CN116876115A - High-strength ultrahigh-modulus polyacrylonitrile-based carbon fiber and preparation method thereof - Google Patents
High-strength ultrahigh-modulus polyacrylonitrile-based carbon fiber and preparation method thereof Download PDFInfo
- Publication number
- CN116876115A CN116876115A CN202310880791.0A CN202310880791A CN116876115A CN 116876115 A CN116876115 A CN 116876115A CN 202310880791 A CN202310880791 A CN 202310880791A CN 116876115 A CN116876115 A CN 116876115A
- Authority
- CN
- China
- Prior art keywords
- temperature
- fiber
- modulus
- carbon fiber
- polyacrylonitrile
- 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.)
- Granted
Links
Classifications
-
- 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
- D01F9/20—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from polyaddition, polycondensation or polymerisation products
- D01F9/21—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from polyaddition, polycondensation or polymerisation products from macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
- D01F9/22—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from polyaddition, polycondensation or polymerisation products from macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds from polyacrylonitriles
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Textile Engineering (AREA)
- Inorganic Fibers (AREA)
Abstract
本发明涉及碳纤维制备技术领域，公开一种高强度超高模量的聚丙烯腈基碳纤维及其制备方法。包括步骤：步骤1，对聚丙烯腈纤维进行预氧化、低温碳化得到低温碳化纤维；步骤2，将低温碳化纤维进行六温区梯度升温高温碳化处理，高温碳化处理过程中纤维总牵伸倍率为‑7.0％～‑1.0％，总处理时间为4min～12min，得到高温碳化纤维；步骤3，对高温碳化纤维进行超高温石墨化处理得到所述高强度超高模量的聚丙烯腈基碳纤维。通过对高温碳化的多温区处理，提高最终热处理温度，优化牵伸倍率、处理时间等工艺参数，制备得到拉伸强度≥4000MPa且拉伸模量≥640GPa的超高模量碳纤维，综合性能非常优异，并具有广阔应用前景。
The invention relates to the technical field of carbon fiber preparation, and discloses a high-strength and ultra-high modulus polyacrylonitrile-based carbon fiber and a preparation method thereof. It includes steps: Step 1, pre-oxidize and low-temperature carbonize the polyacrylonitrile fiber to obtain low-temperature carbonized fiber; Step 2, subject the low-temperature carbonized fiber to six temperature zone gradient heating and high-temperature carbonization treatment, and the total fiber drafting ratio during the high-temperature carbonization treatment is ‑7.0%～‑1.0%, the total processing time is 4min～12min, and high-temperature carbonized fiber is obtained; in step 3, the high-temperature carbonized fiber is subjected to ultra-high temperature graphitization treatment to obtain the high-strength ultra-high modulus polyacrylonitrile-based carbon fiber. Through multi-temperature zone treatment of high-temperature carbonization, increasing the final heat treatment temperature, and optimizing process parameters such as draft ratio and processing time, ultra-high modulus carbon fibers with tensile strength ≥4000MPa and tensile modulus ≥640GPa were prepared. The overall performance is very good. Excellent and has broad application prospects.
Description
Technical Field
The invention relates to the technical field of carbon fiber preparation, in particular to a high-strength ultrahigh-modulus polyacrylonitrile-based carbon fiber and a preparation method thereof.
Background
Because of the excellent performances of high specific strength, high specific modulus, low density, corrosion resistance, fatigue resistance and the like, the carbon fiber has been widely applied to the fields of aerospace, sports and leisure, new energy, civil construction and the like. The carbon fibers are classified according to their tensile modulus, and can be classified into standard modulus (230-240 GPa), medium modulus (290-300 GPa), high modulus (350-600 GPa) and ultra-high modulus (> 600 GPa). The ultra-high modulus carbon fiber has the characteristics of excellent ultra-high modulus, high heat conduction, high electric conduction and the like, and can endow the composite structural member with ultra-low thermal expansion and high rigidity, so that the composite structural member becomes the optimal material for the satellite spacecraft heat dissipation plate, and can be further applied to various industrial fields such as industrial zero heat deformation rollers, robot structural members, light high-rigidity bicycle frames and the like.
The ultra-high modulus carbon fibers may be classified into pitch-based ultra-high modulus carbon fibers and Polyacrylonitrile (PAN) -based ultra-high modulus carbon fibers according to the type of precursor fibers. Because the mesophase pitch has the characteristic of easy graphitization, the pitch fiber is used as a precursor to easily prepare the ultra-high modulus carbon fiber, such as coal pitch-based carbon fiber of Japanese graphite fiber company and Japanese Mitsubishi chemical petroleum pitch-based carbon fiber, but the tensile strength of the pitch-based ultra-high modulus carbon fiber is generally low (both are obviously lower than 4000 MPa), such as Mitsubishi chemical K1352U-type pitch-based ultra-high modulus carbon fiber tensile modulus 620GPa and tensile strength 3600MPa, and the ultra-high modulus characteristic of low strength leads to extremely high brittleness of the fiber, and broken filaments, broken filaments and the like are extremely easy to form in the subsequent product processing process, thereby influencing the processing manufacturability.
Compared with mesophase pitch, PAN belongs to a material difficult to graphitize, so that the preparation of the ultra-high modulus carbon fiber by taking PAN fiber as a precursor has higher difficulty, the highest modulus of the PAN-based carbon fiber commercialized worldwide at present is M60J type carbon fiber of Dongli company, japan, and the tensile modulus of the fiber is 588GPa, but the tensile strength of the fiber is only 3820MPa.
