DD212257A1 - METHOD FOR THE PRODUCTION OF HEAVY METALS ADSORBING POLYMERS ON ALIPHATE BASE - Google Patents

Abstract

The invention relates to a process for the preparation of adsorbents based on polymers of aliphatic structure, which are particularly well suited for the adsorption of heavy metals. These adsorbents are prepared by reaction of halogen-containing crosslinked and / or uncrosslinked polymers with amines to intermediates having at least one primary and any number of secondary amino group, which are reacted in a second reaction step to adsorbents with substituted thiourea groups by reaction with acyl isothiocyanates and / or mustardes and / or the reaction product of thiocyanates and aliphatic halocarboxylic acid esters and / or haloethers.

Description

245779 7

YEB CKEMIEKOMBIIiAT 3ITTSRi ¹ ELD 3itterfeld, 2. 12. 1S82

2313

Process for the preparation of heavy metal adsorbing polymers based on aliphatics

1. Field of the invention

Crosslinked polymers with sulfur-containing anchor groups are adsorbents with specific properties. Specifically, such polymers bearing thiourea or substituted thiourea have the ability to adsorb metal ions, in particular mercury and noble metal ions. Such polymers have the advantageous properties of highly adsorbing these metal ions even at low pHs and high premix salt concentrations. These properties open up new interesting possibilities in the field of separation and extraction of these metals and thus to solve raw material and environmental problems.

2. Characteristic of the known technical readings

The invention relates to adsorbents having substituted thiourea groups based on halogen-containing polymers of an aliphatic structure.

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Similar sorbents are described on the basis of condensation products, vinylaromatic polymers and aliphatic polymers based on aldehydes, thiourea, thiosemicarbazide and thiocarbazide Kondensatioiisprodukte be prepared with the appropriate properties (DE-OS 2128 302) Non-crosslinked vinyl aromatic polystyrene resins are described in DE-OS 2312 2. In addition to amino groups, they contain thiourea groupings. However, the adsorption capacity for heavy metal ions in the strongly acidic pH range is unsatisfactory These disadvantages were overcome by using styrene-divinylbenzene copolymers of specific porosity (DD-PS 1122 77, DD-PS 117 137, DE-OS 2 314 756, US Pat. DE-OS 2 364 368, DE-OS 2 ^ 29 944). The prerequisite is that these polymers have primary and / or 3ekundäure amino groups, which are then reacted with thiocyanic acid, salts of thiocyanic acid, thioureas or a mustard oil in the presence of a suspending agent to Thiourstoffgruppen-containing polymers.

Similar structures are described in SU-PS 523 113. Starting materials are chloromethyl-containing styrene-divinylbenzene copolymers or copolymers of г-Спіогте ^ уі-З-Ѵіпуірутіііпз, which are reacted with aromatic amines or diamines and then reacted in an acidic medium with ammonium thiocyanate to the thiourea adsorbent. DE-OS 2 312 233 discloses, among other structures, adsorbents based on halogen-containing aliphatic polymers. The following nitrogen-sulfur-containing groups are introduced by appropriate reactions of the aminated products:

Thiourea groups, isothiocyanate groups, thiosemicarbazide groups, thiobiuret groups, N-thioaminobiuret groups.

The preferred working range of these adsorbents is at the pH values of 3 to 7. The problems of targeted crosslinking and mechanical stability are thereby not eliminated. These

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shifts are improved by subjecting polyvinyl chloride to partial dehydrochlorination (DS-OS 2 326 366) and subsequently reacting with amines and a reagent of the G group thiazoi, dithiocarbaminate, thiourea, thioliguin, carbon disulfide, sodium sulfide, sodium bisulfite and thiocyanate. However, this did not solve the problem of the influence of pH and the better compatibility properties.

3. Object of the invention

The object of the invention was to produce thiourea-containing adsorbents based on halogen-containing aliphatic polymers having improved properties. Particular importance should be attached to a better complexing capacity and the exchange kinetics of the adsorbents for such metals as mercury, silver and other heavy metals.

