CN110331470B - Ribbon polyacrylonitrile carbon fiber and preparation method thereof - Google Patents
Ribbon polyacrylonitrile carbon fiber and preparation method thereof Download PDFInfo
- Publication number
- CN110331470B CN110331470B CN201910731644.0A CN201910731644A CN110331470B CN 110331470 B CN110331470 B CN 110331470B CN 201910731644 A CN201910731644 A CN 201910731644A CN 110331470 B CN110331470 B CN 110331470B
- Authority
- CN
- China
- Prior art keywords
- carbon fiber
- polyacrylonitrile
- ribbon
- fiber
- micrometers
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
- C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
- C08F220/42—Nitriles
- C08F220/44—Acrylonitrile
- C08F220/46—Acrylonitrile with carboxylic acids, sulfonic acids or salts thereof
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
- D01D5/00—Formation of filaments, threads, or the like
- D01D5/12—Stretch-spinning methods
-
- 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)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Textile Engineering (AREA)
- General Chemical & Material Sciences (AREA)
- Mechanical Engineering (AREA)
- Health & Medical Sciences (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Inorganic Fibers (AREA)
- Artificial Filaments (AREA)
Abstract
The invention discloses a ribbon polyacrylonitrile carbon fiber and a preparation method thereof, wherein the preparation method comprises the following steps: (1) copolymerizing an acrylonitrile monomer, itaconic acid and methyl acrylate with a solvent to obtain a polymer spinning solution; (2) spinning the polymer spinning solution by a spinneret plate with spinneret orifices, solidifying and drafting the polymer spinning solution by a coagulating bath to form ribbon polyacrylonitrile nascent fiber, and preparing ribbon polyacrylonitrile protofilament after primary drafting, washing, oiling, drying, densifying, secondary drafting and heat setting the ribbon polyacrylonitrile nascent fiber; (3) and pre-oxidizing, carbonizing at low temperature and carbonizing at high temperature to obtain the banded polyacrylonitrile carbon fiber. Compared with the traditional carbon fiber with a circular section, the long axis of the strip-shaped polyacrylonitrile carbon fiber obtained by the method can reach 22.3-24.2 micrometers, the short axis of the strip-shaped polyacrylonitrile carbon fiber can reach 5.1-5.4 micrometers, the titer can reach 0.154-0.174 tex, the tensile strength of a monofilament is not lower than 5.4GPa, and the tensile modulus can reach 294 GPa.
Description
Technical Field
The invention belongs to the technical field of carbon materials, and particularly relates to a ribbon polyacrylonitrile carbon fiber and a preparation method thereof.
Background
The high-performance polyacrylonitrile carbon fiber has excellent performances of high specific strength, high specific modulus, high temperature resistance and the like, is used as a reinforcement of a composite material, and is widely applied to the fields of military affairs, aviation, aerospace, civil industry, sports and leisure and the like.
The polyacrylonitrile carbon fiber is obtained by preoxidation and carbonization of polyacrylonitrile precursor, and the preoxidation process is converted into a heat-resistant trapezoidal structure through cyclization, dehydrogenation and oxidation reactions, and can withstand the high-temperature carbonization process. The oxidation reaction in the pre-oxidation process can accelerate the cyclization and dehydrogenation reactions, and meanwhile, the oxidative crosslinking forms a crosslinking network structure with more excellent stability. The oxidation reaction involves oxygen molecules diffusing in the radial direction of the fiber, the diameter of the PAN precursor with the circular cross section is too large, the diffusion path of oxygen is enlarged, and the difference of a skin-core structure is easily formed during pre-oxidation, so that the performance of the carbon fiber is influenced. The existing research shows that when the diameter of the precursor is less than 11 microns, a homogeneous pre-oxidation structure can be formed, and the tensile strength of the carbon fiber can reach 5.4 GPa; when the filament diameter is larger than 11 μm, it is difficult to eliminate the pre-oxidized sheath-core structure. Therefore, the diameter of the carbon fiber product provided by home and abroad carbon fiber enterprises at present is only 7 microns at most, and the tensile strength of the carbon fiber with the diameter can only reach 4.9GPa at most. However, the demand for large-sized carbon fibers is increasing, and it is difficult to obtain large-sized carbon fibers having excellent properties by using the conventional techniques.
