CN111663363B - Aramid nanofiber/polyimide composite paper and preparation method thereof - Google Patents
Aramid nanofiber/polyimide composite paper and preparation method thereof Download PDFInfo
- Publication number
- CN111663363B CN111663363B CN202010498787.4A CN202010498787A CN111663363B CN 111663363 B CN111663363 B CN 111663363B CN 202010498787 A CN202010498787 A CN 202010498787A CN 111663363 B CN111663363 B CN 111663363B
- Authority
- CN
- China
- Prior art keywords
- polyimide
- anf
- mica
- fibrid
- fiber
- 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
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
- D21H13/10—Organic non-cellulose fibres
- D21H13/20—Organic non-cellulose fibres from macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
- D21H13/26—Polyamides; Polyimides
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
- C08G73/06—Polycondensates having nitrogen-containing heterocyclic rings in the main chain of the macromolecule
- C08G73/10—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
- C08G73/1003—Preparatory processes
- C08G73/1007—Preparatory processes from tetracarboxylic acids or derivatives and diamines
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
- C08G73/06—Polycondensates having nitrogen-containing heterocyclic rings in the main chain of the macromolecule
- C08G73/10—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
- C08G73/1067—Wholly aromatic polyimides, i.e. having both tetracarboxylic and diamino moieties aromatically bound
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H15/00—Pulp or paper, comprising fibres or web-forming material characterised by features other than their chemical constitution
- D21H15/02—Pulp or paper, comprising fibres or web-forming material characterised by features other than their chemical constitution characterised by configuration
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/03—Non-macromolecular organic compounds
- D21H17/05—Non-macromolecular organic compounds containing elements other than carbon and hydrogen only
- D21H17/09—Sulfur-containing compounds
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/63—Inorganic compounds
- D21H17/64—Alkaline compounds
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/63—Inorganic compounds
- D21H17/66—Salts, e.g. alums
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/63—Inorganic compounds
- D21H17/67—Water-insoluble compounds, e.g. fillers, pigments
- D21H17/68—Water-insoluble compounds, e.g. fillers, pigments siliceous, e.g. clays
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21J—FIBREBOARD; MANUFACTURE OF ARTICLES FROM CELLULOSIC FIBROUS SUSPENSIONS OR FROM PAPIER-MACHE
- D21J5/00—Manufacture of hollow articles by transferring sheets, produced from fibres suspensions or papier-mâché by suction on wire-net moulds, to couch-moulds
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Inorganic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Dispersion Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Paper (AREA)
Abstract
The invention relates to aramid nano-fiber/polyimide composite paper and a preparation method thereof. The preparation method disclosed by the invention is simple in preparation process and high in operability, and the product has excellent mechanical properties, electric insulation properties and the like, so that the application field is widened.
Description
Technical Field
The invention belongs to the field of composite paper, and particularly relates to aramid nano-fiber/polyimide composite paper and a preparation method thereof.
Background
Aramid Nanofiber (ANF) is a novel polymer nanofiber newly developed in recent years, and has the dual advantages of aramid fiber and polymer nanofiber. The exposed functional groups of the ANF obtained by the deprotonation method are easy to form hydrogen bonds with other matrixes or reinforcements, and the ANF is in a gel form in an aqueous solution and has high interface bonding performance and self-assembly performance. Based on the excellent performance, the aramid nano-fiber based composite material with excellent mechanical system energy, heat resistance, ageing resistance and the like can be developed by utilizing a solvent exchange method and a layer-by-layer self-assembly technology.
Chinese patent CN 108316056A discloses an aramid nano-fiber film composite aramid paper and a preparation method thereof, wherein forming nets with different meshes are used for respectively obtaining ANF films as a surface layer and a bottom layer, aramid chopped fibers and aramid pulp or aramid fibrid paper are used as a core layer, then three layers are laminated and compounded, the aramid nano-fiber film composite aramid paper is obtained through post-treatment, the three layers are compounded together by directly utilizing the compatibility of aramid fibers, the interface bonding of the three layers is easy to occur, the mechanical property is reduced due to slippage, and meanwhile, other insulating materials are not added, so that the electrical insulating property of the final product is slightly low. Chinese invention patent CN 110485195A discloses a preparation method of aramid nano-fiber-based insulating paper, which comprises the steps of mixing an ANF/DMSO dispersion liquid with an inorganic insulating material/DMSO dispersion liquid to obtain a sol, replacing the sol with water to obtain hydrogel, and drying to obtain the aramid nano-fiber-based insulating paper.
