance and the like. Therefore, as a light functional structural material, the foam carbon has a good development prospect in the fields of aerospace, chemical industry, energy, environment, electronics and the like.
The foam carbon is affected by shrinkage stress in the carbonization and graphitization processes, obvious cracks can be generated at ligaments and foam walls, the compressive strength of the foam carbon is reduced, the improvement of the heat conductivity coefficient can be affected, in order to obtain higher heat conductivity coefficient, the graphitization temperature of more than 3000 ℃ is generally needed, higher requirements on energy consumption and production cost are provided, and the application of the foam carbon is severely limited.
The performance of the carbon foam is not only influenced by preparation conditions, but also closely related to the properties of the precursor. In order to obtain the foam carbon with uniform pores, high thermal conductivity and high compressive strength, a large number of experiments show that the softening point of the mesophase pitch suitable for foaming is 280-350 ℃, and meanwhile, the mesophase pitch is required to have proper viscosity and have the highest intermediate content. This limits the preparation and application of carbon foam to some extent.
Foam carbon applied in scenes such as aerospace heat management phase change materials and the like requires low density, high porosity, high heat conduction and high strength, but indexes are mutually contradictory and restricted, and the preparation of high-performance foam carbon with harmonious indexes of low density, high porosity, high heat conduction and high strength is very difficult.
Disclosure of Invention
The purpose of the invention is as follows: the invention aims to provide graphite fiber composite foam carbon with high porosity, high strength and high heat conductivity; the invention also aims to provide a preparation method of the graphite fiber composite foam carbon.
The technical scheme is as follows: according to the graphite fiber composite foam carbon, the mesophase pitch-based graphite fibers are compounded on the ligament part of the foam carbon and are oriented, and the porosity of the foam carbon is more than 77%.
The preparation method of the graphite fiber composite foam carbon comprises the following steps:
(1) Uniformly dispersing the mesophase pitch-based graphite fiber powder in the mesophase pitch powder;
(2) Compacting and foaming the powder to obtain mesophase pitch carbon foam;
(3) And oxidizing, carbonizing and graphitizing the mesophase pitch carbon foam to obtain the foam carbon.
Preferably, the diameter of the mesophase pitch-based graphite fiber in the step (1) is 5-20 μm, the length is 20-200 μm, the thermal conductivity is more than 600W/(m.K), and the tensile strength is more than 1000MPa; more preferably, the mesophase pitch-based graphite fibers have a diameter of 8 to 15 μm, a length of 25 to 150 μm, a thermal conductivity of > 900W/(m.K), and a tensile strength of >1000MPa. The mesophase pitch-based graphite fiber is a graphite microcrystal material formed by highly orienting and arranging flaky graphite microcrystals along the fiber axis direction, has the performance advantages of high modulus and high thermal conductivity, has the thermal conductivity coefficient of 1000W/(m.K), and has simple production process and low production cost compared with filament and short-cut graphite fibers.
Preferably, the softening point of the mesophase pitch in the step (1) is less than 280 ℃, the volatile component is 15-25%, the ash content is less than 0.1%, the toluene insoluble content is more than 80%, and the mesophase content is more than 70%; more preferably, the softening point of the mesophase pitch is 240-280 ℃, the volatile matter is 15-25%, the ash content is less than 0.1%, the toluene insoluble matter content is more than 85%, the mesophase content is more than 75%, and the particle size is less than or equal to 75 μm. The performance of the foam carbon is closely related to the properties of the mesophase pitch, mainly expressed by light component content, mesophase content, softening point, viscosity and the like, and is divided into the following parts:
the mesophase content directly influences the degree of molecular arrangement orientation at the ligament of the cell, the degree of molecular arrangement orientation at the ligament is high, the graphitization degree is high, and the heat conductivity of the foam carbon is high, but the high mesophase content generally causes the softening point to be too high.