Disclosure of Invention
The invention aims to solve the technical problem of providing a ribbon polyacrylonitrile carbon fiber and a preparation method thereof, the method comprises the steps of adopting a spinneret plate with a ribbon spinneret orifice to carry out spinning, then carrying out coagulation and drafting forming through a coagulating bath to obtain a ribbon polyacrylonitrile nascent fiber, carrying out primary drafting, water washing, oiling, drying, densification, secondary drafting and heat setting to obtain a ribbon polyacrylonitrile precursor, and in the process of pre-oxidation, because of the existence of a precursor short shaft, an oxygen diffusion path is short, oxygen elements can be easily diffused into the precursor through the precursor short shaft to obtain a homogeneous pre-oxidation structure, and finally carrying out carbonization to obtain the high-performance carbon fiber.
In one aspect of the invention, a method of making a ribbon-shaped polyacrylonitrile carbon fiber is provided. According to an embodiment of the invention, the method comprises: (1) copolymerizing an acrylonitrile monomer, itaconic acid and methyl acrylate with a solvent to obtain a polymer spinning solution; (2) spinning the polymer spinning solution by a spinneret plate with spinneret orifices, solidifying and drafting the polymer spinning solution by a coagulating bath to form ribbon polyacrylonitrile nascent fiber, and preparing ribbon polyacrylonitrile protofilament after primary drafting, washing, oiling, drying, densifying, secondary drafting and heat setting the ribbon polyacrylonitrile nascent fiber; (3) and pre-oxidizing, carbonizing at low temperature and carbonizing at high temperature to obtain the banded polyacrylonitrile carbon fiber.
Preferably, in the step (2), the spinneret plate is provided with a plurality of strip-shaped spinneret holes, the long axis of each spinneret hole is 0.40-0.45 mm, and the short axis of each spinneret hole is 0.050-0.055 mm.
Preferably, in the step (2), the temperature of the polymer spinning solution is 50-70 ℃, and the spinning speed is 2.25-3.75 m/min.
Optionally, the coagulation is carried out in a three-stage coagulation bath, the primary coagulation drafting speed is 1.8-3 m/min, and the primary coagulation bath temperature is 35-55 ℃.
Preferably, in the step (2), the long axis of the ribbon-shaped polyacrylonitrile nascent fiber is 390 to 440 micrometers, and the short axis of the ribbon-shaped polyacrylonitrile nascent fiber is 49 to 64 micrometers.
Preferably, in the step (2), the primary draft has a draft magnification of 3 to 9 times, preferably 4.5 to 7 times.
Preferably, in the step (2), after the primary drawing, the long axis of the fiber is 55-85 micrometers, and the short axis of the fiber is 15-22 micrometers.
Preferably, in the step (2), the draft magnification of the secondary draft is 2 to 4 times, preferably 2.2 to 2.8 times.
Preferably, in the step (2), after the secondary drawing, the long axis of the fiber is 30 to 33 micrometers, and the short axis of the fiber is 10.6 to 11.4 micrometers.
Preferably, in the step (2), the fineness of the ribbon-shaped polyacrylonitrile precursor is 0.30 to 0.36 tex.
In yet another aspect of the present invention, a ribbon-shaped polyacrylonitrile carbon fiber is provided. According to the embodiment of the invention, the ribbon-shaped polyacrylonitrile carbon fiber is prepared by the method.
Preferably, the long axis of the carbon fiber is 22.3-24.2 micrometers, the short axis is 5.1-5.4 micrometers, the fineness is 0.154-0.174 tex, the monofilament tensile strength is not lower than 5.4GPa, and the tensile modulus is 294 GPa.
The invention adopts a spinneret plate with strip spinneret orifices for spinning, then the spinning is carried out by coagulation bath for solidification and drafting forming to obtain strip polyacrylonitrile nascent fiber, and the strip polyacrylonitrile protofilament is prepared by primary drafting, water washing, oiling, drying, densification, secondary drafting and heat setting, namely, the short axis size of the precursor is kept or slightly reduced, the long axis size of the precursor is increased, and in the pre-oxidation process of the strip-shaped polyacrylonitrile precursor, because of the existence of the short axis of the precursor, the oxygen diffusion path is short, oxygen molecules can be easily diffused into the precursor through the short axis of the precursor, the formation of a skin-core structure is reduced, a homogeneous pre-oxygen structure is obtained, and because the diffusion path of oxygen is shortened, therefore, the time of the pre-oxidation process is reduced, the production efficiency is improved, the production cost is reduced, the high-performance carbon fiber can be prepared after carbonization, and the problem that the cross section size of the traditional PAN fiber is limited is hopefully solved. When the short axis of the carbon fiber is equal to the diameter of the cross section of the round carbon fiber, the strip-shaped carbon fiber has a larger long axis, so that the sectional area is larger (the sectional area of the carbon fiber is increased by 4 times compared with the sectional area of the round carbon fiber), and the preparation efficiency of the carbon fiber and the preparation efficiency of the composite material are greatly improved. Compared with the traditional carbon fiber with a circular section, the long axis of the strip-shaped polyacrylonitrile carbon fiber can reach 22.3-24.2 microns, the short axis of the strip-shaped polyacrylonitrile carbon fiber can reach 5.1-5.4 microns, the titer can reach 0.154-0.174 tex, the tensile strength of a monofilament is not lower than 5.4GPa, and the tensile modulus can reach 294 GPa.