The Polyimide (PI) fibrids are fibrous or film-like fibrids formed by precipitating a polyimide stock solution from a poor solvent thereof under high-speed stirring. The method has simple process, and the prepared fibrid has the advantages of stable performance, large specific surface area, low crystallinity, easy processing and forming, and the like. In the paper making process, the polyimide fibrids play roles in connection, filling and stress transmission, and the mechanical property of the finished paper is further improved.
Disclosure of Invention
The invention aims to solve the technical problem of providing the aramid nano-fiber/polyimide composite paper and the preparation method thereof, wherein the composite paper has excellent mechanical properties, electric insulation properties and the like, and the application field is widened.
The invention provides aramid nano-fiber/polyimide composite paper, wherein the upper layer and the lower layer of the composite paper are aramid nano-fiber, and the middle layer is a polyimide fibrid (PI)/mica composite layer.
The mass ratio of the upper layer to the lower layer to the middle layer is 10-40: 20-80: 10-40.
The composite paper has a basis weight of 50g/m2～100g/m2。
The invention also provides a preparation method of the aramid nano-fiber/polyimide composite paper, which comprises the following steps:
(1) mixing the cleaned aramid fiber ANF, potassium hydroxide KOH and dimethyl sulfoxide DMSO, sealing, placing at room temperature, continuously stirring to obtain an ANF/DMSO solution, and adding deionized water to wash to obtain an ANF water dispersion;
(2) injecting the polyimide stock solution after the post-treatment into a precipitating agent to obtain polyimide fibrid suspension, and washing, filtering and vacuum drying to obtain polyimide fibrid; dispersing the polyimide/mica into water, and performing ultrasonic dispersion with mica to obtain polyimide fibrid/mica water dispersion;
(3) sequentially obtaining an ANF layer, a polyimide fibrid/mica composite layer and an ANF layer (on a filter membrane) by adopting a vacuum auxiliary filtration mode to form an aramid nano fiber/polyimide composite membrane; and finally, carrying out vacuum drying and hot pressing to obtain the aramid nano-fiber/polyimide composite paper.
The method for cleaning the aramid fiber ANF in the step (1) comprises the following steps: soaking in acetone for 6-12 h, and then washing with deionized water for 4-6 times.
The dosage ratio of the ANF, the KOH and the DMSO in the step (1) is 1g to 1.5g to 500 mL.
The continuous stirring speed in the step (1) is 500-1000 r/min.
And (2) the volume ratio of the deionized water to the DMSO in the step (1) is 1:1, so that ANF is precipitated and repeatedly washed for 4-6 times.
The solid content of the ANF aqueous dispersion in the step (1) is 0.2-1%.
The preparation method of the polyimide stock solution in the step (2) comprises the following steps: adding a diamine monomer into an aprotic polar organic solvent at 0-25 ℃ under the protection of nitrogen, adding a dianhydride monomer after complete dissolution, stirring, and then adding a catalyst for heating cyclization or adding a chemical cyclization agent for chemical cyclization to obtain a polyimide stock solution.
The diamine monomer is one or more of p-phenylenediamine, m-phenylenediamine, hexafluoro-diamine, bisphenol A diether diamine, 4 '-diaminodiphenylmethane and 4, 4' -methylene diphenylamine.
The dianhydride monomer is one or more of pyromellitic dianhydride, benzophenone dianhydride, biphenyl dianhydride, diphenyl ether dianhydride and hydroquinone diether dianhydride.
The molar ratio of the diamine monomer to the dianhydride monomer is as follows: 1: 0.9-1: 1.1.
The aprotic polar organic solvent is dimethylacetamide or N-methylpyrrolidone.
The catalyst is one or more of isoquinoline, acetic anhydride and triethylamine.
The chemical cyclizing agent is one or more of triethylamine, acetic anhydride and pyridine.
Preferably, the aprotic polar organic solvent is N-methylpyrrolidone; the diamine is a mixture of 2, 4-diaminotoluene (TDA) and 4, 4' -diaminodiphenylmethane (MDA); the dianhydride is 3,3 ', 4, 4' -benzophenonetetracarboxylic dianhydride (BTDA). The reaction parameters of the heating cyclization are as follows: polymerizing for 1-3 h at 100 ℃, heating to 120 ℃, polymerizing for 3-5 h, and heating to 180 ℃ for polymerizing for 5-15 h; the chemical cyclizing agent is one or more of triethylamine, acetic anhydride and pyridine, and the molar ratio of the chemical cyclizing agent to the diamine is 0: 1-1: 1; the reaction temperature of the chemical cyclization is 60-80 ℃.
