CN111101225A - Preparation method of polyacrylonitrile nano-fiber - Google Patents
Preparation method of polyacrylonitrile nano-fiber Download PDFInfo
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- CN111101225A CN111101225A CN202010005244.4A CN202010005244A CN111101225A CN 111101225 A CN111101225 A CN 111101225A CN 202010005244 A CN202010005244 A CN 202010005244A CN 111101225 A CN111101225 A CN 111101225A
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- 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
- D01F6/44—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from mixtures of polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds as major constituent with other polymers or low-molecular-weight compounds
- D01F6/54—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from mixtures of polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds as major constituent with other polymers or low-molecular-weight compounds of polymers of unsaturated nitriles
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- 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
- D01F1/00—General methods for the manufacture of artificial filaments or the like
- D01F1/02—Addition of substances to the spinning solution or to the melt
- D01F1/10—Other agents for modifying properties
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- 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
- D01F11/00—Chemical after-treatment of artificial filaments or the like during manufacture
- D01F11/04—Chemical after-treatment of artificial filaments or the like during manufacture of synthetic polymers
- D01F11/06—Chemical after-treatment of artificial filaments or the like during manufacture of synthetic polymers of macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
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Abstract
The invention discloses a preparation method of polyacrylonitrile nano-fiber. The method comprises the following steps: controlling the environmental temperature to be 0-35 ℃ and the humidity to be less than or equal to 20%, and mechanically blending the thermoplastic cellulose material, polyacrylonitrile and ionic liquid to be uniform; controlling the environmental humidity to be less than or equal to 10%, and making strips and granules of the obtained mixture at 160-200 ℃; then spinning by adopting a melt spinning machine, wherein the spinning temperature is 190-210 ℃, the number of holes of a spinneret plate is 30-100, the pump supply is 35-40g/min, and the spinning speed is 400-500m/min, so as to obtain nascent fiber; and ultrasonically dissolving the nascent fiber by using acetone to remove the thermoplastic cellulose material, washing with water, and drying to obtain the polyacrylonitrile nano-fiber with the average diameter of 5-15 nm. The method realizes high-speed spinning of the nano-scale PAN fiber, and is suitable for industrial production.
Description
Technical Field
The invention belongs to the field of preparation of high-performance fiber materials, and particularly relates to a preparation method of polyacrylonitrile nano-fibers.
Background
Polyacrylonitrile (PAN) is characterized by good bulkiness and heat retention, soft hand feeling, good weather resistance, mildew resistance and moth resistance. PAN is typically copolymerized with more than 85% acrylonitrile and other secondary and tertiary monomers to improve the physical and chemical properties of PAN. PAN is mainly used as artificial fiber, commonly called artificial wool; wool, knitted (pure or blended with wool) and woven fabrics, especially suitable for indoor decorative fabrics such as curtains and the like.
With the development of the times, the traditional micron-sized fiber cannot be applied to a plurality of high and new technical fields, and the PAN nano-fiber is used for growing. A large number of researches show that the PAN nanofiber can be widely applied to the fields of membrane materials, sensors, tissue engineering, drug release carriers, filter materials and the like. PAN nanofibers are typically prepared by an electrospinning process, in which a quantity of PAN is dissolved in an organic solvent and the solution is extruded through an injector of an electrospinning apparatus to form fibers. At present, a great amount of literature reports and related patents about electrospinning PAN nanofibers exist, but the core problem of the electrospinning technology is that the yield is too low to perform large-scale production to meet the industrial demand. There are also some documents describing dry-wet spinning method of cellulose and PAN in ionic liquid (cellulose is not thermoplastic polymer material, high speed spinning can not be carried out by using melt spinning machine), or directly mixing ionic liquid and PAN for melt spinning to prepare micron-sized PAN fiber, etc. These methods either produce micron-sized PAN fibers or use low-speed spinning methods, which do not efficiently produce nano-sized PAN fibers.
Disclosure of Invention
The invention aims to provide a preparation method of polyacrylonitrile nano-fiber. The specific technical scheme is as follows:
a preparation method of polyacrylonitrile nano-fiber comprises the following steps:
(1) mixing materials: controlling the environmental temperature to be 0-35 ℃ and the humidity to be less than or equal to 20%, and mechanically blending the thermoplastic cellulose material, Polyacrylonitrile (PAN) and the ionic liquid uniformly to obtain a mixture; the mass ratio of the thermoplastic cellulose material to the polyacrylonitrile is 2.3-19: 1, and the mass ratio of the polyacrylonitrile to the ionic liquid is 1-2: 1;
(2) and (3) granulation: controlling the environmental humidity to be less than or equal to 10%, and preparing strips and cutting the mixture obtained in the step (1) into particles at 160-200 ℃;
(3) melt spinning: spinning the particles obtained in the step (3) by using a melt spinning machine at the spinning temperature of 190-;
(4) cleaning and drying: and (4) putting the nascent fiber obtained in the step (3) into acetone, performing ultrasonic dispersion until the thermoplastic cellulose material is removed, performing ultrasonic oscillation washing with water until the nascent fiber is clean, and drying to obtain the polyacrylonitrile nanofiber.