CN108286090a discloses a preparation method of PAN-based high-strength high-modulus carbon fiber, after conventional preoxidation and low-temperature carbonization of PAN precursor, the orientation of carbon microcrystals can be effectively controlled by increasing the high-temperature carbonization temperature and matching a certain stretching ratio or by increasing the high-temperature carbonization stretching ratio, so as to obtain high-temperature carbonized fiber with an orientation angle of not more than 17.5 degrees, and then high-temperature graphitization hot drawing treatment is carried out at a relatively low high-temperature graphitization temperature, wherein the tensile strength of the prepared fiber is 3.8-5.0 GPa, and the tensile modulus can reach 500-600 GPa, but cannot exceed 600GPa all the time.
It is known that, at present, the east company is developing and commercializing an M65J-type ultra-high modulus carbon fiber with a tensile modulus of 640GPa or more, but from the characteristics of the existing brand-name carbon fiber of the company (the higher the tensile modulus of the carbon fiber is, the more the tensile strength of the carbon fiber is reduced significantly), the tensile strength of the M65J-type ultra-high modulus carbon fiber developed by the east company is expected to be lower than 3800MPa, and may even be only 3600MPa.
In the high-temperature carbonization process, an initial two-dimensional disordered layer graphite structure formed inside the fiber is gradually converted into a three-dimensional graphite microcrystalline structure under the high-temperature drafting effect, and parameters such as microcrystalline size, orientation and the like of the graphite microcrystalline structure are key for influencing the tensile strength and tensile modulus of the final fiber, so that the structural regulation at the stage is one of key ways for preparing the ultra-high modulus carbon fiber. Numerous studies have shown that when high temperature carbonization is performed on carbon fibers of high modulus and below (modulus < 600 GPa), the high temperature carbonization furnace typically consists of 1-5 temperature zones with a maximum temperature of no more than 1600 ℃ (Xuhua etc. < polyacrylonitrile-based carbon fibers > p134, he Fu < carbon fibers and graphite fibers > p 230).
In summary, how to continuously and stably prepare the carbon fiber with high strength and ultrahigh modulus by controlling the microstructure in the fiber forming process becomes one of the hot points and difficulties in the development in a future period.
Disclosure of Invention
Aiming at the problems that Polyacrylonitrile (PAN) has typical graphitization-resistant characteristics in the prior art, the preparation of the ultra-high modulus carbon fiber is extremely difficult, the existing ultra-high modulus carbon fiber is generally low in tensile strength, the ultra-high modulus and the high strength are difficult to combine, and the like, the invention provides a preparation method of the high-strength ultra-high modulus carbon fiber.
In order to achieve the above purpose, the invention adopts the following technical scheme:
a preparation method of high-strength and ultrahigh-modulus polyacrylonitrile-based carbon fiber comprises the following steps:
step 1, pre-oxidizing polyacrylonitrile fibers and carbonizing the polyacrylonitrile fibers at a low temperature to obtain low-temperature carbonized fibers;
step 2, carrying out gradient heating high-temperature carbonization treatment on the low-temperature carbonized fiber in a six-temperature zone, wherein the temperature of the six-temperature zone is 1000-1200 ℃, 1250-1350 ℃, 1300-1500 ℃, 1400-1550 ℃, 1500-1650 ℃, 1600-1800 ℃ and the total drawing multiplying power of the fiber is-7.0% -1.0% and the total treatment time is 4-12 min in the high-temperature carbonization treatment process, so as to obtain the high-temperature carbonized fiber;
and step 3, carrying out ultrahigh-temperature graphitization treatment on the high-temperature carbonized fiber to obtain the high-strength ultrahigh-modulus polyacrylonitrile-based carbon fiber.
Step 2, obtaining 002 interplanar spacing d of the high temperature carbonized fiber 002 Is 0.3485 nm-0.3585 nm, the content of carbon element is 92-97%, and the bulk density is 1.75g/cm 3 ～1.79g/cm 3 。
When the high-temperature carbonization treatment is carried out on the carbon fiber with high modulus and below (modulus is less than 600 GPa) in the prior art, the high-temperature carbonization furnace is generally composed of 1-5 temperature areas, the highest temperature is not more than 1600 ℃, and the inventor of the patent finds that through a great deal of researches: if preparing the ultra-high modulus carbon fiber with the ultra-high modulus grade, especially the modulus higher than 640GPa, the fine control on the internal structure of the fiber in the high-temperature carbonization stage formed by the three-dimensional graphite microcrystal is needed.
Through researches, the method is beneficial to realizing the fine transformation from a two-dimensional disordered layer graphite structure in the fiber to a three-dimensional graphite microcrystalline structure by adopting the gradient temperature rise treatment in a six-temperature zone, the improvement of the final temperature of the heat treatment is beneficial to the initial growth of the three-dimensional graphite microcrystalline structure, and simultaneously, the method realizes the controllability of the internal structure of the high-temperature carbonized fiber by combining the matched design of the heat treatment temperature, the drawing process and other parameters in the high-temperature carbonization stage, and ensures that the 002 interplanar spacing d of the obtained fiber is ensured 002 0.3485 nm-0.3585 nm and 92% of carbon elementThe percent to 97 percent and the bulk density of 1.75g/cm 3 ～1.79g/cm 3 Then the product is subjected to subsequent ultrahigh temperature graphitization treatment to obtain the product with the tensile strength of more than or equal to 4000MPa, the tensile modulus of more than or equal to 640GPa and the bulk density of more than or equal to 1.95g/cm 3 Ultra-high modulus carbon fiber.
In the step 1, PAN fibers are prepared by adopting a wet method, a dry method or a dry spraying wet method, and the specification of fiber tows is 1K-50K.
Preferably, the preoxidation in the step 1 is carried out in an air atmosphere by adopting gradient heating heat treatment in four-six temperature areas, the preoxidation temperature range is 150-280 ℃, the total draft ratio of the fiber is 3.0-8.0%, and the total treatment time is 50-120 min. Further preferably, the pre-oxidation temperature is 180-260 ℃, the total draft ratio of the fiber is 5.0-7.0%, and the treatment time is 80-120 min.
