CN116212665A - Polytetrafluoroethylene microporous membrane and functional preparation process thereof - Google Patents
Polytetrafluoroethylene microporous membrane and functional preparation process thereof Download PDFInfo
- Publication number
- CN116212665A CN116212665A CN202310309630.6A CN202310309630A CN116212665A CN 116212665 A CN116212665 A CN 116212665A CN 202310309630 A CN202310309630 A CN 202310309630A CN 116212665 A CN116212665 A CN 116212665A
- Authority
- CN
- China
- Prior art keywords
- film
- temperature
- ptfe
- blending
- microporous membrane
- 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
- 229920001343 polytetrafluoroethylene Polymers 0.000 title claims abstract description 107
- 239000004810 polytetrafluoroethylene Substances 0.000 title claims abstract description 107
- 239000012982 microporous membrane Substances 0.000 title claims abstract description 29
- -1 Polytetrafluoroethylene Polymers 0.000 title claims abstract description 26
- 238000002360 preparation method Methods 0.000 title claims abstract description 12
- 238000002156 mixing Methods 0.000 claims abstract description 40
- 238000000034 method Methods 0.000 claims abstract description 34
- 239000000203 mixture Substances 0.000 claims abstract description 26
- 239000006057 Non-nutritive feed additive Substances 0.000 claims abstract description 25
- 230000008569 process Effects 0.000 claims abstract description 23
- 239000002994 raw material Substances 0.000 claims abstract description 18
- 239000000835 fiber Substances 0.000 claims abstract description 17
- 238000005406 washing Methods 0.000 claims abstract description 14
- 239000000945 filler Substances 0.000 claims abstract description 12
- 239000002904 solvent Substances 0.000 claims abstract description 12
- 238000002679 ablation Methods 0.000 claims abstract description 3
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 claims description 17
- 239000000843 powder Substances 0.000 claims description 17
- 239000011231 conductive filler Substances 0.000 claims description 13
- 239000004626 polylactic acid Substances 0.000 claims description 13
- 239000000463 material Substances 0.000 claims description 12
- 229920000747 poly(lactic acid) Polymers 0.000 claims description 11
- 229920003229 poly(methyl methacrylate) Polymers 0.000 claims description 11
- 239000004926 polymethyl methacrylate Substances 0.000 claims description 11
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 9
- 239000002245 particle Substances 0.000 claims description 9
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 claims description 7
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims description 6
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 6
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 6
- 239000002041 carbon nanotube Substances 0.000 claims description 6
- 229910021393 carbon nanotube Inorganic materials 0.000 claims description 5
- 238000002844 melting Methods 0.000 claims description 5
- 230000008018 melting Effects 0.000 claims description 5
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 claims description 4
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 claims description 4
- 238000007306 functionalization reaction Methods 0.000 claims description 4
- 229910052751 metal Inorganic materials 0.000 claims description 4
- 239000002184 metal Substances 0.000 claims description 4
- 230000001105 regulatory effect Effects 0.000 claims description 4
- VZGDMQKNWNREIO-UHFFFAOYSA-N tetrachloromethane Chemical compound ClC(Cl)(Cl)Cl VZGDMQKNWNREIO-UHFFFAOYSA-N 0.000 claims description 4
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 claims description 3
- 239000004793 Polystyrene Substances 0.000 claims description 3
- 239000003795 chemical substances by application Substances 0.000 claims description 3
- 239000000839 emulsion Substances 0.000 claims description 3
- 239000000155 melt Substances 0.000 claims description 3
- 238000009832 plasma treatment Methods 0.000 claims description 3
- 238000010008 shearing Methods 0.000 claims description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 3
- 229910052582 BN Inorganic materials 0.000 claims description 2
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 claims description 2
- 229920000049 Carbon (fiber) Polymers 0.000 claims description 2
- 239000004952 Polyamide Substances 0.000 claims description 2
- 239000004698 Polyethylene Substances 0.000 claims description 2
- 239000002202 Polyethylene glycol Substances 0.000 claims description 2
- 239000004743 Polypropylene Substances 0.000 claims description 2
- 239000004372 Polyvinyl alcohol Substances 0.000 claims description 2
- 239000006229 carbon black Substances 0.000 claims description 2
- 239000004917 carbon fiber Substances 0.000 claims description 2
- 239000003086 colorant Substances 0.000 claims description 2
- 238000000354 decomposition reaction Methods 0.000 claims description 2
- 238000007772 electroless plating Methods 0.000 claims description 2
- 238000009713 electroplating Methods 0.000 claims description 2
- 229910021389 graphene Inorganic materials 0.000 claims description 2
- 229910002804 graphite Inorganic materials 0.000 claims description 2
- 239000010439 graphite Substances 0.000 claims description 2
- 239000000314 lubricant Substances 0.000 claims description 2
- 229910044991 metal oxide Inorganic materials 0.000 claims description 2
- 150000004706 metal oxides Chemical class 0.000 claims description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 2
