四溴双酚A小试合成工艺探讨

DISCUSSION ON SYNTHESIS PROCESS OF TETRABROMOBISPHENOL-A

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的过程中,副产物三溴苯酚影响了四溴双酚A的收率。通过探讨三溴苯酚的生成机理,研究了反应过程中酸的种类和用量、物料摩尔比、反应温度和反应时间等关键因素对反应的影响,实现了减少三溴苯酚生成,提高四溴双酚A收率的目的。结果表明:酸可催化三溴苯酚的生成;合成四溴双酚A反应的适宜条件为30%硫酸催化,其用量为双酚A投料量的2.2%,n(BPA)∶n(Br_2)∶n(H_2O_2)为1∶2.10∶2.10,反应时间1h,反应温度85℃,产物收率为97.8%,产品纯度为99.8%。

Tribromophenol was found produced as a byproduct in the preparation of tetrabromobisphenol-A from bisphnol-A,bromine and hydrogen peroxide by in-situ bromination-oxidation,which lowered the yield of tetrabromobisphenol-A.Starting from proposing a mechanism for the production of tribromophenol,the influences of key factors such as the kind and amount of acids,molar ratio,reaction temperature and reaction time were investigated and purpose of lowering the production of tribromophenol and promoting the yield of tetrabromobisphenol A was realized.The results indicated that the generation of tribromophenol was an acid-catalyzed reaction.The optimum reaction condition was as follow：catalyst was the 30% of sulfuric acid,the dosage was 2.2% of the mass of bisphenol-A,the molar ratio n（BPA）∶n（Br_2）∶n（H_2O_2）was 1∶2.10∶2.10,the reaction time was 1 h,the reaction temperature was 85℃.Under this reaction condition the yield was 97.3% with a purity of 99.8%.