CN116770444A - Freeze spinning process for preparing high-strength meta-aramid fiber - Google Patents
Freeze spinning process for preparing high-strength meta-aramid fiber Download PDFInfo
- Publication number
- CN116770444A CN116770444A CN202310744368.8A CN202310744368A CN116770444A CN 116770444 A CN116770444 A CN 116770444A CN 202310744368 A CN202310744368 A CN 202310744368A CN 116770444 A CN116770444 A CN 116770444A
- Authority
- CN
- China
- Prior art keywords
- meta
- aramid fiber
- spinning
- solution
- filaments
- 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
- 238000009987 spinning Methods 0.000 title claims abstract description 70
- 229920006231 aramid fiber Polymers 0.000 title claims abstract description 55
- 239000000835 fiber Substances 0.000 claims abstract description 34
- 230000001112 coagulating effect Effects 0.000 claims abstract description 33
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 22
- 238000007710 freezing Methods 0.000 claims abstract description 21
- 230000008014 freezing Effects 0.000 claims abstract description 21
- FXHOOIRPVKKKFG-UHFFFAOYSA-N N,N-Dimethylacetamide Chemical compound CN(C)C(C)=O FXHOOIRPVKKKFG-UHFFFAOYSA-N 0.000 claims abstract description 20
- 238000004519 manufacturing process Methods 0.000 claims abstract description 14
- WZCQRUWWHSTZEM-UHFFFAOYSA-N 1,3-phenylenediamine Chemical compound NC1=CC=CC(N)=C1 WZCQRUWWHSTZEM-UHFFFAOYSA-N 0.000 claims abstract description 13
- FDQSRULYDNDXQB-UHFFFAOYSA-N benzene-1,3-dicarbonyl chloride Chemical compound ClC(=O)C1=CC=CC(C(Cl)=O)=C1 FDQSRULYDNDXQB-UHFFFAOYSA-N 0.000 claims abstract description 12
- 229940018564 m-phenylenediamine Drugs 0.000 claims abstract description 12
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 12
- 238000004108 freeze drying Methods 0.000 claims abstract description 11
- 239000003960 organic solvent Substances 0.000 claims abstract description 11
- HPNMFZURTQLUMO-UHFFFAOYSA-N diethylamine Chemical compound CCNCC HPNMFZURTQLUMO-UHFFFAOYSA-N 0.000 claims abstract description 10
- 230000007935 neutral effect Effects 0.000 claims abstract description 10
- 238000010438 heat treatment Methods 0.000 claims abstract description 5
- 238000003756 stirring Methods 0.000 claims abstract description 4
- 239000000243 solution Substances 0.000 claims description 55
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 19
- 239000000843 powder Substances 0.000 claims description 16
- 230000015271 coagulation Effects 0.000 claims description 9
- 238000005345 coagulation Methods 0.000 claims description 9
- 238000001914 filtration Methods 0.000 claims description 9
- 238000006116 polymerization reaction Methods 0.000 claims description 8
- 238000001035 drying Methods 0.000 claims description 5
- 239000002904 solvent Substances 0.000 claims description 5
- 239000007788 liquid Substances 0.000 claims description 3
- 239000011259 mixed solution Substances 0.000 claims description 2
- 238000006243 chemical reaction Methods 0.000 abstract description 6
- 238000000578 dry spinning Methods 0.000 abstract description 5
- 229920006253 high performance fiber Polymers 0.000 abstract description 5
- 238000002166 wet spinning Methods 0.000 abstract description 5
- 230000007547 defect Effects 0.000 abstract description 4
- 238000005265 energy consumption Methods 0.000 abstract description 4
- 238000002360 preparation method Methods 0.000 abstract description 4
- 239000012535 impurity Substances 0.000 abstract description 3
- 208000012886 Vertigo Diseases 0.000 description 43
- 238000000034 method Methods 0.000 description 15
- 239000004760 aramid Substances 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 238000007493 shaping process Methods 0.000 description 5
- 239000007864 aqueous solution Substances 0.000 description 4
- 238000011282 treatment Methods 0.000 description 3
- 229920003235 aromatic polyamide Polymers 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000003495 polar organic solvent Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229920000049 Carbon (fiber) Polymers 0.000 description 1
- 239000004952 Polyamide Substances 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 239000012752 auxiliary agent Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- FYXKZNLBZKRYSS-UHFFFAOYSA-N benzene-1,2-dicarbonyl chloride Chemical compound ClC(=O)C1=CC=CC=C1C(Cl)=O FYXKZNLBZKRYSS-UHFFFAOYSA-N 0.000 description 1
