Various metallocenes were tested for syndiotactic polymerization Reduc
tion in the amount of costly methylalumoxane (MAO) or replacement with
the other components was accomplished. Small modifications in the met
allocene ligands brought about remarkable differences in the resulting
catalysts concerning their storage stability, H-2 response as well as
stereospecificity. Syndiotactic polypropylene (SPP) in the melt state
behaves very differently compared to isotactic polypropylene (IPP). T
he notion that these polymers have different distributions of molecula
r entanglements are pursued, and verified for the first time. Excellen
t dispersibility of other olefin polymers in SPP matrix contributed to
improve the usefulness of SPP.