Method for forming porous polyurethane membrane

A polyurethane and porous membrane technology, applied in chemical instruments and methods, membrane technology, semi-permeable membrane separation, etc., can solve the problems of decreased membrane tensile strength and elongation at break, reduced membrane moisture permeability, and increased production costs , to achieve the effect of reducing production cost, large porosity and reducing dosage

Active Publication Date: 2013-07-03
WUHAN YONGSEN BIOTECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, there will be some large pores in the polyurethane porous membrane prepared by this method, resulting in a significant decrease in the tensile strength and elongation at break of the membrane.
On the other hand, the polyurethane surface in contact with water will form a dense layer due to the excessive exchange rate between solvent and non-solvent, which greatly reduces the moisture permeability of the film.
The preparation of polyurethane porous membrane by wet method will use a lot of water and other organic solvents, which will increase the production cost and cause serious environmental pollution.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0025] a. Preparation of casting solution

[0026] Due to the characteristics of thermoplastic polyurethane that can be completely dissolved by organic solvents, the solute of the casting solution can be selected from thermoplastic polyurethane CorthaneTM or 80A or 90A or ChronoflexAR or Chronoflex CL or Or one of Elast Eon or Cardiomat or Avcothane. The polyurethane is dissolved in an organic solvent, and the polyurethane is completely dissolved through thorough stirring to prepare a casting solution with a mass fraction of 10%-30%. Place the casting solution in a state of vacuum of -0.1~-0.2MPa for 1~3 hours, use the method of air removal to remove the air in the casting solution within the specified time, and obtain no bubbles, transparent and uniform casting solution.

[0027] Among them, 10-30 parts of polyurethane

[0028] Organic solvent 70~90 parts

[0029] The organic solvent is one of tetrahydrofuran or N,N-dimethylformamide or N,N-dimethylacetamide or N-met...

Embodiment 1

[0039] a Weigh 10g polyurethane (Corethane TM ), fully dissolved in 90g tetrahydrofuran to obtain a casting solution with a concentration of 10%. The casting solution was placed in a vacuum state of -0.1MPa for 1 hour to remove air bubbles.

[0040] b Ultrasonic atomization of distilled water with an ultrasonic atomization generator to prepare atomized microbeads with a size of 1-5 μm, and drain the atomized microbeads into a container equipped with a rocking shaker through a drainage tube, and keep In the state of continuous drainage of atomized microbeads, a heater is installed in the drainage tube to heat the atomized microbeads, and the heating temperature is 10°C.

[0041] c Pour the casting solution made in a into the film-making mold to form a casting solution layer with a thickness of 0.1 mm in the mold, and then place the mold on a swinging shaker surrounded by atomized microbeads. Make a rocking motion, the rocking angle is between 0 and 5 degrees, and the rocking f...

Embodiment 2

[0044] a Weigh 15g polyurethane ( 80A), fully dissolved in 85g N, N-dimethylformamide to obtain a casting solution with a concentration of 15%, and place the casting solution under a vacuum of -0.1MPa for 1 hour to remove air bubbles.

[0045] b Ultrasonic atomization of distilled water with an ultrasonic atomization generator to prepare atomized microbeads with a size of 1-5 μm, and drain the atomized microbeads into a container equipped with a rocking shaker through a drainage tube, and keep In the state of continuous drainage of atomized microbeads, a heater is installed in the drainage tube to heat the atomized microbeads, and the heating temperature is 20°C.

[0046] c Pour the casting solution made in a into the film-making mold to form a casting solution layer with a thickness of 0.5 mm in the mold, and then place the mold on a swinging shaker surrounded by atomized microbeads. Make a rocking motion, the rocking angle is between 0 and 10 degrees, and the rocking frequ...

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Abstract

The invention relates to a method for forming a porous polyurethane membrane, belonging to the technical field of membrane science and engineering. The method for forming the porous polyurethane membrane, provided by the invention, comprises the steps of: dissolving thermoplastic polyurethane in an organic solvent to prepare a membrane casting solution, immersing the membrane casting solution in an environment constituted by atomized microspheres which is prepared by an atomization device and used for solidification, and slowly performing a solidification forming process of the membrane casting liquor from outside to inside. According to the method, the forms of the microspheres on the surface and in the inner part can be effectively controlled in a forming process of the porous polyurethane membrane, and compact structures on the surface layer of the porous polyurethane membrane can be effectively reduced. The formed porous polyurethane membrane has the characteristics of uniformly distributed microspheres on the surface layer, no compact layer structure, uniform inner pore size, and large porosity. The method is simple to operate and has not pollution to the environment, and thedosage of an atomizing solution for solidification is lower. The prepared porous polyurethane membrane has a favorable waterproof breathability, and can be widely applied to the fields of clothes fabrics, leather, medical treatment and public health, and the like.

Description

technical field [0001] The invention relates to a forming method of a polyurethane porous membrane, which belongs to the technical field of membrane science and engineering. Background technique [0002] Polyurethane is an easy-to-process, low-cost high polymer. It has excellent performance, such as: wear resistance, good cold resistance, good hydrolysis resistance, good moisture permeability, simple molecular structure, no chemical pollution when burning in an incinerator, chemical corrosion resistance, good antibacterial properties, good low temperature flexibility, etc. , so it is a non-toxic and harmless environmental protection material, which has no harm to human skin, and is widely used in clothing fabrics, medical hygiene, leather and other fields. [0003] The pore size uniformity and porosity in the polyurethane porous membrane directly affect the various properties of the membrane. If the pore size of the polyurethane porous membrane is not uniform and there are ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B01D71/54
Inventor 杨红军叶青徐卫林李文斌崔卫钢
Owner WUHAN YONGSEN BIOTECH
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