COPOLYMERIZATION OF STYRENE AND DIENES CATALYZED BY 4f METAL COMPOUNDS——Some Features of Copolymerization and Characterizations of the Polymers

A new rare earth catalyst system was found in our laboratory. Not only styrene and iso-prene are copolymerized but also styrene and butadiene are copolymerized with the new catalyst system-4f metal compounds-alkyl aluminium compounds-other components. The copolymers are characterized as the block copolymers containing 4.0-4.5(%) gels, 22.0-97.7(%) cis-l,4-contents and 8.3-79.8 (mol%) styrene contents by means of IR, 1H-NMR,13C-NMR and Dynamic mechanic properties.