Preparation of Syndiotactic Polystyrene Having Broad Molecular Weight Distribution with Catalyst Mixture of Titanocenes

Using a mixture of two kinds of Ti complexes Cp~* Ti (O-Ph-OCH_3) _3/CpTi (O-Ph-OCH_3)_3, which has different catalystic characteristic, the prepared syndiotactic polystyrene had broad molecular weight distribution with polydispersity index over 5, even dimodel distribution. The height of its two peaks can be controlled easily by regulating the constitute of the composite catalysts. However, the composition of Cp~* Ti(O-Ph-OCH_3)_3/Cp~*Ti(O-Ph-F)_3 with nearly same catalystic characteristic is selected , the molecular distribution of obtained polymer doesn't change and MWD is about 2.