RARE-EARTH METAL-INITIATED POLYMERIZATIONS OF POLAR AND NONPOLAR MONOMERS

Organolanthanide(III) initiated polymerization of methyl methacryate g ave both syndiotactic and isotactic living polymers of high molecular weight. Organolanthanide(III) initiated polymerization of alkyl acryla tes also gave high molecular weight poly(alkyl acrylate)s with very na rrow molecular weight distribuion in high yield. Molecular weights of the resulting polymers increased linearly with the conversion. Random and block copolymerizations of alkyl acrylates with methyl methacrylat e were realized successfully. For the sake of development of the olefi n polymerization catalyst, bulky substituents were introduced into Me2 Si bridged Cp rings and they were used as ligands for the lanthanide c omplexes. Tri-and divalent lanthanide complexes with such ligands show ed high activity for olefin polymerization and gave high molecular wei ght polyolefins.