- URXNVXOMQQCBHS-UHFFFAOYSA-N naphthalene;sodium Chemical compound [Na].C1=CC=CC2=CC=CC=C21 URXNVXOMQQCBHS-UHFFFAOYSA-N 0.000 claims description 2
- 239000012188 paraffin wax Substances 0.000 claims description 2
- 229920002647 polyamide Polymers 0.000 claims description 2
- 229920001707 polybutylene terephthalate Polymers 0.000 claims description 2
- 229920000573 polyethylene Polymers 0.000 claims description 2
- 229920001223 polyethylene glycol Polymers 0.000 claims description 2
- 239000005020 polyethylene terephthalate Substances 0.000 claims description 2
- 229920000139 polyethylene terephthalate Polymers 0.000 claims description 2
- 229920001155 polypropylene Polymers 0.000 claims description 2
- 229920002223 polystyrene Polymers 0.000 claims description 2
- 229920002451 polyvinyl alcohol Polymers 0.000 claims description 2
- 239000004800 polyvinyl chloride Substances 0.000 claims description 2
- 229920000915 polyvinyl chloride Polymers 0.000 claims description 2
- 239000011248 coating agent Substances 0.000 claims 1
- 238000000576 coating method Methods 0.000 claims 1
- 230000004048 modification Effects 0.000 abstract description 15
- 238000012986 modification Methods 0.000 abstract description 15
- 239000012528 membrane Substances 0.000 abstract description 12
- 239000011148 porous material Substances 0.000 abstract description 8
- 238000012545 processing Methods 0.000 abstract description 8
- 238000011065 in-situ storage Methods 0.000 abstract description 7
- 230000035699 permeability Effects 0.000 abstract 1
- 238000004519 manufacturing process Methods 0.000 description 12
- 238000000137 annealing Methods 0.000 description 7
- 238000001035 drying Methods 0.000 description 7
- 239000000047 product Substances 0.000 description 7
- 238000001125 extrusion Methods 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- 239000002238 carbon nanotube film Substances 0.000 description 4
- 238000001816 cooling Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 238000003825 pressing Methods 0.000 description 4
- 230000009471 action Effects 0.000 description 3
- 238000003490 calendering Methods 0.000 description 3
- 238000005530 etching Methods 0.000 description 3
- 238000002474 experimental method Methods 0.000 description 3
- 239000011521 glass Substances 0.000 description 3
- 238000007493 shaping process Methods 0.000 description 3
- 206010016654 Fibrosis Diseases 0.000 description 2
- 208000034530 PLAA-associated neurodevelopmental disease Diseases 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 239000003153 chemical reaction reagent Substances 0.000 description 2
- 238000001723 curing Methods 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000010041 electrostatic spinning Methods 0.000 description 2
- 230000004761 fibrosis Effects 0.000 description 2
- 239000008187 granular material Substances 0.000 description 2
- 238000009776 industrial production Methods 0.000 description 2
- 239000002121 nanofiber Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 238000004381 surface treatment Methods 0.000 description 2
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 238000004887 air purification Methods 0.000 description 1
- 239000012752 auxiliary agent Substances 0.000 description 1
- 238000010923 batch production Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 238000005056 compaction Methods 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000010612 desalination reaction Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000010329 laser etching Methods 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 239000003607 modifier Substances 0.000 description 1
- 238000005191 phase separation Methods 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 239000013535 sea water Substances 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 238000009987 spinning Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000011145 styrene acrylonitrile resin Substances 0.000 description 1
- 239000004753 textile Substances 0.000 description 1
- 239000008096 xylene Substances 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
- B01D71/06—Organic material
- B01D71/30—Polyalkenyl halides
- B01D71/32—Polyalkenyl halides containing fluorine atoms
- B01D71/36—Polytetrafluoroethene
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
Abstract
The invention discloses a polytetrafluoroethylene microporous membrane and a functional preparation process thereof. The process comprises the following steps: 1) Blending polytetrafluoroethylene raw materials, processing aids, modified fillers and the like under a certain shear strength; 2) Processing the obtained blend into a blend film at a certain temperature; 3) Removing the processing aid in the blend film by solvent washing or high temperature ablation; 4) And carrying out aftertreatment on the obtained polytetrafluoroethylene microporous membrane according to requirements. The process has flexible equipment, simple and convenient method, economy and high efficiency, the surface of the obtained polytetrafluoroethylene microporous membrane is smooth and flat, the inside of the membrane is in a network structure of nanometer fiber interweaving, the fiber is fine, the porous structure is communicated, and the air permeability is good. The film has high porosity, fine pore diameter, uniform structure, controllable performance, excellent strength and toughness, and flexibility and softness. In-situ functional modification can be carried out on the film in the processing process, so that complex post-treatment modification and processing are avoided.
