CS238421B1 - Cation resin preparation method with dithiocarbamate group - Google Patents

Abstract

The present invention provides a process for preparing a dithiocarbamate cation exchanger group. This is how an anion containing, in particular, secondary amine the group in the active form is left 24 hours in aqueous ammonium hydroxide or alkali hydroxide to a pH of 7.5 to 9. After by filtration, the anion is washed with distilled water water and 1 millimeter of exchange capacity of anion exchange resin was added 1mM ammonium hydroxide and 2 mimimoles of carbon disulfide. The resulting cation exchanger is capable of trapping metal ions from solution.

Description

The present invention relates to a process for preparing a cation exchange resin having a dithiocarbamate group.

The preparation of cation exchangers of this type and cation exchangers of this type are not described in the literature.

The process is described in a process for preparing a cation exchange resin having a dithiocarbamate group according to the invention, which comprises allowing the anion exchange resin containing the secondary amine groups in active form to swell for 24 hours in an aqueous solution of ammonium hydroxide or alkali metal hydroxide at pH 7. 5 to 9.0. After filtration, the anion exchanger is washed with distilled water until neutral and 1 millimole of anion exchange capacity is added with 1 millimole of ammonia in the form of an aqueous solution and 2 millimoles of carbon disulphide.

An advantage of the process according to the invention is that a dithiocarbamate group catheter is obtained which has advantageous properties useful, in particular, for trapping metal ions from solution. The exchange equilibrium is shifted in the direction of formation of the dithiocarbamate metal complexes, and therefore such an ion exchanger is particularly useful for preconcentration in trace analysis and further can be used to purify some electrolytes from contamination by some metal ions present in extremely low concentrations. In the method of preparation, a tightly bound dithiocarbamate group is synthesized on an organic backbone of a polymer or polycondensated type containing at least a secondary amine group by reaction in a mildly alkaline environment, which has advantageous properties in relation to binding - trapping of metal ions from solution, especially elements I, II. III. and IV. b subgroups of the Mendeleyev periodic system. The prepared cation exchanger has completely new, different properties than the ion exchangers produced hitherto.

The subject of the invention is illustrated by way of example.

Weigh 30 g of dry anion exchange resin based on polyethylene amine with primary, secondary and tertiary ion exchange groups into a 250 ml beaker. Its ion exchange capacity is 10 millimoles per g of raw material. (Wofalit L 150). Next, 150 ml of distilled water are added. 5% w / w aqueous ammonia solution. or sodium hydroxide of the same concentration, adjust the pH of the solution to 7.5 ± 0.2 and allow the anion exchange resin to swell for 24 hours with occasional stirring. The swollen anion exchanger is then filtered off and washed with distilled water in a volume of about 2 liters (until the filtrate is neutral) at room temperature. The soaked anion exchanger is introduced into a reaction flask to which 100 ml of distilled water, 90 millimoles of ammonia 30% solution are added, and 180 millimoles of carbon disulphide are added dropwise at a rate of one drop per second from the separatory funnel while stirring at room temperature. . After the addition of carbon disulfide, the reaction mixture was stirred for two hours. The prepared cation exchanger is then washed by decanting at least 6 times with 2 l of distilled water. The cation exchanger thus prepared is filtered through a filter funnel and allowed to air dry in a thin layer at room temperature for 24 hours.

The amount of bound dithiocarbamate groups is calculated by increasing the sulfur content of the ion exchanger before and after the synthesis of the dithiocarbamate group. The dithiocarbamate group cation exchanger so produced has a capacity per dithiocarbamate group of 1 to 2 millimoles per g of dry ion exchange resin.

The dithiocarbamate cation exchanger thus prepared can be advantageously used to reduce the metal ion content in aqueous solutions of different electrolytes and nonelectrolytes.

Claims (1)

SUBJECT Method for preparing a cation exchange resin with a dithiocarbamate group, characterized in that the anion exchange resin containing the secondary amine groups in active form is swollen for 24 hours in an aqueous solution of ammonium hydroxide or an alkali metal hydroxide The mixture is filtered and the anion exchanger is washed with distilled water and then 1 millimole of anion exchange capacity is added with 1 millimole of ammonia in the form of an aqueous solution and 2 millimoles of carbon disulphide.