DE2629542C2 - Cellulose ion exchangers and process for their production - Google Patents

Description

cellulose derivative shown diazotized and then by coupling of couplable, with metal ions Chelating groups implemented. These procedures are described in »Applied Macromolecular Chemie «50 (1976), 151 ff.

Ion exchangers of this type can be used both for the separation of trace elements from water or aqueous Salt solution as well as for the separation of trace elements from organic solvents or solvents · - s Mixtures are used, as described in detail in DE-OS 26 29 541

For cellulose exchangers of the type described, in which η = 1, the manufacturing process used so far can be represented by the following reaction equations:

(1) CeIl-OH - ^ = /,. CeIl-O-CH ₂ -CHr-SO ₂ - ^ f V-NH ₂

+ NaOH X /

+ DMSO

^r ~ S— N = N Cl-

_CeI1 _o_- _C H ₂ ~ CH ₂ -SO ₂ - /

(3) Cell-O-CH ₂ -CH ₂ -SO ₂

\ —N = N-

A certain disadvantage of this reaction can be seen in the fact that the yield of reaction (2) is only about 65% of theory and the yield of reaction (3) is only about 40-60% of theory. As a result, the cellulose exchangers produced in this way contain a considerable amount of free NH ₂ groups and, after decomposition of the diazonium groups formed according to equation (2), free phenol groups. Both groups can interfere with the ion exchangers on the functional group R.

Furthermore, from the German Offenlegungsschrift 22 13 381, a sorbent material for trapping metals known from aqueous solutions, the cellulose derivative containing substituted ammonium groups consists; an anion-forming metal reagent is ionic to the substituted ammonium groups bound. In particular, diethylaminoethyl cellulose and triethylaminoethyl cellulose were used as builder substances. With this sorption material, metals in ionic, complex or colloidally dissolved form or in sparingly soluble suspended form can be captured from solutions. The sorbent material can as such or in admixture with an inactive material, e.g. B. asbestos, quartz or preferably cellulose can be used. The invention relates to cellulose ion exchangers of the general formula

Cell-O-CH ₂ -CH ₂ -SO ₂ -X 'S-OH

where R is the remainder of a group capable of coupling and forming chelate complexes with metal ions and Cell is the Cellulose residue is.

Suitable functional groups R are derived from known metal reagents, for example from 8-hydroxyquinoline, tiron, chromotropic acid, l- (2-hydroxyphenylazo) -2-naphthol (Phan), alizarin S, morin, Dithizone, glyoxal-bis (2-hydroxyanil), N, N'-bis (salicylidene) -l, 2-diaminoethane (Sälen), 1,2-B: s (salicylideneamino) benzene (Salphen), ethylenediamine-N, N'-bis (o-hydroxyphenyl acetic acid) (Chel I), N, N'-di (2-hydroxybenzyl) ethylenediamine-N-N'-diacetic acid (Chel III), N- (2-hydroxybenzyl) ethylenediarnine-N, N ', N'-triacetic acid (Chel II), thioglycolic acid amide, diphenyl carbazide, salicylaldoxime, 5- (4-dimethylaminobenzylidene) rhodanine and thenoyl trifluoroacetone (TTA). These functional groups are each characterized by high distribution coefficients for certain ions, i. H. they are able to bind these metal ions with high selectivity. Table I therefore also gives the selectivity of the functional groups mentioned for certain metal ions as well as their ρΚ, values. It can be seen from this that in many cases chelate complexes with very high stability constants are formed by the ion exchangers of this type often even with a large one Excess of foreign ions, e.g. B. in concentrated salt solutions, are able to use whichever one they prefer To hold ions.

Ion exchangers in which R is the group are particularly preferred

OH

NH ₃

means.
These exchangers can be produced in almost complete yield according to the following reaction scheme:

NH ₂

(4) CeU-OH + Na ⁺ -O ₃ SO-CH ₂ -SO ₂ - ^ ^> - OH (I)

NH ₂

⁽⁵⁾ -CH ₂ -SO ₂ ^ ^ 0H (Π)

N = N ⁺ Cr

> Cell— Ο —CH ₂ -CH ₂ -SO ₂ - (T V-OH

N = N-R

(7) CeIl-O-CH ₂ -CH ₂ -SO ₂ -Cf> -OH (IV)

-HCl

In partial reaction (4), pulverulent or fibrous cellulose is first treated with the compound of the formula I in organic solvents such as dimethyl sulfoxide (DMSO) under the action of sodium hydroxide. This creates the cellulose derivative of the formula II. This depends on the reaction conditions a nitrogen content of 0.6 to 1.4 wt .-%. This then takes place in a manner known per se Diazotization of the compound of formula II, e.g. B. in 5 normal hydrochloric acid, which contains 1% sodium nitrite, for the connection of formula III.

