Three-layer polytetrafluoroethylene hollow fiber composite membrane

A polytetrafluoroethylene and fiber composite technology, applied in membrane, membrane technology, semi-permeable membrane separation and other directions, can solve the problems of weak bonding, poor surface wettability, easy peeling, etc., and achieve good industrial application prospects, Enhanced firmness, excellent mechanical properties

Active Publication Date: 2018-06-12
DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] PTFE hollow fiber membrane has high strength and high porosity, and has the advantages of acid and alkali resistance, high and low temperature resistance, and low surface friction coefficient. Preparation of Composite Membrane by Ethylene Hollow Fiber Membrane
At present, the polytetrafluoroethylene composite membrane is mostly composed of a separation layer and a polytetrafluoroethylene layer. The combination of the two is not firm and it is easy to peel off. Therefore, the concept of an intermediate transition layer is introduced.

Method used

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  • Three-layer polytetrafluoroethylene hollow fiber composite membrane

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] After sieving the PTFE dispersion resin through a 10-mesh sieve, uniformly mix it with 20wt% lubricant at 17°C, and then ripen it at room temperature for 24 hours, then pre-press, degrease, stretch and sinter to prepare a PTFE hollow fiber membrane. The average pore diameter is 1.4 μm, and the porosity is 60%.

[0016] Dissolve 1g of boric acid and 10g of KH-550 in 89g of ethanol, stir and reflux at 80°C for 10min to prepare the surface modifier.

[0017] Soak the PTFE hollow fiber membrane in the surface modifier for 5 minutes, take it out, dry it for 20 minutes, soak it again for 5 minutes, then dry it overnight, put it in an oven, bake it at 90°C for 15 minutes, and get the adhesion transition layer PTFE hollow fiber membrane.

[0018] Dissolve 14g of polyvinylidene fluoride (PVDF) and 8g of ethylene glycol in 78g of dimethylacetamide, mechanically stir for 12 hours at 65°C to prepare a casting solution, filter, and defoam.

[0019] Under 0.2MPa, the modified PTFE ...

Embodiment 2

[0021] After sieving the PTFE dispersion resin through a 10-mesh sieve, uniformly mix it with 20wt% lubricant at 17°C, and then ripen it at room temperature for 24 hours, then pre-press, degrease, stretch and sinter to prepare a PTFE hollow fiber membrane. The average pore diameter is 1.4 μm, and the porosity is 60%.

[0022] Dissolve 1g of boric acid and 20g of KH-550 in 79g of ethanol, stir and reflux at 80°C for 10min to prepare a surface modifier.

[0023] Soak the PTFE hollow fiber membrane in the surface modifier for 5 minutes, take it out, dry it for 20 minutes, soak it again for 5 minutes, then dry it overnight, put it in an oven, bake it at 90°C for 15 minutes, and get the adhesion transition layer PTFE hollow fiber membrane.

[0024] Dissolve 14g of polyvinylidene fluoride (PVDF) and 8g of ethylene glycol in 78g of dimethylacetamide, mechanically stir for 12 hours at 65°C to prepare a casting solution, filter, and defoam.

[0025] Under 0.2MPa, the modified PTFE ho...

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Abstract

The invention belongs to the technical field of membranes, and particularly relates to a three-layer polytetrafluoroethylene hollow fiber composite membrane. The composite membrane is composed of a surface separation layer, a transition layer and a polytetrafluoroethylene supporting layer; and the surface separation layer plays a role of separation, the transition layer plays roles in improving hydrophilicity of a polytetrafluoroethylene surface and strengthening combination of the separation layer and the polytetrafluoroethylene supporting layer, and the polytetrafluoroethylene supporting layer plays a role of skeleton. The three-layer structure is not only limited to a substrate part of the composite membrane, the interior of a membrane pore also has a three-layer structure, and the firmness of the composite membrane structure is further strengthened. The composite membrane provided by the invention has firm combination among composite membrane layer structures, good overall mechanical performance, and good industrial application prospects.

Description

technical field [0001] The invention belongs to the technical field of membranes, and in particular relates to a three-layer polytetrafluoroethylene hollow fiber composite membrane. Background technique [0002] Polytetrafluoroethylene is a highly crystalline polymer of tetrafluoroethylene monomer. It is a white waxy thermoplastic with a relative density of 2.1-2.3 and an elongation of 13%. It is highly crystalline. In PTFE, fluorine atoms replace hydrogen atoms in polyethylene. Since the radius of fluorine atoms is larger than that of hydrogen atoms, the covalent radius of fluorine atoms is larger and they repel each other. The entire macromolecule cannot be zigzag like the C-H molecular chain, C-C The chain is gradually twisted from the planar, fully stretched zigzag conformation of polyethylene to the helical conformation, which just surrounds the carbon chain skeleton that is vulnerable to chemical attack and forms a tight and completely "fluorinated" protective layer, w...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01D69/12B01D71/36B01D67/00B01D69/08
CPCB01D67/0002B01D69/08B01D69/12B01D71/36B01D2325/24
Inventor 康国栋于莎于海军董香灵王付杉曹义鸣
Owner DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI
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