posted on 2021-09-27, 20:04authored byHanrong Li, Feiyan Han, Linjing Jiang, Tongqian Yang, Le Du, Jiqin Zhu
Sulfenamides have attracted much
attention for their significant
role in rubber vulcanization. In this study, a continuous process
to synthesize N-cyclohexyl-2-benzothiazole sulfenamide
(CBS) with microfluidics was developed. The catalytic oxidation of
2-mercaptobenzothiazole (MBT) and cyclohexylamine using pure oxygen
was performed in capillary microreactors with gas–liquid segmented
flow. The residence time was shortened to 200 s owing to the enhancement
of mass transfer in the microreactor. Reaction conditions such as
flow rates, concentrations of copper acetate monohydrate and ammonia,
temperatures, and pressures were systematically investigated. A high
yield toward CBS of 87% was obtained. A simplified kinetic model (0
and 0.56 order with respect to MBT and pure oxygen, respectively)
was established with operation in the kinetic-control region based
on eliminating mass transfer resistance.