This can then by simple coupling reaction to form an ion exchanger based on cellulose of the formula IV, where RH / i-naphthol ^ -naphthylamine, thenoyltrifluoroacetone (TTA), glyoxalbis (2-hydroxyanil), Ethylenediamine-N, N'-bis (o-hydroxyphenylacetic acid} or other compounds, which form chelate complexes with metal ions and are listed by way of example in the table. The emerging Cellulose ion exchangers have a capacity of 0.4 to 1.0 mmol / g.

The reactions (6) and (7) proceed in contrast to other diazotization and coupling reactions polymeric compounds with almost complete yield. Interfering amino and phenolic groups, as they are at the reactions (2) and (3) are obtained, practically do not occur here. So you get exchangers more uniform Composition.

In addition, the phenol radical in the 1-position and the diazo function in the 2-position can be used as additional Coordination points are used in ion exchange. So multidentate chelate exchangers are formed with selective properties.

Finally, by simple diazotization and coupling with a large number of different ligands RH, as mentioned in the table, produced a large number of selective cellulose ion exchangers will.

example 1

A cellulose exchanger of the formula IV, which contained the ur-hydroxy-8- ^ ß-naphthyl radical as the functional group R, was synthesized in three steps.

a) Representation of the cellulose derivative of the formula II

10 g (0.06 mol) of cellulose crosslinked with formaldehyde were _{suspended in 70 ml of dimethyl sulfoxide + 2 ml of H 2} O, and 6 g (0.15 mol) of powdered sodium hydroxide were added with stirring. The mixture was held at 75 ° C for one hour. Subsequently, 21.2 g (0.065 mol) of the compound of the formula I were added, and the reaction mixture was stirred at 75 ° C. for 15 hours. The reaction was terminated by adding 100 ml of 100% strength hydrochloric acid, and the reaction product was filtered off and washed several times with hot water and acetone. 9 g of the compound of the formula II were isolated. The substance had a nitrogen content of 1.27%. _{An H 2} N content of 0.9 mmol / g was calculated from the nitrogen analysis.

b) diazotization of the compound of formula II

5 g (0.03 mol) of the compound of the formula · II with the above H ₂ N-content of 0.9 mmol / g were suspended at 0 ⁰ C in 100 ml 5 N hydrochloric acid, and 20 ml of NaNO ₂ solution containing 2 g (0.029 mol) of NaNO _{2 was} added dropwise. The reaction mixture was ^{stirred at 0 °} C. for one hour. The resulting diazonium compound of the formula III was separated off as a canary-yellow substance by filtration through a glass frit and washed out several times at 0 ° C. with distilled water. The compound of the formula III was reacted further after a short time, as described under c).

c) Coupling of the resulting diazonium derivative of the formula III. with 2-naphthol

5 g of the diazonium compound of the formula III were added at 10 ° C. with stirring to 150 ml of 4.8% strength 2-naphthol (M solution, the pH of which had been adjusted to 12.5 with 2.2 g of NaOH a response time

After 5 minutes the dark reaction product was filtered off with water, acetone and dilute hydrochloric acid washed out and dried under reduced pressure. 4.8 g of exchanger were included l- (2'-Hydroxyphenylazo) -2-naphthol obtained as a functional group. The N content was 2.50%. Of the Exchanger of the formula IV shown in this way was in the Η form in 1 M NaCl solution with 0.1 N NaOH titrated. The titration curve, as well as the N analysis mentioned under a), showed a capacity of 0.9 mmol / g. The Η-form of the exchanger of the formula IV had a red color, in the Na-form it was Exchanger dark purple and became when loaded with heavy metal ions such as iron ions, copper ions or uranyl ions black-brown.

A further exchanger of the formula IV with /? - naphthylamine as the radical RH was prepared in an analogous manner.