Drawings
FIG. 1 is a schematic flow diagram of a method for making a polyacrylonitrile carbon fiber in ribbon form according to an embodiment of the present invention;
fig. 2 is a bottom view of a spinneret plate employed in the present invention;
FIG. 3 is an enlarged view of the orifices of a spinneret plate used in the present invention;
FIG. 4 is a photograph of a cross section of the polyacrylonitrile precursor in the form of a ribbon obtained in example 1 under an optical microscope;
FIG. 5A is an electron micrograph of a cross section of a polyacrylonitrile carbon fiber in a ribbon form obtained in example 1;
FIG. 5B is an electron micrograph of a cross section of the polyacrylonitrile fiber in band form obtained in example 2;
FIG. 5C is an electron micrograph of the surface of the polyacrylonitrile carbon fiber in ribbon form obtained in example 1;
FIG. 6A is a surface electron microscope photograph of round polyacrylonitrile carbon fiber obtained by comparative example;
FIG. 6B is a cross-sectional electron micrograph of round polyacrylonitrile carbon fiber obtained by the comparative example.
Detailed Description
The present invention will be further described with reference to the following examples and fig. 1-3 thereof, which are illustrative and not limiting, and the scope of the present invention is not limited thereby.
The titer unit tex, is defined herein as the mass (g) of a filament having a length of 1000 m.
In one aspect of the invention, a method of making a ribbon-shaped polyacrylonitrile carbon fiber is provided. According to an embodiment of the invention, with reference to fig. 1, the method comprises:
s1: copolymerizing acrylonitrile monomer, itaconic acid, methyl acrylate and solvent
In the step, acrylonitrile, itaconic acid, methyl acrylate and azodiisobutyronitrile are copolymerized with a solvent dimethyl sulfoxide to obtain a polymer spinning solution. Specifically, in the process, dimethyl sulfoxide (DMSO) is used as a solvent, Azodiisobutyronitrile (AIBN) is used as an initiator to carry out ternary solution copolymerization on acrylonitrile, methyl acrylate and itaconic acid at the temperature of 60-70 ℃, preferably 65 ℃, and the reaction is carried out for 12-36 hours, preferably 24 hours, so as to obtain a polymer spinning solution, wherein the mass ratio of acrylonitrile to methyl acrylate to itaconic acid is (90-99.5): 0-7: 0.5-5. And then removing unreacted monomers in the polymer spinning solution under the conditions of stirring at 60-70 ℃, preferably 65 ℃ and a vacuum degree of more than 0.095MPa, stopping stirring after 7-9 hours, preferably 8 hours, and standing and defoaming under the same vacuum condition of 55-65 ℃, preferably 60 ℃ to obtain the polyacrylonitrile spinning solution.
S2: spinning the polymer spinning solution by a spinneret plate with spinneret orifices, solidifying and drafting by a coagulating bath to form ribbon polyacrylonitrile nascent fiber, and subjecting the ribbon polyacrylonitrile nascent fiber to primary drafting, water washing, oiling, drying and densifying, secondary drafting and heat setting
In the step, the obtained polymer spinning solution is spun by a spinneret plate with spinneret orifices, and then is coagulated and drawn by a coagulating bath to form ribbon-shaped polyacrylonitrile nascent fiber, and the ribbon-shaped polyacrylonitrile nascent fiber is subjected to primary drawing, washing, oiling, drying, densification, secondary drawing and heat setting to obtain ribbon-shaped polyacrylonitrile precursor fiber. The inventor finds that the spinneret plate with the strip-shaped spinneret holes is adopted for spinning, then the spinning is carried out through coagulation and drafting forming of a coagulating bath to obtain strip-shaped polyacrylonitrile nascent fibers, and the strip-shaped polyacrylonitrile protofilaments are obtained through primary drafting, water washing, oiling, drying, densification, secondary drafting and heat setting, namely under the condition that the change of the short axis dimension of the protofilaments is not large, the long axis dimension of the protofilaments is increased.
