| abstract |
Effective amounts of low molecular weight brominated polystyrenes unexpectedly provide good property retention and yet achieve desired flame retardance, for example, UL-94 VO in high impact polystyrene. In contrast, high molecular weight brominated styrene polymers (degree of polymerization equals 2,000) do not provide good property retention such as impact strength and toughness in high impact polystyrene. The degree of polymerization of the brominated polystyrenes of the present invention is generally from about 3 to about 20 and can have a considerable variation in the amount of halogenation. The high impact polystyrenes blended with the low molecular weight brominated polystyrenes are readily processed by conventional equipment. |