In some embodiments, the pre-oxidation in step 1 employs a six temperature zone gradient temperature rise process, each temperature zone temperature range is 180 ℃ to 195 ℃, 195 ℃ to 215 ℃, 200 ℃ to 220 ℃, 210 ℃ to 230 ℃, 225 ℃ to 240 ℃, 230 ℃ to 250 ℃, respectively.
Preferably, the low-temperature carbonization in the step 1 is carried out in a high-purity nitrogen gas by adopting four-seven temperature zone heat treatment, the low-temperature carbonization temperature range is 300-1000 ℃, the total fiber draft ratio is 2.0-10.0%, and the total treatment time is 3-12 min. Further preferably, the low-temperature carbonization temperature ranges from 350 ℃ to 900 ℃, the total draft ratio of the fiber ranges from 3.0% to 7.0%, and the treatment time ranges from 3min to 8min.
Still more preferably, in step 1, the low-temperature carbonization is performed in a high-purity nitrogen gas by adopting five-seven temperature zone gradient heating heat treatment, the low-temperature carbonization temperature ranges from 350 ℃ to 900 ℃, the total draft ratio of the fiber ranges from 3.0% to 7.0%, and the total treatment time ranges from 3min to 8min.
The high-temperature carbonization treatment process in the step 2 is carried out under the protection of high-purity nitrogen.
Preferably, the ultra-high temperature graphitization in the step 3 adopts single temperature zone heat treatment, the treatment temperature is 2300-3000 ℃, the draft ratio is 2.0-10.0%, and the treatment time is 2-10 min. Further preferably, the ultra-high temperature graphitization temperature is 2500-2800 ℃, the total draft ratio of the fiber is 5.0-8.0%, and the treatment time is 4-6 min.
And 3, performing ultra-high temperature graphitization treatment under the protection of high-purity nitrogen and/or argon.
The invention also provides the high-strength and ultra-high-modulus polyacrylonitrile-based carbon fiber prepared by the preparation method, wherein the tensile strength is more than or equal to 4000MPa, the tensile modulus is more than or equal to 640GPa, and the bulk density is more than or equal to 1.95g/cm 3 。
Compared with the prior art, the invention has the following beneficial effects:
according to the invention, the technological parameters are comprehensively designed and optimized through the high-temperature carbonization stage, and the six-temperature-zone refined temperature zone control, the higher heat treatment final temperature, the heat treatment temperature coupling design in the gradient heating process of each temperature zone, the high-magnification drafting and the like are mainly utilized, and the key technological parameters of each stage are coupled, so that the key structural parameters of the fiber microcrystalline structure, the element content, the bulk density and the like after the high-temperature carbonization are controlled in a specific range, and finally the polyacrylonitrile-based carbon fiber with the ultrahigh modulus and the high strength is realized.
Drawings
Fig. 1 is a physical view of a carbon fiber sample to be tensile tested by treating the impregnated and reinforcing sheet in comparative example 1.
Fig. 2 is a stress-strain curve of the carbon fiber in tensile test prepared in comparative example 1.
Figure 3 XRD pattern of the fiber after high temperature carbonization in example 1.
Fig. 4 stress strain curve of the ultra-high modulus carbon fiber prepared in example 1 was measured in tensile test.
Detailed Description
The present invention will be described in further detail with reference to the following examples in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention. Modifications and equivalents will occur to those skilled in the art upon understanding the present teachings without departing from the spirit and scope of the present teachings.
The raw materials used in the following embodiments are all commercially available. Bulk density testing of carbon fibers made in the following embodiments: and testing the bulk density of the obtained carbon fiber according to the national standard GB-T30019-2013 carbon fiber density. The sample is weighed in air during testing, and is completely immersed in the sample at least 0.2g/cm less than the sample density 3 Re-weighing the sample in the liquid with known density, calculating the sample density according to the Archimedes law, wherein the mass indication values of the sample in two media are different, and calculating the bulk density of the carbon fiber.
Fiber tensile properties: the tensile properties of the carbon fibers are tested according to the national standard GB-T3362-2017 carbon fiber multifilament tensile property test method.
Comparative example 1
(1) Performing 6-temperature zone pre-oxidation treatment on the 6K polyacrylonitrile fiber by adopting a pre-oxidation furnace to obtain pre-oxidized fiber, wherein the pre-oxidation temperature of the 6-temperature zone is 180 ℃, 205 ℃, 215 ℃, 225 ℃, 230 ℃, 245 ℃ and the total draft ratio of the 6.5 percent, the pre-oxidation time of each temperature zone is 16min, and the total treatment time is 96min; the pre-oxidized fiber is subjected to low-temperature carbonization treatment in five temperature areas to obtain low-temperature carbonized fiber, wherein the temperature areas are respectively 300 ℃, 550 ℃, 650 ℃, 750 ℃, 900 ℃, the draft ratio is 6.0%, and the total residence time of the fiber is 5min;
(2) The low-temperature carbonized fiber is subjected to high-temperature carbonization treatment in four temperature areas to obtain high-temperature carbonized fiber, wherein the temperature of each temperature area is 1100 ℃, 1300 ℃, 1450 ℃, 1550 ℃, the draft ratio is-3.0%, and the fiber treatment time is 4min;
the structural indexes such as 002 interplanar spacing and the like obtained through microstructure test are shown in table 10;
(3) And further carrying out ultrahigh-temperature graphitization treatment on the high-temperature carbonized fiber by adopting a high-temperature graphitization furnace, wherein the treatment temperature is 2700 ℃, the draft ratio is 6%, and the residence time is 4min, so as to prepare the carbon fiber.
