| abstract |
Flame retardant poly(alkenyl aromatic) oligomers and lower molecular weight polymers having bromine substituents on the aromatic nucleus are prepared by cationic polymerization from the corresponding brominated monomers, for example, bromostyrene, in an organic solvent, using a Lewis acid catalyst and an aromatic chain transfer agent. The lower molecular weights enable greater tolerance with other thermoplastic polymers, and as a result compatible flame retardant blends with good ductile impact properties are possible. |