Microporous membrane and its preparing process and use thereof

A technology of microporous membrane and porous net, applied in chemical instruments and methods, membrane technology, semi-permeable membrane separation, etc., can solve the problems of slow development of industrial production, difficulty in large-scale industrialization, high spinning temperature, etc., and achieve production cost Effects of low cost, narrow pore size distribution, and simple manufacturing method

Inactive Publication Date: 2005-11-30
WUHAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, due to its high price and high spinning temperature, the development of industrial production is slow
In addition, it has been reported that cellulose and urea react at high temperature to form cellulose carbamate, which is then directly dissolved in dilute alkali to obtain spinning solution (Finnish Patent 61003; Finnish Patent 62318; U.S. Patent 4404369), but the amount of urea is high, Moreover, there are by-products, which are difficult to industrialize on a large scale

Method used

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  • Microporous membrane and its preparing process and use thereof

Examples

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Effect test

Embodiment 1

[0014] Take 8.4 g of cotton linter cellulose pulp (500 degree of polymerization), add 200 g of 7wt% NaOH / 12wt% urea mixed aqueous solution precooled to -10°C, stir at room temperature for 5 minutes, and the cellulose is completely dissolved. Centrifuge at 10,000 rpm at 15° C. for 30 minutes with an ultracentrifuge to degas it to obtain a transparent cellulose solution. Use a glass tube with copper wires (diameter 0.5mm) tied at both ends to scrape the film on the glass plate and immediately put it in 15°C and 15wt%Na 2 SO 4 After coagulation and regeneration in the aqueous solution for 15 minutes, take it out and rinse it with water. Wet membranes were kept in 2 wt% formaldehyde / 20 wt% isopropanol aqueous solution as porous membranes for separation and permeation etc. The wet membranes were directly subjected to pore size and water flux measurements. In order to measure its mechanical properties, the wet film is pasted on a plexiglass plate and dried naturally in the air to...

Embodiment 2

[0016] Take 8.4 g of cotton linter cellulose pulp (polymerization degree 500), add 200 g of 7wt% NaOH / 11wt% urea mixed aqueous solution precooled to -12°C, stir at room temperature for 5 minutes, and the cellulose is completely dissolved. Centrifuge at 10,000 rpm at 15° C. for 30 minutes with an ultracentrifuge to degas it to obtain a transparent cellulose solution. Use a glass tube with copper wires (diameter 0.5mm) tied at both ends to scrape the film on the glass plate and immediately put it in 25°C, 5wt% (NH 4 ) 2 SO 4 After coagulation and regeneration in the aqueous solution for 10 minutes, take it out and rinse it with water. Wet membranes were kept in 2 wt% formaldehyde / 20 wt% isopropanol aqueous solution as porous membranes for separation and permeation etc. The wet membranes were directly subjected to pore size and water flux measurements. In order to measure its mechanical properties, the wet film is pasted on a plexiglass plate and dried naturally in the air to...

Embodiment 3

[0018] Take 8.4 g of cotton linter cellulose pulp (500 degree of polymerization), add 200 g of 7wt% NaOH / 12wt% urea mixed aqueous solution precooled to -10°C, stir at room temperature for 5 minutes, and the cellulose is completely dissolved. Centrifuge at 10,000 rpm at 15° C. for 30 minutes with an ultracentrifuge to degas it to obtain a transparent cellulose solution. Use a glass tube with copper wires (diameter 0.5mm) tied at both ends to scrape the film on the glass plate, immediately put it in pure water at 25°C to solidify, regenerate for 15 minutes, take it out, and rinse it with water. Wet membranes were kept in 2 wt% formaldehyde / 20 wt% isopropanol aqueous solution as porous membranes for separation and permeation etc. The wet membranes were directly subjected to pore size and water flux measurements. In order to measure its mechanical properties, the wet film is pasted on a plexiglass plate and dried naturally in the air to obtain a regenerated cellulose film, which ...

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Abstract

The invention discloses a microporous barrier and its preparation and usage. The microporous barrier is made by cellulose and is air-entrapping structure with average pore size no more than 60nm and factor of porosity of 81-87%. The steps: dissolving cellulose in caustic soda and aquacare aqueous solution to produce concentrated cellulose solution; scratch membrane on glass plate by doctor blading process; congealing in coagulating bath to get microporous barrier. The invention has the advantages of narrow pore size distribution, fine penetrability, perfect mechanical property and light transmittance ratio.

Description

technical field [0001] The invention relates to a microporous membrane, a preparation method and application thereof, and belongs to the field of natural polymers, and also belongs to the fields of chemical engineering, agriculture, environmental engineering, and separation engineering. Background technique [0002] Plant cellulose is the most abundant renewable resource on earth and is expected to become one of the main chemical raw materials in the 21st century. However, traditionally, cellulose processing and film production is always through chemical modification, that is, converting cellulose into soluble cellulose derivatives, and then regenerating with solvents to obtain regenerated cellulose films, such as the common celluloid produced by the viscose method. Cellphane or regenerated cuprophane (Cuprophane) produced by the copper ammonia method (ZL 02132866.8). So far, the viscose method that has been industrialized to prepare cellophane has a history of more than 10...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08J5/18
Inventor 张俐娜茅源蔡杰周金平
Owner WUHAN UNIV
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