ANIONIC-POLYMERIZATION AND CO-POLYMERIZATION OF PARA-BROMOSTYRENE

Monodispersed poly(4-bromostyrenes) (PBs) and their block copolymers with styrene, isoprene, and 3-methylbutene were prepared and characterized by GPC and NMR. The effectiveness of Bs as a flame retarding constituent of polymeric systems seems to be much more pronounced when it is incorporated in a 'block' than in a random fashion. A considerably larger fraction of PBs is required to achieve the same Limited oxygen index when the respective homopolymers are blended. Spatial distribution of the easily charred microdomains in the block copolymers is believed to be responsible for this phenomenon.