And (3) carrying out post-treatment in the step (2) including filtering, defoaming and diluting.
The precipitation agent in the step (2) is a mixed solution consisting of deionized water and one or more of ethanol, methanol and an aprotic polar organic solvent; wherein the aprotic polar organic solvent is N-methylpyrrolidone, N-dimethylformamide or N, N-dimethylacetamide. The volume ratio of the precipitating agent to the polymerization liquid is 10-50: 1.
the injection in the step (2) is specifically as follows: the stirring speed is 2000-10000 r/min, the injection speed is 0.5-1 mL/min, and the stirring time is 1-2 min after the solution is completely injected.
The mass ratio of the polyimide fibrid to the mica in the step (2) is 1: 9-9: 1. The ultrasonic dispersion time with mica is 0.5-1 h.
The hot pressing process parameters in the step (3) are as follows: the pressure is 5-25 MPa, and the time is 5-240 min; the technological parameters of vacuum drying are as follows: the temperature is 40-80 ℃ and the time is 1-10 h.
The aramid nano-fiber/polyimide composite paper is a sandwich structure composite paper with an ANF layer, a polyimide fibrid/mica composite layer and an ANF layer sequentially formed in a vacuum-assisted filtering mode, PI fibrid and mica in the middle layer are stacked to form a brick mud structure, meanwhile, fibrid plays a role of a binder to be connected with the ANF layer, the mechanical property, the heat resistance and the like of the composite paper are further improved, and in addition, the electrical insulation property of the composite paper is also improved due to the addition of the mica.
Advantageous effects
(1) According to the invention, the ANF and PI fibrid/mica composite layers are laminated layer by a vacuum auxiliary filtration method to prepare the composite paper with a sandwich structure, and the method is simple and has high operability.
(2) The mica is added in the invention, so that the electrical insulation performance of the composite paper can be improved, and meanwhile, the mica and the fibrids can be wound and stacked, so that the mechanical strength is improved.
(3) On the other hand, the polyimide fibrid of the invention can be used as a binder to connect the upper and lower ANF layers, and the ANF on the upper layer can be absorbed into the gap of the middle layer in the vacuum filtration process, so that the comprehensive performance of the composite paper is greatly improved.
Detailed Description
The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.
First, experimental medicine
Second, testing method
1. Tensile index
According to GB/T12914-2008 constant-rate loading method, a tensile strength tester is used to stretch a specimen of a prescribed size to break under constant-rate loading, measure the tensile strength thereof, and calculate the tensile index from the obtained result and the quantitative amount of the specimen.
2. Tensile strength
The paper is cut into sample strips with the length of 100mm and the width of 5mm, the tensile test is carried out on a universal material testing machine, each sample is tested repeatedly for 5 times, and the average value is taken.
3. Thermal stability test
And (3) testing the temperature index of the sample at the thermal weight loss of 5% by using a thermogravimetric analyzer to represent the thermal stability of the composite paper.
4. Breakdown strength test
The breakdown voltage of the paper is measured according to the ASTM-149 standard, and a power frequency rapid boosting method is adopted, namely the boosting speed is controlled, so that the breakdown time of the fiber paper is 15-20 s.
Example 1
(1) Treating aramid fiber ANF with acetone for 10 hours, washing with deionized water for 5 times, mixing the washed aramid fiber, potassium hydroxide KOH and dimethyl sulfoxide DMSO in a ratio of 1g to 1.5g to 500mL, sealing, placing at room temperature, continuously stirring for one week (stirring speed is 500r/min) to obtain a reddish brown ANF/DMSO solution, and then adding deionized water to wash for several times to obtain an ANF aqueous dispersion (solid content is 0.5%).