The mesophase pitch with high softening point has low light components, and the obtained foam carbon has less light component overflow, less pore-foam ligament cracks and high strength in the carbonization and graphitization process, but needs higher foaming temperature. At the temperature, because the high-softening-point asphalt has large molecular weight and low free radical activation energy, thermal shrinkage polymerization is easily caused and rapid curing is easily carried out in the foaming process, the viscoelasticity is poor, the fluidity is poor, the cells cannot be fully expanded, the formed cells are small in quantity, fine and uneven in distribution, the porosity of the obtained foam carbon is low, and the density, the heat conductivity coefficient and the compression strength are relatively high.
The mesophase pitch with low softening point has high light component content, so that the foaming is not uniform, and meanwhile, the volatilization of the light component in the carbonization process can cause too large contraction degree of the pore foam ligament, so that cracks are generated, and the strength and the heat conductivity of the foam carbon are relatively poor. But the foaming temperature is low, the consistency of the foaming process is good, the product performance is stable, and the high-porosity low-density foam carbon can be more easily obtained due to the high light component and low viscosity.
Preferably, the mass ratio of the mesophase pitch-based graphite fibers to the mesophase pitch in the step (1) is 1 to 10 percent; more preferably, the mass ratio of the mesophase pitch-based graphite fibers to the mesophase pitch is 2% to 8%.
Preferably, the foaming conditions of the mesophase pitch in the step (2) are: under inert atmosphere, heating to 400-550 ℃ at a heating rate of 1-3 ℃/min, the initial pressure is 0-2 Mpa, the final pressure is 2-8 Mpa, and the temperature is kept for 1-3 h when the temperature is 10-30 ℃ higher than the softening point of the asphalt in the heating process.
Preferably, the oxidation process in step (3) is: under the air atmosphere, heating to 300-400 ℃ at the heating rate of 1-5 ℃/min, and keeping the temperature for 0.5-3 h; the carbonization process comprises the following steps: under inert atmosphere, heating to 800-1500 ℃ at the heating rate of 1-3 ℃/min, and keeping the temperature for 30-120 min; the graphitization process is as follows: under inert atmosphere, the temperature is raised to 2000-3100 ℃, and the constant temperature is kept for 0.5-1 h.
The invention provides a preparation method of low-density, high-porosity, high-strength and high-heat-conductivity foam carbon by compounding two materials of low-softening-point mesophase pitch and mesophase pitch-based graphite fiber, which not only expands the selection range of the mesophase pitch of raw materials, but also further improves the performance of the foam carbon. The graphite fiber and the mesophase pitch with low softening point are compounded and foamed, the characteristics of low viscosity, high light component content and easiness in obtaining the high-porosity low-density foam carbon with low softening point are utilized, the graphite fiber powder is added into the low-softening point pitch, the viscoelasticity of the graphite fiber powder is adjusted, the carbonization shrinkage degree of the pitch is reduced to reduce ligament cracks, meanwhile, the compression strength can be improved under the action of the graphite fiber serving as a framework, the heat conductivity coefficient can be effectively improved due to the high heat conductivity of the graphite fiber, the foam carbon with high porosity, low density, high strength and high heat conductivity is obtained, and all performance indexes are well coordinated. The reliability and consistency of the foaming process are improved by reducing the foaming temperature in the preparation process.
Has the advantages that: compared with the prior art, the invention has the following remarkable advantages: on the premise of high porosity, the graphite fiber composite foam carbon has excellent performances of high strength and high heat conduction, and the porosity is more than 77%; after carbonization at 1200 ℃, the compression strength of the carbon foam can reach 15.6MPa to the maximum; after the graphite is graphitized at 2200 ℃, the compression strength of the foam carbon can reach 8.1MPa maximally.
