Process For Manufacture Of Brominated Flame Retardant BTBPE

The process for manufacture of brominated flame retardant 1,2-Bis(2,4,6-tribromophenoxy)ethane (BTBPE) was investigated in this thesis which includes two parts:the synthetic process of 2,4,6-tribromophenol and BTBPE.2,4,6-Tribromophenol was synthesized by bromination of phenol with bromine at 95℃in chlorobenzene. The H2O2 was used as in situ oxidant which oxidized the produced byproduct HBr to bromine in the reaction system. This process recycled the HBr in situ and decreased the cost of production. Chlorobenzene, as the solvent, lowered the cost and pollution discharge for its high recovery property. The reaction condition was optimized, and the satisfactory molar ratio of phenol:bromine:hydrogen peroxide is 1:1.57:1.8. Under the optimized condition,2,4,6-tribromophenol was prepared with a yield of 94% with purity≥99%.The target product BTBPE was synthesized by the condensation of 2,4,6-tribromophenol with 1,2-dichloroethane in the presence of base Na2CO3. The optimized manufacture reaction condition is as follows:the molar ratio of 2,4,6-tribromophenol,1,2-dichloroethane, and Na2CO3 is 2:1:3; DMF as the solvent; reaction temperature 95℃; reaction time 25 h. The filtrate and the residues after purification were both recycled in the next reaction, and the average yield of the recycled reaction is 98.5%. The purity of the final product BTBPE is≥99%.In conclusion, a manufacture process for synthesis of brominated flame retardant, BTBPE, was developed in this thesis using phenol as raw material, and the total yield is above 92%. The pilot scale and commercial scale production were successfully realized in our factory, and the product BTBPE meets nicely the foreign customers' requirement.