(2) Adding N-methylpyrrolidone (NMP) into a three-neck flask under the protection of nitrogen, adding 2, 4-diaminotoluene (TDA) and diphenylmethane diamine (MDA) at room temperature under stirring, stirring to dissolve, adding 3,3 ', 4, 4' -Benzophenone Tetracarboxylic Dianhydride (BTDA), wherein TDA: MDA: BTDA is 1:1:2, and continuing stirring for 5 hours. Then adding a few drops of isoquinoline, heating to 100 ℃ for reaction for 1h, reacting at 120 ℃ for 3h, and reacting at 180 ℃ for 12 h. To obtain polyimide stock solution with solid content of 15 percent. And carrying out post-treatment on the obtained polyimide stock solution, including filtration, defoaming and dilution to 5 wt%. Then injecting the stock solution into water at a speed of 1mL/min by using a 20mL syringe with the diameter of 2.1cm at a stirring speed of 5000 r/min; ethanol: n-methylpyrrolidone ═ 1: 7: 3 (the ratio of the stock solution to the precipitating agent is 1:10), and continuously stirring for 1min to obtain polyimide fibrid suspension; washing, filtering and drying to obtain polyimide fibrids; dispersing the polyimide PI fibrid/mica aqueous dispersion into water, and ultrasonically dispersing the polyimide PI fibrid/mica aqueous dispersion for 1h to obtain polyimide PI fibrid/mica aqueous dispersion, wherein the mass ratio of the PI fibrid to the mica is 1: 9;
(3) utilizing a vacuum-assisted filtration mode, performing suction filtration by using a Buchner funnel with the diameter of 15cm, firstly depositing a layer of ANF film on filter paper, then depositing a PI precipitated fiber/mica composite layer, and finally depositing a layer of ANF, wherein the upper layer comprises: an intermediate layer: the lower layer mass ratio is 10: 8: and 10, forming the aramid nano fiber/polyimide composite film. And then carrying out vacuum drying at 60 ℃ for 5h and hot pressing at 10MPa for 100min to obtain the aramid nano-fiber/polyimide composite paper with a sandwich structure.
The temperature of the aramid nanofiber/polyimide composite paper obtained in the embodiment is 517 ℃ when the thermal weight loss is 5%; the tensile index is 48.1 N.m/g; the tensile strength is 75.4 MPa; the dielectric strength was 46.3 KV/mm.
Example 2
(1) Treating aramid fiber ANF with acetone for 10 hours, washing with deionized water for 5 times, mixing the washed aramid fiber, potassium hydroxide KOH and dimethyl sulfoxide DMSO in a ratio of 1g to 1.5g to 500mL, sealing, placing at room temperature, continuously stirring for one week (stirring speed is 500r/min) to obtain a reddish brown ANF/DMSO solution, and then adding deionized water to wash for several times to obtain an ANF aqueous dispersion (solid content is 0.5%).
(2) Adding N-methylpyrrolidone (NMP) into a three-neck flask under the protection of nitrogen, adding 2, 4-diaminotoluene (TDA) and diphenylmethane diamine (MDA) at room temperature under stirring, stirring to dissolve, adding 3,3 ', 4, 4' -Benzophenone Tetracarboxylic Dianhydride (BTDA), wherein TDA: MDA: BTDA is 1:1:2, and continuing stirring for 5 hours. Then adding a few drops of isoquinoline, heating to 100 ℃ for reaction for 1h, reacting at 120 ℃ for 3h, and reacting at 180 ℃ for 12 h. To obtain polyimide stock solution with solid content of 15 percent. And carrying out post-treatment on the obtained polyimide stock solution, including filtration, defoaming and dilution to 5 wt%. Then injecting the stock solution into water at a speed of 1mL/min by using a 20mL syringe with the diameter of 2.1cm at a stirring speed of 5000 r/min; ethanol: n-methylpyrrolidone ═ 1: 7: 3 (the ratio of the stock solution to the precipitating agent is 1:10), and continuously stirring for 1min to obtain polyimide fibrid suspension; washing, filtering and drying to obtain polyimide fibrids; dispersing the polyimide PI fibrid/mica aqueous dispersion into water, and ultrasonically dispersing the polyimide PI fibrid/mica aqueous dispersion for 1h to obtain polyimide PI fibrid/mica aqueous dispersion, wherein the mass ratio of the PI fibrid to the mica is 5: 5;
(3) utilizing a vacuum-assisted filtration mode, performing suction filtration by using a Buchner funnel with the diameter of 15cm, firstly depositing a layer of ANF film on filter paper, then depositing a PI precipitated fiber/mica composite layer, and finally depositing a layer of ANF, wherein the upper layer comprises: an intermediate layer: the lower layer mass ratio is 1: 8: 1, forming the aramid nano fiber/polyimide composite film. And then carrying out vacuum drying at 60 ℃ for 5h and hot pressing at 10MPa for 100min to obtain the aramid nano-fiber/polyimide composite paper with a sandwich structure.
The temperature of the aramid nano-fiber/polyimide composite paper obtained in the embodiment is 513 ℃ when the thermal weight loss is 5%; the tensile index is 52 N.m/g; the tensile strength is 84.6 MPa; the dielectric strength was 40.3 KV/mm.