- 239000004917 carbon fiber Substances 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- RAYLUPYCGGKXQO-UHFFFAOYSA-N n,n-dimethylacetamide;hydrate Chemical compound O.CN(C)C(C)=O RAYLUPYCGGKXQO-UHFFFAOYSA-N 0.000 description 1
- 229920002647 polyamide Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 229920005594 polymer fiber Polymers 0.000 description 1
- 239000002861 polymer material Substances 0.000 description 1
- -1 polypropylene Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
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
- D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
- D01F6/58—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products
- D01F6/60—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products from polyamides
- D01F6/605—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products from polyamides from aromatic polyamides
-
- 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
- D01D10/00—Physical treatment of artificial filaments or the like during manufacture, i.e. during a continuous production process before the filaments have been collected
- D01D10/06—Washing or drying
-
- 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
- D01D5/04—Dry spinning methods
-
- 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
- D01D5/06—Wet spinning methods
-
- 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
- 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
- D01D5/14—Stretch-spinning methods with flowing liquid or gaseous stretching media, e.g. solution-blowing
Landscapes
- Engineering & Computer Science (AREA)
- Textile Engineering (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Artificial Filaments (AREA)
Abstract
The invention relates to the field of high-performance fiber preparation, in particular to a freeze spinning process for preparing high-strength meta-aramid fiber, which comprises the following steps of: s1, under the protection of nitrogen, m-phenylenediamine is dissolved in N, N-dimethylacetamide under stirring, m-phthaloyl chloride is added in batches, diethylamine is added after the reaction to adjust the pH of the solution to be neutral, and then the solution is filtered to obtain spinning solution; s2, heating the spinning solution, feeding the spinning solution into a spinneret, extruding the spinning solution into filaments at a certain spinning rate, feeding the filaments into an air layer, then feeding the filaments into a first coagulating bath, and feeding the filaments into a second coagulating bath under the action of a tractor to replace the organic solvent to obtain fibers A; s3, freezing the fiber A, and freeze-drying to obtain the meta-aramid fiber. The invention improves the problems of high concentration, high energy consumption and low production efficiency of the spinning solution required by the dry spinning and improves the problems of uneven crystallinity, more impurities or defects and unstable strength of the fiber obtained by the wet spinning.
Description
Technical Field
The invention relates to the field of high-performance fiber preparation, in particular to a freeze spinning process for preparing high-strength meta-aramid fiber.
Background
The meta-aramid fiber is a high-performance fiber, and the production background can be traced to the initial 60 s of the 20 th century, and the Dupont company of the United states first realizes the commercial production of polyamide high-performance fiber aramid fiber. Thereafter, aramid fibers are increasingly accepted by the industry and continue to be increased and improved as yet another important high performance fiber following carbon fibers. Because of the excellent mechanical property, chemical stability, high temperature resistance, flame retardance and the like, the modified polypropylene composite material is widely applied to the industrial fields of military, aerospace, ships, automobiles, electronics, buildings and the like.
The meta-aramid fiber spinning technology is to make meta-aramid fiber with a spinning machine by dissolving meta-aramid polymer material in polar organic solvent with high vapor pressure after a series of chemical treatments. The technology mainly comprises the links of spinning solution preparation, spinning, stretching, shaping, drying and the like.
In the preparation stage of the spinning solution, m-phenylenediamine and phthaloyl chloride react in a polar organic solvent at a certain temperature to generate a high molecular polymer, and then other auxiliary agents are added. The meta-aramid fiber spinning solution with higher molecular weight and better solubility is prepared.