The tensile properties and bulk densities of carbon fibers were tested, wherein the main tensile properties index was an average of 6 effective samples made from multifilament gum dipping and both ends of the samples were bonded using paper sheets as reinforcing sheets prior to the tensile test, as shown in FIG. 1The test data are shown in the following table 1, and the carbon fiber has the tensile strength of 3038MPa, the tensile modulus of 588GPa, the elongation of 0.52% and the bulk density of 1.93g/cm 3 The stress-strain curve at the time of the tensile test is shown in fig. 2.
Table 1 shows the main performance index of the carbon fiber
| Sample numbering | Tensile Strength/MPa | Tensile modulus/GPa | Elongation/% |
| 1 | 3320 | 611 | 0.54 |
| 2 | 2750 | 646 | 0.43 |
| 3 | 2980 | 543 | 0.55 |
| 4 | 3010 | 552 | 0.55 |
| 5 | 3210 | 625 | 0.51 |
| 6 | 2960 | 551 | 0.54 |
| Mean value of | 3038 | 588 | 0.52 |
Comparative example 2
The procedure and parameters of step (1) are the same as those of comparative example 1
(2) The low-temperature carbonized fiber is subjected to high-temperature carbonization treatment in five temperature areas to obtain high-temperature carbonized fiber, wherein the temperature of each temperature area is 1100 ℃, 1300 ℃, 1450 ℃, 1550 ℃ and 1700 ℃, the draft ratio is-3.0%, and the fiber treatment time is 5min;
the structural indexes such as 002 interplanar spacing and the like obtained through microstructure test are shown in table 10;
the procedure and parameters of step (3) were the same as those of comparative example 1.
The carbon fiber was subjected to tensile properties and bulk density tests, wherein the main tensile properties index was an average value of 6 effective samples, and the test data are shown in Table 2 below, and the carbon fiber was tested to obtain a tensile strength 3405MPa, a tensile modulus 618GPa, an elongation of 0.55% and a bulk density of 1.94g/cm 3 。
Table 2 Main Performance index of carbon fiber prepared
| Sample numbering | Tensile Strength/MPa | Tensile modulus/GPa | Elongation/% |
| 1 | 3730 | 633 | 0.59 |
| 2 | 3490 | 664 | 0.52 |
| 3 | 3410 | 596 | 0.57 |
| 4 | 3130 | 593 | 0.53 |
| 5 | 3500 | 601 | 0.58 |
| 6 | 3170 | 621 | 0.51 |
| Mean value of | 3405 | 618 | 0.55 |
Comparative example 3
The procedure and parameters of step (1) are the same as those of comparative example 1
(2) The low-temperature carbonized fiber is subjected to high-temperature carbonization treatment in six temperature areas to obtain high-temperature carbonized fiber, wherein the temperature of each temperature area is 1100 ℃, 1300 ℃, 1450 ℃, 1500 ℃, 1600 ℃, 1700 ℃, the draft ratio is 0.5%, and the fiber treatment time is 5min;
the structural indexes such as 002 interplanar spacing and the like obtained through microstructure test are shown in table 10;
the procedure and parameters of step (3) were the same as those of comparative example 1.
The carbon fiber was subjected to tensile properties and bulk density tests, wherein the main tensile properties index was an average value of 6 effective samples, and the test data are shown in Table 3 below, and the tensile strength 3855MPa, tensile modulus 639GPa, elongation 0.60% and bulk density 1.95g/cm of the carbon fiber were obtained by the tests 3 。
Table 3 Main Performance index of the carbon fiber prepared
| Sample numbering | Tensile Strength/MPa | Tensile modulus/GPa | Elongation/% |
| 1 | 3550 | 666 | 0.53 |
| 2 | 3910 | 605 | 0.65 |
| 3 | 4090 | 660 | 0.62 |
| 4 | 3890 | 643 | 0.60 |
| 5 | 3610 | 620 | 0.58 |
| 6 | 4080 | 639 | 0.64 |
| Mean value of | 3855 | 639 | 0.60 |
Comparative example 4
The procedure and parameters of step (1) are the same as those of comparative example 1
(2) The low-temperature carbonized fiber is subjected to high-temperature carbonization treatment in six temperature areas to obtain high-temperature carbonized fiber, wherein the temperature of each temperature area is 1100 ℃, 1300 ℃, 1450 ℃, 1500 ℃, 1650 ℃, 1700 ℃, the draft ratio is-8.0%, and the fiber treatment time is 4min;
the structural indexes such as 002 interplanar spacing and the like obtained through microstructure test are shown in table 10;
the procedure and parameters of step (3) were the same as those of comparative example 1.