Preferably, the thermoplastic cellulosic material of step (1) is Cellulose Acetate Butyrate (CAB) and the ionic liquid is 1-butyl-3-methylimidazolium chloride ([ Bmim ] Cl).
Preferably, the viscosity average molecular weight of the polyacrylonitrile obtained in the step (1) is 5 × 104-7×104g/mol。
Preferably, the particle size of the particles in the step (2) is 1-5 mm.
Preferably, the diameter of the polyacrylonitrile nano-fiber in the step (4) is less than or equal to 20 nm.
Preferably, the drying temperature in the step (4) is 20-60 ℃.
The invention has the beneficial effects that:
aiming at the problem that the PAN nanofiber produced by the traditional electrostatic spinning process is low in efficiency, the method adopts a melt spinning process, and effectively improves the production efficiency. The principle is that the plasticizing effect of [ Bmim ] Cl is utilized to weaken the extremely strong dipole effect among PAN molecular chains. During the melt spinning process, the PAN is effectively stretched due to the action of winding and traction force to form the nano-scale fiber. The matrix CAB has the functions of effectively dispersing PAN, destroying the continuous phase of PAN, forming an independent phase and promoting the molding of the nanofiber. The method realizes the high-speed spinning of 400-500m/min, the diameter of the prepared PAN nanofiber reaches 5-15nm, the appearance of the fiber is good, the impurities are few, and the method is suitable for industrial production.
Drawings
Fig. 1 is a microscopic topography of PAN nanofibers prepared by the melt spinning process of example 1.
Detailed Description
For the sake of simplicity, in the following examples, cellulose acetate butyrate is abbreviated as CAB, 1-butyl-3-methylimidazolium chloride is abbreviated as [ Bmim ] Cl, and polyacrylonitrile is abbreviated as PAN.
Example 1
The viscosity average molecular weight of the selected PAN starting material was 5.2X 104g/mol, the matrix of the blend being a thermoplastic CAB and the plasticizer being [ Bmim [ ]]And (4) Cl. Wherein the mass ratio of CAB to PAN solid powder is strictly controlled to be 7:3, and the mass ratio of PAN to [ Bmim ]]The mass ratio of Cl is 6: 4. PAN, CAB and [ Bmim ] are mixed mechanically]Cl was mixed (5-10 minutes) until homogeneous, the temperature of the environment was controlled at 0-35 ℃ and the humidity was not higher than 20%. And (3) preparing the mixture into strips and granules (the particle size of the granules is 3mm), controlling the temperature of the twin-screw to be 180 ℃, and controlling the environmental humidity to be not higher than 10%. The granulated particles were placed in a sealed desiccator.
And (3) carrying out high-speed spinning by adopting a melt spinning machine, wherein the spinning temperature is 200 ℃, the number of holes of a spinneret plate is 64, the pump supply is 40g/min, and the spinning speed is 400m/min to obtain the nascent fiber. Dissolving the obtained nascent fiber by using acetone, performing ultrasonic dispersion for 30 minutes, and removing the matrix CAB; and then washing with deionized water by ultrasonic oscillation for 5-10 minutes, and drying in a drying oven at 40 ℃ to obtain the PAN nanofiber (the diameter distribution of which is 5-15nm as shown in figure 1).
Example 2
The viscosity average molecular weight of the selected PAN starting material was 7X 104g/mol, the matrix of the blend being a thermoplastic CAB and the plasticizer being [ Bmim [ ]]And (4) Cl. Wherein the mass ratio of CAB to PAN solid powder is strictly controlled to be 9.5:0.5, and the mass ratio of PAN to [ Bmim ]]The mass ratio of Cl is 6: 4. PAN, CAB and [ Bmim ] are mixed mechanically]Cl was mixed (5-10 minutes) until homogeneous, the temperature of the environment was controlled at 0-35 ℃ and the humidity was not higher than 20%. And (3) preparing the mixture into strips and granules (the particle size of the granules is 3mm), controlling the temperature of the twin-screw to be 180 ℃, and controlling the environmental humidity to be not higher than 10%. The granulated particles were placed in a sealed desiccator.
And (3) carrying out high-speed spinning by adopting a melt spinning machine, wherein the spinning temperature is 190 ℃, the number of holes of a spinneret plate is 64, the pump supply is 38g/min, and the spinning speed is 450m/min, so as to obtain the nascent fiber. Dissolving the obtained nascent fiber by using acetone, performing ultrasonic dispersion for 30 minutes, and removing the matrix CAB; and then washing the fiber by deionized water ultrasonic oscillation for 5 to 10 minutes, and then drying the fiber in a drying oven at 40 ℃ to obtain the PAN nanofiber (the diameter distribution is 5 to 15 nm).
