Polymerization of butadiene in polystyrene with a homogeneous Ziegler-Natta catalyst.

Polybutadiene - polystyrene blends have been prepared with a Ti(OBu) sub 4 - Et sub 3 Al catalyst by an in situ polymerization technique. The polybutadiene synthesized within the polystyrene matrix had a higher cis 1,4 content than did solution polymerized polybutadiene. It was determined that this difference is attributable to a lower concentration of monomer around the catalyst site when the reaction occurs in a polymer below its glass transition temperature. X-ray fluorescence and TEM studies proved that the polybutadiene was evenly distributed across the thickness of the blends, Phase separated domains with sizes varying from 500angstroms to 2,000angstroms existed in these materials. This size is smaller than observed in high impact polystyrene.