4 * Presentation of the invention of the invention

The object of the invention was to react aalogenhal'ige aliphatic polymers so that thiourea group-containing polymers result in improved properties. Surprisingly, it has now been found that substituted thiourea-containing adsorbents obtained when halogen-containing polymers of aliphatic structure, which may be both crosslinked and unmatched, converted in a first Reakxionsschri't with amines to intermediates in the anionic group at least one primary and Contain any number of secondary amino groups, which are then reacted in a second reaction step to substituted thiourea groups entsaltenden adsorbents. The reaction is carried out with acyl isothiocyanates and / or mustard oils and / or the reaction product of thiocyanates and aliphatic halocarboxylic acid esters and / or halogen ethers. Particularly suitable halogen-containing polymers of aliphatic structure are polyvinyl chloride

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and chlorinated polyethylenes. The methods of reacting halogen-containing aliphatic polymers, especially those of polyvinyl chloride and chlorinated polyethylenes with amines, have already been described several times, as have the syntheses of the starting polymers. However, it is the Toraussetzung for the process according to the invention that only those amines are used for the amination reaction, the products with primary and / or selcundären amino groups provide. Suitable amines for the amination reaction are ammonia, monomethylamine, ethylenediamine, propylenediamine, 1,2-diaminopropane, diethylenetriamine, triethylenetetramine, tetraethylenepentamine or dipropylenetriamine. Preferred amines are ethylenediamine, diethylenetriamine and propylenediamine. The amines are advantageously reacted as aqueous solutions in the concentration range from SO to 90 percent by weight amine in the temperature range from 100 to 200 C at 1 to 24 hours reaction time.

Pur the process according to the invention favorable reaction conditions are in the consensus range of 75 to 30 weight percent Axain at 120 to 150 C and 6-3 hours of reaction time. The aminated products can be used as anion exchangers, which is also known. However, surprisingly, they can be converted in high conversions to adsorbents with substituted thiourea groups. For this purpose, the amine-containing products are completely converted into the free amine form by caustic treatment and reacted with acyl isothiocyanates and / or mustard oils and / or the reaction product of thiocyanates and aliphatic halocarboxylic acid esters and / or ealogenethem to form substituted thiourea group-containing adsorbents. As acylisothiocyanates isothiocyanates sit aliphatic, acid radical, such as. 3. represents acetyl group and the propionyl group as well as with aromatic acid radical, such as. 3. the 3enzyl group, are used. The acyl isothiocyanates can be z. 3, produce by simple reaction of the acid chloride with potassium thiocyanate.

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In addition to the examples mentioned, it is possible to use other acid chlorides as well as other inorganic and / or organic thiocyanates. Bine particularly advantageous variant of the method according to the invention consists in a Sintopfreaktion. For this purpose, for example Kaliuinthiocyanat be dissolved in acetone and benzoyl chloride added in portions and the reaction carried out at temperatures ranging from the room temperature to the boiling point. The amino-containing polymer is then added to the reaction solution, without isolation of the intermediate, and the reaction is carried out at 50-60 ° C. The by-products of the first reaction stage do not interfere. Elaborate isolation operations of isothiocyanates thus eliminated. Suitable solvents or suspending agents are liquids or mixtures which are inert to the reactants under the reaction conditions. For example, aromatics, ethers and ketones may be mentioned. Advantageously, those solvents are used which on the one hand are swelling agents for the polymers carrying amino groups and, on the other hand, solvents for the starting materials and intermediates

 Examples of preferred solvents for the reaction include acetone and cyclohexanone. The reaction conditions of temperature and time can be varied widely for both reaction steps. In general, temperatures of 20 C to the boiling temperature of the system and reaction times of 2 to 25 hours are sufficient. Both parameters are essentially dependent on the Are and the structure of the amino groups carrying polymers, liach same Reaktionsprinsi? and reaction conditions, halocarboxylic acid esters and halogenated ethers with thiocyanates can be converted to corresponding intermediates and these in turn with the aliphatic polymers containing amino groups

 Preferred halogenated carboxylic acid esters are, for example, methyl chloroformate and ethyl chloroacetate and monochloro-imidyl ethers for the formation of ethylethoxyl oil as alkali metal ethers.

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The erfindungsgenäß prepared substituted thiourea containing polymers have a good complexing ability and thus high Adsorptionsvermcgen for metals such as mercury and silver. They are particularly characterized by their high absorption capacity for mercury, even with a high proportion of premds and low pH values. The absorption capacity is 20 to 30 times higher than adsorbents of comparable structures based on aromatic polymers and acrylates.

