二氧化硫脲的制备

Preparation of thiourea dioxide

以硫脲和双氧水为原料,通过考察物料配比、溶液使用量、温度、pH值、母液循环利用、添加剂种类、养晶时间等诸多因素对二氧化硫脲收率的影响,优化了反应条件,提高了产品的质量和收率。实验结果表明,适宜的反应条件:温度为3~5℃,p H为4,最佳滴加双氧水的速度为6 s/滴,双氧水和硫脲配比为1.8∶1,溶剂为水,水用量为45 mL,反应时间为1.5 h,最佳添加剂为醋酸钾、碳酸氢铵,母液的循环使用的次数为1次。在该适宜的反应条件下,产品的收率>90%;而在以蒸馏水为溶剂的适宜的反应条件下,产品产率也达到了88%。

Thiourea dioxide was prepared by feed of two rawmaterials thiourea and hydrogen peroxide, during this synthetic process more parameters were consider, such as feed ratios, mother solvent, the volume of solvent, temperature, p H,different kind of additives, the crystal growth time, after think about those conditions more reasonable process was obtained and finally the quality of product and yield were promoted. Experimental results showthat the best technological parameters were confirmed, which temperature is 3~5 ℃, pH is 4, the feed ratios of hydrogen peroxide is 6 s/drop, feed ratios of thiourea and hydrogen peroxide is 1.8∶1, water is a good solvent for this process and the using amount is 45 mL, the whole reaction lasting 1.5 h, potassium acetate and ammonium bicarbonate are the prior additives for this reaction, during this process the total cycle index is 1. Based on this process, the final yield was beyond 90%, using water as reaction solvent the target productivity reached to 88%.