Example 3
(1) Treating aramid fiber ANF with acetone for 10 hours, washing with deionized water for 5 times, mixing the washed aramid fiber, potassium hydroxide KOH and dimethyl sulfoxide DMSO in a ratio of 1g to 1.5g to 500mL, sealing, placing at room temperature, continuously stirring for one week (stirring speed is 500r/min) to obtain a reddish brown ANF/DMSO solution, and then adding deionized water to wash for several times to obtain an ANF aqueous dispersion (solid content is 0.5%).
(2) Adding N-methylpyrrolidone (NMP) into a three-neck flask under the protection of nitrogen, adding 2, 4-diaminotoluene (TDA) and diphenylmethane diamine (MDA) at room temperature under stirring, stirring to dissolve, adding 3,3 ', 4, 4' -Benzophenone Tetracarboxylic Dianhydride (BTDA), wherein TDA: MDA: BTDA is 1:1:2, and continuing stirring for 5 hours. Then adding a few drops of isoquinoline, heating to 100 ℃ for reaction for 1h, reacting at 120 ℃ for 3h, and reacting at 180 ℃ for 12 h. To obtain polyimide stock solution with solid content of 15 percent. And carrying out post-treatment on the obtained polyimide stock solution, including filtration, defoaming and dilution to 5 wt%. Then injecting the stock solution into water at a speed of 1mL/min by using a 20mL syringe with the diameter of 2.1cm at a stirring speed of 5000 r/min; ethanol: n-methylpyrrolidone ═ 1: 7: 3 (the ratio of the stock solution to the precipitating agent is 1:10), and continuously stirring for 1min to obtain polyimide fibrid suspension; washing, filtering and drying to obtain polyimide fibrids; dispersing the polyimide PI fibrid/mica aqueous dispersion into water, and ultrasonically dispersing the polyimide PI fibrid/mica aqueous dispersion for 1h to obtain polyimide PI fibrid/mica aqueous dispersion, wherein the mass ratio of the PI fibrid to the mica is 9: 1;
(3) utilizing a vacuum-assisted filtration mode, performing suction filtration by using a Buchner funnel with the diameter of 15cm, firstly depositing a layer of ANF film on filter paper, then depositing a PI precipitated fiber/mica composite layer, and finally depositing a layer of ANF, wherein the upper layer comprises: an intermediate layer: the lower layer mass ratio is 1: 8: 1, forming the aramid nano fiber/polyimide composite film. And then carrying out vacuum drying at 60 ℃ for 5h and hot pressing at 10MPa for 100min to obtain the aramid nano-fiber/polyimide composite paper with a sandwich structure.
The temperature of the aramid nanofiber/polyimide composite paper obtained in the embodiment is 523 ℃ when the thermal weight loss is 5%; a tensile index of 54.5 N.m/g; the tensile strength is 82 MPa; the dielectric strength was 38.1 KV/mm.
Example 4
(1) Treating aramid fiber ANF with acetone for 10 hours, washing with deionized water for 5 times, mixing the washed aramid fiber, potassium hydroxide KOH and dimethyl sulfoxide DMSO in a ratio of 1g to 1.5g to 500mL, sealing, placing at room temperature, continuously stirring for one week (stirring speed is 500r/min) to obtain a reddish brown ANF/DMSO solution, and then adding deionized water to wash for several times to obtain an ANF aqueous dispersion (solid content is 0.5%).
(2) Adding N-methylpyrrolidone (NMP) into a three-neck flask under the protection of nitrogen, adding 2, 4-diaminotoluene (TDA) and diphenylmethane diamine (MDA) at room temperature under stirring, stirring to dissolve, adding 3,3 ', 4, 4' -Benzophenone Tetracarboxylic Dianhydride (BTDA), wherein TDA: MDA: BTDA is 1:1:2, and continuing stirring for 5 hours. Then adding a few drops of isoquinoline, heating to 100 ℃ for reaction for 1h, reacting at 120 ℃ for 3h, and reacting at 180 ℃ for 12 h. To obtain polyimide stock solution with solid content of 15 percent. And carrying out post-treatment on the obtained polyimide stock solution, including filtration, defoaming and dilution to 5 wt%. Then injecting the stock solution into water at a speed of 1mL/min by using a 20mL syringe with the diameter of 2.1cm at a stirring speed of 5000 r/min; ethanol: n-methylpyrrolidone ═ 1: 7: 3 (the ratio of the stock solution to the precipitating agent is 1:10), and continuously stirring for 1min to obtain polyimide fibrid suspension; washing, filtering and drying to obtain polyimide fibrids; dispersing the polyimide PI fibrid/mica aqueous dispersion into water, and ultrasonically dispersing the polyimide PI fibrid/mica aqueous dispersion for 1h to obtain polyimide PI fibrid/mica aqueous dispersion, wherein the mass ratio of the PI fibrid to the mica is 5: 5;
(3) utilizing a vacuum-assisted filtration mode, performing suction filtration by using a Buchner funnel with the diameter of 15cm, firstly depositing a layer of ANF film on filter paper, then depositing a PI precipitated fiber/mica composite layer, and finally depositing a layer of ANF, wherein the upper layer comprises: an intermediate layer: the lower layer mass ratio is 25: 50: and 25, forming the aramid nano fiber/polyimide composite film. And then carrying out vacuum drying at 60 ℃ for 5h and hot pressing at 10MPa for 100min to obtain the aramid nano-fiber/polyimide composite paper with a sandwich structure.