Drawings
FIG. 1 is a scanning electron micrograph of a carbon foam obtained in example 1;
FIG. 2 is another SEM image of the carbon foam obtained in example 1;
FIG. 3 is a scanning electron micrograph of the carbon foam obtained in comparative example 1;
FIG. 4 is another scanning electron micrograph of the carbon foam obtained in comparative example 1;
FIG. 5 is a scanning electron micrograph of the carbon foam obtained in example 2;
FIG. 6 is another SEM image of a carbon foam obtained in example 2;
FIG. 7 is a scanning electron micrograph of the carbon foam obtained in comparative example 3.
Detailed Description
The technical scheme of the invention is further explained by combining the attached drawings.
The analytical instruments and methods used in the examples were as follows:
scanning electron microscope: COXEM EM-30AX PLUS +
Softening point: miller drop point softening point tester DP70
Thermal conductivity: laser thermal conductivity instrument-LFA 467
Strength: universal testing machine
Example 1
The graphite fiber composite foam carbon is characterized in that mesophase pitch-based graphite fibers are compounded on ligament parts of the foam carbon and are oriented, and the porosity of the obtained foam carbon is 77.3%.
The preparation method of the graphite fiber composite foam carbon comprises the following steps:
(1) Sequentially adding the mesophase pitch powder and 8 percent (mass ratio) of graphite fiber powder into 50 percent ethanol water solution, carrying out ultrasonic treatment for 30min, drying, and compacting the powder in a mold;
(2) And (3) placing the die in a high-pressure reaction kettle, replacing with nitrogen for 3 times, pressurizing to 1Mpa, heating to 290 ℃ at the heating rate of 10 ℃/min, keeping the temperature for 1h, continuing heating to 480 ℃ at the heating rate of 2 ℃/min, keeping the temperature for 1h, and naturally cooling to room temperature to obtain the carbon foam.
(3) And (3) oxidation: keeping the temperature for 1h at 400 ℃ in the air atmosphere. The air flow rate is based on the uniform and sufficient oxidation of the carbon foam and the removal of the heat of oxidation reaction.
(4) Carbonizing: under inert atmosphere, the temperature is raised to 1200 ℃ at the rate of 2 ℃/min, and the temperature is kept for 30min.
(5) Graphitizing: under inert atmosphere, the room temperature is raised to 2600-3100 ℃, and the temperature is kept constant for 30min.
Wherein the softening point of the mesophase pitch is 263 ℃, the volatile matter is 23.5 percent, the ash content is 253ppm, and the toluene insoluble matter is 90 percent. Grinding the mesophase pitch into powder, sieving with a 200-mesh sieve, and taking undersize products.
The graphite fiber has the length distribution of 25-50 microns accounting for 10%, 50-110 microns accounting for 85%, 110-150 microns accounting for 5%, the diameter of 8 microns, the heat conduction of 993W/(m.K) and the tensile strength of 1223MPa.
The volume density of the foam carbon is 0.5g/cm 3 And the porosity is 77.3%. After carbonization at 1200 ℃, the compressive strength of the carbon foam is 15.6MPa, and a scanning electron microscope is shown as figures 1 and 2. After the graphite is graphitized at 2200 ℃, the compressive strength of the foam carbon is 8.1MPa, and the thermal conductivity is 82.4W/(m.K); after the graphitization at 2600 ℃, the compressive strength of the foam carbon is 5.8MPa, and the thermal conductivity is 112.1W/(m.K); after graphitization at 3100 ℃, the compressive strength of the foam carbon is 4.1MPa, and the thermal conductivity is 145.7W/(m.K).
Comparative example 1
The mesophase pitch powder and graphite fiber mixture in example 1 was replaced with the mesophase pitch powder to prepare a carbon foam under the same conditions as in example 1, and scanning electron microscopes were used as shown in fig. 3 and 4.
The volume density of the foam carbon is 0.38g/cm 3 And the porosity is 82.7%. After carbonization at 1200 ℃, the compressive strength of the carbon foam is 3.3MPa. After the graphite is graphitized at 2200 ℃, the compressive strength of the foam carbon is 2.1MPa, and the thermal conductivity is 32W/(m.K); after the graphitization at 2600 ℃, the compressive strength of the foam carbon is 1.4MPa, and the thermal conductivity is 39W/(m.K); after graphitization at 3100 ℃, the compressive strength of the foam carbon is 0.8MPa, and the thermal conductivity is 57W/(m.K).