The carbon fiber was subjected to tensile properties and bulk density tests, wherein the main tensile properties index was an average value of 6 effective samples, and the test data are shown in Table 4 below, and the tensile strength 4132MPa, tensile modulus 610GPa, elongation 0.68% and bulk density 1.94g/cm of the carbon fiber were obtained by the tests 3 。
Table 4 shows the main performance index of the carbon fiber
| Sample numbering | Tensile Strength/MPa | Tensile modulus/GPa | Elongation/% |
| 1 | 3930 | 614 | 0.64 |
| 2 | 4190 | 607 | 0.69 |
| 3 | 4120 | 616 | 0.67 |
| 4 | 4280 | 583 | 0.73 |
| 5 | 4120 | 630 | 0.65 |
| 6 | 4150 | 607 | 0.68 |
| Mean value of | 4132 | 610 | 0.68 |
Example 1
The preparation method of the high-strength ultrahigh-modulus carbon fiber comprises the following steps:
(1) Performing 6-temperature zone pre-oxidation treatment on the 6K polyacrylonitrile fiber by adopting a pre-oxidation furnace to obtain pre-oxidized fiber, wherein the pre-oxidation temperature of the 6-temperature zone is 180 ℃, 205 ℃, 215 ℃, 225 ℃, 230 ℃, 245 ℃ and the total draft ratio of the 6.5 percent, the pre-oxidation time of each temperature zone is 16min, and the total treatment time is 96min; the pre-oxidized fiber is subjected to low-temperature carbonization treatment in five temperature areas to obtain low-temperature carbonized fiber, wherein the temperature areas are respectively 300 ℃, 550 ℃, 650 ℃, 750 ℃, 900 ℃, the draft ratio is 6.0%, and the total residence time of the fiber is 5min;
(2) The low-temperature carbonized fiber is subjected to high-temperature carbonization treatment in six temperature areas to obtain high-temperature carbonized fiber, wherein the temperature of each temperature area is 1050 ℃, 1300 ℃, 1400 ℃, 1450 ℃, 1550 ℃, 1750 ℃, the draft ratio is-4.0%, and the fiber treatment time is 4min;
the XRD spectrum of the fiber after high-temperature carbonization is shown in figure 3, obvious 002 peaks exist near 2θ=25°, the smaller the half-height width is, the higher the graphitization degree is, and the structural performance indexes such as 002 interplanar spacing and the like obtained through microstructure test are shown in table 10;
(3) And further carrying out ultrahigh-temperature graphitization treatment on the high-temperature carbonized fiber by adopting a high-temperature graphitization furnace, wherein the treatment temperature is 2700 ℃, the draft ratio is 6%, and the residence time is 4min, so that the ultrahigh-modulus carbon fiber is prepared.
The carbon fiber was subjected to tensile properties and bulk density tests, wherein the main tensile properties index was an average value of 6 effective samples, and the test data are shown in Table 5 below, and the ultra-high modulus carbon fiber was tested to obtain a tensile strength 4210MPa, a tensile modulus 646GPa, an elongation of 0.66% and a bulk density of 1.96g/cm 3 The stress-strain curve at the time of the tensile test is shown in fig. 4.
Table 5 shows the main performance index of the high-strength and ultra-high-modulus carbon fiber
| Sample numbering | Tensile Strength/MPa | Tensile modulus/GPa | Elongation/% |
| 1 | 4340 | 641 | 0.68 |
| 2 | 4170 | 662 | 0.63 |
| 3 | 4070 | 601 | 0.68 |
| 4 | 4170 | 676 | 0.62 |
| 5 | 4430 | 676 | 0.66 |
| 6 | 4080 | 620 | 0.66 |
| Mean value of | 4210 | 646 | 0.66 |
Example 2
The preparation method of the high-strength high-modulus carbon fiber comprises the following steps:
the procedure and parameters of step (1) were the same as in example 1.
(2) The low-temperature carbonized fiber is subjected to high-temperature carbonization treatment in six temperature areas to obtain high-temperature carbonized fiber, wherein the temperature of each temperature area is 1100 ℃, 1300 ℃, 1400 ℃, 1450 ℃, 1600 ℃, 1780 ℃, the draft ratio is-5.5%, and the fiber treatment time is 5min;
the structural indexes such as 002 interplanar spacing and the like obtained through microstructure test are shown in table 10;
the procedure and parameters of step (3) were the same as in example 1.
The carbon fiber was subjected to tensile properties and bulk density tests, wherein the main tensile properties index was an average value of 6 effective samples, and the test data are shown in Table 6 below, and the ultra-high modulus carbon fiber was tested to obtain a tensile strength of 4277MPa, a tensile modulus of 655GPa, an elongation of 0.66% and a bulk density of 1.97g/cm 3 。
Table 6 shows the main performance index of the high-strength and ultra-high-modulus carbon fiber
| Sample numbering | Tensile Strength/MPa | Tensile modulus/GPa | Elongation/% |
| 1 | 4250 | 666 | 0.64 |
| 2 | 4420 | 672 | 0.66 |
| 3 | 4650 | 677 | 0.69 |
| 4 | 4170 | 619 | 0.67 |
| 5 | 4020 | 675 | 0.60 |
| 6 | 4150 | 623 | 0.67 |
| Mean value of | 4277 | 655 | 0.66 |
Example 3
The preparation method of the high-strength high-modulus carbon fiber comprises the following steps:
the procedure and parameters of step (1) were the same as in example 1.
(2) The low-temperature carbonized fiber is subjected to high-temperature carbonization treatment in six temperature areas to obtain high-temperature carbonized fiber, wherein the temperature of each temperature area is 1100 ℃, 1300 ℃, 1450 ℃, 1500 ℃, 1600 ℃, 1700 ℃, the draft ratio is-3.0%, and the fiber treatment time is 5min;
the structural indexes such as 002 interplanar spacing and the like obtained through microstructure test are shown in table 10;
the procedure and parameters of step (3) were the same as in example 1.
The carbon fiber was subjected to tensile properties and bulk density tests, wherein the main tensile properties index was an average value of 6 effective samples, and the test data are shown in Table 7 below, and the ultra-high modulus carbon fiber was tested to obtain a tensile strength 4138MPa, a tensile modulus 640GPa, an elongation of 0.65% and a bulk density of 1.96g/cm 3 。
Table 7 shows the main performance index of the high-strength and ultra-high-modulus carbon fiber
| Sample numbering | Tensile Strength/MPa | Tensile modulus/GPa | Elongation/% |
| 1 | 4030 | 606 | 0.67 |
| 2 | 4010 | 631 | 0.63 |
| 3 | 4460 | 683 | 0.65 |
| 4 | 4180 | 672 | 0.62 |
| 5 | 3870 | 618 | 0.63 |
| 6 | 4280 | 630 | 0.68 |
| Mean value of | 4138 | 640 | 0.65 |
Example 4
The preparation method of the high-strength high-modulus carbon fiber comprises the following steps:
the procedure and parameters of step (1) were the same as in example 1.