Example 3
The viscosity average molecular weight of the selected PAN starting material was 6.2X 104g/mol, the matrix of the blend being a thermoplastic CAB and the plasticizer being [ Bmim [ ]]And (4) Cl. Wherein the mass ratio of CAB to PAN solid powder is strictly controlled to be 8:2, and the mass ratio of PAN to [ Bmim ]]The mass ratio of Cl is 6: 4. PAN, CAB and [ Bmim ] are mixed mechanically]Cl was mixed (5-10 minutes) until homogeneous, the temperature of the environment was controlled at 0-35 ℃ and the humidity was not higher than 20%. And (3) preparing the mixture into strips and granules (the particle size of the granules is 3mm), controlling the temperature of the twin-screw to be 180 ℃, and controlling the environmental humidity to be not higher than 10%. The granulated particles were placed in a sealed desiccator.
And (3) carrying out high-speed spinning by adopting a melt spinning machine, wherein the spinning temperature is 190 ℃, the number of holes of a spinneret plate is 64, the pump supply is 40g/min, and the spinning speed is 500m/min to obtain the nascent fiber. Dissolving the obtained nascent fiber by using acetone, performing ultrasonic dispersion for 30 minutes, and removing the matrix CAB; and then washing the fiber by deionized water ultrasonic oscillation for 5 to 10 minutes, and then drying the fiber in a drying oven at 40 ℃ to obtain the PAN nanofiber (the diameter distribution is 5 to 15 nm).
Example 4
The viscosity average molecular weight of the selected PAN starting material was 6.8X 104g/mol, the matrix of the blend being a thermoplastic CAB and the plasticizer being [ Bmim [ ]]And (4) Cl. Wherein the mass ratio of CAB to PAN solid powder is strictly controlled to be 8.5:1.5, and the mass ratio of PAN to [ Bmim ]]The mass ratio of Cl is 6: 4. PAN, CAB and [ Bmim ] are mixed mechanically]Cl was mixed (5-10 minutes) until homogeneous, the temperature of the environment was controlled at 0-35 ℃ and the humidity was not higher than 20%. And (3) preparing the mixture into strips and granules (the particle size of the granules is 3mm), controlling the temperature of the twin-screw to be 180 ℃, and controlling the environmental humidity to be not higher than 10%. The granulated particles were placed in a sealed desiccator.
And (3) carrying out high-speed spinning by adopting a melt spinning machine, wherein the spinning temperature is 190 ℃, the number of holes of a spinneret plate is 64, the pump supply is 40g/min, and the spinning speed is 500m/min to obtain the nascent fiber. Dissolving the obtained nascent fiber by using acetone, performing ultrasonic dispersion for 30 minutes, and removing the matrix CAB; and then washing the fiber by deionized water ultrasonic oscillation for 5 to 10 minutes, and then drying the fiber in a drying oven at 40 ℃ to obtain the PAN nanofiber (the diameter distribution is 5 to 15 nm).
Claims (6)
1. A preparation method of polyacrylonitrile nano-fiber is characterized by comprising the following steps:
(1) mixing materials: controlling the environmental temperature to be 0-35 ℃ and the humidity to be less than or equal to 20%, and mechanically blending the thermoplastic cellulose material, polyacrylonitrile and ionic liquid uniformly to obtain a mixture; the mass ratio of the thermoplastic cellulose material to the polyacrylonitrile is 2.3-19: 1, and the mass ratio of the polyacrylonitrile to the ionic liquid is 1-2: 1;
(2) and (3) granulation: controlling the environmental humidity to be less than or equal to 10%, and preparing strips and cutting the mixture obtained in the step (1) into particles at 160-200 ℃;
(3) melt spinning: spinning the particles obtained in the step (3) by using a melt spinning machine at the spinning temperature of 190-;
(4) cleaning and drying: and (4) putting the nascent fiber obtained in the step (3) into acetone, performing ultrasonic dispersion until the thermoplastic cellulose material is removed, performing ultrasonic oscillation washing with water until the nascent fiber is clean, and drying to obtain the polyacrylonitrile nanofiber.
2. The preparation method of polyacrylonitrile nano-fiber according to claim 1, characterized in that, the thermoplastic cellulose material in step (1) is cellulose acetate butyrate, and the ionic liquid is 1-butyl-3-methylimidazole chloride.
3. The method for preparing polyacrylonitrile nanofibers according to claim 2, wherein the viscosity average molecular weight of polyacrylonitrile in step (1) is 5 x 104-7×104g/mol。
4. The preparation method of the polyacrylonitrile nano-fiber according to the claim 2, wherein the particle size of the particles in the step (2) is 1-5 mm.
5. The preparation method of the polyacrylonitrile nano fiber according to the claim 2, wherein the diameter of the polyacrylonitrile nano fiber in the step (4) is less than or equal to 20 nm.
6. The preparation method of the polyacrylonitrile nano-fiber according to the claim 2, wherein the drying temperature in the step (4) is 20-60 ℃.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112695401A (en) * | 2020-12-28 | 2021-04-23 | 镇江市高等专科学校 | Preparation method and application of plasticized melt-spun commercial-grade active PAN precursor |
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