In the spinning stage, meta-aramid fibers are typically dry spun or wet spun, and patents that may be referenced include: CN202110281090.6, CN 202111491249.3, etc. The principle of dry spinning is that the spinning solution of meta-aramid is drawn into fiber through a jet orifice rotating at high speed, and an air layer is formed in the process of flowing through the polymer fiber in the drawing process, so that the fiber is quickly condensed and solidified, and then enters a drawing area for drawing treatment, so that the strength and modulus of the fiber are enhanced. Finally, the fiber is molded by processes such as shaping treatment, cooling and the like. Wet spinning is carried out by extruding spinning liquid into coagulating bath, dissolving spinning liquid in different solutions, displacing solvent, shaping, stretching, shaping, drying, and shaping.
However, the meta-aramid fiber spinning process also has some problems, and dry spinning requires high concentration of spinning solution, high energy consumption and low production efficiency. The fiber obtained by wet spinning has uneven crystallinity, more impurities or defects and unstable strength.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a freeze spinning process for preparing high-strength meta-aramid fiber, improves the spinning process of meta-aramid fiber, overcomes the defects and the shortcomings of the process in the prior art, and has good mechanical properties and good market application prospect.
The invention is realized by the following technical scheme:
a freeze spinning process for preparing high-strength meta-aramid fiber comprises the following steps:
s1, under the protection of nitrogen, m-phenylenediamine powder is dissolved in N, N-dimethylacetamide under stirring, then m-phthaloyl chloride powder is added in batches according to a proportion for polymerization reaction, diethylamine solution is added after the polymerization reaction to adjust the pH value of the solution to be neutral, and then spinning solution is obtained through filtration;
s2, heating the spinning solution, feeding the spinning solution into a spinneret through a metering pump, extruding the spinning solution into filaments by the spinneret, feeding the filaments into an air layer, performing hot stretching in the air layer, then feeding the filaments into a first coagulating bath, and feeding the filaments into a second coagulating bath under the action of a tractor to replace the filaments with an organic solvent to obtain fibers A;
s3, freezing and stretching the fiber A, and then freezing and drying to obtain the meta-aramid fiber.
Preferably, in S1, the molar ratio of m-phenylenediamine to isophthaloyl chloride is 1 (1-1.1).
Preferably, in S1, the mass fraction of the spinning solution is 15-25 wt%.
Preferably, in S1, the polymerization reaction is carried out at a temperature of 25 to 30℃for 30 to 60 minutes.
Preferably, in S2, the temperature of the spinning solution after heating is 70 to 100 ℃.
Preferably, in the S2, the rotation speed of a metering pump is 5-10 r/min, the spinning speed is 5-15 m/min and the air layer height is 10-20 mm in the spinning process.
Preferably, in S2, the solvent is a mixed solution of water and N, N-dimethylacetamide in the first coagulation bath, and the temperature is 5-50 ℃; wherein the volume fraction ratio of water to N, N-dimethylacetamide is (1-9): 1.
preferably, in S2, the heat stretch ratio is 1.1-1.5 and the temperature is 80-100 ℃.
Preferably, in S2, the second coagulation bath is an aqueous solution at a temperature of 0 to 10 ℃.
Preferably, in S3, the freezing stretching ratio is 1.0-1.2, the freezing temperature is-20 to-10 ℃, and the freezing time is 10-min.
Preferably, in S3, the vacuum degree is 15-30 Pa, the temperature is-50 ℃ and the time is 24-48 h in the freeze drying process.
