CN87106024A

CN87106024A - The preparation method of reclaimed cellulosic porous membrane

Info

Publication number: CN87106024A
Application number: CN87106024.8A
Authority: CN
Inventors: 张俐娜; 肖玲; 程淑玉; 聂学光
Original assignee: Wuhan University WHU
Current assignee: Wuhan University WHU
Priority date: 1987-08-28
Filing date: 1987-08-28
Publication date: 1988-04-06
Also published as: CN1009901B; CN1037843A; CN1004050B

Abstract

The invention discloses the several method of preparation reclaimed cellulosic porous membrane.Adopt cotton, Mierocrystalline cellulose, sulphate cellulose (M η=0.77～20 * 10 ⁴) cadmium ethylenediamine, cupri ethylene diamine, cuprammonium or Paraformaldehyde 96/dimethyl sulphoxide solution, prepared the Hydrophilized porous membrane of a series of mean pore sizes with casting method from 20-400 , but these film organic solvent-resistants, obdurability is better.The semi-permeable membranes that is used as membrane osmometer has selects perviousness preferably, can reach osmotic equilibrium rapidly.It is better to be used for the different sized molecules effects of polymers soln ultra-filtration and separation.They also can be used as dialysis tubing, the separation under low temperature or room temperature of various polymkeric substance or microbial solution, concentrate, medical macromolecular materials such as purification film and artificial kidney, pancreas.

Description

Reclaimed cellulosic porous membrane belongs to a kind of important novel material-functional membrane in the field of fine chemical, is typical hydrophilic film.

Since the seventies, the functional membrane development is very rapid, and principal item has soluble cotton, cellulose acetate, mixed cellulose ester, polymeric amide, tetrafluoroethylene, polyvinyl chloride, regenerated cellulose etc.In recent years, various countries are more to the research of good comprehensive properties regenerated cellulose film, Soviet Union certificate of invention Su, 1047 928(1983), the clear 56-24008(1981 of day disclosure special permission communique), clear 58-89625(1983), West Germany's monograph 3002438(1980) mention respectively with copper ammon solution and prepare regenerated cellulose film or artificial silk.French Patent N ⁰8106153(1981), day clear 60-187307(1985 of disclosure special permission communique) all mention with organic solvent such as LiCl/N-methyl-2-pyrrolidone, LiCl/ N,N-DIMETHYLACETAMIDE, formulations prepared from solutions regenerated cellulose films such as Paraformaldehyde 96/dimethyl sulfoxide (DMSO).Soviet Union magazine Ж П Х 41(10) 1968 mention with cadmium ethylenediamine formulations prepared from solutions regenerated cellulose film, industrial of famous Japanese Asahi Chemical Industry fiber research adopts the copper ammon solution that contains other positively charged ion and solvent to prepare various regenerated cellulose films.It is substantial different that the present invention and above-mentioned prior art have, and proposed the novel method of preparation reclaimed cellulosic porous membrane.

Main points of the present invention are that Mierocrystalline cellulose can be dissolved in some metal ion complex solvent with complex form, also can be dissolved in to contain N ₂O ₄, LiCl or Paraformaldehyde 96 several organic solvent systems.In Paraformaldehyde 96/dimethyl sulfoxide solvent, the primary hydroxyl methylolation on 6 of the Mierocrystalline celluloses, thus dissolving forms cellulose solution.

According to membrane formation mechanism, as cellulosic solvent, more be poor solvent, can promote crystallite to form more, so key problem in technology is to solidify the preceding solubleness that reduces cellulose solution.Comparatively freezing film helps its regularity under the demulcent condition, peptizer should be able to dissolve each other with cellulosic solvent and don't make cellulose dissolution, select the mixed solvent of organic solvent or organic solvent to make peptizer, the cellulose complex compound structure can not only be destroyed effectively and process of setting relatively relaxes, simultaneously, organic solvent is easy to reclaim by distillation.