The temperature of the aramid nano-fiber/polyimide composite paper obtained in the embodiment is 501 ℃ when the thermal weight loss is 5%; the tensile index is 58 N.m/g; the tensile strength is 86.3 MPa; the dielectric strength was 37.7 KV/mm.
Example 5
(1) Treating aramid fiber ANF with acetone for 10 hours, washing with deionized water for 5 times, mixing the washed aramid fiber, potassium hydroxide KOH and dimethyl sulfoxide DMSO in a ratio of 1g to 1.5g to 500mL, sealing, placing at room temperature, continuously stirring for one week (stirring speed is 500r/min) to obtain a reddish brown ANF/DMSO solution, and then adding deionized water to wash for several times to obtain an ANF aqueous dispersion (solid content is 0.5%).
(2) Adding N-methylpyrrolidone (NMP) into a three-neck flask under the protection of nitrogen, adding 2, 4-diaminotoluene (TDA) and diphenylmethane diamine (MDA) at room temperature under stirring, stirring to dissolve, adding 3,3 ', 4, 4' -Benzophenone Tetracarboxylic Dianhydride (BTDA), wherein TDA: MDA: BTDA is 1:1:2, and continuing stirring for 5 hours. Then adding a few drops of isoquinoline, heating to 100 ℃ for reaction for 1h, reacting at 120 ℃ for 3h, and reacting at 180 ℃ for 12 h. To obtain polyimide stock solution with solid content of 15 percent. And carrying out post-treatment on the obtained polyimide stock solution, including filtration, defoaming and dilution to 5 wt%. Then injecting the stock solution into water at a speed of 1mL/min by using a 20mL syringe with the diameter of 2.1cm at a stirring speed of 5000 r/min; ethanol: n-methylpyrrolidone ═ 1: 7: 3 (the ratio of the stock solution to the precipitating agent is 1:10), and continuously stirring for 1min to obtain polyimide fibrid suspension; washing, filtering and drying to obtain polyimide fibrids; dispersing the polyimide PI fibrid/mica aqueous dispersion into water, and ultrasonically dispersing the polyimide PI fibrid/mica aqueous dispersion for 1h to obtain polyimide PI fibrid/mica aqueous dispersion, wherein the mass ratio of the PI fibrid to the mica is 5: 5;
(3) utilizing a vacuum-assisted filtration mode, performing suction filtration by using a Buchner funnel with the diameter of 15cm, firstly depositing a layer of ANF film on filter paper, then depositing a PI precipitated fiber/mica composite layer, and finally depositing a layer of ANF, wherein the upper layer comprises: an intermediate layer: the lower layer mass ratio is 40: 20: and 40, forming the aramid nano fiber/polyimide composite film. And then carrying out vacuum drying at 60 ℃ for 5h and hot pressing at 10MPa for 100min to obtain the aramid nano-fiber/polyimide composite paper with a sandwich structure.
The temperature of the aramid nanofiber/polyimide composite paper obtained in the embodiment is 517 ℃ when the thermal weight loss is 5%; a tensile index of 51.4 N.m/g; the tensile strength is 83.6 MPa; the dielectric strength was 35.2 KV/mm.
Claims (8)
1. A preparation method of aramid nano fiber/polyimide composite paper comprises the following steps:
(1) mixing the cleaned aramid fiber ANF, potassium hydroxide KOH and dimethyl sulfoxide DMSO, sealing, placing at room temperature, continuously stirring to obtain an ANF/DMSO solution, and adding deionized water to wash to obtain an ANF water dispersion;
(2) injecting the polyimide stock solution after the post-treatment into a precipitating agent to obtain polyimide fibrid suspension, and washing, filtering and vacuum drying to obtain polyimide fibrid; dispersing the polyimide/mica into water, and performing ultrasonic dispersion with mica to obtain polyimide fibrid/mica water dispersion;
(3) sequentially obtaining an ANF layer, a polyimide fibrid/mica composite layer and an ANF layer by adopting a vacuum auxiliary filtering mode to form an aramid nano fiber/polyimide composite film; and finally, carrying out vacuum drying and hot pressing to obtain the aramid nano-fiber/polyimide composite paper.