(2) The low-temperature carbonized fiber is subjected to high-temperature carbonization treatment in six temperature areas to obtain high-temperature carbonized fiber, wherein the temperature of each temperature area is 1100 ℃, 1300 ℃, 1450 ℃, 1550 ℃, 1650 ℃, 1750 ℃, the draft ratio is-3.0%, and the fiber treatment time is 6min;
the structural indexes such as 002 interplanar spacing and the like obtained through microstructure test are shown in table 10;
the procedure and parameters of step (3) were the same as in example 1.
The carbon fiber was subjected to tensile properties and bulk density tests, wherein the main tensile properties index was an average value of 6 effective samples, and the test data are shown in Table 8 below, and the ultra-high modulus carbon fiber was tested to obtain a tensile strength 4145MPa, a tensile modulus 644GPa, an elongation of 0.66% and a bulk density of 1.96g/cm 3 。
Table 8 shows the main performance index of the high-strength and ultra-high-modulus carbon fiber
| Sample numbering | Tensile Strength/MPa | Tensile modulus/GPa | Elongation/% |
| 1 | 4420 | 627 | 0.70 |
| 2 | 3990 | 659 | 0.63 |
| 3 | 3990 | 664 | 0.63 |
| 4 | 4380 | 624 | 0.69 |
| 5 | 3910 | 662 | 0.62 |
| 6 | 4180 | 630 | 0.66 |
| Mean value of | 4145 | 644 | 0.66 |
Example 5
The preparation method of the high-strength high-modulus carbon fiber comprises the following steps:
the procedure and parameters of step (1) were the same as in example 1.
(2) The low-temperature carbonized fiber is subjected to high-temperature carbonization treatment in six temperature areas to obtain high-temperature carbonized fiber, wherein the temperature of each temperature area is 1100 ℃, 1300 ℃, 1450 ℃, 1500 ℃, 1600 ℃, 1750 ℃, the draft ratio is-1.5%, and the fiber treatment time is 5min;
the structural indexes such as 002 interplanar spacing and the like obtained through microstructure test are shown in table 10;
the procedure and parameters of step (3) were the same as in example 1.
The carbon fiber was subjected to tensile properties and bulk density tests, wherein the main tensile properties index was an average value of 6 effective samples, and the test data are shown in Table 9 below, and the ultra-high modulus carbon fiber was tested to obtain tensile strength 4012MPa, tensile modulus 641GPa, elongation of 0.63% and bulk density of 1.96g/cm 3 。
Table 9 shows the main performance index of the high-strength and ultra-high-modulus carbon fiber
| Sample numbering | Tensile Strength/MPa | Tensile modulus/GPa | Elongation/% |
| 1 | 3990 | 606 | 0.66 |
| 2 | 3860 | 655 | 0.59 |
| 3 | 3970 | 624 | 0.64 |
| 4 | 3840 | 609 | 0.63 |
| 5 | 4200 | 724 | 0.58 |
| 6 | 4210 | 630 | 0.67 |
| Mean value of | 4012 | 641 | 0.63 |
Table 10 comparative and example structural parameters of high temperature carbonized fiber and main performance index of graphitized fiber
The comparative examples 1 and 2 show that the fiber structure transformation at the high-temperature carbonization stage can be regulated and controlled to a certain extent by optimizing the number of temperature intervals, the temperature interval in the comparative example 1 is less, the temperature domain distribution range is uneven, the high-temperature carbonization termination temperature is lower, the formation of the three-dimensional graphite microcrystalline structure in the fiber is insufficient, the crystal face spacing of the high-temperature carbonized fiber is higher, and the carbon content and the bulk density are lower.
In the comparative example 2, after the two-dimensional disordered layer graphite structure in the fiber is converted into the three-dimensional graphite microcrystalline structure by increasing the temperature zone and the high-temperature carbonization termination temperature to 1700 ℃, the increase of the termination temperature is beneficial to the growth of the graphite microcrystalline structure, so that the improvement of the subsequent fiber performance is beneficial, and the tensile strength and the tensile modulus of the fiber after graphitization treatment are improved compared with those in the comparative example 1, so that the reasonable arrangement of the temperature zone has obvious influence on the mechanical performance of the fiber after final graphitization; however, the temperature distribution in each temperature region is wider, and the regulation and control of the refined structure in the fiber are insufficient, so that the density of the fiber body is lower and the densification degree is lower after high-temperature carbonization, and the tensile modulus of the final fiber is higher than 600GPa but the tensile strength is lower.
In comparative example 3, the temperature zone in the high-temperature carbonization stage was reasonably designed and distributed, but since the draft ratio was 0.5% positive draft, the stacked structure inside the fiber in the high-temperature carbonization stage was closely arranged under tension to result in higher bulk density, and too high draft tension easily caused fiber breakage and generation of hairline, resulting in a decrease in the tensile strength of the final fiber.
In comparative example 4, the draw ratio was only-8.0%, and the tensile modulus of the fiber after the subsequent graphitization treatment was low due to the low draw tension, which resulted in shrinkage of the fiber and a decrease in bulk density due to the escape of non-carbon elements during the high temperature carbonization stage, which resulted in poor orientation during the fiber formation.
As can be seen from the observations of examples 1-5, the optimal regulation and control of the internal structure of the fiber in the high-temperature carbonization stage are realized under the cooperation of the parameters by the coupling design of key parameters such as the number of temperature intervals, the drafting tension, the processing time and the like in the high-temperature carbonization stage, and the fiber with the tensile strength of 4000MPa or more, the tensile modulus of 640GPa or more and the bulk density of 1.95g/cm or more is prepared by subsequent graphitization based on the optimized regulation and control 3 High strength ultra-high modulus carbon fibers of (a).
The above embodiments are merely preferred embodiments of the present invention, and are not intended to limit the present invention. Any simple modification, variation and equivalent variation of the above embodiments according to the technical substance of the invention still fall within the scope of the technical solution of the invention.