Mierocrystalline cellulose cadmium ethylenediamine solution is more stable than copper ammon solution, and the content of its solvability and CdO and quadrol has substantial connection.As CdO: quadrol: water=7.4: 27: in the time of the 65.6(weight ratio), it have very strong dissolving power to fiber, and reduces with temperature and to increase.This solvent is placed certain hour in air after, owing to the quadrol volatilization causes that change of component becomes poor solvent.This cellulose solution is the alkali salt complex compound, so diluted acid, and organic acid, organic solvent and mixes with small amount of water solvent or alcohol can be used as peptizer.Behind the film coagulation forming, can improve its transparency carrying out drying treatment below 70 ℃; But the mean pore size of film can reduce 6-7 doubly.

Paraformaldehyde 96 in fibrination polyoxymethylene/dimethyl sulphoxide solution need be removed with high temperature (more than 100 ℃) gasification,, all will heat-treat before and after solidifying for this reason.Alcohols, organic solvents such as tetrahydrofuran (THF) can be used as peptizer.When making peptizer with alcohol, the film mean pore size increases with pure carbon atom number.Table 1 illustrates with the different influences to permeability with its peptizer under the filming condition of a kind of prescription.In addition, this film is better to solvent adaptability, when they use as the semi-permeable membranes of permeameter, converts toluene solvant to from dimethyl formamide, adapts to after 2 hours, with dynamic osmometry mensuration polystyrene standards (M _n=41.56 * 10 ⁴, Japanese Japan Cao Da) number-average molecular weight, measurement result M _n=42.2 * 10 ⁴Coincide with set-point, and osmotic pressure discrepancy in elevation H is fine to the linear relationship of volumetric flow rate (dv)/(dt) mapping.They also have higher low molecular retention rate than the similar film RC52 of the U.S..

Cuprammonium or cupri ethylene diamine solvent be dissolving cellulos comparatively fast, because their easy oxidative degradation, so must add antioxygen such as Na ₂SO ₃, sucrose.When adopting the 10%NaOH aqueous solution to make peptizer, film shrinks terrible, is generally about 60%, adopts organic solvent then can obviously reduce shrinking percentage as peptizer, in 5%.Using 87% dimethyl formamide/11% water, 2% quadrol to make peptizer, to obtain shrinkability little, the film that obdurability is good.

Table 1

Peptizer methanol Virahol n-Octanol

Perviousness is in the dimethyl formamide 0.87 2.66 4.88 29.7

G×10 ¹³/cm ³sg ^-1

Bore dia/

20 37 47 122

Porosity/% 53 50 56 50

With method for preparing the aperture from 20

To 400

Various apertures reclaimed cellulosic porous membrane.The strong Firmware of these films, organic solvent such as ability tetrahydrofuran (THF), toluene, ketone, alcohols, dimethyl methyl methane amide and diluted acid, dilute alkaline aqueous solution.They have selective permeation speed preferably.Separate as semi-permeable membranes in the membrane osmometer and polymkeric substance, spissated ultra-filtration membrane all obtains effect preferably.They also can be used as dialysis tubing, various polymkeric substance or microbial solution low temperature, room temperature condition separate down, concentrated, purification film, medical macromolecular materials such as artificial kidney or pancreas, use cheap timber, agricultural-product (bagasse, Pericarppium arachidis hypogaeae) is made broad-spectrum functional membrane and is had higher economic worth.

One of embodiments of the invention are, the 110ml quadrol is dissolved in the 240ml water, add 27g Cdo and stirred 1 hour under 0 ℃ of condition, obtain water white transparency cadmium ethylenediamine solution, store standby down at 0 °-5 ℃.

1g Mierocrystalline cellulose (M _η=16.6 * 10 ⁴) and 1g cotton (M _η=20 * 10 ⁴) be dissolved in the 60ml cadmium ethylenediamine solution, stir under 0-5 ℃ and became transparent thick liquid in 30 minutes, after filtration, after the degassing, with two ends is Glass tubing knifing on sheet glass that copper wire (diameter 0.3mm) is arranged, and places 1 hour under 30 ℃ of conditions in Fume Hoods, puts in the peptizer then, film is peeled off from sheet glass naturally about 1 hour, successively at 4% sulfuric acid, plasticising in 20% glycerine is kept in 20% Virahol/2% formalin at last after the water flushing.After oven dry under 70 ℃ of conditions, the film mean pore size is by 140

Reduce to 20

As having of above-mentioned peptizer: 10% acetic acid, 80% dimethyl formamide/18% water/2% quadrol, 90% ethanol or methyl alcohol.

