ETHENE PROPENE COPOLYMERIZATION BY [ME2C(3-RCP)(FLU)]ZRCL2/MAO (R = H, ME, PR-ISO, BU-TERT)/

Ethene/propene copolymerisations were carried out at 30 degrees C and 60 degrees C using four different metallocenes [Me2C(3-RCp)(Flu)]ZrCl2 (R = H, Me, Pr-iso, Bu-tert). With increasing size of the substituent distinct changes in the copolymerisation behaviour and polymer micros tructure were observed. A copolymerisation model taking into account t he heterotopic nature of the metallocenes has been developed which fit s the experimental triad distributions obtained. It is concluded that copolymerisation proceeds via chain migratory insertion for R = H and Me whereas a retention mechanism is found for R = Bu-tert. For R = Pr- iso especially at 60 degrees C a defective alternating mechanism seems to be operative.