COMPOSITION FOR PREPARATION OF HOLLOW FIBER POROUS MEMBRANE AND PREPARATION METHOD USING THE SAME

• US 20110147300A1
• Filed: 03/01/2011
• Published: 06/23/2011
• Est. Priority Date: 09/01/2008
• Status: Active Grant

• Current Assignee: Tianjin Polytechnic University
• Original Assignee: Tianjin Polytechnic University
• Inventors: XIAO, Changfa, AN, Shulin, HU, Xiaoyu, LIANG, Haixian
• Granted Patent: US 9,095,819 B2
• Time in Patent Office: Days
• US Class Current: 210/500.23
• CPC Class Codes: B01D 2323/081 Heating
• CPC Class Codes: B01D 2323/12 Specific ratios of components used
• CPC Class Codes: B01D 67/002 from melts
• CPC Class Codes: B01D 69/08 Hollow fibre membranes manufacture of hollow fibres D01D5/24, D01F1/08
• CPC Class Codes: B01D 69/087 Details relating to the spinning process
• CPC Class Codes: B01D 71/301 Polyvinylchloride
• CPC Class Codes: B01D 71/34 Polyvinylidene fluoride
• CPC Class Codes: B01D 71/54 Polyureas; Polyurethanes

Abstract

A composition for preparation of a hollow fiber porous membrane including 40-60 wt. % a polymer matrix, 20-30 wt. % an organic mixed solution, and 20-40 wt. % a water-soluble substance. The polymer matrix is a polymer capable of dissolving in an organic solvent and melt processing. The organic mixed solution is a mixture comprising 60-90 wt. % a first liquid soluble to the polymer matrix and 10-40 wt. % a second liquid insoluble to the polymer matrix. The water-soluble substance is a water-soluble polymer, a low molecular weight water-soluble particle, or a mixture thereof. A method for producing the hollow fiber porous membrane using the composition including a) preparing the organic mixed solution, b) mixing the components of the composition, c) applying melt spinning, d) drawing, and e) washing. The hollow fiber membrane has high strength, large flux, and low cost.

Claims

1. A composition for preparation of a hollow fiber porous membrane, the composition comprising

a) a polymer matrix 40-60 wt. %;

b) an organic mixed solution 20-30 wt. %, and

c) a water-soluble substance 20-40 wt. %;

wherein

said polymer matrix is a polymer capable of dissolving in an organic solvent and melt processing;

said organic mixed solution is a mixture comprising 60-90 wt. % a first liquid soluble to the polymer matrix and 10-40 wt. % a second liquid insoluble to the polymer matrix; and

said water-soluble substance is a water-soluble polymer, a low molecular weight water-soluble particle, or a mixture thereof.

2. The hollow fiber porous membrane of claim 1, wherein said polymer matrix is polyvinylidene difluoride, polyurethane, or polyvinyl chloride.

3. The hollow fiber porous membrane of claim 1, wherein said first liquid is dimethylacetamide, dimethylformamide, or dimethylsulfoxide.

4. The hollow fiber porous membrane of claim 1, wherein said second liquid is polysorbate, tetraethylene glycol, triethylene glycol, 1,3-butanediol, 1,4-butanediol, water, or a mixture thereof.

5. The hollow fiber porous membrane of claim 1, wherein said water-soluble polymer is polyethylene oxide, polyvinyl pyrrolidone, polyethylene glycol, polyvinyl alcohol, or a mixture thereof.

6. The hollow fiber porous membrane of claim 1, wherein said low molecular weight water-soluble particle is a micron inorganic particle and/or a micron organic particle, with an average particle size not more than 10 μ

m.

7. The hollow fiber porous membrane of claim 6, wherein said micron inorganic particle is lithium chloride, potassium chloride, sodium chloride, calcium chloride, or a mixture thereof.

8. The hollow fiber porous membrane of claim 6, wherein said micron organic particle is urea, sucrose, sodium glutamate, or a mixture thereof.

9. A method for producing a hollow fiber porous membrane using the composition of claim 1, the method comprising the steps of

a) uniformly mixing said first liquid with said second liquid in above-mentioned proportion to yield said organic mixed solution;

b) if said low molecular weight water-soluble particle used as said water-soluble substance, uniformly mixing said low molecular weight water-soluble particle with said mixed solution in above-mentioned proportion, and then mixing a resulting mixture with said polymer matrix;

or, if said water-soluble polymer used as said water-soluble substance, uniformly mixing said polymer matrix with said water-soluble polymer in above-mentioned proportion, and then mixing a resulting mixture with said mixed solution;

or, if said low molecular weight water-soluble particle and said water-soluble polymer both used as said water-soluble substance, mixing said polymer matrix with said water-soluble polymer and mixing said low molecular weight water-soluble particle with said mixed solution, respectively, and then mixing the resulting two mixtures uniformly;

c) melting an obtained mixture from step b) at a melting temperature of said polymer matrix±

30°

C., and extruding using a hollow fiber spinning pack; and

d) drawing an extrudant from step c) through a 15-100 mm steam bath or air bath, followed by through a first bath and a second bath, and washing said extrudant with water for more than 2 h under a tension for fixing length of follow fiber membrane;

said first bath being a cold water bath and said second bath being an air bath, water bath, oil bath, or steam bath, with a temperature≧

20°

C.

10. The method of claim 9, wherein said steam bath or air bath has a distance of 30 mm.

11. The method of claim 9, wherein said second bath is a steam bath or oil bath.

12. The method of claim 9, wherein prior to washing with water, said extrudant is washed with 1-98 wt. % an ethanol aqueous solution.

13. The method of claim 9, wherein said polymer matrix is polyvinylidene difluoride, polyurethane, or polyvinyl chloride.

14. The method of claim 9, wherein said first liquid is dimethylacetamide, dimethylformamide, or dimethylsulfoxide.

15. The method of claim 9, wherein said second liquid is polysorbate, tetraethylene glycol, triethylene glycol, 1,3-butanediol, 1,4-butanediol, water, or a mixture thereof.

16. The method of claim 9, wherein said water-soluble polymer is polyethylene oxide, polyvinyl pyrrolidone, polyethylene glycol, polyvinyl alcohol, or a mixture thereof.

17. The method of claim 9, wherein said low molecular weight water-soluble particle is a micron inorganic particle and/or a micron organic particle, with an average particle size not more than 10 μ

m.