Comparative example 2
The graphite fiber powder in the embodiment 1 was replaced with polyacrylonitrile carbon fiber powder, which was obtained by pulverizing Dongli Toray T700K, and the fiber length distribution was 25 μm to 50 μm accounting for 10%,50 μm to 110 μm accounting for 86%,110 μm to 150 μm accounting for 4%, the diameter was 8 μm, and the tensile strength was 4900MPa. The preparation conditions were the same as in example 1.
The volume density of the foam carbon is 0.48g/cm 3 And porosity of 78.1%. After carbonization at 1200 ℃, the compressive strength of the foam carbon is 9.6MPa, and after graphitization at 2200 ℃, the compressive strength of the foam carbon is 3.1MPa, and the thermal conductivity is 30W/(m.K); after the graphitization at 2600 ℃, the compressive strength of the foam carbon is 2.2MPa, and the thermal conductivity is 41W/(m.K); after graphitization at 3100 ℃, the compressive strength of the foam carbon is 1.7MPa, and the thermal conductivity is 59W/(m.K).
The data of foam carbon before and after the polyacrylonitrile carbon fiber powder is added in a contrast mode can be seen, the added polyacrylonitrile carbon fiber can effectively improve the compressive strength in the carbonization stage, but after graphitization, the compressive strength and the heat conductivity coefficient of the foam carbon are not effectively improved due to the characteristic that the polyacrylonitrile carbon fiber is difficult to graphitize.
Example 2
The graphite fiber composite foam carbon is characterized in that mesophase pitch-based graphite fibers are compounded on ligament parts of the foam carbon and are oriented, and the porosity of the obtained foam carbon is 79.5%.
The preparation method of the graphite fiber composite carbon foam is the same as that of example 1, except that the ratio of the graphite fiber powder and the mesophase pitch powder in example 1 is replaced by 4.
The volume density of the foam carbon is 0.45g/cm 3 And a porosity of 79.5%. After carbonization at 1200 ℃, the compressive strength of the carbon foam is 13.1MPa. After the graphitization at 2200 ℃, the compressive strength of the foam carbon is 6.2MPa, and the thermal conductivity is 81.5W/(m.K); after the graphitization at 2600 ℃, the compressive strength of the foam carbon is 3.3MPa, and the thermal conductivity is 106.4W/(m.K); after graphitization at 3100 ℃, the compressive strength of the foam carbon is 2.7MPa, and the thermal conductivity is 139.6W/(m.K).
The thermal conductivity and compressive strength were lower than those of example 1, but significantly higher than those of comparative example 1.
Example 3
The graphite fiber composite foam carbon is characterized in that mesophase pitch-based graphite fibers are compounded on ligament parts of the foam carbon and are oriented, and the porosity of the obtained foam carbon is 80.5%.
The preparation method of the graphite fiber composite carbon foam is the same as that in example 1, except that the ratio of the graphite fiber powder to the mesophase pitch powder in example 1 is replaced by 2.
The volume density of the foam carbon is 0.43g/cm 3 And the porosity is 80.5%. After carbonization at 1200 ℃, the compressive strength of the carbon foam is 11MPa. After the graphite is graphitized at 2200 ℃, the compressive strength of the foam carbon is 5.8MPa, and the thermal conductivity is 69W/(m.K); after the graphitization at 2600 ℃, the compressive strength of the foam carbon is 2.6MPa, and the thermal conductivity is 92W/(m.K). After graphitization at 3100 ℃, the compressive strength of the foam carbon is 2.2MPa, and the thermal conductivity is 129.3W/(m.K).
