Preparation of anti-reversion agent disodium hexamethylene-1,6-dithiosulfate dihydrate

Abstract

Anti-reversion agent disodium hexa-methylene-1,6-dithiosulfate dihydrate was synthesized using 1,6-dichlorohexane and sodium thiosulfate pentahydrate. The synthesis conditions of its crude product were investigated through orthogonal experiment and single factor experiments. In the recrystallization purification experiment, the solubility of sodium thiosulfate in ethanol-water solution system at different temperatures was combined to obtain the optimal ethanol concentration, recrystallization temperature and crystallization times in the recrystallization process. Finally, the synthesized product was analyzed by Fourier transform infrared spectroscopy, X-ray diffraction and thermogravimetry analysis-differential scanning calorimetry. The results showed that the optimum reaction conditions for synthesizing disodium hexamethylene-1,6-dithiosulfate dihydrate were as follows: mass fraction of 1,6-dichlorohexane 14%, mass ratio of ethanol to water 3/4, pH value of reaction system 9, and reaction temperature 83 ℃. At this time, the purity and yield of the crude pro-duct were the highest. The product with purity of over 97% and one-pass yield of over 80% could be obtained by using ethanol solution with mass fraction of 80% and recrystallizing twice at 20 ℃.

Keywords

• disodium hexamethylene-1
• 6-dithiosulfate dihydrate，anti-reversion agent，1