Description
Technical Field
The invention relates to the technical field of membranes, in particular to a polytetrafluoroethylene microporous membrane and a functional preparation process thereof.
Background
The information disclosed in the background of the invention is only for enhancement of understanding of the general background of the invention and is not necessarily to be taken as an admission or any form of suggestion that this information forms the prior art already known to a person of ordinary skill in the art.
Polytetrafluoroethylene (PTFE) microporous films with micro-nano scale porous structures have wide application in air purification, ultra-clean filtration, sea water desalination, electrical industry, textile fabrics, sealing and other aspects. However, due to the high melting point, high melt viscosity, and the insolubility of PTFE in any solvent, it is difficult to prepare PTFE microporous films by conventional melt blowing, spinning, phase separation, and the like. Meanwhile, due to the characteristics of low surface energy, high stability, high crystallinity and the like of PTFE, the functionalized modified polytetrafluoroethylene porous membrane product is difficult to produce.
Currently, the mainstream commercial PTFE microporous membrane manufacturing process is to manufacture a porous structure by uniaxial or biaxial stretching. In actual production, the quality of the final product is affected by the mixing mode, the design of an extrusion die orifice, the precision of calendaring equipment, the arrangement mode of a compression roller, the drying mode, the design of stretching equipment, the stretching rate, the multiplying power and other factors, and the properties of the PTFE microporous membrane are greatly different. Therefore, the equipment investment and the process required for preparing the PTFE microporous membrane by the traditional stretching method are large and complex. In addition, the mechanical properties of the produced PTFE microporous films are anisotropic due to the directional stretching action, which causes inconvenience in use. The electrostatic spinning technology is an advanced nanofiber manufacturing process, which can be used to manufacture organic or inorganic nanofiber stacks, films with porous structures. In the application of the PTFE porous membrane, the mixed solution of PTFE emulsion and additive can form jet flow under the action of high-voltage electric field, and a layer of fiber superposition film is formed on a base material by curing, and the preparation of the PTFE porous membrane is realized after sintering and shaping. The morphology of the film depends on factors such as voltage, solution composition, fluid flow rate, etc., and the diameter of the resulting PTFE fiber is about 0.5 to 3 microns. However, the electrostatic spinning process has low production efficiency and high batch production cost, and is not widely applied to actual commercial production. In addition, the preparation of the PTFE porous film can be realized by methods such as laser etching, pore-forming of pore-forming agents and the like, but the film obtained by the processes has low porosity and high process cost, and is difficult to realize industrial production. In addition, the functional modification of the PTFE film is still very difficult, but PTFE has a high melting point, no fluidity above the melting temperature, extremely stable physical and chemical properties of PTFE, and is insoluble in any solvent, and the efficient functional modification by the traditional melt blending or solution blending method is difficult. Meanwhile, due to the extremely low surface energy and stable molecular structure of PTFE, the conventional surface treatment has poor modification effect.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides a PTFE microporous membrane and a functional preparation process thereof. The process utilizes blending equipment to directly blend PTFE raw materials, processing aids, modified fillers and the like and then process the PTFE raw materials into films, and the PTFE is fibrillated and forms a mutually entangled fiber network under the strong shearing action during blending. And removing the processing auxiliary agent from the obtained film to obtain the microporous film formed by interweaving and stacking PTFE fibers, and realizing in-situ modification. The method has the advantages that firstly, the PTFE microporous film can be obtained through simple blending, film making and post-treatment, the equipment is simple, convenient and flexible, complex processing technology and high-cost processing equipment are not needed, the cost is low, the production is efficient, and the method can be applied to large-scale industrial production; secondly, the PTFE microporous membrane manufactured by the process has fine fiber, high porosity, fine pore diameter, uniform morphology and higher strength and toughness; thirdly, in the blending process, a modifier can be added to realize in-situ modification, so that the functionalized PTFE microporous film is obtained, and complex procedures such as surface modification and the like required by later functionalization of the product are avoided.