2. The method of claim 1, wherein: the dosage ratio of the ANF, the KOH and the DMSO in the step (1) is 1g to 1.5g to 500 mL.
3. The method of claim 1, wherein: the solid content of the ANF aqueous dispersion in the step (1) is 0.2-1%.
4. The method of claim 1, wherein: the preparation method of the polyimide stock solution in the step (2) comprises the following steps: adding a diamine monomer into an aprotic polar organic solvent at 0-25 ℃ under the protection of nitrogen, adding a dianhydride monomer after complete dissolution, stirring, and then adding a catalyst for heating cyclization or adding a chemical cyclization agent for chemical cyclization to obtain a polyimide stock solution.
5. The method of claim 4, wherein: the diamine monomer is one or more of p-phenylenediamine, m-phenylenediamine, hexafluoro-diamine, bisphenol A diether diamine, 4 '-diaminodiphenylmethane and 4, 4' -methylene diphenylamine; the dianhydride monomer is one or more of pyromellitic dianhydride, benzophenone dianhydride, biphenyl dianhydride, diphenyl ether dianhydride and hydroquinone diether dianhydride; the aprotic polar organic solvent is dimethylacetamide or N-methylpyrrolidone; the catalyst is one or more of isoquinoline, acetic anhydride and triethylamine; the chemical cyclizing agent is one or more of triethylamine, acetic anhydride and pyridine.
6. The method of claim 1, wherein: the precipitation agent in the step (2) is a mixed solution consisting of deionized water and one or more of ethanol, methanol and an aprotic polar organic solvent; wherein the aprotic polar organic solvent is N-methylpyrrolidone, N-dimethylformamide or N, N-dimethylacetamide; the volume ratio of the precipitating agent to the polymerization liquid is 10-50: 1.
7. the method of claim 1, wherein: the mass ratio of the polyimide fibrid to the mica in the step (2) is 1: 9-9: 1.
8. The method of claim 1, wherein: the hot pressing process parameters in the step (3) are as follows: the pressure is 5-25 MPa, and the time is 5-240 min; the technological parameters of vacuum drying are as follows: the temperature is 40-80 ℃ and the time is 1-10 h.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010498787.4A CN111663363B (en) | 2020-06-04 | 2020-06-04 | Aramid nanofiber/polyimide composite paper and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010498787.4A CN111663363B (en) | 2020-06-04 | 2020-06-04 | Aramid nanofiber/polyimide composite paper and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111663363A CN111663363A (en) | 2020-09-15 |
| CN111663363B true CN111663363B (en) | 2021-08-31 |
Family
ID=72385991
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010498787.4A Active CN111663363B (en) | 2020-06-04 | 2020-06-04 | Aramid nanofiber/polyimide composite paper and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111663363B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112920467A (en) * | 2021-01-26 | 2021-06-08 | 齐鲁工业大学 | Carboxymethyl cellulose/aramid nanofiber composite membrane and preparation method and application thereof |
| CN112812380A (en) * | 2021-01-26 | 2021-05-18 | 齐鲁工业大学 | Sodium alginate/aramid nanofiber composite membrane and preparation method and application thereof |
| CN114854082A (en) * | 2022-04-28 | 2022-08-05 | 陕西科技大学 | Light polyimide composite sponge and preparation method thereof |
| CN115787344A (en) * | 2022-11-17 | 2023-03-14 | 四川大学 | Preparation method of high-strength, high-thermal-conductivity and high-heat-resistance insulating aramid nanofiber composite paper |
| CN116604914B (en) * | 2023-05-24 | 2024-07-09 | 哈尔滨理工大学 | Three-dimensional structure high-heat-conductivity mica tape and preparation method and application thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105369672A (en) * | 2015-10-20 | 2016-03-02 | 陕西科技大学 | Polyimide fiber mica paper and preparation method thereof |
| CN108071042A (en) * | 2017-12-14 | 2018-05-25 | 东华大学 | A kind of preparation method of the pure polyimides extrusion coating paper of self-adhesion junction type |
| CN108316056A (en) * | 2018-02-11 | 2018-07-24 | 陕西科技大学 | A kind of aramid nano-fiber Film laminated aramid paper and preparation method thereof |