Specifically, the obtained polymer spinning solution is sequentially subjected to spinning by a spinneret plate with strip-shaped spinneret holes, coagulation drawing by a coagulation bath, primary drawing, water washing, oiling, drying, densification, secondary drawing and heat setting, wherein referring to fig. 2 and 3, the spinneret plate 1 is provided with a plurality of strip-shaped spinneret holes, the long axis L of each spinneret hole is 0.40-0.45 mm, the short axis W of each spinneret hole is 0.050-0.055 mm, the temperature of the polymer spinning solution is 50-70 ℃, the spinning speed is 2.25-3.75 m/min, a three-stage coagulation bath is adopted in the coagulation process, the three-stage coagulation bath is a mixed solution of dimethyl sulfoxide and water, the concentration of a first-stage coagulation bath is 72-77 wt%, preferably 74 wt%, the temperature is 35-55 ℃, the coagulation time is 20-50 seconds, the coagulation drawing speed is 1.8-3 m/min, the concentration of a second-stage coagulation bath is 40-50 wt%, preferably 45 wt%, the temperature is room temperature, the solidification time is 20-50 seconds, the concentration of a three-stage solidification bath is 10-20 wt%, preferably 15 wt%, the temperature is room temperature, the solidification time is 20-50 seconds, and the solidification traction speed in the two-stage solidification and three-stage solidification processes is the same as that in the first-stage solidification process, because a polymer spinning solution has an extrusion swelling effect through a spinneret orifice, the extrusion swelling effect is inhibited through controlling the conditions to form the strip-shaped polyacrylonitrile nascent fiber in the solidification process, and because the strand silk contains a large amount of solvent, the deformation rate of the nascent fiber is maximum, preferably the solidification draft ratio is controlled to be 0.8, the primary draft ratio of the strip-shaped polyacrylonitrile nascent fiber obtained through solidification in boiling water is 3-9 times, preferably 4.5-7 times (relative to the speed of leaving the three-stage solidification bath), the minor axis of the fiber is 15-22 mu m, the major axis is 55-85 mu m, and then water washing is, the washing process adopts gradient temperature rise, washing is carried out in a water bath at the temperature of 50, 60, 65, 70, 75 and 80 ℃ for 10-25 seconds in sequence, the total washing time is controlled to be 60-150 seconds, the washed fiber is oiled to be dried and densified, the drying temperature is 110 ℃ and the drying time is 30-45 seconds, the dried fiber is secondarily drawn in superheated steam or high-temperature steam, the secondary drawing multiplying power is 2.0-4.0 times, preferably 2.2-2.8 times, the minor axis of the secondarily drawn fiber is 10.6-11.4 mu m, the major axis of the secondarily drawn fiber is 30-33 mu m, and then heat setting is carried out to obtain the strip-shaped protofilament polyacrylonitrile, the titer of the strip-shaped polyacrylonitrile protofilament is 0.30-0.36 tex and is 4 times of that of the round-section polyacrylonitrile protofilament, and one strip-shaped protofilament is equivalent to 4 round-section filaments.
It should be noted that other conditions of the spinning process are determined by those skilled in the art according to actual needs, and are not described herein again.
S3: pre-oxidizing, low-temperature carbonizing and high-temperature carbonizing strip-shaped polyacrylonitrile protofilament
In the step, the obtained ribbon-shaped polyacrylonitrile precursor is subjected to preoxidation, low-temperature carbonization and high-temperature carbonization to obtain the ribbon-shaped polyacrylonitrile carbon fiber. Specifically, the strip-shaped polyacrylonitrile precursor is subjected to pre-oxidation treatment for 50-100 minutes in a pre-oxidation furnace with an air atmosphere and at a temperature of 220-270 ℃, and then is subjected to carbonization treatment in a low-carbon furnace with a nitrogen atmosphere at a temperature of 350-800 ℃ and a high-carbon furnace with a nitrogen atmosphere at a temperature of 1100-1600 ℃ in sequence to obtain the strip-shaped polyacrylonitrile carbon fiber. The long axis of the strip-shaped polyacrylonitrile carbon fiber prepared by the method is 22.3-24.2 microns, the short axis is 5.1-5.4 microns, the titer is 0.154-0.174 tex, the tensile strength of a monofilament is not lower than 5.4GPa, and the tensile modulus is 294 GPa.
It should be noted that other conditions of the pre-oxidation and carbonization processes are determined by those skilled in the art according to actual needs, and are not described herein.
