RECENT ADVANCES IN OLEFIN POLYMERIZATION

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.