NEW SYNDIOSPECIFIC CATALYSTS FOR STYRENE POLYMERIZATION

(Eta5-Tetramethylcyclopentadienyl)-, (eta5-tetraphenylcyclopentadienyl )-, (diphenylphosphi-no)tetramethylcyclopentadienyl)-, and rimethylsil yl)tetramethylcyclopentadienyl)titanium triisopropoxide have been synt hesized and characterized. Their catalytic activities for syndiospecif ic styrene polymerization have been compared with the reference compou nd (eta5-cyclopentadienyl)titanium triisopropoxide. (Eta5-Tetramethylc yclopentadienyl)titanium triisopropoxide is the best catalyst precurso r, giving rise to catalysts having the highest activity to produce pol ystyrene with the highest syndiotactic yield and molecular weight.