In a second aspect of the invention, a ribbon-shaped polyacrylonitrile carbon fiber is provided. According to an embodiment of the present invention, the carbon fiber is prepared by the above method. Specifically, the long axis of the belt-shaped carbon fiber is 22.3-24.2 microns, the short axis of the belt-shaped carbon fiber is 5.1-5.4 microns, the titer of the belt-shaped carbon fiber is 0.154-0.174 tex, the tensile strength of a monofilament is not lower than 5.4GPa, and the tensile modulus of the monofilament is 294GPa, and the preparation efficiency of the carbon fiber and the composite material can be greatly improved as one belt-shaped section carbon fiber is nearly 4 times that of a round section carbon fiber. In addition, the carbon fiber with the belt-shaped section has large specific surface area, so that the bonding force between the fiber and the matrix can be enhanced, and the performance of the composite material is more excellent. And the belt-shaped carbon fiber has good wetting property to liquid, and has better composite property when being used for preparing composite materials. The round monofilament has a small section, a plurality of gaps are formed among fibers of the composite material prepared from the fibers with the same mass fraction, the composite material needs to be filled with resin, the bonding force between the fibers and a matrix is reduced, and the carbon fibers with the belt-shaped section can be used for better filling the composite material.
The invention will now be described with reference to specific examples, which are intended to be illustrative only and not to be limiting in any way.
Example 1
Mixing acrylonitrile, methyl acrylate and itaconic acid with a solvent dimethyl sulfoxide (DMSO), adding an initiator Azobisisobutyronitrile (AIBN), and carrying out acrylonitrile solution copolymerization, wherein the monomer and the comonomer are added into a polymerization kettle according to the proportion of 97.2 percent of the acrylonitrile, 1.6 percent of the methyl acrylate and 1.2 percent of the itaconic acid based on the total mass of the added comonomer, then adding the DMSO solvent, controlling the monomer acrylonitrile to account for 22 percent of the total mass of a polymerization system, reacting for 24 hours at the temperature of 65 ℃, carrying out demonomerization and deaeration on the obtained polymerization solution, storing the polymerization solution at 60 ℃ for wet spinning, passing a polymer spinning solution through a metering pump, a candle filter and a spinneret plate with spinneret holes, wherein the number of the spinneret holes is 22, the pore diameter is 0.05 multiplied by 0.4mm (W multiplied by L), the speed of the spinning solution passing through the spinneret plate is 3.75m/min, and sequentially entering the dimethyl sulfoxide with the mass concentration of 74 percent and the spinneret plate with the, 45% and 15% of a three-stage coagulation bath system consisting of dimethyl sulfoxide and water, wherein the temperature of a first-stage coagulation bath is 45 ℃, the temperature of a second-stage coagulation bath and a third-stage coagulation bath is room temperature, multi-stage fiber forming is carried out, the speed of a strand silk leaving the first-stage coagulation bath, the speed of the strand silk leaving the second-stage coagulation bath and the speed of the third-stage coagulation bath are all 3m/min, the coagulation drafting (defined as the ratio of the speed of the strand silk leaving the coagulation bath to the speed of spinning) is 0.8, a strip-shaped coagulated strand silk is obtained, the strand silk is subjected to multi-stage water washing by boiling water once drafting, the primary drafting multiple is 4.5 times, the water washing adopts gradient temperature rise, the temperature is sequentially 50, 60, 65, 70, 75 and 80 ℃; performing secondary drafting by superheated steam for 2.27 times, and performing heat setting to obtain polyacrylonitrile protofilament (the cross-sectional morphology of which is shown in figure 4), wherein the protofilament is subjected to pre-oxidation treatment in six pre-oxidation furnaces at the temperatures of 220, 230, 240, 250, 260 and 270 ℃ respectively in air atmosphere for 90 minutes; treating in a three-temperature-zone low-temperature carbonization furnace at the temperature of 350, 450 and 800 ℃ respectively in a nitrogen atmosphere; and (3) under the nitrogen atmosphere, treating the carbon fiber in a two-temperature-zone high-temperature carbonization furnace at the temperature of 1100 ℃ and 1600 ℃ respectively to obtain the carbon fiber, wherein the section appearance of the carbon fiber is shown as a figure 5A, and the surface appearance of the carbon fiber is shown as a figure 5C.
Example 2
The polymerization formula of example 1 was charged into a polymerization reactor, and polymerization, demonomerization and defoaming were carried out under the same process conditions to obtain a spinning solution. Spinning, solidifying, primary drawing, washing, oiling, drying and densifying according to the embodiment 1, and performing superheated steam secondary drawing on the dried and densified fibers by 2.41 times to obtain polyacrylonitrile precursor fibers through heat setting. Carrying out pre-oxidation treatment on the protofilament in six pre-oxidation furnaces with the temperatures of 220 ℃, 230 ℃, 240 ℃, 250, 260 and 270 ℃ respectively under the air atmosphere for 80 minutes; treating in a three-temperature-zone low-temperature carbonization furnace at the temperature of 350, 450 and 800 ℃ respectively in a nitrogen atmosphere; and (3) under the nitrogen atmosphere, treating the carbon fiber in a two-temperature-zone high-temperature carbonization furnace at the temperature of 1100 ℃ and 1600 ℃ respectively to obtain the carbon fiber, wherein the section appearance of the carbon fiber is shown in figure 5B.
