SU1315455A1 - Method for removing hexyl alcohol and admixtures of mono- and dihexylphosphoric acids from trihexylphosphate - Google Patents

Abstract

This invention relates to the chemistry of organophosphorus compounds, in particular to the purification of trihexyl phosphate (THF) from hexyl alcohol and impurities of mono- and dihexylphosphoric acids. Increasing the purity of THF is achieved by using other raw materials and other process conditions. Purification is carried out by diluting technical THF with hexane followed by treating the resulting solution with an alkaline dimethylsulfoxide solution. Then a layer containing trihexphosphate in hexane is separated and treated (2 times) with dimethyl sulfoxyde. Hexane is distilled off. The method allows THF to be purified not only from impurities of an acidic nature, but also from impurities of hexyl alcohol. with SP 4 SL

Description

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This invention relates to the chemistry of organophosphorus compounds, namely to an improved method for purifying trihexyl phosphate (THF) from hexyl alcohol and impurities of mono- and dihexyl phosphoric acids; High purity THF. Is used in the manufacture of highly sensitive ion-selective electrodes.

The aim of the invention is to increase the purity of the trihexyl phosphate.

Example 1. 10 ml of THF containing 0.5 M / l of acid impurities diluted with hexane in a 1: 1 volume ratio are shaken with 10 ml of dimethyl sulfoxide (DMSO) for 1-2 minutes. After delamination, the THF phase is washed with an equal volume of water from traces of dimethyl sulfoxide, and the hexane is distilled off under reduced pressure. Acidic impurities in THF are determined by potentiometric titration with a solution of potassium hydroxide in ethanol. As an indicator electrode, an ESL-43-07 glass electrode is used. The reference electrode (EVL-1MZ) is filled with 10 M / l solution (C | gHj) NBr in methyl alcohol. The content of acidic impurities in the finished product 2 H O M / L. Hexyl alcohol is determined by gas chromatography. Its content after cleaning is reduced by 3-4 times.

Example2. 10 ml of THF containing 0.5 M / L acidic impurities are diluted with hexane in a 1: 1 volume ratio, shaken twice with 10 ml of DMSO for 1-2 minutes; After separation of the mixture into phases, the trihexyl phosphate phase in hexane is treated with an equal volume of water, the hexane is distilled off. The content of hexyl alcohol in the final product is 0.5-0.7% by volume, the content of acidic impurities is 2 M / l,

Example 3. 10 ml THF containing 0.5 M / l acid impurities is diluted with hexane in a 1: 1 volume ratio and shaken with 10 ml of a water-dimethyl sulfoxide KOH solution (2 M). Then phase THF in hexane ob52

Work out 2-3 times with water, hexane is distilled off under reduced pressure. The content of acidic impurities in the final product is 1-10 M / l, the content of hexyl alcohol is about 14%.

Example4. 10 ml of THF containing 0.5 M / l of 1 acid mixes are diluted with hexane in a 1: 1 volume ratio, shaken with 10 ml of water-dimethyl sulfoxide KOH solution (1 M), then the THF in hexane is treated with pure dimethyl sulfoxide and 2-3 times with water. Hexane is distilled off. The content of acidic impurities in the final product is 1-10 M / l, the content of hexyl alcohol is 1.4%.

Example5. 10 ml THF containing 0.5 M / l acid impurities is diluted with hexane in a volume ratio of 1: 1 and shaken with 10 ml of an aqueous dimethyl sulfoxide KOH solution (2 M). Then, another 10 ml of dimethyl sulfoxide is treated twice, washed with an equal volume of water, and the hexane is distilled off under reduced pressure. The content of acidic impurities L-10 M / L, hexyl alcohol remains in trace amounts.

Thus, the use of the proposed method allows to purify THF not only from impurities of an acidic nature, but also from impurities of hexyl alcohol.

Claims (1)

Invention Formula The method of purifying trihexyl phosphate from hexyl alcohol and impurities of mono- and dihexyl phosphoric acids by diluting technical trihexyl phosphate with hexane and treating the resulting solution with an alkaline agent, characterized in that, in order to increase the purity of the trihexyl phosphate, dimethyl sulfonium is used as an alkaline agent. layer containing three-. hexyl phosphate in hexane, twice treated with dimethyl sulfoxide and hexane distilled.