Example 2

A cellulose ion exchanger of the formula FV with thenoyl trifluoroacetone (TTA) as a functional group was synthesized similarly to Example 1 in three steps. Steps a) and b) were identical to those in Example 1. In stage c) the following procedure was carried out:

c) 5 g of the diazonium compound of the formula III were added at 10 ^° C. with stirring to 150 ml of 4.4% strength TTA solution (130 ml of H ₂ O + 20 ml of methanol), the pH of which was 1.0 g of NaOH was set to 12.4. After 10 minutes the dark reaction product was filtered off, washed with acetone, dilute hydrochloric acid and distilled water and. dried under reduced pressure. 4.7 g of exchanger with thenoyl trifluoroacetone as the functional group were obtained. The N content was 2.40%. The titration curves with the N content resulted in a capacity of 0.85 mmol / g for the TTA exchanger. In the Η form the exchanger was red, in the Na form it was brown.

In an analogous manner, exchangers with functional groups R were prepared, which differ from the following Derive connections:

1. Glyoxal-bis (2-hydroxyanil)

2. Ethylenediamine-N, N'-bis (o-hydroxyphenylacetic acid)

3. 1,8-dihydroxynaphthalene-3,6-disulfonic acid (chromotropic acid)

The exchangers that have been prepared according to the method described are relatively resistant to acids and, depending on the type of functional group R, are characterized by a high selectivity. The resistance to acids is so high that in 0.1 molar HCl or HNO ₃ there is no noticeable loss of capacity within 24 hours, while in 1 molar HCl or HNO ₃ the capacity loss at room temperature is about 5% within 24 hours and in 3 molar HCl or HNO _{3 is} about 20% under the same conditions

The exchangers are used in the Η shape. The exchanger, which was produced according to Example 1, selectively exchanges Cu ²⁺ ions, and the glyoxal bis (2-hydroxyanil) exchanger exchanges UO ²⁺ ions. so

υιτ * ntuutusLUC] DlUU dULll ill ÄUlü & uilloitwii oiaiZjitsouixgfii, * .. υ, Ui \ jyj i-rx navrjuvouug, uif 111 11111 * 111 uauigu-

stops roughly equivalent to sea water, capable of selective exchange of the named ions. The logarithms the separation factors in 0.5 M NaCl solution for glyoxal-bis (2-hydroxyanil) in the pH range between and 7 for uranyl ions versus tin ions and nickel ions about 1.5, for copper ions versus zinc ions and nickel ions also about 1.5, for uranyl ions versus magnesium ions about 2.7 and for copper ions compared to magnesium ions also 2.7. (The separation factor gives the ratio of the distribution coefficients

Tabel

Functional groups 8-hydroxyquinoline

OH

Tiron

OH

HO ₃ S

OH

SO ₂ H

Chromotropic acid OH OH

HO ₃ S Phan

SO ₃ H

OHH O

Alizarin S

O OH

OH

SO ₃ H

Selectivity for (pKi values in brackets)

H ⁺ (9.5), Hg ²⁺ , Cu ²⁺ (13),

Fe ³⁺ (14.5), UO ₂ ¹⁺ (11), Lu ³⁺ (12)

H ⁺ (12), Fe ³⁺ (20.8), Hf ⁴⁺ (24.7), Cu ²⁺ (14), Al ³⁺ (17)

H ⁺ (14), Fe ³⁺ (23), Al ³⁺ (17.4), UOl ⁺ (16.6), Cu ²⁺ (13.3)

H ⁺ (12.4), Cu ²⁺ (23), Hg ²⁺ , UO ²⁺ ,

Al ³⁺ , Zr ⁴⁺ , Se ³⁺ , Y ³⁺ , lanthanides

Morin

HO

HO

OH

OH

Al ³⁺ , Be ²⁺ , Se ³⁺ , Ga ³⁺ , In ³⁺ , Ti ⁴⁺ , Zr ⁴⁺

continuation

Functional groups

Selectivity for (pKp values in brackets)

Dithizone

N = N-

S = C

NH-NH-

HiS metals

Glyoxalbis (2-hydroxyanil)
CH-CH

/ V

N N

, 2 + r. ,, 2+

OH

OH

Halls

N-CH ₂ -CH ₂ -N CH CH

(OI) А9

OH OH

Salpha

N N

/ V

CH CH

OH

HO

Chel I

COOH CH ₂ -CH ₂ HOOC I / VL

CH-NH NH-CH

Chel II

CH ₂ COOH CH ₂ COOH

CH ₂ -N-CH ₂ CH ₂ -N-CH ₂

OH

HFO

UOf, Cu

H ⁺ (11), UOl ⁺ (21), Ni ²⁺ (5)