Example 3
The polymerization formula of example 1 was charged into a polymerization reactor, and polymerization, demonomerization and defoaming were carried out under the same process conditions to obtain a spinning solution. Spinning, solidifying, primary drawing, washing, oiling, drying and densifying according to the embodiment 1, and performing superheated steam secondary drawing on the dried and densified fibers by 2.50 times to obtain polyacrylonitrile precursor fibers through heat setting. Carrying out pre-oxidation treatment on the protofilament in six pre-oxidation furnaces with the temperatures of 220 ℃, 230 ℃, 240 ℃, 250, 260 and 270 ℃ respectively under the air atmosphere for 70 minutes; treating in a three-temperature-zone low-temperature carbonization furnace at the temperature of 350, 450 and 800 ℃ respectively in a nitrogen atmosphere; and (3) under the nitrogen atmosphere, treating the carbon fiber in a two-temperature-zone high-temperature carbonization furnace at the temperature of 1100 ℃ and 1600 ℃ respectively to obtain the carbon fiber.
Example 4
The polymerization formula of example 1 was charged into a polymerization reactor, and polymerization, demonomerization and defoaming were carried out under the same process conditions to obtain a spinning solution. Spinning, solidifying, primary drawing, washing, oiling, drying and densifying according to the embodiment 1, and performing superheated steam secondary drawing on the dried and densified fibers by 2.62 times to obtain polyacrylonitrile precursor fibers through heat setting. Carrying out pre-oxidation treatment on the protofilament in six pre-oxidation furnaces with the temperatures of 220 ℃, 230 ℃, 240 ℃, 250, 260 and 270 ℃ respectively under the air atmosphere for 60 minutes; treating in a three-temperature-zone low-temperature carbonization furnace at the temperature of 350, 450 and 800 ℃ respectively in a nitrogen atmosphere; and (3) under the nitrogen atmosphere, treating the carbon fiber in a two-temperature-zone high-temperature carbonization furnace at the temperature of 1100 ℃ and 1600 ℃ respectively to obtain the carbon fiber.
Comparative example
The acrylonitrile solution copolymerization is carried out by taking Azobisisobutyronitrile (AIBN) as an initiator and dimethyl sulfoxide (DMSO) as a solvent. Adding acrylonitrile monomer and methyl acrylate comonomer and itaconic acid into a polymerization kettle according to the proportion of acrylonitrile with the mass concentration of 97.2 percent, methyl acrylate with the mass concentration of 1.6 percent and itaconic acid with the mass concentration of 1.2 percent, adding DMSO as a solvent, controlling the mass concentration of the acrylonitrile monomer in the polymerization system to be 22 percent, reacting for 24 hours at the temperature of 65 ℃, removing monomers and defoaming the obtained polymerization solution, and putting the polymerization solution into a storage kettle with the temperature of 60 ℃ for wet spinning. The method is characterized in that a spinneret plate with the aperture of 0.05 and the number of 1000 holes is adopted, the spinning speed is 3.75m/min, gradient solidification forming is carried out in three solidification bath tanks with the dimethyl sulfoxide concentration of 74 percent (first condensation), 45 percent (second condensation) and 15 percent (third condensation) respectively in a solidification bath (consisting of dimethyl sulfoxide and water), the speed of leaving the first condensation solidification bath tank is 3m/min, the temperatures of a primary solidification bath tank, a secondary solidification bath tank and a tertiary solidification bath tank are respectively 45 ℃, 25 ℃ and 25 ℃, the primary solidification bath tank, the secondary solidification bath tank and the tertiary solidification bath tank are subjected to boiling water primary drafting by 4.5 times, water washing (water washing temperature is 60 ℃), hot roller oiling and drying (drying temperature is 110 ℃), and the secondary drafting is.
The protofilament is subjected to preoxidation treatment in six preoxidation furnaces with the temperatures of 220 ℃, 230 ℃, 240 ℃, 250, 260 and 270 ℃ respectively under the air atmosphere, the preoxidation time is 60 minutes, the protofilament is treated in a three-temperature-region low-temperature carbonization furnace with the nitrogen atmosphere at the temperatures of 350 ℃, 450 and 800 ℃, the protofilament is treated in a two-temperature-region high-temperature carbonization furnace with the nitrogen atmosphere at the temperatures of 1100 and 1600 ℃, electron micrographs of the surface morphology and the section morphology of the carbon fiber are respectively shown in FIGS. 6A and 6B, and the diameter of the carbon fiber is 5.4 mu m according to the ruler measurement and calculation.
