| abstract |
Styrene polymers or copolymers containing bromine are manufactured by cationic polymerization of the monomer, or of the monomer plus a copolymerizable monomer of the isobutylene or nuclear-alkylated styrene type, in an organic solvent in the presence of a Lewis acid catalyst. Bromine is then added to the solution without first working up the latter. The catalyst used for the bromination is the same as that used for the polymerization. If necessary, fresh catalyst may be added before the bromination. After completion of the bromination the reaction solution is extracted with water until it is bromide-free, and the solvent, generally a halohydrocarbon, is then stripped off. Products containing up to about 80% by weight of bromine may be obtained. They have a pale yellowish color and exhibit no significant decomposition up to 340° C. They may be used as flame-proofing agents for thermoplastics. |