Claims (10)
1. The preparation method of the high-strength ultrahigh-modulus polyacrylonitrile-based carbon fiber is characterized by comprising the following steps of:
step 1, pre-oxidizing polyacrylonitrile fibers and carbonizing the polyacrylonitrile fibers at a low temperature to obtain low-temperature carbonized fibers;
step 2, carrying out gradient heating high-temperature carbonization treatment on the low-temperature carbonized fiber in a six-temperature zone, wherein the temperature of the six-temperature zone is 1000-1200 ℃, 1250-1350 ℃, 1300-1500 ℃, 1400-1550 ℃, 1500-1650 ℃, 1600-1800 ℃ and the total drawing multiplying power of the fiber is-7.0% -1.0% and the total treatment time is 4-12 min in the high-temperature carbonization treatment process, so as to obtain the high-temperature carbonized fiber;
and step 3, carrying out ultrahigh-temperature graphitization treatment on the high-temperature carbonized fiber to obtain the high-strength ultrahigh-modulus polyacrylonitrile-based carbon fiber.
2. The method for preparing the high-strength ultrahigh-modulus polyacrylonitrile-based carbon fiber according to claim 1, wherein the high-temperature carbon fiber 002 interplanar spacing d obtained in the step 2 002 Is 0.3485 nm-0.3585 nm, the content of carbon element is 92-97%, and the bulk density is 1.75g/cm 3 ～1.79g/cm 3 。
3. The method for preparing the high-strength ultrahigh-modulus polyacrylonitrile-based carbon fiber according to claim 1, wherein the polyacrylonitrile fiber in the step 1 is prepared by adopting a wet method, a dry method or a dry-spray wet method, and the specification of fiber tows is 1K-50K.
4. The method for preparing the polyacrylonitrile-based carbon fiber with high strength and ultrahigh modulus according to claim 1, wherein the pre-oxidation in the step 1 is carried out in an air atmosphere by adopting gradient heating heat treatment in four to six temperature areas, the pre-oxidation temperature ranges from 150 ℃ to 280 ℃, the total draft ratio of the fiber ranges from 3.0% to 8.0%, and the total treatment time ranges from 50 minutes to 120 minutes.
5. The method for preparing the polyacrylonitrile-based carbon fiber with high strength and ultrahigh modulus according to claim 1, wherein the low-temperature carbonization in the step 1 is carried out in high-purity nitrogen by adopting four-seven temperature zone gradient heating heat treatment, the low-temperature carbonization temperature ranges from 300 ℃ to 1000 ℃, the total drawing multiplying power of the fiber ranges from 2.0% to 10.0%, and the total treatment time ranges from 3min to 12min.
6. The method for preparing the high-strength ultrahigh-modulus polyacrylonitrile-based carbon fiber according to claim 1, wherein the ultrahigh-temperature graphitization in the step 3 adopts single-temperature zone heat treatment, the treatment temperature is 2300-3000 ℃, the draft ratio is 2.0-10.0%, and the treatment time is 2-10 min.
7. The method for preparing the high-strength ultrahigh-modulus polyacrylonitrile-based carbon fiber according to claim 1, wherein the high-temperature carbonization treatment process in the step 2 is performed under the protection of high-purity nitrogen.
8. The method for preparing the high-strength ultrahigh-modulus polyacrylonitrile-based carbon fiber according to claim 1, wherein the ultrahigh-temperature graphitization treatment in the step 3 is performed under the protection of high-purity nitrogen and/or argon.
9. The method for preparing the high-strength ultrahigh-modulus polyacrylonitrile-based carbon fiber according to claim 1, wherein in the step 1, low-temperature carbonization is carried out in high-purity nitrogen by adopting five-seven temperature zone gradient heating heat treatment, the low-temperature carbonization temperature range is 350-900 ℃, the total drawing rate of the fiber is 3.0-7.0%, and the total treatment time is 3-8 min.
10. The high-strength ultrahigh-modulus polyacrylonitrile-based carbon fiber produced by the production process according to any one of claims 1 to 9, wherein the tensile strength is not less than 4000MPa, the tensile modulus is not less than 640GPa, and the bulk density is not less than 1.95g/cm 3 。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310880791.0A CN116876115B (en) | 2023-07-18 | 2023-07-18 | A high-strength, ultra-high-modulus polyacrylonitrile-based carbon fiber and its preparation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310880791.0A CN116876115B (en) | 2023-07-18 | 2023-07-18 | A high-strength, ultra-high-modulus polyacrylonitrile-based carbon fiber and its preparation method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN116876115A true CN116876115A (en) | 2023-10-13 |
| CN116876115B CN116876115B (en) | 2026-01-09 |
Family
ID=88271076
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310880791.0A Active CN116876115B (en) | 2023-07-18 | 2023-07-18 | A high-strength, ultra-high-modulus polyacrylonitrile-based carbon fiber and its preparation method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116876115B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN119150662A (en) * | 2024-08-14 | 2024-12-17 | 中国科学院山西煤炭化学研究所 | Intelligent development method for preparation process of polyacrylonitrile-based carbon fiber |
| WO2025112886A1 (en) * | 2023-11-30 | 2025-06-05 | 中国石油化工股份有限公司 | Polyacrylonitrile pre-oxidized fiber, preparation method therefor and use thereof |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005179794A (en) * | 2003-12-16 | 2005-07-07 | Toho Tenax Co Ltd | Method for producing carbon fiber |