The properties of the polyacrylonitrile filaments and carbon fibers obtained in examples 1 to 4 and comparative example are shown in table 1.
TABLE 1 Polyacrylonitrile precursor and carbon fiber Properties
Claims (13)
1. A method of making a polyacrylonitrile carbon fiber in ribbon form, comprising:
(1) copolymerizing an acrylonitrile monomer, itaconic acid and methyl acrylate with a solvent to obtain a polymer spinning solution;
(2) spinning the polymer spinning solution by a spinneret plate with spinneret orifices, solidifying and drafting the polymer spinning solution by a coagulating bath to form ribbon polyacrylonitrile nascent fiber, and preparing ribbon polyacrylonitrile protofilament after primary drafting, washing, oiling, drying, densifying, secondary drafting and heat setting the ribbon polyacrylonitrile nascent fiber;
(3) pre-oxidizing, carbonizing at low temperature and carbonizing at high temperature to obtain the ribbon-shaped polyacrylonitrile carbon fiber,
wherein the content of the first and second substances,
in the step (2), the spinneret plate is provided with a plurality of strip-shaped spinneret orifices, the long axis of each spinneret orifice is 0.40-0.45 mm, the short axis of each spinneret orifice is 0.050-0.055 mm,
in the step (3), the long axis of the carbon fiber is 22.3-24.2 micrometers, and the short axis is 5.1-5.4 micrometers.
2. The method according to claim 1, wherein in the step (2), the temperature of the polymer spinning solution is 50 to 70 ℃ and the spinning speed is 2.25 to 3.75 m/min.
3. The method according to claim 1, wherein in the step (2), the coagulation is performed in a three-stage coagulation bath, the primary coagulation drawing speed is 1.8-3 m/min, and the primary coagulation bath temperature is 35-55 ℃.
4. The method according to claim 1, wherein in step (2), the long axis of the ribbon-shaped polyacrylonitrile nascent fiber is 390 to 440 micrometers, and the short axis is 49 to 64 micrometers.
5. The method according to claim 1, wherein in the step (2), the draft magnification of the primary draft is 3 to 9 times.
6. The method according to claim 1 or 5, wherein in the step (2), the draft magnification of the primary draft is 4.5 to 7 times.
7. The method according to claim 5, wherein in the step (2), after the primary drawing, the long axis of the fiber is 55-85 micrometers, and the short axis is 15-22 micrometers.
8. The method according to claim 1, wherein in the step (2), the draft magnification of the secondary draft is 2 to 4 times.
9. The method according to claim 1 or 8, wherein in the step (2), the draft magnification of the secondary draft is 2.2 to 2.8 times.
10. The method according to claim 8, wherein in the step (2), after the secondary drawing, the long axis of the fiber is 30 to 33 micrometers, and the short axis is 10.6 to 11.4 micrometers.
11. The method according to claim 1, wherein in the step (2), the fineness of the ribbon-shaped polyacrylonitrile filaments is 0.30-0.36 tex.
12. A ribbon-shaped polyacrylonitrile carbon fiber, wherein the ribbon-shaped polyacrylonitrile carbon fiber is prepared by the method of any one of claims 1 to 11.