In order to achieve the above purpose, the present invention uses the following technical scheme:
the invention provides a method for manufacturing PTFE microporous membrane by directly blending and then processing into membrane and washing/ablating treatment and a direct in-situ functionalization modification process in the production process thereof.
Further, the functionalization preparation process of the polytetrafluoroethylene microporous membrane comprises the following steps:
1) After the blending equipment is regulated to a certain temperature, the materials are put into a feeding port of the blending equipment for blending, and the temperature and the pressure of the equipment are controlled so as to regulate and control the shearing strength to realize the PTFE fibrosis;
2) The obtained blending product is processed and formed into a blending film at a certain temperature;
3) Washing the blend film with a solvent or ablating the blend film by high-temperature treatment to remove the processing aid, so as to obtain a PTFE microporous film;
the material comprises polytetrafluoroethylene raw material and processing aid.
Preferably, the processing aid in step 1) is a material having fluidity and viscosity at a certain temperature, such as polypropylene, polyethylene, polylactic acid, polyvinyl chloride, polyamide, polyvinyl alcohol, polyethylene glycol, polystyrene, polymethyl methacrylate, polyethylene terephthalate, polybutylene terephthalate, paraffin wax, and the like. Preferably, the processing aid is used in an amount of 50 to 99% based on the total mass of the material.
Preferably, in the step 1), the PTFE raw material is selected to have a relative molecular mass of more than 100 ten thousand, and is in the form of emulsion or powder, so as to ensure good fiberization effect of PTFE. The PTFE particles may be surface-coated with a modifying treatment using PMMA, SAN, PS or the like to avoid agglomeration. The preferred PTFE content is 1 to 50% based on the total mass of the material.
Preferably, in the step 1), the blending equipment is a single screw or multi screw extruder, a mixer, a roll mill, etc., the blending temperature is adjusted within the range of 10-100 ℃ higher than the melting temperature of the processing aid according to the state of the processing aid, the melt shear strength is 5-30 MPa, and the blending time lasts for 3-60 minutes, so that the melt strength and the degree of fibrosis of PTFE can be regulated and controlled.
In step 1), a proper modified filler is further selected during blending according to the product requirement, such as carbon black, carbon fiber, carbon nanotube, graphene, metal powder, metal fiber, two-dimensional Mxene and other conductive fillers, boron nitride, graphite, metal oxide and other heat conductive fillers, colorant, fluorescent agent and other color-changing fillers, and a lubricant can be added to improve the porosity and the pore diameter, or a tough phase can be added to improve the toughness. The amount of the modified filler is 1 to 50% based on the total mass of the film product.
Preferably, in the step 2), the blend product can be molded or rolled into a film at a temperature lower than 370 ℃, or cut into a film at a temperature lower than 50 ℃, or stretched into a film by a single/biaxial stretching and expanding device, and the thickness of the blend film is 0.02-2 mm.
Preferably, in the step 3), a suitable solvent and temperature are selected according to the nature of the processing aid, such as water, chloroform, N-dimethylformamide, dimethyl sulfoxide, xylene, methanol, ethanol, methylene chloride, acetone, carbon tetrachloride, etc., or high temperature ablation is performed at a temperature higher than the volatilization temperature or decomposition temperature of the processing aid.
Preferably, in the step 3), the obtained PTFE film may be annealed at a temperature lower than 370 ℃, and the PTFE film is clamped and fixed by a clamp.
Preferably, in the step 3), the obtained PTFE film may be subjected to a post-treatment such as a plasma treatment or a sodium naphthalene treatment to hydrophilize it, an electroless plating or an electroplating treatment to conductively modify it, as required.
Compared with the prior art, the invention has the beneficial effects that:
1) The PTFE microporous membrane is prepared by direct blending, membrane manufacturing and etching, and a series of complex procedures such as mixing, pre-extrusion, calendaring, curing, longitudinal stretching, transverse stretching and sintering in the traditional process are not needed; the equipment investment is small, and a large amount of expensive equipment in the traditional process is not needed.
2) The PTFE microporous membrane has fine fiber, high porosity, fine pore diameter, uniform morphology and good strength and flexibility.
