Mechanism for Impurities Forming During the Synthesis of DNS and Optimization of DNS Preparation
CHANG Gui-xia~(1,2),DU Jun-xia~3,PENG Wen-chao~1,WANG Shu-lan~1,ZHANG Feng-bao~1(1.School of Chemical Engineering & Technology,Tianjin University,Tianjin 300072,China;2.Department of Environmental & Chemical Engineering,Yingkou College of Vocational Technology,Yingkou 115000,Liaoning Province,China;3.Huayu Chemical Co.,Cangzhou 061000,Hebei Province,China)
(1,2),DU Jun-xia~3,PENG Wen-chao~1,WANG Shu-lan~1,ZHANG Feng-bao~1(1.School of Chemical Engineering & Technology,Tianjin University,Tianjin 300072,China;2.Department of Environmental & Chemical Engineering,Yingkou College of Vocational Technology,Yingkou 115000,Liaoning Province,China;3.Huayu Chemical Co.,Cangzhou 061000,Hebei Province,China
Abstract：
The oxidation of p-nitrotoluene-2-sulfonic acid to prepare 4,4′-dinitrostilbene-2,2′-disulfonic acid(DNS) was monitored,and the mechanism for the formation of by-products 4-nitrobenzaldehyde-2-sulfonic acid (NBS) and 4-nitro-2-sulfobenzonic acid(NSB) was suggested.By investigating the influences of temperature,pH value,recrystallization times and solar light on the purity and recovery of DNS,optimized conditions for the recrystallization of DNS were obtained: about 85 ℃ and pH=9—10.Finally,4,4′-diaminostilbene-2,2′-disulfonic acid(DSD) with high quality was synthesized from DNS after purification.
CHANG Gui-xia~.Mechanism for Impurities Forming During the Synthesis of DNS and Optimization of DNS Preparation[J]. Chemcial Industry and Engineering, 2008,25(4): 294-297
2008, Vol. 25 
