尿素液相热解合成氰尿酸的研究

摘要

Cyanuric acid was prepared by liquid-phase pyrolysis of urea in the solvent.Through a large number of contrast tests,an appropriate solvent RJ-X was determined.The process conditions for the synthesis of cyanuric acid from liquid-phase pyrolysis of urea in the solvent RJ-X were optimized.The effects of charging method,catalyst,feed ratio,reaction time and times of solvent recycle on the reaction were investigated.The results showed that the appropriate reaction conditions were as follows:charging method A,no catalyst,the ratio of urea and the solvent 1:3.0 (g/mL),reaction time 5 h,nitrogen as shielding gas,solvent recycle nine times.Under the conditions,the yield of cyanuric acid was 84.3％,the purity was 98.8％ and the color of the product was white.The product was characterized by IR,the spectrogram was exactly the same as that of commercially available products.%以尿素为原料,在溶剂中液相热解制备氰尿酸.通过大量对比试验,确定了一种较适宜的溶剂RJ-X.对以RJ-X为溶剂将尿素进行液相热解反应合成氰尿酸的工艺条件进行了优化,考察了加料方式、催化剂、投料比、反应时间、溶剂循环次数对反应的影响.结果表明,适宜的反应条件为:加料方式A,不使用催化剂,尿素与溶剂的比例为1∶3.0(g/mL),反应时间5h,通入氮气保护,溶剂可循环使用9次.在此条件下,氰尿酸的产率为84.3％,纯度98.8％,产品为白色.用红外对产品进行了表征,其谱图与市售产品完全一致.