3) In-situ modification of the high-concentration filler can be realized in the blending process, and complex procedures such as post-treatment modification and the like required by the traditional process are avoided.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention.
FIG. 1 is a flow chart of a process for preparing and in situ compounding modification of PTFE microporous membranes of the present invention.
FIG. 2 is a photograph of a sample of PTFE microporous membrane prepared in example 1.
FIG. 3 is a microscopic electron microscopic image of the PTFE microporous film prepared in example 1.
Fig. 4 is a photograph of a sample of the PTFE/carbon nanotube conductive porous film prepared in example 2.
Fig. 5 is a microscopic electron microscopic image of the conductive porous film of PTFE/carbon nanotube prepared in example 2.
FIG. 6 is a microscopic electron microscopic image of the hydrophilic microporous membrane of PTFE prepared in example 2.
Fig. 7 is a water contact angle of the PTFE hydrophilic microporous membrane prepared in example 2.
Detailed Description
It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the invention. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
As introduced by the technical background, the traditional PTFE microporous film processing technology has the defects of high investment, complex technology, anisotropic product, relatively low porosity, low strength, need of post-treatment and the like. The invention provides a method for preparing a PTFE microporous membrane and performing in-situ functional modification on the PTFE microporous membrane by directly blending a membrane by utilizing a shear-induced fiber-forming behavior, which mainly comprises the following operation steps:
1) After the extrusion equipment and the pressing equipment are regulated to a certain temperature, PTFE raw materials, processing aids, modified fillers and the like are simultaneously put into a feeding port for blending.
2) The blend melt or paste obtained after blending is processed into a blend film by means of pressing, stretching, cutting and the like under a certain temperature condition.
3) And washing the blend film with a solvent or ablating the blend film by high-temperature treatment to remove the processing aid and annealing to obtain the PTFE microporous film.
Example 1
Taking polylactic acid (PLA) as a processing aid and PTFE powder for blending extrusion to prepare the PTFE microporous film, the raw materials are PLA particles produced by Nature holes company and PTFE powder produced by Mitsubishi chemical company. And (3) drying PLA and PTFE raw material particles, and then carrying out experiments. The blending device is a double-screw extruder, the film making device is a hot press, the washing reagent is dichloromethane, and the annealing equipment is a high-temperature tube furnace.
Firstly, preheating a double-screw extruder and a hot press to 180 ℃;
secondly, after preheating, the screw starts to rotate, PTFE powder and PLA granule raw materials with mass ratios of 0.5:9.5, 2:8 and 4:6 are respectively poured into a feeding port to be blended, the blend circulates in the screw for 10 minutes, and the screw pressure is controlled to be 10-15 megapascals.
And thirdly, after the circulation is finished, opening the die head of the extruder to take out the blend, transferring the blend to a hot press for pressing to obtain a blend film with the thickness of 0.2 mm, and cooling and shaping.
Fourth, after cutting the film into a circular film having a diameter of about 5 cm, it was immersed in 200 ml of methylene chloride solvent for 6 hours to dissolve the PLA phase in the film. Repeatedly washing the film by using a Soxhlet extractor to thoroughly remove residual PLA, taking out the PTFE film after washing, and naturally drying the PTFE film on a glass flat plate and taking down the PTFE film.
And fifthly, fixing the PTFE film on a clamp, and placing the clamp in a tube furnace for annealing at the set temperature of 340 ℃ for 15 minutes. And taking out the PTFE microporous membrane after the annealing is finished, and naturally cooling to room temperature.
In this example, the obtained PTFE microporous membrane is as shown in FIG. 2, the surface of the membrane is smooth and flat, the morphology is uniform, and the thickness of the obtained membrane is about 2 μm, 12 μm and 30 μm respectively according to the proportion of the PTFE/PLA. The porous structure of the internal fiber is shown in FIG. 3, the PTFE fiber is fine, and the diameter is about 100-200 nm. The average pore diameter is about 100-300 nanometers and the film porosity is above 60 percent as measured by a capillary flow pore diameter analyzer. The tensile strength of the film is about 30-35 MPa, and the elongation at break is more than 50%.
Example 2
The conductive porous membrane of PTFE is prepared by taking carbon nano tubes as conductive filler (CNT), polymethyl methacrylate (PMMA) as processing aid and PTFE powder raw material, wherein the raw material is PMMA particles produced by Qimei company, CNT powder produced by Mitsubishi chemical company and PTFE powder produced by Mitsubishi chemical company. After drying PMMA raw material particles, PTFE raw material powder and CNT powder, experiments were carried out. The blending device is a double-screw extruder, the film-making device is a roll squeezer, and the etching solvent is N, N-Dimethylformamide (DMF). The preparation process is shown in figure 1.