Two of embodiments of the invention are: 6g sulphate cellulose (M _η=1.9 * 10 ⁴Be dissolved in the 220ml dimethyl sulfoxide (DMSO), with the 3g cotton at N ₂110 ℃ were heated 3 hours in the gas, add the 28g Paraformaldehyde 96 again, continue stirring down at 115 ℃ and made dissolving in 2 hours, after filtration, carry out knifing (thickness 1mm) after the degassing, again successively at 100 ℃ of hot air driers, placed respectively in the room temperature Fume Hoods 20 minutes, put into then in the peptizer more than 2 hours, take out the back on 60 ℃ of flat boards dry 3 hours, plasticising and boil film is peeled off in 20% aqueous glycerin solution at last has organic solvents such as methyl alcohol, ethanol, Virahol, n-Octanol as above-mentioned peptizer.

Three of embodiments of the invention are, 2g Mierocrystalline cellulose and 2g cotton be dissolved in the 50g cupri ethylene diamine (mol ratio is a copper: quadrol: water=1.2: 2.3: 45) and the 50g cuprammonium (mol ratio is a copper: ammonia: in mixed solvent water=0.4: 4.5: 45), add 0.8g Na ₂SO ₃Cellulose solution after filtration, the degassing after, knifing on sheet glass (thickness 0.25mm), in Fume Hoods, placed 1 hour under 30 ℃ of conditions again, put into then in the solidification liquid to blue decoloration, again successively at 10% acetic acid, placed respectively in 4% aqueous sulfuric acid 10 minutes, and washed back plasticising 1 hour in 20% aqueous glycerin solution, be kept in 20% Virahol/2% formalin.As above-mentioned peptizer 87% dimethyl formamide/11% water/2% quadrol, 95% ethanol etc. are arranged.

Claims

1, a kind of preparation method of reclaimed cellulosic porous membrane is characterized in that:

1.1 in weight ratio is CdO: quadrol: dissolving cellulos in the cadmium ethylenediamine solvent of water=7.4: 27: 65.6;

1.2 above-mentioned cellulose solution is delayed at dull and stereotyped upper reaches under 30 ℃ of ventilation conditions and placed 1 hour, puts into and carries out coagulation forming in the peptizer, said peptizer is 10% acetic acid, 80% dimethyl formamide/18% water/2% quadrol, 95% ethanol or methyl alcohol;

1.3 handle and be kept in 20% isopropanol water solution with 4% sulfuric acid at ambient temperature behind the cellulose solution freezing film, after this film drying treatment, the aperture is from 140

Reduce to 20

2, a kind of preparation method of reclaimed cellulosic porous membrane is characterized in that:

2.1 dissolving cellulos in 12.7g Paraformaldehyde 96 and 100ml dimethyl sulfoxide (DMSO) mixed solvent;

2.2 above-mentioned cellulose solution is delayed at dull and stereotyped upper reaches, place 100 ℃ of hot air driers successively, placed respectively in the room temperature Fume Hoods 20 minutes, put into and carry out freezing film in the peptizer, said peptizer is a methyl alcohol, ethanol, Virahol or n-Octanol, to with a kind of prescription, the carbon atom number of alcohol reduces to 1 from 8, and the film mean pore size reduces to 20 from 122

;

2.3 behind the cellulose solution freezing film, under 60-70 ℃ of condition, put in 20% glycerine plasticising after the aftertreatment again and boil film is peeled off.

3, a kind of preparation method of reclaimed cellulosic porous membrane is characterized in that:

3.1 cupri ethylene diamine (mol ratio is a copper: quadrol: water=1.2: 2.2: 45) and cuprammonium (mol ratio is a copper: ammonia: dissolving cellulos in the mixed solvent (1: 1) water=0.4: 4.5: 45);

3.2 above-mentioned cellulose solution is delayed at dull and stereotyped upper reaches, places 1 hour under 30 ℃ of ventilation conditions, puts into peptizer then and carries out coagulation forming, said peptizer is 87% dimethyl formamide/11% water/2% quadrol;

3.3 behind the cellulose solution freezing film, successively in 10% acetic acid, placed 15 minutes in 4% aqueous sulfuric acid, water is rinsed well then, is kept in 20% Virahol/2% formalin.