| JP2010229578A (en) * | 2009-03-26 | 2010-10-14 | Toray Ind Inc | Polyacrylonitrile-based continuous carbon fiber bundle, and method for producing the same |
| US20110158895A1 (en) * | 2009-12-30 | 2011-06-30 | Industrial Technology Research Institute | High module carbon fiber and method for fabricating the same |
| US20150094401A1 (en) * | 2012-04-18 | 2015-04-02 | Mitsubishi Rayon Co., Ltd. | Carbon Fiber Bundle and Method of Producing Carbon Fibers |
| CN108193324A (en) * | 2017-12-26 | 2018-06-22 | 宜兴市天宇世纪高新科技有限公司 | A kind of production technology of polyacrylonitrile-based carbon fibre |
| CN111621878A (en) * | 2020-03-13 | 2020-09-04 | 北京化工大学 | Large-diameter high-strength medium-mode and high-strength high-mode carbon fiber with surface groove structure and preparation method thereof |
| CN113373554A (en) * | 2021-06-09 | 2021-09-10 | 山西钢科碳材料有限公司 | Low-ash polyacrylonitrile-based fiber, polyacrylonitrile-based carbon fiber and preparation method thereof |
-
2023
- 2023-07-18 CN CN202310880791.0A patent/CN116876115B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005179794A (en) * | 2003-12-16 | 2005-07-07 | Toho Tenax Co Ltd | Method for producing carbon fiber |
| JP2010229578A (en) * | 2009-03-26 | 2010-10-14 | Toray Ind Inc | Polyacrylonitrile-based continuous carbon fiber bundle, and method for producing the same |
| US20110158895A1 (en) * | 2009-12-30 | 2011-06-30 | Industrial Technology Research Institute | High module carbon fiber and method for fabricating the same |
| US20150094401A1 (en) * | 2012-04-18 | 2015-04-02 | Mitsubishi Rayon Co., Ltd. | Carbon Fiber Bundle and Method of Producing Carbon Fibers |
| CN108193324A (en) * | 2017-12-26 | 2018-06-22 | 宜兴市天宇世纪高新科技有限公司 | A kind of production technology of polyacrylonitrile-based carbon fibre |
| CN111621878A (en) * | 2020-03-13 | 2020-09-04 | 北京化工大学 | Large-diameter high-strength medium-mode and high-strength high-mode carbon fiber with surface groove structure and preparation method thereof |
| CN113373554A (en) * | 2021-06-09 | 2021-09-10 | 山西钢科碳材料有限公司 | Low-ash polyacrylonitrile-based fiber, polyacrylonitrile-based carbon fiber and preparation method thereof |
Non-Patent Citations (2)
| Title |
|---|
| 张国良等: "高温碳化工艺与聚丙烯腈基碳纤维力学性能的关联性", 《合成纤维》, vol. 46, no. 11, 30 November 2017 (2017-11-30), pages 13 - 15 * |
| 王文胜等: "高温碳化温度对碳纤维性能的影响", 《化工科技》, vol. 22, no. 06, 31 December 2014 (2014-12-31), pages 12 - 13 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2025112886A1 (en) * | 2023-11-30 | 2025-06-05 | 中国石油化工股份有限公司 | Polyacrylonitrile pre-oxidized fiber, preparation method therefor and use thereof |
| CN119150662A (en) * | 2024-08-14 | 2024-12-17 | 中国科学院山西煤炭化学研究所 | Intelligent development method for preparation process of polyacrylonitrile-based carbon fiber |
Also Published As
| Publication number | Publication date |
|---|---|
| CN116876115B (en) | 2026-01-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN116876115B (en) | A high-strength, ultra-high-modulus polyacrylonitrile-based carbon fiber and its preparation method | |
| Chand | Review carbon fibers for composites | |
| CN102051711B (en) | Process for producing polyacrylonitrile based carbon fibers | |
| US8703091B2 (en) | High modulus graphite fiber and manufacturing method thereof | |
| CN103541042B (en) | High modulus graphite fiber and its manufacturing method | |
| CN101910480A (en) | Flame-resistant fiber and method for producing carbon fiber | |
| Liu et al. | Microwave treatment of pre-oxidized fibers for improving their structure and mechanical properties | |
| CN110067044A (en) | A kind of PAN based graphite fiber and preparation method thereof | |
| Li et al. | The positive role of mesophase-pitch-based carbon fibers in enhancing thermal response behavior in Carbon/Carbon composites | |
| CN103184590A (en) | Preparation method of carbon fiber with strength of 4,800-5,000MPa | |
| Luo et al. | Thermal expansion behaviors of unidirectional carbon/carbon composites from 800 to 2500° C | |
| CN109023592B (en) | A kind of carbon fiber with high tensile strength and high tensile modulus and preparation method thereof | |
| TW201122165A (en) | High module carbon fiber and fabricating method thereof | |
| CN108286090A (en) | A kind of preparation method of polyacrylonitrile-radical high-strength high-modules carbon fibre | |
| Li et al. | Preparation, microstructure and properties of three-dimensional carbon/carbon composites withhigh thermal conductivity | |
| Song et al. | Graphene-modified C/C composites for enhanced directional thermal conductivity | |
| CN101787589B (en) | Preparation method of graphene film strip with linear section | |
| CN211522400U (en) | Microwave heating carbon fiber precursor annealing-pre-oxidation treatment equipment | |
| CN108203848A (en) | A kind of hot high modulus pitch-based carbon fiber of high-strength highly-conductive and preparation method thereof | |
| CN108642605B (en) | High-strength high-modulus carbon fiber and preparation method thereof | |
| JPH08156110A (en) | Manufacture of carbon fiber reinforced carbon composite material | |
| CN111892417A (en) | A kind of carbon fiber composite material and preparation method thereof | |
| CN113249826B (en) | Graphitized carbon fiber with high carbon element content and preparation method thereof | |
| CN111621879B (en) | Polybenzazole graphite fiber and preparation method thereof | |
| CN114197111A (en) | Preparation method of universal asphalt-based carbon fiber non-woven felt |
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 |