In the first step, PTFE powder, CNT powder and PMMA particle raw materials with mass ratios of 3:0.5:6.5, 3:1:6 and 2:2:6 are poured into a stirring barrel to be evenly premixed.
And secondly, heating the double-screw extruder and the roller press to 180 ℃, putting the premix into a feeding port, starting a screw, and circularly blending the blend in the screw for 10 minutes, wherein the cavity pressure is controlled to be 13-15 megapascals.
And thirdly, after the circulation is finished, opening an extruder die head, transferring the blend paste to a rolling device for calendaring and film making to obtain the blend film with the thickness of 0.2 mm.
And fourthly, feeding the film into a DMF solvent pool for etching to dissolve PMMA phase in the film. Repeatedly washing the film by using a Soxhlet extractor to thoroughly remove residual PMMA, taking out the PTFE/CNT film after washing, and naturally drying the PTFE/CNT film on a glass flat plate and taking down the PTFE/CNT film.
And fifthly, fixing the PTFE/CNT film on a clamp for compaction, and annealing by using a flat plate hot press, wherein the set temperature is 340 ℃ and the time is 10 minutes. And taking out the PTFE/CNT microporous membrane after the annealing is finished, and naturally cooling to room temperature.
In this example, the resulting PTFE microporous membrane was black in surface and flat and uniform as shown in FIG. 4. The internal fiber porous structure is shown in fig. 5, the PTFE fibers are fine, and the CNTs are distributed in the voids around the PTFE fibers. The pore diameter is about 100-300 nanometers, the porosity of the film is about 46-55%, the tensile strength is about 30MPa, the elongation at break is more than 50%, and the conductivity of the film is about 0.13S/m, 97S/m and 850S/m respectively according to the different using amount ratio of PTFE/CNT.
Example 3
Taking polylactic acid (PLA) as a processing aid and PTFE powder for blending extrusion to prepare the PTFE microporous hydrophilic film, wherein the raw material is PLA particles produced by Nature holes company and PTFE powder produced by Mitsubishi chemical company. And (3) drying PLA and PTFE raw material particles, and then carrying out experiments. The blending device is a double-screw extruder, the film making device is a hot press, the washing reagent is dichloromethane, and the annealing equipment is a high-temperature tube furnace.
Firstly, preheating a double-screw extruder and a hot press to 180 ℃;
and secondly, after preheating, starting to rotate a screw, pouring PTFE powder and PLA granule raw materials with the mass ratio of 2:8 into a feeding port for blending, and circulating the blend in the screw for 10 minutes, wherein the screw pressure is controlled to be 7 megapascals.
And thirdly, after the circulation is finished, opening the die head of the extruder to take out the blend, transferring the blend to a hot press for pressing to obtain a blend film with the thickness of 0.03 mm, and cooling and shaping.
Fourth, the film was immersed in 200 ml of methylene chloride solvent for 3 hours to dissolve the PLA phase in the film. Repeatedly washing the film by using a Soxhlet extractor to thoroughly remove residual PLA, taking out the PTFE film after washing, and naturally drying the PTFE film on a glass flat plate and taking down the PTFE film.
And fifthly, placing the film in a plasma surface treatment instrument, vacuumizing, introducing oxygen, treating for 90 seconds by using oxygen plasma, and taking out the film.
In this example, the internal fiber porous structure is shown in FIG. 6, the PTFE fibers are fine, about 100 to 200 nm in diameter, about 100 to 300 nm in pore size, and about 70% in film porosity. The hydrophilicity of the film was significantly improved after plasma treatment as shown in fig. 7.
The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A functional preparation process of a polytetrafluoroethylene microporous membrane is characterized by comprising the following steps:
1) After the blending equipment is regulated to a certain temperature, the materials are put into a feeding port of the blending equipment for blending, and the temperature and the pressure of the equipment are controlled so as to regulate and control the shearing strength to realize polytetrafluoroethylene fiberization;
2) The obtained blending product is processed and formed into a blending film at a certain temperature;
3) Washing the blend film with a solvent or ablating the blend film by high-temperature treatment to remove the processing aid, so as to obtain a polytetrafluoroethylene microporous membrane;
the material comprises polytetrafluoroethylene raw material and processing aid.