Compared with the prior art, the invention has the following beneficial effects:
according to the freeze spinning process for preparing the high-strength meta-aramid fiber, firstly, spinning can be completed on the premise of low concentration by combining dry spinning and wet spinning. The hot stretching can remove partial moisture on the surface of the filament, and the surface of the filament can be cured and pre-oriented in the air. Then the mixture enters a coagulating bath for solvent exchange, and is further coagulated and molded. The dry-wet method can reduce the concentration of the spinning solution, reduce extrusion pressure and energy consumption, and improve the number of spinning nozzles, thereby improving the problems of high concentration, high energy consumption and low production efficiency of the spinning solution required by dry spinning. And then, the organic solvent in the fiber is completely replaced in the second coagulating bath aqueous solution and then is subjected to freeze-stretching, so that the internal structure of the fiber during stretching can be fixed, the fiber orientation degree is higher, the crystallinity is more uniform, then, the moisture in the fiber is removed through freeze drying, the fiber keeps a better internal structure, has stronger and more uniform mechanical properties, and the problems of uneven crystallinity, more impurities or defects and unstable strength of the obtained fiber due to the deformation of the internal structure caused by the drying process in the wet spinning process are improved. The prepared meta-aramid fiber has good mechanical properties and good market application prospect.
Drawings
FIG. 1 is a flow chart of a freeze-spinning process;
fig. 2 is a stress-strain diagram of various embodiments.
Detailed Description
The invention will now be described in further detail with reference to specific examples, which are intended to illustrate, but not to limit, the invention.
The invention discloses a freeze spinning process for preparing high-strength meta-aramid fiber, which comprises the following steps of:
s1, under the protection of nitrogen, m-phenylenediamine powder is dissolved in N, N-dimethylacetamide under stirring, the m-phthaloyl chloride powder is added into the mixture in a proportion of 1 (1) to 1.1) for polymerization reaction in 3-5 batches, the polymerization reaction is carried out for 30-60min at 25-0 ℃, diethylamine is added to adjust the pH of the solution to be neutral, and the spinning solution with the mass fraction of 15-5 wt% is obtained through filtration.
S2, feeding the spinning solution at 70-100 ℃ into a spinneret through a metering pump with the rotating speed of 5-0 r/min, extruding into filaments at the spinning speed of 5-15 m/min, feeding into an air layer with the height of 10-0 mm, and carrying out hot stretching in the air layer, wherein the hot stretching ratio is 1.1-5, and the temperature is 80-100 ℃. Then the fiber A is obtained by entering a first coagulating bath with the temperature of 5-50 ℃ and a second coagulating bath with the temperature of 0-0 ℃ under the action of a tractor and displacing with an organic solvent.
Wherein the volume fraction ratio of the solution water to the N, N-dimethylacetamide in the first coagulating bath is (1-9): 1. the second coagulation bath is an aqueous solution.
S3, freezing and stretching the fiber A (namely freezing the fiber A in the stretching process), wherein the freezing and stretching ratio is 1.0-1.2, the temperature is minus 20-minus 10 ℃, and the time is 10-20 min in the freezing and stretching process.
And then putting the mixture into a freeze dryer, and freeze-drying the mixture for 24 to 48 hours at the vacuum degree of 15 to 30Pa and the temperature of-50 ℃ to remove water to obtain the meta-aramid fiber.
The invention also discloses meta-aramid fiber prepared by the freeze spinning process for preparing the high-strength meta-aramid fiber.
Example 1
S1, under the protection of nitrogen, m-phenylenediamine powder is dissolved in N, N-dimethylacetamide, stirred and dissolved, m-phthaloyl chloride powder is added in 3 batches according to the molar mass ratio of 1:1, the mixture is reacted for 30min at 25 ℃, diethylamine is added to adjust the pH of the solution to be neutral, and the spinning solution with the mass fraction of 15wt% is obtained through filtration.
S2, feeding the spinning solution at 70 ℃ into a spinneret through a metering pump with the rotating speed of 10r/min, extruding into filaments at the spinning speed of 15m/min, feeding into an air layer with the height of 20mm, and carrying out hot stretching in the air layer, wherein the hot stretching ratio is 1.1, and the temperature is 100 ℃. Then the fiber A is obtained by entering a first coagulating bath with the temperature of 50 ℃ and entering a second coagulating bath with the temperature of 10 ℃ under the action of a tractor and replacing the second coagulating bath with an organic solvent.
