SU1426983A1 - Solution for forming membrane - Google Patents

Abstract

The invention relates to the field of chemical technology, in particular to the preparation of semipermeable membranes for ultrafiltration based on celkhpos. The invention makes it possible to increase the section. The capacity of membranes is up to 89% due to the fact that a solution containing, in wt.%: cellulose, 2.1-7.2; diethylaminoethylcellulose 0.7-4.9 and solvent up to 100%. As a solvent, the solution contains a mixture of dimethylformamide, dimethyl acetamide or dimethyl sulfoxide with nitrogen oxide (IV) with a ratio of the components of the mixture (4-5): 1. (Or trifluoro-acetic acid. 2 tab.

Description

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This invention relates to chemical technology, in particular to the preparation of: semi-permeable P-G x cellulose-based ultrafiltration membranes. The aim of the invention is to increase the separating ability of cellulose membranes.

A composition of the following composition is prepared, wt%:

i Cellulose 1.75-7.0 Diethylaminoethylcellulose (DEAEC) C-5.25 Solvent 93 A mixture of 1 dimethylformamide (DMF) is used as a solvent for preparing the composition - examples 3, A, 5, 8, dimethylacetamide (DMAA) - example 6 or dimethyl sulfoxide; (DMSO is example 7 with nitrogen oxide (IV) 1 with a ratio of components of 4.3: 1. j For this 1.75-7.0 wt.% sulphate: cellulose with SC-60 and 0 -5.25 wt.% DEAEC T2 6 09-644-74 (total polymer weight 7.0 wt.%) Is dissolved in 93 wt.% DMF (or, DMSO) mixed with nitrogen oxide (IV) with their - 4.3: 1 ratio (for example, 75.5 wt.% DMF and 17.5 wt.% hydroxy and nitrogen (IV). Poluchenny solution is filtered, deaerated and coated using a slot die onto a substrate of non-woven polypropylene vderzhivayut 2 min brightening spirit and immersed in water.

The formed membrane is washed to a constant pH of the wash water.

Characteristics of the membranes are given in table. one;

Characterization of the membranes is carried out on an FM02-200 membrane filter at 0.1 MPa and 25 ° C. 0.1% -. Aqueous solutions of bovine (M 68000) and egg (M 45000) albumin are used as membrane calibrants. The capacity (G) of the membranes, the retention capacity with respect to the calibrating substances (R), and the degree of separation of solutes f are determined, where the retention coefficients for effective and egg albumin, respectively.

Example 10. Prepared similarly to the described composition of the following composition, wt.%:

Cellulose 7.2

DEAETS0,8

Solvent 92.0

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As a solvent, a mixture of DMFL and rxnd of nitrogen (IV) is used with a ratio of 4: 1 (73.6% by weight of DMF and 18.4% by weight of nitric oxide). The preparation of the membrane is carried out as described above.

The membrane capacity is 24.5 l / m h, RY 99%, RI 80%, F 19%.

Example 11. Preparing a composition of the following composition, wt.%:

Cellulose 3.5

DEAETS 1.5 Solvent 95

As the latter, a mixture of DMF and nitrogen (IV) oxide is used with a ratio of 5: 1, i.e. 79.2 wt.% DMF and 15.8 wt.% Nitric oxide.

The preparation of the membrane and the determination of its characteristics are carried out as described.

The productivity of the obtained membrane is 60.8, Ry 95%, RI 45%, p 50%,

Example 12. Preparing the composition according to its composition, wt.%:

Cellulose 7

DEAETS 1

TFUK 92

For this, 7% by weight of sulfate cellulose with SP-800 and 1% by weight of DEAEC are dissolved at 50 ° C in 92% by weight of anhydrous trifluoroacetic acid to form a transparent solution. The solution is filtered. It is deaerated, applied with a slit die with a fixed gap on the fabric backing and immersed in water. The formed membrane is washed off with water from the acid and its characteristics are determined.

The performance of the membrane is 50.7 R 98%, Kg 80%, P 18%.

The productivity of the membrane obtained from the solution, which does not contain the DEAEC cellulose composition: TFA 8.92 wt.%, Is 58.3 l / m h, K 98%, RI 95%, f 3%.

Example 13. Obtaining a known solution composition, wt.%:

Cellulose73

PVC .9

PAN11,5

Nitric oxide (IV) 8

DMFA96

314

On the basis of this relationship, the composition of the solution for the preparation of membranes was as follows, m.h: C 3.9j PVC 0.48, PAN 0.62; nitric oxide (IV) 7.3, DH # A 87.7.

Preparation of the solution is carried out by mixing two solutions of the following composition: solution I - C 3.9; nitric oxide (IV) 7.3 DMF 77.7 and solution II - PVC 0.48; PAN 0.62, DMF 10.0.

For this, 3.9 May, h. sulphate pulp with SP 820 is poured with a pre-prepared mixture of 7 7.3 May, h. nitric oxide (IV) and 77.7 May, h, DMF and stirred until a clear viscous solution was obtained, 0.48 May, h. PVC polyvinyl chloride brand C-70 and 0.62 mph., PAN nitrile polyacryl is poured on 10 May, h, DMF and dissolved for 30 min at 50 C. Then the solution is drained and stirred for 3 hours,

The formation of membranes is carried out by applying a thin layer of solution on a polished surface, followed by immersion in a precipitation bath (water at 20 s). The formed membrane is washed off of residual solvent and its filtration characteristics are determined.

The data obtained are given in table. 2,

Claims (1)

Invention Formula 1, A solution for forming membranes containing cellulose, a solvent and a modifying agent, characterized in that, in order to increase the separating capacity of the membrane network, the solution contains as a modifying agent diethylaminoethyl cellulose when the ratio of components, wt.%; Cellulose2,1-7,2 Diethylaminocellulose 0.7-4.9 Renter 2, Rathvor according to claim 1, characterized in that it contains as a solvent a mixture of dimethylformamide, dimethylacetamide or dimethyl sulfoxide with nitrogen oxide (IV) with the ratio of components (4-5): 1 or trifluoroacetic acid. Examples provided for comparison. Table 1 note membrane retention factors for bovine and albumin albumin, respectively, f is the degree of separation of solutes, Table 2