Thermostable ring-brominated polystyrene prodn. - using iron or ferric chloride as catalyst for bromination of polystyrene in chloro-hydrocarbon solvent

摘要

In the prodn. of thermostable, ring-brominated polystyrenes (I) by bromination of polystyrene (II) dissolved in chlorohydrocarbons (III) at -20 degrees C to +40 degrees C in the presence of a Lewis acid catalyst, Fe or FeCl3 is used as catalyst. Pref. (II) has a mol. wt. of 50000-500000 and (III) is pref. CH2Cl2. After washing the reaction soln. with water, (I) is pref. pptd. with MeOH and sepd. (I) are specified for use in the prodn. of flame-retardant moulding compsns. They are also useful in paints. Heat-resistant prods. are obtd. without the use of special conditions or additives.