Fluorine-containing polymer flat sheet membrane and method for preparing same

A polymer film, polymer technology, applied in chemical instruments and methods, membrane technology, semi-permeable membrane separation, etc., can solve the problem of poor corrosion resistance and thermal stability, difficult to achieve FEP separation membrane preparation, PVDF separation membrane mechanical strength Insufficient and other problems, to achieve the effect of excellent corrosion resistance and thermal stability, good mechanical strength, uniform distribution of openings

Inactive Publication Date: 2018-12-25
宁波绿色方舟环境工程有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, PVDF separation membranes prepared by the traditional non-solvent-induced phase separation method (NIPS method) often have shortcomings such as insufficient mechanical strength, poor corrosion resistance, and poor thermal stability.
However, FEP is insoluble in most organic solvents, and the traditional NIPS method is difficult to realize the preparation of FEP separation membranes. So far, there are few reports on FEP membranes.

Method used

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  • Fluorine-containing polymer flat sheet membrane and method for preparing same
  • Fluorine-containing polymer flat sheet membrane and method for preparing same
  • Fluorine-containing polymer flat sheet membrane and method for preparing same

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preparation example Construction

[0020] The invention provides a kind of preparation method of fluoropolymer flat film, it comprises the steps:

[0021] a) mixing the fluorine-containing polymer, the porogen and the dispersant to obtain a premix;

[0022] b) making the premix into a fluoropolymer film, and clamping the fluoropolymer film between moulds;

[0023] c) placing the mold holding the fluoropolymer film in an airtight container, and raising the temperature of the airtight container to 180°C to 360°C;

[0024] d) Introduce supercritical carbon dioxide into the airtight container until the pressure in the airtight container reaches 15MPa-40MPa, and maintain the predetermined time T under this pressure, so that the supercritical carbon dioxide is evenly distributed in the fluoropolymer film;

[0025] e) Relieving the pressure in the airtight container, foaming the supercritical carbon dioxide in the fluoropolymer film to obtain a primary fluoropolymer film, wherein the pressure relief speed of the airt...

Embodiment 1

[0050] Step (1) Extrude 940g of polyvinylidene fluoride (PVDF), 50g of calcium carbonate, and 10g of calcium stearate through a twin-screw extruder at 190°C to 210°C to make a uniform PVDF composite material.

[0051] Step (2) Pass the PVDF composite material through a molding machine at 200° C., 10 MPa, and hot press for 10 minutes to make a PVDF composite material sheet with a thickness of 100 μm. The PVDF composite sheet is clamped between flat moulds, and the gap between the flat moulds is 150 microns.

[0052] Step (3) Put the flat mold assembly holding the PVDF composite material sheet into the autoclave, connect the supercritical carbon dioxide device, feed carbon dioxide, and purge for 4 minutes under low pressure. And set the autoclave temperature to 210 °C.

[0053] Step (4) After the temperature of the autoclave is stabilized, fill the supercritical carbon dioxide fluid to a pressure of 30 MPa; keep the constant temperature and pressure for 15 minutes.

[0054] St...

Embodiment 2

[0058] Step (1) Extrude 940g of polyvinylidene fluoride (PVDF), 5g of erucamide, 30g of polyoxyethylene, and 25g of polyvinylpyrrolidone through a twin-screw extruder at 190°C to 210°C to prepare a uniform PVDF composite material.

[0059] Step (2) Pass the PVDF composite material through a molding machine at 200° C., 10 MPa, and hot press for 10 minutes to make a PVDF composite material sheet with a thickness of 100 μm. The PVDF composite sheet is clamped between flat moulds, and the gap between the flat moulds is 150 microns.

[0060] Step (3) Put the flat mold assembly holding the PVDF composite material sheet into the autoclave, connect the supercritical carbon dioxide device, feed carbon dioxide, and purge for 4 minutes under low pressure. And set the autoclave temperature to 210 °C.

[0061] Step (4) After the temperature of the autoclave is stabilized, fill the supercritical carbon dioxide fluid to a pressure of 30 MPa; keep the constant temperature and pressure for 15...

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Abstract

The invention provides a method for preparing a fluorine-containing polymer flat sheet membrane. The method includes steps of placing molds clamped with fluorine-containing polymer membranes in closedcontainers and increasing the temperatures of the closed containers until the temperatures of the closed containers range from 180 DEG C to 360 DEG C; filling the closed containers with supercriticalcarbon dioxide until the pressures of the closed containers range from 15 MPa to 40 MPa; relieving the pressures for the closed containers and foaming the supercritical carbon dioxide in the fluorine-containing polymer membranes to obtain fluorine-containing polymer primary membranes with first open pores; soaking the fluorine-containing polymer primary membranes in etching solution, and etchingpore-forming agents in the fluorine-containing polymer primary membranes to form a plurality of second open pores so as to obtain the fluorine-containing polymer flat sheet membrane. The invention further provides the fluorine-containing polymer flat sheet membrane.

Description

technical field [0001] The invention relates to the technical field of polymer membrane materials, in particular to a fluorine-containing polymer flat membrane and a preparation method thereof. Background technique [0002] Membrane separation technology is a new type of separation technology widely used in water treatment, environmental protection, chemical industry, energy, medicine, food, biology and other fields. At present, the commonly used separation membrane materials are polyvinylidene fluoride (PVDF), polysulfone (PS), sulfonated polysulfone (SPS), polysulfone amide (PSA), polyethersulfone (POS), polyacrylonitrile (PAN) and cellulose etc. This type of separation membrane is usually prepared by the non-solvent precipitation gel phase inversion method (NIPS). However, the separation membranes prepared by this method often have disadvantages such as insufficient mechanical strength, poor corrosion resistance, and poor thermal stability. [0003] Fluoropolymer is a ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01D67/00B01D69/06B01D71/34
CPCB01D67/0034B01D69/06B01D71/34
Inventor 刘富林海波范德胜范燚张利娟
Owner 宁波绿色方舟环境工程有限公司
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