Method for preparing polyvinylidene fluoride microporous film

A technology of polyvinylidene fluoride and microporous membrane, which is applied in chemical instruments and methods, membrane technology, semi-permeable membrane separation, etc. It can solve the problems of flat membranes that need to be improved and few membrane components, and achieve controllable microporous structure , Uniform micropore distribution and low energy consumption

Inactive Publication Date: 2014-11-19
BEIJING UNIV OF CHEM TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In recent years, researchers at home and abroad have conducted in-depth research on polyvinylidene fluoride film formation, but there are not many PVDF membranes for industrial use and membrane modules made of this membrane, especially the preparation of flat membranes needs to be improved.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] Embodiment 1: Weigh 12g of polyvinylidene fluoride powder resin by mass fraction, solvent N,N-dimethylformamide 84g, porogen dimethyl phthalate 4g, mix and stir in a three-necked flask, Put the three-necked flask into a constant temperature water bath, stir and dissolve in a water bath at 75°C, and dissolve at a constant temperature for 4 hours until the casting solution is a clear and transparent uniform system, then let it stand for degassing for 1 hour, and use a scraper to evenly dissolve the casting solution Scrape on a glass plate, knife edge thickness: 0.15mm, knife edge width: 0.3mm, the thin layer of solution formed is about 0.15mm thick, quickly immerse the thin layer of solution into the gel bath with deionized water, The temperature of the gel bath is 25°C. After 30 seconds, the gelled film is peeled off and quickly immersed in the film-forming bath. The film-forming bath is composed of dimethyl phthalate and acetone in a ratio of 15:85, and the film is forme...

Embodiment 2

[0025] Embodiment 2: Weigh 12g of polyvinylidene fluoride powder resin by mass fraction, solvent N,N-dimethylformamide 84g, porogen dibutyl phthalate 4g, mix and stir in a three-necked flask, Put the three-necked flask into a constant temperature water bath, stir and dissolve in a water bath at 75°C, and dissolve at a constant temperature for 4 hours until the casting solution is a clear and transparent uniform system, then let it stand for degassing for 1 hour, and use a scraper to evenly dissolve the casting solution Scrape on a glass plate, knife edge thickness: 0.15mm, knife edge width: 0.3mm, the thin layer of solution formed is about 0.15mm thick, quickly immerse the thin layer of solution into the gel bath with deionized water, The temperature of the gel bath is 25°C. After 30 seconds, the gelled film is peeled off and quickly immersed in the film-forming bath. The film-forming bath is composed of dibutyl phthalate and acetone in a ratio of 15:85, and the film is formed ...

Embodiment 3

[0026] Embodiment 3: Weigh 12g of polyvinylidene fluoride powder resin by mass fraction, solvent N,N-dimethylformamide 84g, porogen diisooctyl phthalate 4g, mix and stir in a three-necked flask , put the three-neck flask into a constant temperature water bath, stir and dissolve in a water bath at 75°C, and dissolve at a constant temperature for 4 hours until the casting solution is a clear and transparent uniform system, then let it stand for degassing for 1 hour, and evenly mix the casting solution with a scraper Scraping on a glass plate, knife edge thickness: 0.15mm, knife edge width: 0.3mm, the thin layer of solution formed is about 0.15mm thick, quickly immerse the thin layer of solution into the gel bath with deionized water , the temperature of the gel bath is 25°C, and the gelled film is peeled off and immersed in the film-forming bath rapidly in 30s. The film-forming bath is composed of diisooctyl phthalate and acetone according to the ratio of 15:85. The temperature ...

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PUM

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Abstract

The invention relates to technology for preparing a polyvinylidene fluoride microporous film. The method adopts non-water-soluble ester pore-forming additives, changes the traditional film preparation technology of immersion precipitation phase separation, and is characterized in that N,N-dimethylformamide is selected and used as a solvent, dimethyl phthalate, dibutyl phthalate and dioctyl phthalate are selected and used as pore-forming additives, and dibutyl phthalate is preferable. Compared with water-soluble inorganic salt micromolecules like lithium chloride, ammonium chloride and sodium nitrate (NaNO3), as well as low-molecular-weight water-soluble polyethylene glycol, polyvinylpyrrolidone, glycerin and the like, the film prepared by adopting the non-water-soluble ester pore-forming additives has the advantages of very regular microporous structure, even micropore distribution, narrow pore size distribution of micropores, and controllable microporous structure. In addition, the preparation method realizes low energy consumption and zero emission in a production process, the operation is simple, large-scale continuous production can be realized, the technology controllability is high, and the product is stable in quality.

Description

1. Technical field [0001] The invention relates to the preparation of a polyvinylidene fluoride microporous film, specifically uses a specific porogen and adopts an immersion precipitation method to prepare the microporous film, and belongs to the field of polymer material processing. 2. Background technology [0002] Polyvinylidene fluoride is a crystalline polymer with excellent performance. It has excellent mechanical strength, anti-ultraviolet and weathering resistance, and good chemical stability. These advantages make PVDF an ideal phase inversion film-forming material. In recent years, researchers at home and abroad have conducted in-depth research on polyvinylidene fluoride film formation, but there are not many PVDF membranes for industrial use and membrane modules made of this membrane, especially the preparation of flat membranes needs to be improved. [0003] Since polyvinylidene fluoride has the above advantages and can be salivated into a film with better perfo...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01D71/34B01D69/06B01D67/00
Inventor 苑会林邢胜俐
Owner BEIJING UNIV OF CHEM TECH
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