In combination with the above examples, the thermal conductivity and compressive strength of the composite carbon foam decreased with decreasing graphite fiber ratio, but were still higher than the carbon foam prepared with mesophase pitch alone.
Example 4
The preparation method of the graphite fiber composite foam carbon comprises the following steps:
(1) The proportion of the graphite fiber to the mesophase pitch is 8 (mass ratio) to 100, and the graphite fiber and the mesophase pitch are uniformly mixed by the method in the embodiment 1;
(2) And (3) placing the die in a high-pressure reaction kettle, replacing with nitrogen for 3 times, pressurizing to 0.5Mpa, heating to 340 ℃ at the heating rate of 10 ℃/min, keeping the temperature for 1h, continuing heating to 520 ℃ at the heating rate of 2 ℃/min, keeping the temperature for 1h, and naturally cooling to room temperature to obtain the carbon foam.
(3) And (3) oxidation: keeping the temperature of 400 ℃ for 1h under the air atmosphere. The air flow rate is based on the uniform and sufficient oxidation of the carbon foam and the removal of the heat of oxidation reaction.
(4) Carbonizing: under inert atmosphere, the temperature is raised to 1200 ℃ at the heating rate of 2 ℃/min, and the temperature is kept for 30min.
(5) Graphitizing: and (3) under an inert atmosphere, heating the room temperature to 2600 ℃, and keeping the temperature for 30min.
Wherein the softening point of the mesophase pitch is 315 ℃, the volatile matter is 16.8 percent, the ash content is 228ppm, and the toluene insoluble matter is 98 percent. Grinding the mesophase pitch into powder, sieving with a 200-mesh sieve, and taking undersize products. The graphite fibers were the same as those used in example 1.
The foam carbon has a bulk density of 0.85g/cm as shown in FIG. 7 by scanning electron microscope 3 And, porosity 61.3%. After carbonization at 1200 ℃, the compressive strength of the foam carbon is 169MPa, and after graphitization at 2200 ℃, the compressive strength of the foam carbon is 9.5MPa, and the thermal conductivity is 85W/(m.K); after the graphitization at 2600 ℃, the compressive strength of the foam carbon is 5.3MPa, and the thermal conductivity is 115W/(m.K). After graphitization at 3100 ℃, the compressive strength of the foam carbon is 4.2MPa, and the thermal conductivity is 158.7W/(m.K).
Although the strength and the thermal conductivity are improved, the volume density is increased, and the scanning electron microscope shows that the size of the bubbles is uneven, the porosity is low, and the adding amount of the graphite fibers is too high.
Comparative example 4
A carbon foam was prepared by replacing the ratio of the graphite fiber powder of example 4 to the mesophase pitch powder with 0 3 And porosity 76.3%.After carbonization at 1200 ℃, the compressive strength of the carbon foam is 6.3MPa. After the graphitization at 2200 ℃, the compressive strength of the foam carbon is 4.3MPa, and the thermal conductivity is 56W/(m.K); after the graphitization at 2600 ℃, the compressive strength of the foam carbon is 2.5MPa, and the thermal conductivity is 80W/(m.K). After graphitization at 3100 ℃, the compressive strength of the foam carbon is 2MPa, and the thermal conductivity is 115W/(m.K).
The strength and the heat conductivity coefficient of the foam carbon obtained by independently foaming the low-softening-point intermediate phase asphalt are lower than those of the foam carbon obtained by independently foaming the high-softening-point intermediate phase asphalt, but the performance of the low-softening-point intermediate phase asphalt is greatly improved after the low-softening-point intermediate phase asphalt is compounded with the graphite fiber, and the strength and the heat conductivity coefficient of the foam carbon are higher than those of the foam carbon obtained by independently foaming the high-softening-point intermediate phase asphalt.
