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Method for preparing polyvinylidene fluoride hollow fiber alloy film

A polyvinylidene fluoride and polyvinylidene fluoride resin technology, which is applied in the field of preparing polyvinylidene fluoride hollow fiber alloy membranes, can solve the problems of dissolution loss, rising inlet pressure, and decreasing hydrophilicity, and achieves stable chemical properties and improved The effect of crush resistance

Active Publication Date: 2009-07-22
HANGZHOU WATER TREATMENT TECH DEV CENT +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

One is that when the polyvinylidene fluoride hollow fiber membrane is used for a long time, due to the dissolution and loss of the hydrophilic polymer additive, the hydrophilicity of the polyvinylidene fluoride hollow fiber membrane decreases, resulting in a serious decline in its pollution resistance. In practical engineering applications, the membrane flux is restored just after chemical cleaning, and after sewage is introduced, the inlet pressure of the membrane rises quickly, which shortens the cleaning cycle of the membrane device.
The second is that the anti-crush mechanical properties of the membrane filaments are poor. For the external pressure hollow fiber membrane, when the filtration pressure increases, the water output of the membrane will drop significantly due to the flattening of the membrane filaments.

Method used

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  • Method for preparing polyvinylidene fluoride hollow fiber alloy film
  • Method for preparing polyvinylidene fluoride hollow fiber alloy film

Examples

Experimental program
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Effect test

Embodiment 1

[0029] Example 1: Dimethylacetamide (Korea Samsung, industrial first-grade pure, the same below) 63wt%, polyvinylidene fluoride resin (Solef 6010, the same below) 18wt%, chlorinated polyvinyl chloride resin (chlorine content 68%) 3wt%, polyethylene glycol 5wt%, propylene glycol 11wt%, stirred and dissolved uniformly at 60°C, and defoamed. The conventional solution phase transfer method in the prior art is used for spinning, the coagulant in the coagulation bath is water, the spinning core liquid is a 50wt% dimethylacetamide aqueous solution, and the spinning traction speed is 50m / min. An externally pressured polyvinylidene fluoride hollow fiber porous membrane with an inner diameter of 0.60 mm, a wall thickness of 0.20 mm, a burst pressure of 0.42 MPa, and an externally compressed flattening pressure of 0.30 MPa was obtained. After being thoroughly cleaned with absolute ethanol and dried, the contact angle of the outer surface of the hollow fiber membrane is 67 0 . Pure water init...

Embodiment 2

[0031] Example 2: Dimethylacetamide 63wt%, polyvinylidene fluoride resin 19wt%, chlorinated polyvinyl chloride resin 2wt%, polyvinylpyrrolidone (K-30) 5wt%, propylene glycol 11wt%, stirred at 60°C Dissolve uniformly and defoam. The conventional solution phase transfer method in the prior art is used for spinning, the coagulant in the coagulation bath is water, the spinning core liquid is a 50wt% dimethylacetamide aqueous solution, and the spinning traction speed is 50m / min. An externally pressured polyvinylidene fluoride hollow fiber porous membrane with an inner diameter of 0.6 mm, a wall thickness of 0.20 mm, a burst pressure of 0.41 MPa, and an externally compressed flattening pressure of 0.28 MPa was obtained. After fully washing with absolute ethanol and drying, the contact angle of the outer surface of the hollow fiber membrane is 66 0 . Pure water initial permeation flux 970L / m 2 ·H@0.1MPa20℃, membrane separation pore size is 0.10μm.

Embodiment 3

[0033] The solvent used in Example 3 and Comparative Example 3 was dimethylformamide (DMF), the low-molecular non-solvent used was ethylene glycol, and the water-soluble polymer used was polyethylene glycol.

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Abstract

The invention provides-uses chlorinated polynvinyl chloride resin for preparing a polyvinylidene fluoride hollow fiber alloy membrane to solve the problem of the permanent hydrophilicity of the polyvinylidene fluoride hollow fiber alloy membrane and improve the compressive rigidity of the polyvinylidene fluoride hollow fiber alloy membrane. The invention also provides a method for preparing the polyvinylidene fluoride hollow fiber alloy membrane, which adopts a wet method or a dry-wet method spinning process. The mass percent of spinning membrane producing liquid takes the total mass of the spinning membrane producing liquid as reference. The invention adopts the chlorinated polynvinyl chloride resin to perform blending modification on polyvinylidene fluoride membrane material to prepare the polyvinylidene fluoride hollow fiber alloy membrane. The method has the advantages of obtaining the polyvinylidene fluoride alloy membrane with lasting hydrophilicity, having the capability of improving the anti-squeezing property of polyvinylidene fluoride membrane, strengthening the function of the differential phase of the spinning membrane producing liquid, and obtaining the high flux hollow fiber membrane.

Description

Technical field [0001] The invention relates to a method for preparing polyvinylidene fluoride hollow fiber alloy membranes using chlorinated polyvinyl chloride resin. Background technique [0002] Hollow fiber membranes are mainly used for filtration or dialysis in various fields. [0003] The formation mechanism of the hollow fiber membrane involved in the present invention is solution phase transfer to form a membrane, that is, the membrane-forming polymer, organic solvent, and pore-forming agent are mixed in a certain proportion, dissolved uniformly, and then passed through the spinning nozzle to enter the coagulation bath. The solvent and pore-forming agent in the polymer solution enter the coagulant phase, and the polymer precipitates into a polymer hollow fiber membrane due to the phase transfer. A hollow fiber separation membrane with a certain pore size can be obtained by controlling the spinning dope formula, spinning process parameters and hollow fiber post-processing ...

Claims

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Application Information

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IPC IPC(8): B01D71/34B01D69/08
Inventor 吕晓龙谭永文
Owner HANGZHOU WATER TREATMENT TECH DEV CENT
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