Wherein the volume fraction ratio of the solution water to the N, N-dimethylacetamide in the first coagulating bath is 1:1.
s3, carrying out freeze-stretching on the fiber A, wherein the stretching ratio is 1.0, freezing for 10min at the temperature of minus 20 ℃ in the stretching process, then putting into a freeze dryer, and freeze-drying for 24h at the vacuum degree of 30Pa and the temperature of minus 50 ℃ to remove water to obtain the meta-aramid fiber.
The product obtained in this example has the following properties: meta-aramid fiber tensile strength: 3.5GPa, meta-aramid fiber modulus: 28.3GPa.
Example 2
S1, under the protection of nitrogen, m-phenylenediamine powder is dissolved in N, N-dimethylacetamide, stirred and dissolved, isophthaloyl dichloride powder is added in 4 batches according to the mass ratio of 1:1.05, reaction is carried out for 45min at 28 ℃, diethylamine is added to adjust the pH of the solution to be neutral, and the spinning solution with the mass fraction of 20wt% is obtained through filtration.
S2, feeding the spinning solution at 85 ℃ into a spinneret through a metering pump with the rotating speed of 8r/min, extruding into filaments at the spinning speed of 10m/min, feeding the filaments into an air layer with the height of 15mm, and carrying out hot stretching in the air layer, wherein the hot stretching ratio is 1.3, and the temperature is 90 ℃. Then the fiber A is obtained by entering a first coagulating bath with the temperature of 25 ℃ and entering a second coagulating bath with the temperature of 5 ℃ under the action of a tractor and replacing the second coagulating bath with an organic solvent.
Wherein the volume fraction ratio of the solution water to the N, N-dimethylacetamide in the first coagulating bath is 4:1.
and S3, carrying out freeze-stretching on the fiber A, wherein the stretching ratio is 1.1, freezing for 15min at the temperature of minus 15 ℃ in the stretching process, then putting into a freeze dryer, and freeze-drying for 36h at the vacuum degree of 25Pa and the temperature of minus 50 ℃ to remove water to obtain the meta-aramid fiber.
The product obtained in this example has the following properties: meta-aramid fiber tensile strength: 3.8GPa, meta-aramid fiber modulus: 30.3GPa.
Example 3
S1, under the protection of nitrogen, m-phenylenediamine powder is dissolved in N, N-dimethylacetamide, stirred and dissolved, isophthaloyl dichloride powder is added in 5 batches according to the molar mass ratio of 1:1.1, the reaction is carried out for 60min at 30 ℃, diethylamine is added to adjust the pH of the solution to be neutral, and the spinning solution with the mass fraction of 25wt% is obtained through filtration.
S2, feeding the spinning solution at 100 ℃ into a spinneret through a metering pump with the rotating speed of 5r/min, extruding into filaments at the spinning speed of 5m/min, feeding into an air layer with the height of 10mm, and carrying out hot stretching in the air layer, wherein the hot stretching ratio is 1.5, and the temperature is 80 ℃. Then the fiber A is obtained by entering a first coagulating bath with the temperature of 5 ℃ and entering a second coagulating bath with the temperature of 0 ℃ under the action of a tractor and replacing the second coagulating bath with an organic solvent.
Wherein the volume fraction ratio of the solution water to the N, N-dimethylacetamide in the first coagulation bath is 9:1.
and S3, carrying out freeze-stretching on the fiber A, wherein the stretching ratio is 1.2, freezing for 20min at the temperature of minus 10 ℃ in the stretching process, then putting into a freeze dryer, and freeze-drying for 48h at the vacuum degree of 15Pa and the temperature of minus 50 ℃ to remove water to obtain the meta-aramid fiber.
The product obtained in this example has the following properties: meta-aramid fiber tensile strength: 4.1GPa, meta-aramid fiber modulus: 29.8GPa.