Comparative example 5
A carbon foam was prepared by replacing the ratio of the graphite fiber powder of example 4 to the mesophase pitch powder with 2. The volume density of the carbon foam is 0.57g/cm 3 And porosity of 74.1%. After carbonization at 1200 ℃, the compressive strength of the carbon foam is 10.2MPa. After the graphite is graphitized at 2200 ℃, the compressive strength of the foam carbon is 5.9MPa, and the thermal conductivity is 63W/(m.K); after the graphitization at 2600 ℃, the compressive strength of the foam carbon is 2.7MPa, and the thermal conductivity is 95W/(m.K). After graphitization at 3100 ℃, the compressive strength of the foam carbon is 2.3MPa, and the thermal conductivity is 125.6W/(m.K).
In combination with the above examples, it can be seen that the addition of a large amount of graphite fibers to the high softening point mesophase pitch results in excessive viscosity, increased bulk density of the carbon foam, non-uniform cells, and low porosity. The addition of a small amount of graphite fiber has a limited effect on improving the compressive strength and the heat conductivity of the carbon foam.
Claims (10)
1. A graphite fiber composite foam carbon is characterized in that: the mesophase pitch-based graphite fibers are composited in ligament portions of the carbon foam and are oriented, and the porosity of the carbon foam is more than 77%.
2. A method for preparing the graphite fiber composite carbon foam of claim 1, comprising the steps of:
(1) Uniformly dispersing the mesophase pitch-based graphite fiber powder in the mesophase pitch powder;
(2) Compacting and foaming the powder to obtain mesophase pitch carbon foam;
(3) And oxidizing, carbonizing and graphitizing the mesophase pitch carbon foam to obtain the foam carbon.
3. The method for preparing graphite fiber composite carbon foam according to claim 2, characterized in that: in the step (1), the diameter of the mesophase pitch-based graphite fiber is 5-20 microns, the length of the mesophase pitch-based graphite fiber is 20-200 microns, the heat conductivity coefficient is more than 600W/(m.K), and the tensile strength is more than 1000MPa.
4. The method for preparing graphite fiber composite carbon foam according to claim 2, wherein: in the step (1), the softening point of the mesophase pitch is less than 280 ℃, the volatile component is 15-25%, the ash content is less than 0.1%, the toluene insoluble substance is more than 80%, and the mesophase content is more than 70%.
5. The method for preparing graphite fiber composite carbon foam according to claim 2, characterized in that: the mass ratio of the mesophase pitch-based graphite fibers to the mesophase pitch in the step (1) is 1-10%.
6. The method for preparing graphite fiber composite carbon foam according to claim 2, characterized in that: the mass ratio of the mesophase pitch-based graphite fibers to the mesophase pitch in the step (1) is 2-8%.
7. The method for preparing graphite fiber composite carbon foam according to claim 2, characterized in that: the foaming conditions of the mesophase pitch in the step (2) are as follows: under inert atmosphere, heating to 400-550 ℃ at a heating rate of 1-3 ℃/min, the initial pressure is 0-2 Mpa, the final pressure is 2-8 Mpa, and the temperature is kept for 1-3 h when the temperature is 10-30 ℃ higher than the softening point of the asphalt in the heating process.
8. The method for preparing graphite fiber composite carbon foam according to claim 2, characterized in that: the oxidation process in the step (3) is as follows: under the air atmosphere, the temperature is raised to 300-400 ℃ at the heating rate of 1-5 ℃/min, and the constant temperature is kept for 0.5-3 h.
9. The method for preparing graphite fiber composite carbon foam according to claim 2, wherein: the carbonization process in the step (3) is as follows: under inert atmosphere, heating to 800-1500 ℃ at the heating rate of 1-3 ℃/min, and keeping the temperature for 30-120 min.