13. The carbon fiber according to claim 12, wherein the carbon fiber has a major axis of 22.3 to 24.2 μm, a minor axis of 5.1 to 5.4 μm, a fineness of 0.154 to 0.174tex, a monofilament tensile strength of not less than 5.4GPa, and a tensile modulus of 294 GPa.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910731644.0A CN110331470B (en) | 2019-08-08 | 2019-08-08 | Ribbon polyacrylonitrile carbon fiber and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910731644.0A CN110331470B (en) | 2019-08-08 | 2019-08-08 | Ribbon polyacrylonitrile carbon fiber and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110331470A CN110331470A (en) | 2019-10-15 |
| CN110331470B true CN110331470B (en) | 2020-09-11 |
Family
ID=68149104
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910731644.0A Active CN110331470B (en) | 2019-08-08 | 2019-08-08 | Ribbon polyacrylonitrile carbon fiber and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110331470B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112080816B (en) * | 2020-08-24 | 2021-10-01 | 北京化工大学 | Carbon fiber with cellulose nanocrystal-polyacrylonitrile composite fiber as precursor and preparation method thereof |
| CN115506044B (en) * | 2021-06-23 | 2024-02-27 | 吉林碳谷碳纤维股份有限公司 | Preparation method of 50K carbon fiber precursor, precursor and carbon fiber |
| CN115506050B (en) * | 2021-06-23 | 2024-03-01 | 吉林碳谷碳纤维股份有限公司 | Preparation method of 48k carbon fiber precursor, 48k carbon fiber precursor and 48k carbon fiber |
| CN114045561A (en) * | 2021-12-02 | 2022-02-15 | 山东越神新材料科技有限公司 | Method for preparing special-shaped cross-section precursor for carbon fiber from acrylic fiber |
| CN114836841A (en) * | 2022-05-17 | 2022-08-02 | 中复神鹰碳纤维股份有限公司 | Method for directly preparing low-titer protofilament after dry-jet wet spinning and drying |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1920132A (en) * | 2006-09-05 | 2007-02-28 | 东华大学 | Preparation method of abnormity PAN-base carbon fiber protofilament |
| CN109252251A (en) * | 2018-08-09 | 2019-01-22 | 北京化工大学 | Major diameter wet-dry change polyacrylonitrile-based carbon fibre and preparation method thereof |
| CN109082730A (en) * | 2018-08-09 | 2018-12-25 | 北京化工大学 | Major diameter polyacrylonitrile-based carbon fibre and preparation method thereof |
| CN109537106B (en) * | 2018-11-09 | 2021-05-18 | 中国科学院山西煤炭化学研究所 | Method for preparing precursor fiber, pre-oxidized fiber or carbon fiber of carbon fiber with special-shaped section by high-speed dry jet spinning |
-
2019
- 2019-08-08 CN CN201910731644.0A patent/CN110331470B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN110331470A (en) | 2019-10-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110331470B (en) | Ribbon polyacrylonitrile carbon fiber and preparation method thereof | |
| CN101724922B (en) | Method for preparing high-strength polyacrylonitrile-based precursor for carbon fiber | |
| CN111139554B (en) | High-permeability polyacrylonitrile-based carbon fiber and preparation method thereof | |
| CN102733009B (en) | High strength polyacrylonitrile-base carbon fibers having structured surface grooves, and preparation method thereof | |
| CN109023594B (en) | Polyacrylonitrile carbon fiber with ultrahigh strength and medium-high modulus property and preparation method thereof | |
| CN108823683A (en) | Polyacrylonitrile carbon fiber and preparation method thereof | |
| CN109252251A (en) | Major diameter wet-dry change polyacrylonitrile-based carbon fibre and preparation method thereof | |
| CN104231158B (en) | A kind of preparation method of carbon fiber PAN precursor | |
| CN109082730A (en) | Major diameter polyacrylonitrile-based carbon fibre and preparation method thereof | |
| CN111945251A (en) | Ultrahigh-strength medium-modulus polyacrylonitrile-based carbon fiber and preparation method thereof | |
| CN111304784A (en) | Preparation method of large-diameter high-strength medium-modulus carbon fiber and high-strength high-modulus carbon fiber | |
| CN110565212A (en) | Preparation method of high-performance low-cost polyacrylonitrile-based carbon fiber | |
| CN111218733B (en) | Preparation method of large-diameter high-strength medium-modulus carbon fiber | |
| CN112226851B (en) | Preparation method of polyacrylonitrile-based carbon fiber | |
| CN112760752A (en) | PAN-based carbon fiber and preparation method thereof | |
| CN115584573A (en) | T700-grade wet large-tow carbon fiber and preparation method and application thereof | |
| JP4887219B2 (en) | Method for producing carbon fiber precursor acrylonitrile fiber | |
| CN111621878B (en) | Large-diameter high-strength medium-modulus and high-strength high-modulus carbon fiber with surface groove structure and preparation method thereof | |
| CN111088536B (en) | Oiling method of polyacrylonitrile protofilament | |
| JP2002146681A (en) | Method of producing carbon fiber and precursor thereof and method of applying finishing oil | |
| CN113388921B (en) | Dry-method carbon fiber precursor and preparation method thereof | |
| CN111254521B (en) | Large-diameter high-strength medium-modulus carbon fiber with surface groove structure and preparation method thereof | |
| JPH02264011A (en) | Acrylic fiber for graphite fibers | |
| CN115232246B (en) | Polymer for polyacrylonitrile-based large-tow carbon fiber, preparation method and polyacrylonitrile-based large-tow carbon fiber | |
| CN116024676A (en) | Preparation method of high-strength high-modulus carbon fiber precursor wet spinning |
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 |