Example 4
S1, under the protection of nitrogen, m-phenylenediamine is dissolved in N, N-dimethylacetamide, stirred and dissolved, isophthaloyl dichloride is added in 5 batches according to the molar mass ratio of 1:1.1, the reaction is carried out for 60min at 30 ℃, diethylamine is added to adjust the pH value of the solution to be neutral, and the spinning solution with the mass fraction of 25wt% is obtained through filtration.
S2, feeding the spinning solution at 100 ℃ into a spinneret through a metering pump with the rotating speed of 6r/min, extruding into filaments at the spinning speed of 5m/min, feeding the filaments into an air layer with the height of 12mm, and carrying out hot stretching in the air layer, wherein the hot stretching ratio is 1.5, and the temperature is 80 ℃. Then the fiber A is obtained by entering a first coagulating bath with the temperature of 15 ℃ and entering a second coagulating bath with the temperature of 5 ℃ under the action of a tractor and replacing the second coagulating bath with an organic solvent.
Wherein the volume fraction ratio of the solution water to the N, N-dimethylacetamide in the first coagulation bath is 9:1
And S3, carrying out freeze-stretching on the fiber A, wherein the stretching ratio is 1.2, freezing for 20min at the temperature of minus 10 ℃ in the stretching process, then putting into a freeze dryer, and freeze-drying for 48h at the vacuum degree of 15Pa and the temperature of minus 50 ℃ to remove water to obtain the meta-aramid fiber.
The product obtained in this example has the following properties: meta-aramid fiber tensile strength: 3.9GPa, meta-aramid fiber modulus: 28.5GPa.
Example 5
S1, under the protection of nitrogen, m-phenylenediamine powder is dissolved in N, N-dimethylacetamide, stirred and dissolved, isophthaloyl dichloride powder is added in 5 batches according to the molar mass ratio of 1:1.1, the reaction is carried out for 60min at 30 ℃, diethylamine is added to adjust the pH of the solution to be neutral, and the spinning solution with the mass fraction of 25wt% is obtained through filtration.
S2, feeding the spinning solution at 100 ℃ into a spinneret through a metering pump with the rotating speed of 7r/min, extruding into filaments at the spinning speed of 5m/min, feeding the filaments into an air layer with the height of 14mm, and carrying out hot stretching in the air layer, wherein the hot stretching ratio is 1.5, and the temperature is 80 ℃. Then the fiber A is obtained by entering a first coagulating bath with the temperature of 25 ℃ and entering a second coagulating bath with the temperature of 5 ℃ under the action of a tractor and replacing the second coagulating bath with an organic solvent.
Wherein the volume fraction ratio of the solution water to the N, N-dimethylacetamide in the first coagulation bath is 9:1.
and S3, carrying out freeze-stretching on the fiber A, wherein the stretching ratio is 1.2, freezing for 20min at the temperature of minus 10 ℃ in the stretching process, then putting into a freeze dryer, and freeze-drying for 48h at the vacuum degree of 15Pa and the temperature of minus 50 ℃ to remove water to obtain the meta-aramid fiber.
The product obtained in this example has the following properties: meta-aramid fiber tensile strength: 4.0GPa, meta-aramid fiber modulus: 28.3GPa.
Example 6
S1, under the protection of nitrogen, m-phenylenediamine powder is dissolved in N, N-dimethylacetamide, stirred and dissolved, isophthaloyl dichloride powder is added in 5 batches according to the molar mass ratio of 1:1.1, the reaction is carried out for 60min at 30 ℃, diethylamine is added to adjust the pH of the solution to be neutral, and the spinning solution with the mass fraction of 25wt% is obtained through filtration.
S2, feeding the spinning solution at 100 ℃ into a spinneret through a metering pump with the rotating speed of 9r/min, extruding into filaments at the spinning speed of 5m/min, feeding the filaments into an air layer with the height of 18mm, and carrying out hot stretching in the air layer, wherein the hot stretching ratio is 1.5, and the temperature is 80 ℃. Then the fiber A is obtained by entering a first coagulating bath with the temperature of 45 ℃ and entering a second coagulating bath with the temperature of 5 ℃ under the action of a tractor and replacing the second coagulating bath with an organic solvent.