10. The method for preparing graphite fiber composite carbon foam according to claim 2, wherein: the graphitization process in the step (3) is as follows: under inert atmosphere, the temperature is raised to 2000-3100 ℃, and the constant temperature is kept for 0.5-1 h.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211054652.4A CN115448747A (en) | 2022-08-30 | 2022-08-30 | Graphite fiber composite foam carbon and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211054652.4A CN115448747A (en) | 2022-08-30 | 2022-08-30 | Graphite fiber composite foam carbon and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115448747A true CN115448747A (en) | 2022-12-09 |
Family
ID=84300060
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211054652.4A Pending CN115448747A (en) | 2022-08-30 | 2022-08-30 | Graphite fiber composite foam carbon and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115448747A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117383954A (en) * | 2023-12-12 | 2024-01-12 | 湖南大学 | Carbon skeleton material and preparation method and application thereof |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB8414925D0 (en) * | 1983-06-15 | 1984-07-18 | Lorraine Carbone | Production of carbon-containing materials |
| US6183854B1 (en) * | 1999-01-22 | 2001-02-06 | West Virginia University | Method of making a reinforced carbon foam material and related product |
| DE10011013A1 (en) * | 2000-03-07 | 2001-09-20 | Schunk Kohlenstofftechnik Gmbh | Production of carbon foam, used as insulator, catalyst, core material for sandwich structure or reinforcing material or for tribological application or part, involves foaming mixture of carbonizable polymer and blowing agent and pyrolysis |
| US20050281730A1 (en) * | 2004-06-21 | 2005-12-22 | Theriault Philip C | Microporous graphite foam and process for producing same |
| WO2006023419A1 (en) * | 2004-08-16 | 2006-03-02 | Jing Wang | Processes for producing monolithic porous carbon disks from aromatic organic precursors |
| CN1884055A (en) * | 2006-05-26 | 2006-12-27 | 东华大学 | Method for modifying intermediate phase bitumicarb foam materials |
| CN101434388A (en) * | 2008-12-05 | 2009-05-20 | 华东理工大学 | Preparation of small pore diameter carbon foam |
| CN101900021A (en) * | 2009-01-23 | 2010-12-01 | 通用汽车环球科技运作公司 | Efficient and light weight thermoelectric waste heat recovery system |
| CN103910350A (en) * | 2014-03-17 | 2014-07-09 | 华东理工大学 | Preparing method of large-size low-heat-conductivity-coefficient high-strength foam carbon |
-
2022
- 2022-08-30 CN CN202211054652.4A patent/CN115448747A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB8414925D0 (en) * | 1983-06-15 | 1984-07-18 | Lorraine Carbone | Production of carbon-containing materials |
| US6183854B1 (en) * | 1999-01-22 | 2001-02-06 | West Virginia University | Method of making a reinforced carbon foam material and related product |
| DE10011013A1 (en) * | 2000-03-07 | 2001-09-20 | Schunk Kohlenstofftechnik Gmbh | Production of carbon foam, used as insulator, catalyst, core material for sandwich structure or reinforcing material or for tribological application or part, involves foaming mixture of carbonizable polymer and blowing agent and pyrolysis |
| US20050281730A1 (en) * | 2004-06-21 | 2005-12-22 | Theriault Philip C | Microporous graphite foam and process for producing same |
| WO2006023419A1 (en) * | 2004-08-16 | 2006-03-02 | Jing Wang | Processes for producing monolithic porous carbon disks from aromatic organic precursors |
| CN1884055A (en) * | 2006-05-26 | 2006-12-27 | 东华大学 | Method for modifying intermediate phase bitumicarb foam materials |
| CN101434388A (en) * | 2008-12-05 | 2009-05-20 | 华东理工大学 | Preparation of small pore diameter carbon foam |
| CN101900021A (en) * | 2009-01-23 | 2010-12-01 | 通用汽车环球科技运作公司 | Efficient and light weight thermoelectric waste heat recovery system |
| CN103910350A (en) * | 2014-03-17 | 2014-07-09 | 华东理工大学 | Preparing method of large-size low-heat-conductivity-coefficient high-strength foam carbon |
Non-Patent Citations (1)
| Title |
|---|
