| Name | 3,6-bis(bromomethyl)-1,2,4,5-tetrabromobenzene |
| Synonyms | α,α',2,3,5,6-hexabromo-p-xylene 1,4-Bis(bromomethyl)-2,3,5,6-tetrabromobenzene 3,6-bis(bromomethyl)-1,2,4,5-tetrabromobenzene 1,2,4,5-Tetrabromo-3,6-bis(bromomethyl)benzene Benzene, 1,2,4,5-tetrabromo-3,6-bis(bromomethyl)- |
| CAS | 39568-99-5 |
| EINECS | 254-521-5 |
| Molecular Formula | C8H4Br6 |
| Molar Mass | 579.54 |
| Density | 2.718g/cm3 |
| Flash Point | 239.1 ℃ |
| Refractive Index | 1.699 |
| Physical and Chemical Properties | The chemical product is white crystal with a melting point of 272.5 ℃. |
| Use | Use of this product is a new pollution-free fiber flame retardant, compared with conventional products of polybrominated diphenyl ether, the addition of the flame retardant, in the high polymer heat train or combustion, no toxic dibenzobis and polybrominated dibenzofurans were produced. This class of flame retardants is popular among the new flame retardants introduced in the United States in the 90 s of the 20th century. This product is easy to use, can be added directly in the textile (polyester, viscose, blended, cotton, pure polyester) post-processing, at room temperature to complete the whole process of finishing. |
| Raw Materials | P-XYLENE |
Storage and transportation of general chemicals. Store in a dry and ventilated place.
1. Synthesis of Tetrabromo p-xylene
Add 1000kg of bromine and 3kg of anhydrous AlBr3 to the reactor in sequence. Cool to 0~3 ℃ with ice salt water, and slowly add 80kg of xylene while stirring. When blocky substances or high viscosity appear in the reaction kettle, add 450kg of bromine for dilution. During the dilution process, the temperature can be controlled at 30-35 ℃. After the lump disappears, it is cooled to 10-15 ℃ and the remaining xylene is added. The reaction is carried out at 20 ℃ for 4-6 hours to evaporate excess bromine. Filter and dry the reaction solution in a centrifuge. Recrystallization with methanol, melting point 253-254 ℃.
2. Synthesis of Hexabromo p-xylene
Add 80kg of carbon tetrachloride to the reaction kettle, and add 42kq of the prepared tetrabromo-p-xylene under stirring. Under N2 protection, slowly add a solution of brominated carbon tetrachloride (32kg of bromine dissolved in 50L of carbon tetrachloride), heat and reflux for 15 hours. Then cool to around 3 ℃. Centrifuge filtration, dry to obtain α,α', 2,3,5,6-Hexabromo-p-xylene.
synthesis of tetrabromop-xylene 1 000 kg bromine and 3 kg anhydrous AlBr3 were sequentially added to the reactor. Cool with ice brine to 0~3 ℃, and slowly add 80 kg xylene under stirring. When lumps or viscosity are too large in the reaction kettle, 450 kg of bromine is added for dilution, and the temperature can be controlled at 30~35 ℃ during dilution. After the lumps disappear, cool to 10~15 ℃, continue to add the remaining xylene, and react at 20 ℃ for 4~6 h. Steam out excess bromine. Put the reaction liquid into a centrifuge to filter and spin dry. Recrystallization with methanol, melting point 253~254 ℃.
Synthesis of Hexabromop-xylene 80 kg of carbon tetrachloride was added to the reaction kettle, and 42 kg of the prepared tetrabromop-xylene was added under stirring. Under the protection of N2, slowly add bromine carbon tetrachloride solution (32kg bromine dissolved in 50L carbon tetrachloride), heat reflux for 15 h. Then cool to about 3 ℃. Centrifugal filtration and drying to obtain α,α',2,3,5, 6-hexabromop-xylene.