| CN109680552A (en) * | 2017-10-18 | 2019-04-26 | 江苏先诺新材料科技有限公司 | Polyimide/Nano fibre composite paper and preparation method thereof |
| CN209487250U (en) * | 2019-04-14 | 2019-10-11 | 淮安市君睿创智工业设计有限公司 | A kind of Kapton aromatic polyamide paper softness composite mica tape |
-
2020
- 2020-06-04 CN CN202010498787.4A patent/CN111663363B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105369672A (en) * | 2015-10-20 | 2016-03-02 | 陕西科技大学 | Polyimide fiber mica paper and preparation method thereof |
| CN109680552A (en) * | 2017-10-18 | 2019-04-26 | 江苏先诺新材料科技有限公司 | Polyimide/Nano fibre composite paper and preparation method thereof |
| CN108071042A (en) * | 2017-12-14 | 2018-05-25 | 东华大学 | A kind of preparation method of the pure polyimides extrusion coating paper of self-adhesion junction type |
| CN108316056A (en) * | 2018-02-11 | 2018-07-24 | 陕西科技大学 | A kind of aramid nano-fiber Film laminated aramid paper and preparation method thereof |
| CN209487250U (en) * | 2019-04-14 | 2019-10-11 | 淮安市君睿创智工业设计有限公司 | A kind of Kapton aromatic polyamide paper softness composite mica tape |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111663363A (en) | 2020-09-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111663363B (en) | Aramid nanofiber/polyimide composite paper and preparation method thereof | |
| CN111636239B (en) | Preparation method of polyimide fibrid electromagnetic shielding paper | |
| Yao et al. | Robust strong electrospun polyimide composite nanofibers from a ternary polyamic acid blend | |
| CN106977763B (en) | A kind of preparation method of aramid nano-fiber aeroge | |
| CN109942851A (en) | A kind of low dielectric coefficient polyimide hybrid film and application | |
| CN111472193B (en) | Para-aramid nano-fiber mica paper and preparation method thereof | |
| CN104309232B (en) | Acid-resisting and alkali-resisting porous film enhanced by polyimide nanofiber and preparation method and application of porous film | |
| CN113604045A (en) | Thermoplastic polyimide resin composite film with low dielectric property and preparation method thereof | |
| CN108071042A (en) | A kind of preparation method of the pure polyimides extrusion coating paper of self-adhesion junction type | |
| CN102219902A (en) | Polymide molding powder and preparation method thereof | |
| CN114854083B (en) | Ultralight hydrophobic polyimide aerogel and preparation method and application thereof | |
| CN102839560B (en) | Preparation method of polyimide fiber paper | |
| CN109666979A (en) | The preparation method of polyimide nano-fiber | |
| Li et al. | Highly flexible, large scaled and electrical insulating polyimide composite paper with nanoscale polyimide fibers | |
| EP0573974B1 (en) | Polyimide paper, polyimide composite paper and process for producing these products | |
| CN112961349B (en) | High-performance transparent polyimide, polyimide film and preparation method thereof | |
| CN106835342A (en) | The polymer nanofiber of high intensity is prepared using BPDA/PDA series polyimides | |
| CN109680552B (en) | Polyimide/nano fiber composite paper and preparation method thereof | |
| CN108085769A (en) | A kind of preparation method of Cross-linkable polyimides fibrid | |
| CN105506769B (en) | A kind of polyamic acid fibrid and polyimides fibrid and preparation method thereof | |
| CN116231227B (en) | Preparation method of quadruple hydrogen bond crosslinking type polyimide lithium-ion battery diaphragm | |
| CN105037725A (en) | Polyimide oligomer, and preparation method and application thereof | |
| CN110079884A (en) | A kind of preparation method of high-specific surface area polyimides fibrid | |
| CN102816431B (en) | Superfine fiber porous film and preparation method and application thereof | |
| CN115693021A (en) | Polyimide fiber/aerogel composite membrane and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20220228 Address after: Building 5, China Shengze textile technology pioneer park, no.1188, West 2nd Ring Road, Shengze Town, Wujiang District, Suzhou City, Jiangsu Province Patentee after: Jiangsu new vision advanced functional fiber Innovation Center Co.,Ltd. Address before: 201620 No. 2999 North Renmin Road, Songjiang new town, Songjiang District, Shanghai. Patentee before: DONGHUA University |
|
| TR01 | Transfer of patent right |