| 肖长发等: "高性能纤维产业技术发展研究", 国防工业出版社, pages: 246 - 247 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117383954A (en) * | 2023-12-12 | 2024-01-12 | 湖南大学 | Carbon skeleton material and preparation method and application thereof |
| CN117383954B (en) * | 2023-12-12 | 2024-02-20 | 湖南大学 | Carbon skeleton material and preparation method and application thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110155978B (en) | Wood-based carbon foam and composite materials and related methods | |
| CN110872193B (en) | Preparation method of high-thermal-conductivity graphene/chopped carbon fiber composite material | |
| US6797251B1 (en) | Method of making carbon foam at low pressure | |
| CN115448747A (en) | Graphite fiber composite foam carbon and preparation method thereof | |
| JP3142587B2 (en) | Carbonaceous composition, carbon material for fuel cell and method for producing the same | |
| CN107722595B (en) | Preparation method of fiber-graphene-thermoplastic polyarylether multi-scale composite material | |
| CN114438783A (en) | Preparation method of high-thermal-conductivity C/C composite material | |
| CN101560097B (en) | AIN/C composite foam material and preparation method thereof | |
| WO2007058299A1 (en) | Composite material | |
| CN110894338B (en) | Controllable deformation accurate regulation and control composite material based on super-elastic network and preparation method and application thereof | |
| CN105272330A (en) | Method for quickly preparing carbon/carbon composite with high thermal conductivity | |
| CN115073198A (en) | High-thermal-conductivity graphitized porous carbon/carbon composite material and preparation method thereof | |
| CN113773043B (en) | Preparation method of low-density carbon fiber reinforced carbon aerogel composite material | |
| CN115613212A (en) | Preparation method of carbon fiber felt | |
| CN101289329B (en) | Method for preparing blocky carbon nano fibers composite material | |
| JP2005262391A (en) | Composite material composed of nano carbon and carbonaceous second filler and its manufacturing method | |
| JP2005129507A (en) | Graphitic powder for fuel cell separator, and fuel cell separator | |
| JPH05330915A (en) | Production of carbon/carbon composite material | |
| JPH0456788B2 (en) | ||
| CN110002881B (en) | Preparation method of carbon fiber reinforced porous molybdenum disilicide ceramic material | |
| KR102481131B1 (en) | Manufacturing method of continuous skeletal porous carbon material for application to supercapacitor | |
| CN115636684B (en) | Preparation method of carbon fiber heat-insulating hard felt | |
| JPH0456789B2 (en) | ||
| JPH06135770A (en) | Carbonaceous preformed body, its production and production of electrode substrate | |
| CN115472441B (en) | CNT-modified short fiber/wood ceramic electrode and preparation method and application thereof |
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 | ||
| TA01 | Transfer of patent application right | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20230529 Address after: Room 201, building A, No. 1, front Bay Road, Qianhai Shenzhen Shenzhen Hong Kong cooperation zone (Shenzhen Qianhai business secretary Co., Ltd.), Guangdong, China Applicant after: Yigao Carbon Materials Holdings (Shenzhen) Co.,Ltd. Address before: Hongkong China Java Road No. 363 23 floor Applicant before: Yigao Carbon Materials Technology Co.,Ltd. Effective date of registration: 20230529 Address after: Hongkong China Java Road No. 363 23 floor Applicant after: ECO ENVIRONMENTAL ENERGY RESEARCH INSTITUTE Ltd. Address before: No. 3, Gangfeng Road, Jiangsu Yangtze River International Chemical Industrial Park, Suzhou, Jiangsu 215,634 Applicant before: Yigao environmental protection energy technology (Zhangjiagang) Co.,Ltd. Effective date of registration: 20230529 Address after: Hongkong China Java Road No. 363 23 floor Applicant after: Yigao Carbon Materials Technology Co.,Ltd. Address before: Hongkong China Java Road No. 363 23 floor Applicant before: ECO ENVIRONMENTAL ENERGY RESEARCH INSTITUTE Ltd. |
|
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20221209 |