The following exemplary embodiments are intended to explain the invention in more detail without restricting it to them.

example 1

120 g PVC with a diameter of 0.3 - 0.8 mm is heated with a mixture of 500 ml Athyldiamin and 14-4 ml of water for 6 hours at 120 C in an autoclave. After the excess amine has been sucked off and washed with water, the exchanger is treated with 5% NaOH for complete conversion into the anin form and subsequently washed with water until free of alkali and dried. In a sulfonating flask equipped with stirrer and thermometer, 60 g of KSCIi are dissolved in 400 ml of acetone and added dropwise 35 g of 3ensoylchlorid and stirred at 50 C for 4 hours. Subsequently, 40 g of the synthesized anion exchanger are added and stirred at 50 C for 15 hours. The product is washed with acetone and then with water. The analysis provides the following results:

Total weight capacity basic: 3.70 meq / g

'.Vas serge hai t: 52,4 : Ό

Total weight capacity of mercury: 9.95 meq / g

total volume capacity of mercury: 3 ₅ 1 <3 aval / ml

Total weight capacity of silver: 2.43 meq / g

Total weight capacity copper: 3 »5O nval / g

Elemental analysis: II: 3,13, o; 3: 4,77 ; <>

19 ^ U

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Example 2

In a sulphonation flask of the same equipment as in Example 1, 100 g of SSClT are dissolved in 400 g of acetone and 30 g of acetyl chloride are added dropwise and stirred at 55 G for 4 hours. Thereafter, 65 g of an aminated product, prepared analogously to Example 1, and stirred at 55 ° G for 15 hours. The product is separated, mix acetone and then washed with 7 / asser

 The analysis yields the following results:

Total weight capacity basic: Water content:

Total Weight Capacity Mercury: Total Volume Capacity Mercury: Total Volume Capacity Silver: Total Capacity Copper:

Slementaranalyse:

2.34 meq / g 57.7 £ 7.31 meq / g 2.95 aval / ml 3.10 meq / g 1.79 meq / g

IT: 9.70 = S; S: 5.23 #

Example 3

Analogously to Example 2, 100 g of KSCIi are dissolved in 400 si of acetone and 9.5 g of methyl chloroformate are sugetropft. The Ilachreaction occurs for 3 hours at 40 G and 1 hour at 55

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Below who

the 60 g of a, analogously to Example 1, sit amethylenediamine aminated

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Entered product in the amine form and stirred at 52 C for 10 hours. After the reaction, the product is separated and washed with acetone and water. The following analysis results are obtained:

Total weight capacity basic: 2.56 meq / g '"Vas sergehalt:

Gross Weight Capacity Mercury: Total Voids Capacity Mercury: Total Volume Capacity Silver: Total Volume Capacity Copper:

40.4 jS 9.21 aval / g 3.20 meq / g 4.72 mvai / g 2.27 meq / g

Slenentarsanalyse:

21: 3,63 £ i S: 9,19; «

M D. MRL 19 υ

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Example 4-

100 g of KSCU are dissolved in 400 ml of acetone in the same apparatus as in the previous examples and treated dropwise with l-lo nochlordimethyläther. Dia Uachreaktion success 6 hours at 50 G. Thereafter, 50 g of a product aminated in Example 1 are added and stirred at 55 C for 3 hours. The mixture is separated off, washed with acetone and subsequently with water, the following analytical results are obtained:

Total weight capacity basic: 2.71 meq / g

Water content: 37.3 ^

Total weight capacity of mercury: 9.20 meq / g

Total volume capacity of mercury: 3.37 nval / ml

Total weight capacity silver: 5.27 meq / g

Total weight capacity copper: 2.04 meq / g

Elementary analysis: U; 8.31 fo; S: 8.76 ίί

Example 5

In a sulphonation flask of the same equipment as described above, 50 g of KSCiI are dissolved in 250 ml of acetone and admixed dropwise with 63 g of ethyl chloroacetate and stirred at 55 ° C. for 3 hours. Add 3 lbs. Of a amеізріеі aminated product to the heatshape and treat at 55 ° C for 15 hours. It is separated and washed out as described. The analysis shows the following results:

Gross weight capacity basic: 3.44 meq / g

7 / water content: 66.7? »

Total Exposure Capacity Mercury: 3.60 meq / g

Total volume capacity of mercury: 2.75 meq / mi

Total weight capacity of silver: 0.53 meq / g

Total weight capacity copper: 3.60 meq / g

Segmental analysis: IT: 6.73 ) Ό; S: 1.6 fo

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Claims (1)

- 9 - 2313 245779 7 Statement of Authority 21 2 2 5 7 Process for the preparation of heavy metals adsorbing polymers on the basis of polishing aliphatic structure, characterized in that in the first reaction step halogen-containing crosslinked and / or uncrosslinked polymers, such as polyvinyl chloride and / or chlorinated polyethylene, with amines зи polymers having at least one primary and any number secondary .Aminogruppen are transferred in the anionic group, which are converted in a second reaction step to Adsorb en ti en with substituted Thiohamstofxgruppen by reaction with acyl isothiocyanates and / or mustard oils and / or the reaction product of thiocyanato and aliphatic halocarboxylic acid esters and / or Halogenäthem.