2. The functionalized preparation process according to claim 1, wherein the processing aid in step 1) is a material having fluidity and viscosity at a certain temperature, and is selected from one or more of polypropylene, polyethylene, polylactic acid, polyvinyl chloride, polyamide, polyvinyl alcohol, polyethylene glycol, polystyrene, polymethyl methacrylate, polyethylene terephthalate, polybutylene terephthalate, and paraffin; preferably, the processing aid is used in an amount of 50 to 99% based on the total mass of the material.
3. The process according to claim 1, wherein in step 1), the PTFE material selected has a relative molecular mass of greater than 100 tens of thousands, and is in the form of emulsion or powder; preferably, PMMA and SAN are used for coating and modifying PTFE particles; preferably, the PTFE content is 1 to 50wt% based on the total mass of the material.
4. The process according to claim 1, wherein in step 1), the blending equipment used is a single-screw or multi-screw extruder, a kneader, a roll mill; the blending temperature is adjusted within the range of 10-100 ℃ higher than the melting temperature of the processing aid according to the state of the processing aid, the melt shear strength is 5-30 MPa, and the blending time lasts for 3-60 minutes.
5. The functionalized preparation process according to claim 1, wherein in the step 1), a modified filler is further added during blending, and the modified filler is one or more selected from the group consisting of an electrically conductive filler, a thermally conductive filler, a color-changing filler, a lubricant, and a tough phase; the conductive filler is selected from one or more of carbon black, carbon fiber, carbon nano tube, graphene, metal powder, metal fiber and two-dimensional Mxene, the heat conductive filler is selected from one or more of boron nitride, graphite and metal oxide, and the color-changing filler is selected from one or more of coloring agent and fluorescent agent; the amount of the modified filler is 1 to 50% based on the total mass of the film product.
6. The process according to claim 1, wherein in step 2), the blended product is molded or rolled into a film at a temperature lower than 370 ℃, or cut into a film at a temperature lower than 50 ℃, or stretched into a film by a single/double-shaft stretching device, and the thickness of the blended film is 0.02-2 mm.
7. The process according to claim 1, wherein in step 3), a suitable solvent and temperature are selected for washing or high temperature ablation is performed at a temperature higher than the volatilization temperature or decomposition temperature of the processing aid, depending on the nature of the processing aid; the processing aid is one or more selected from water, chloroform, N-dimethylformamide, dimethyl sulfoxide, dimethylbenzene, methanol, ethanol, methylene dichloride, acetone and carbon tetrachloride.
8. The process according to claim 1, wherein in step 3), the obtained polytetrafluoroethylene microporous membrane is annealed at a temperature lower than 370 ℃.
9. The process according to claim 1, wherein in step 3), the obtained polytetrafluoroethylene microporous membrane is subjected to a post-treatment comprising a plasma treatment, a sodium naphthalene treatment, an electroless plating or an electroplating treatment.
10. A polytetrafluoroethylene microporous membrane prepared by the functionalization process of any one of claims 1-9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310309630.6A CN116212665A (en) | 2023-03-23 | 2023-03-23 | Polytetrafluoroethylene microporous membrane and functional preparation process thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310309630.6A CN116212665A (en) | 2023-03-23 | 2023-03-23 | Polytetrafluoroethylene microporous membrane and functional preparation process thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116212665A true CN116212665A (en) | 2023-06-06 |
Family
ID=86577016
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310309630.6A Pending CN116212665A (en) | 2023-03-23 | 2023-03-23 | Polytetrafluoroethylene microporous membrane and functional preparation process thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116212665A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117883985A (en) * | 2024-03-14 | 2024-04-16 | 保视丽(上海)新材料科技有限公司 | Preparation method of modified polytetrafluoroethylene composite nanofiltration membrane |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1052434A (en) * | 1989-12-07 | 1991-06-26 | 大金工业株式会社 | The production method of multilayer polytetrafluoroethylporous porous membrane |