<2b),

Subgroup elements

H ⁺ (Γ2), Fe ³⁺ (40), Cu ²⁺ , Lu ³⁺ (20) other subgroup elements ¹ Ph 20 (values as for EDTA)

continuation

Functional groups

Chel III

HOOC-CH ₂ CH ₂ COOH

I /

N-CH ₂ CH ₂ N

CH ₂ CH ₂ COOH

OH

N- (2-hydroxybenzyl) iminodiacetic acid

CH ₂ COOH OH /

CH ₂ -N

[j] CH ₂ COOH

Thioglycolic acid amide (I) '

-NH-CO-CH ₂ -SH

Selectivity for (in brackets ρΚ, values)

Subgroup ions Hg ²⁺ , Cd ²⁺ , H ₂ S metals

Thioglycolic acid amide (II)

NH-CO - CH ₂ -SH

Diphenyl carbazide

NH-NH-

O = C

NH-NH-

Salicylaldoxime
OH

Hg ²⁺ , Cd ²⁺ , H ₂ S metals

Cd ²⁺ , Hg ²

Cu ²⁺ , Fe ³⁺ , Pb ²⁺

5- (4-dimethylamino-benzylidene> rhodanine HN CO

Au ³⁺ , Pd ²⁺ , Pt, Ag ⁺

1629542

continuation

Functional groups

Thenoyl trifluoroacetone

CO — CH ₂ —CO — CE ₃

Nitrosonaphthol

OH

OH

2,4-diamino- (pyridyl-2-azo> benzene (5-U-PADAB) H ₂ N

NH,

4,4'-bis (-dimethylamino) -thiobeiizoptienoii S.

(CHj) ₂ N

C -N (CH ₃ ),

4-methoxy-2- (thiazolyl-2-azo) phenol (TAM) OCH ₃

N = N

OH

2,2'-Iminodibenzoic acid (vanadone) COOH HOOC

Chel IV

Selectivity for (in Hammer pK _r values)

three-valued metaUions, four-valued metaUions

Co ²⁺ , Cu ²⁺ , Ni ²⁺

^ Co ²⁺

Hg ²⁺ ^ Pd ²⁺

Hg ²⁺ (very selective)

VOj, Cu ²⁺ , Ni ²⁺

Claims (3)

Patent claims: 1. Cellulose ion exchanger of the general formula CEU O-CH ₂ - CH ₂ -SO ₂ - (^ O OH N = N-R where R is the remainder of a group capable of coupling and forming chelate complexes with metal ions and Cell is the Cellulose residue is. 2. Ion exchanger according to claim 1, characterized in that R is the group OH or NH, is. 3. A method for the production of ion exchangers according to claim 1 or 2, characterized in that that you get the compound of the formula Na ⁺ "O ₃ S O - CH ₂ - CH ₂ -SO ₂ reacts with cellulose in the presence of alkali, diazotized the cellulose derivative obtained and then couples with couplable compounds that form chelate components with metal ions. From the German Offenlegungsschrift 24 37 594 an ion exchanger based on cellulose is of the formula R-N = SO ₂ -CH ₂ -CH ₂ -O-Cell known, in which R is a group which forms chelate complexes with metal ions, η = O or 1 and Cell is the remainder of the cellulose molecule. Suitable functional groups R are derived from known metal reagents, for example from 8-hydroxyquinoline, tiron, chromotropic acid, l- (2-hydroxyphenylazo) -2-naphthol (Phan), alizarin S and Morin. Such cellulose-based ion exchangers can be produced in various ways. On the one hand, when η in the above formula = O, it is possible to react cellulose or cellulose-like compounds with S-hydroxyethyl sulfone derivatives, the compound preferably being R-SO ₂ -CH ₂ -CH ₂ -O-SO ₃ Na is reacted with cellulose. Here, R has the meaning described above. Another method for producing such ion exchangers is used when η = 1. Then the cellulose and an amino derivative des./?-Hydroxyethylsulfons, z. B. PH ₂ NC ₆ H ₄ -SO ₂ -CH ₂ -CH ₂ -O-SO ₃ Na