Method for preparing hydrophilic polytetrafluoroethylene hollow fiber film

A technology of polytetrafluoroethylene and fiber membranes, which is applied in the field of hollow fiber membrane preparation, can solve the problems of non-alkali resistance, strong hydrophobicity of polytetrafluoroethylene hollow fiber membranes, and limited application fields, and achieve low cost and great practicality The effect of value and method is simple and easy

Active Publication Date: 2013-11-20
ZHEJIANG SCI-TECH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Patent CN202129031U adopts the method of wrapping the outer wall of a polytetrafluoroethylene hollow fiber support body with an aperture range of 0.5 to 2 mm and a microporous polytetrafluoroethylene membrane layer with an aperture range of 0.02 to 0.5 mm to prepare a polytetrafluoroethylene hollow fiber membrane. In addition to the production and preparation of the PTFE hollow fiber support, it is also necessary to cut and wrap the microporous PTFE membrane, which is a complex process and requires high equipment
Patent CN102284251A prepares polytetrafluoroethylene hollow fiber membranes by continuously wrapping polytetrafluoroethylene flat membranes on polyester (PET) fiber braided tube supports. Alkaline PET fiber braided tube is used as a support, which limits its application field
Patent CN102941025A mixes and presses the blank of polytetrafluoroethylene dispersion resin and extrusion aid through a pusher to form a polytetrafluoroethylene hollow tube, and longitudinally stretches and sinters the polytetrafluoroethylene hollow tube in an oven The polytetrafluoroethylene hollow fiber membrane is obtained by shaping. The polytetrafluoroethylene hollow fiber membrane obtained by this method has strong hydrophobicity and cannot be used for microfiltration separation. It can only be used for separation processes such as membrane distillation.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] a) Preparation of silica sol: Add ammonia water dropwise into absolute ethanol, the volume ratio of ammonia water and absolute ethanol is 1:50, stir at 40°C for 20 minutes to form a mixed solution of ammonia water and ethanol, and then add ammonia water and ethanol to the mixed solution Ethyl orthosilicate is added dropwise in the middle, the volume ratio of ammonia water ethanol mixed solution and ethyl orthosilicate is 1:50, stirs 60 minutes under 60 ℃, forms silica sol;

[0022] b) Mixing: Select polytetrafluoroethylene dispersion resin powder with a molecular weight of 2 million, mix polytetrafluoroethylene dispersion resin powder, liquid paraffin and silica sol in a mass percentage of 1:0.22:0.05, and statically mix at 40°C Place for 60 hours to fully mix the polytetrafluoroethylene dispersion resin powder, liquid paraffin, and silica sol to form polytetrafluoroethylene materials;

[0023] c) Compaction and extrusion: Press the polytetrafluoroethylene material on a...

Embodiment 2

[0028] a) Preparation of silica sol: Add ammonia water dropwise into absolute ethanol, the volume ratio of ammonia water and absolute ethanol is 5:50, stir at 40°C for 20 minutes to form a mixed solution of ammonia water and ethanol, and then add ammonia water and ethanol to the mixed solution Ethyl orthosilicate is added dropwise in the middle, the volume ratio of ammonia water ethanol mixed solution and ethyl orthosilicate is 10:50, stirs 120 minutes under 60 ℃, forms silica sol;

[0029] b) Mixing: Select polytetrafluoroethylene dispersion resin powder with a molecular weight of 10 million, mix polytetrafluoroethylene dispersion resin powder, petroleum ether and silica sol in a mass percentage of 1:0.40:0.20, and statically mix at 20°C Place it for 80 hours to fully mix the polytetrafluoroethylene dispersion resin powder, petroleum ether and silica sol to form a polytetrafluoroethylene material;

[0030] c) Compacting and extrusion: Press the polytetrafluoroethylene materia...

Embodiment 3

[0035]a) Preparation of silica sol: Add ammonia water dropwise into absolute ethanol, the volume ratio of ammonia water and absolute ethanol is 3:50, stir at 40°C for 20 minutes to form a mixed solution of ammonia water and ethanol, and then add ammonia water and ethanol to the mixed solution Ethyl orthosilicate is added dropwise in the middle, the volume ratio of ammonia water ethanol mixed solution and ethyl orthosilicate is 4:50, stirs 80 minutes under 60 ℃, forms silica sol;

[0036] b) Mixing: Select polytetrafluoroethylene dispersion resin powder with a molecular weight of 5 million, mix polytetrafluoroethylene dispersion resin powder, kerosene and silica sol in a mass percentage of 1:0.28:0.10, and let stand at 25°C After 70 hours, the polytetrafluoroethylene dispersed resin powder, kerosene, and silica sol are fully mixed to form polytetrafluoroethylene materials;

[0037] c) Compaction and extrusion: Press the polytetrafluoroethylene material on a compactor to form a ...

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Abstract

The invention discloses a method for preparing a hydrophilic polytetrafluoroethylene hollow fiber film. The method comprises: mixing polytetrafluoroethylene dispersed resin powder, extrusion aid and silica sol, compacting them, forming polytetrafluoroethylene hollow tubes by extruding blanks through an extruder, carrying out vertical stretching and thermoforming by sintering in a baking oven, and then obtaining the hydrophilic polytetrafluoroethylene hollow fiber film by a grafting reaction. An average aperture of the outer layer of the hydrophilic polytetrafluoroethylene hollow fiber film is 0.10-1.0mum, an average aperture of the internal layer is 5.0-20mum, the wall thickness is 0.1-0.5mm, and the water filtrating speed is 0.1-3m<3>/m<2>*h(filtrating pressure is 0.01-0.2MPa). The method is mainly used in a microfiltration separating process, and can be used in the fields of industrial waste water treatment, production material liquid pretreatment and seawater desalination pretreatment.

Description

technical field [0001] The invention relates to a preparation method of a hollow fiber membrane, in particular to a preparation method of a hydrophilic polytetrafluoroethylene hollow fiber membrane. Background technique [0002] my country's water resources are short, and more than 400 of the more than 600 cities in the country have insufficient water supply. Our country's rivers, lakes, domestic and industrial sewage need to be rectified urgently. At present, the membrane method is considered to be the most effective and cheapest way to treat sewage worldwide. Microfiltration is a membrane separation technology driven by pressure difference and intercepting particles with a particle size between 0.05 and 10 microns. It is mainly used in the advanced treatment and reuse of municipal sewage and industrial wastewater, drinking water purification, and reverse osmosis pretreatment. , Separation and refining of food and chemical products and other fields. In the microfiltratio...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01D71/78B01D69/08B01D67/00
Inventor 朱海霖郭玉海张萍陈清陈辉方琳美陈建勇
Owner ZHEJIANG SCI-TECH UNIV
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