| US20100320142A1 (en) * | 2006-04-03 | 2010-12-23 | Jijun Ge | Atmospheric pressure microwave plasma treated porous membranes |
| CN108786497A (en) * | 2018-06-29 | 2018-11-13 | 合肥炫升环保材料科技有限公司 | A kind of preparation method of graphene polytetrafluoroethylcomposite composite micro porous film |
| CN114534510A (en) * | 2022-02-16 | 2022-05-27 | 深圳华源再生医学有限公司 | Polytetrafluoroethylene fiber membrane and preparation method and application thereof |
| CN114874485A (en) * | 2022-06-22 | 2022-08-09 | 山东大学 | High-thermal-conductivity polytetrafluoroethylene nanofiber membrane and manufacturing process thereof |
-
2023
- 2023-03-23 CN CN202310309630.6A patent/CN116212665A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1052434A (en) * | 1989-12-07 | 1991-06-26 | 大金工业株式会社 | The production method of multilayer polytetrafluoroethylporous porous membrane |
| US20100320142A1 (en) * | 2006-04-03 | 2010-12-23 | Jijun Ge | Atmospheric pressure microwave plasma treated porous membranes |
| CN108786497A (en) * | 2018-06-29 | 2018-11-13 | 合肥炫升环保材料科技有限公司 | A kind of preparation method of graphene polytetrafluoroethylcomposite composite micro porous film |
| CN114534510A (en) * | 2022-02-16 | 2022-05-27 | 深圳华源再生医学有限公司 | Polytetrafluoroethylene fiber membrane and preparation method and application thereof |
| CN114874485A (en) * | 2022-06-22 | 2022-08-09 | 山东大学 | High-thermal-conductivity polytetrafluoroethylene nanofiber membrane and manufacturing process thereof |
Non-Patent Citations (2)
| Title |
|---|
| GEORGE WYPYCH: "《填料手册（第二版）》", 31 October 2002, 北京：中国石化出版社, pages: 435 * |
| 施良和: "《高分子科学的今天与明天》", 30 September 1994, 北京：化学工业出版社, pages: 36 - 37 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117883985A (en) * | 2024-03-14 | 2024-04-16 | 保视丽(上海)新材料科技有限公司 | Preparation method of modified polytetrafluoroethylene composite nanofiltration membrane |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| RU2504604C2 (en) | Articles made of pure carbon nanotubes, made from superacid solutions and methods for production thereof | |
| JP4824561B2 (en) | Microporous PVDF film and manufacturing method | |
| JP6911757B2 (en) | Fluid Separation Membrane, Fluid Separation Membrane Module and Porous Carbon Fiber | |
| US9095819B2 (en) | Composition for preparation of hollow fiber porous membrane and preparation method using the same | |
| CN109509856B (en) | Aromatic polyamide microporous membrane and preparation method and application thereof | |
| CN103772902B (en) | One has micro-nano co-continuous vesicular structure polyoxymethylene nano-porous thin film and preparation method thereof | |
| KR102331373B1 (en) | Micropore separation membrane and its manufacturing method of bidrectional tensile coating for lithium ion batteries | |
| CN116212665A (en) | Polytetrafluoroethylene microporous membrane and functional preparation process thereof | |
| WO2013127252A1 (en) | Method for preparing perfluoro polymer hollow fiber membrane | |
| CN111086181A (en) | Preparation method of lithium battery diaphragm | |
| CN111408284A (en) | Polytetrafluoroethylene microporous membrane and preparation method thereof | |
| CN114874485B (en) | High-thermal-conductivity polytetrafluoroethylene nanofiber membrane and manufacturing process thereof | |
| CN108677597B (en) | Microporous PTFE composite carbon nanotube paper and preparation method thereof | |
| CN112467303B (en) | Degradable lithium battery diaphragm and preparation method thereof | |
| CN110860217B (en) | Green preparation method of pressure response type polyvinylidene fluoride hollow fiber membrane | |
| CN109065802B (en) | Battery composite diaphragm, lithium ion battery and preparation method | |
| CN115337798B (en) | Large-aperture PVDF hollow fiber membrane with stable crystal form and preparation method thereof | |
| CN111318174A (en) | Method for preparing block copolymer hollow fiber membrane based on selective swelling method | |
| CN103030852B (en) | Polymer microporous membrane and its preparation method | |
| JP2011079879A (en) | Method for producing porous polytetrafluoroethylene body | |
| KR20070103187A (en) | Porous poly(vinylidene fluoride) hollow fiber membranes composed of both fibril and nodular structures | |
| JPS6157328A (en) | Manufacture of polytetrafluoroethylene porous material | |
| CN116219569A (en) | Polytetrafluoroethylene porous fiber and manufacturing and modifying process thereof | |
| JPH0668864A (en) | Separator for battery | |
| JP3539441B2 (en) | Porous ethylene tetrafluoride resin and method for producing the same |
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 |