Method for preparing perfluoroalkyl ethanol

Abstract

The invention discloses a method for preparing perfluoroalkyl ethanol. The method comprises the following steps: enabling perfluoroalkyl ethyl iodide, a mixed solvent and water to react, and separating and purifying the obtained mixture containing perfluoroalkyl ethanol, by-product olefins, solvent salt and water, thereby obtaining the perfluoroalkyl ethanol product, wherein the separation and purification comprise the following steps: (1) adding a mixture containing perfluoroalkyl ethanol, by-product olefins, solvent salt and water into a rectifying tower for performing reduced pressure distillation, controlling the vacuum degree to be -0.91 to -0.96MPa so as to obtain distillate containing perfluoroalkyl ethanol, by-product olefins and water and bottom liquid, performing strong base treatment on the bottom liquid, and filtering to obtain the recycled mixed solvent; and (2) performing azeotropic distillation on the distillate, thereby obtaining the mixed solution of the by-product olefins and water and the product perfluoroalkyl ethanol. The method disclosed by the invention has the advantages of simplicity in process, greening, environment friendliness, convenience, high efficiency and low cost.

Description

technical field [0001] The invention relates to a preparation method of perfluoroalkyl alcohol, which belongs to the technical field of fluorine-containing fine chemicals. Background technique [0002] Perfluoroalkylethanol is an important intermediate for the synthesis of perfluoroalkyl surfactants and functional materials. It is widely used in various fields such as textile, military industry, electronics, aerospace, anticorrosion, chemical industry, etc., and its preparation method is a research hotspot in recent years. [0003] For example, the patent EP0247614B1 discloses a preparation method of perfluoroalkyl diols. First, the perfluoroalkyl diiodide, copper sulfate, acetonitrile, and water are reacted at 160° C. for 12 hours, and then the obtained reactant is mixed with 10% The NaOH solution was reacted at 70° C. for 2 hours to obtain 96% perfluoroalkyl glycol. [0004] Patent US685562 discloses a method of adopting CuO-loaded Si-P-Al catalyst and gas-phase hydrolys...

AI Technical Summary

Problems solved by technology

The disadvantage is that it requires high equipment and high reaction temperature, making it difficult to implement industrially

[0008] The above separation process needs to use a large amount of water for multiple washings in the liquid separation process, so a large amount of waste water is generated; the patent US4219681 needs to add low-carbon chain hydrocarbon alcohols in the azeotropic distillation, and finally produces alcohol waste liquid after separation

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