Wherein the volume fraction ratio of the solution water to the N, N-dimethylacetamide in the first coagulation bath is 9:1. the second coagulation bath is an aqueous solution.
And S3, carrying out freeze-stretching on the fiber A, wherein the stretching ratio is 1.2, freezing for 20min at the temperature of minus 10 ℃ in the stretching process, then putting into a freeze dryer, and freeze-drying for 48h at the vacuum degree of 15Pa and the temperature of minus 50 ℃ to remove water to obtain the meta-aramid fiber.
The product obtained in this example has the following properties: meta-aramid fiber tensile strength: 4.2GPa, meta-aramid fiber modulus: 28.5GPa.
Fig. 2 shows stress-strain curves of meta-aramid fibers prepared in the above examples, and it can be seen that the prepared fibers have tensile strengths of more than 3.5GPa and moduli of more than 28GPa. The meta-aramid fiber prepared in example 6 had a maximum tensile strength of 4.2GPa and the meta-aramid fiber prepared in example 2 had a maximum modulus of 30.3GPa.
The foregoing description of the preferred embodiment of the present invention is not intended to limit the technical solution of the present invention in any way, and it should be understood that the technical solution can be modified and replaced in several ways without departing from the spirit and principle of the present invention, and these modifications and substitutions are also included in the protection scope of the claims.
Claims (10)
1. The freeze spinning process for preparing the high-strength meta-aramid fiber is characterized by comprising the following steps of:
s1, under the protection of nitrogen, m-phenylenediamine powder is dissolved in N, N-dimethylacetamide under stirring, then m-phthaloyl chloride powder is added in batches according to a proportion for polymerization reaction, diethylamine solution is added after the polymerization reaction to adjust the pH value of the solution to be neutral, and then spinning solution is obtained through filtration;
s2, heating the spinning solution, feeding the spinning solution into a spinneret through a metering pump, extruding the spinning solution into filaments by the spinneret, feeding the filaments into an air layer, performing hot stretching in the air layer, then feeding the filaments into a first coagulating bath, and feeding the filaments into a second coagulating bath under the action of a tractor to replace the filaments with an organic solvent to obtain fibers A;
s3, freezing and stretching the fiber A, and then freezing and drying to obtain the meta-aramid fiber.
2. The process for preparing a high-strength meta-aramid fiber as claimed in claim 1, wherein in S1, the molar ratio of meta-phenylenediamine to isophthaloyl dichloride is 1 (1-1.1).
3. The process for preparing a high-strength meta-aramid fiber according to claim 1, wherein the mass fraction of the spinning solution in S1 is 15wt% to 25wt%.
4. The process for preparing a meta-aramid fiber having high strength according to claim 1, wherein the polymerization reaction is performed at a temperature of 25 to 30 ℃ for 30 to 60 minutes in S1.
5. The process for preparing a high-strength meta-aramid fiber according to claim 1, wherein the temperature of the spinning solution after heating is 70 to 100 ℃ in S2.
6. The process for preparing high-strength meta-aramid fiber according to claim 1, wherein in S2, the rotation speed of the metering pump is 5-10 r/min, the spinning rate of the spinneret is 5-15 m/min, and the height of the air layer is 10-20 mm.
7. The process for preparing high-strength meta-aramid fiber according to claim 1, wherein in S2, the solvent in the first coagulation bath is a mixed solution of water and N, N-acetamide at 5 to 50 ℃; wherein the volume fraction ratio of water to N, N-dimethylacetamide is (1-9): 1.
8. the process for preparing a high-strength meta-aramid fiber according to claim 1, wherein in S2, the heat stretching ratio is 1.1 to 1.5 at a temperature of 80 to 100 ℃ at the time of heat stretching; the solvent in the second coagulating bath is water solution at 0-10 deg.c.
