溴素/双氧水溴化双酚A过程中酸的催化作用

STUDY ON THE CATALYTIC BEHAVIOR OF ACIDS IN BROMINATION OF BISPHENOL-A BY BROMINE/HYDROGEN PEROXIDE

研究了氯苯/水介质中,以溴素/双氧水为溴化剂,采用原位溴化-氧化法合成四溴双酚A的方法 ,考察了硫酸、盐酸、磷酸、氢溴酸、对甲苯磺酸和十二烷基苯磺酸等质子酸在溴化过程中的作用,并阐示了酸催化作用原理。实验结果表明,较佳的工艺条件是:n(双酚A)∶n(Br_2)∶n(H_2O_2)=1∶2.05∶2.15,十二烷基苯磺酸用量为双酚A质量的2.2%,熟化温度为85℃,熟化时间为1h,在此条件下,四溴双酚A的收率为97.8%,产物纯度为99.7%。研究表明,十二烷基苯磺酸的相转移作用是其催化性能更优的主要原因。

Tetrabromobisphenol-A was prepared from bisphenol-A,bromine and hydrogen peroxide by in-situ bromination-oxidation in chlorobenzene-water as solvent.The catalytic effects of sulfuric acid,hydrochloric acid,phosphoric acid,hydrobromic acid,p-toluenesulfonic acid and dodecylbenzenesulfonic acid were investigated and the catalytic mechanism was elucidated.The experimental results showed that the proper synthetic condition was as following：molecular ration of bisphenol-A,bromine and hydrogenperoxide was 1∶2.05∶2.15,the mass ratio of dodecylbenzenesulfonic acid was2.2% of bisphenol-A,aging temperature was 85℃,aging time was 1h,upon the above condition the yield of tetrabromobisphenol-A was 97.8% with a purity of more than 99.7% measured by HPLC.It was the phase transfer catalytic ability made dodecylbenzenesulfonic acid a good catalyst.