9. The process for preparing high-strength meta-aramid fiber according to claim 1, wherein in S3, liquid nitrogen is used for freezing for 10-20S; during the freezing and stretching, the freezing and stretching ratio is 1.0-1.2, the temperature is minus 20-minus 10 ℃ and the time is 10-20 min.
10. The process for preparing a meta-aramid fiber having high strength according to claim 1, wherein in S3, the degree of vacuum is 15 to 30Pa, the temperature is-50 ℃ and the time is 24 to 48 hours during the freeze-drying.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310744368.8A CN116770444A (en) | 2023-06-21 | 2023-06-21 | Freeze spinning process for preparing high-strength meta-aramid fiber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310744368.8A CN116770444A (en) | 2023-06-21 | 2023-06-21 | Freeze spinning process for preparing high-strength meta-aramid fiber |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116770444A true CN116770444A (en) | 2023-09-19 |
Family
ID=88007583
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310744368.8A Pending CN116770444A (en) | 2023-06-21 | 2023-06-21 | Freeze spinning process for preparing high-strength meta-aramid fiber |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116770444A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117844042A (en) * | 2024-03-08 | 2024-04-09 | 泰和新材集团股份有限公司 | Preparation method of meta-aramid aerogel fiber |
-
2023
- 2023-06-21 CN CN202310744368.8A patent/CN116770444A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117844042A (en) * | 2024-03-08 | 2024-04-09 | 泰和新材集团股份有限公司 | Preparation method of meta-aramid aerogel fiber |
| CN117844042B (en) * | 2024-03-08 | 2024-05-14 | 泰和新材集团股份有限公司 | Preparation method of meta-aramid aerogel fiber |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN116770444A (en) | Freeze spinning process for preparing high-strength meta-aramid fiber | |
| CN101195933B (en) | Method for producing Lyocell fibre for tire cord | |
| CN101161880A (en) | Method for preparing polyacrylonitrile-based carbon fiber precursor fiber | |
| Wei et al. | Posttreatment of the dry-spun fibers obtained from regenerated silk fibroin aqueous solution in ethanol aqueous solution | |
| CN1710160A (en) | Method for preparing meta aromatic polyamide fiber | |
| CN109402774B (en) | Anti-fibrillation cellulose fiber and preparation method thereof | |
| CN113463222B (en) | High-orientation-degree alginic acid fiber and preparation method thereof | |
| CN113718364A (en) | Graphene high-strength impact-resistant aramid fiber and preparation method thereof | |
| KR101551418B1 (en) | Process for preparing polyketon fiber | |
| CN113668091B (en) | High-strength high-elongation heterocyclic aromatic polyamide fiber and preparation process thereof | |
| CN107723830A (en) | A kind of preparation method and application of high-tenacity graphene oxide grafting nylon fibre | |
| CN108611705B (en) | Preparation method of polyacrylonitrile-based high-performance carbon fiber | |
| CN102851756A (en) | Polyacrylonitrile fiber stretching method | |
| KR100930204B1 (en) | Aramide fiber and method for manufacturing the same | |
| JPH07189019A (en) | Production of regenerated cellulose formed product | |
| CN102021665A (en) | Preparation method of ultrahigh molecular weight polyamide 6 fiber | |
| KR20110071256A (en) | Process for preparing aromatic polyamide filament | |
| CN114134595B (en) | Preparation method of high-modulus poly (p-phenylene benzobisoxazole) fiber | |
| CN114606602B (en) | Preparation method of 25k carbon fiber and carbon fiber | |
| CN114134597B (en) | Latex-lyocell composite fiber and preparation method thereof | |
| CN117966294B (en) | Fiber and preparation method thereof | |
| CN115434027B (en) | Preparation method of high-strength compact polyacrylonitrile fiber and polyacrylonitrile-based carbon fiber | |
| KR20190037664A (en) | Method of manufacturing para aramid fiber and para aramid fiber manufactured thereby | |
| CN116949586A (en) | Production process for improving meta-aramid fiber breaking strength and heat resistance | |
| CN116876098A (en) | Preparation method of copolymerization modified meta-aramid fiber |
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 |