Ethylene/propylene and ethylene/propylene/5-ethylidene-2-norbornene copolymerizations on metallocene/(2,6-tBu2PhO-)AliBu2 catalyst systems

This work explores new catalytic systems for the synthesis of ethylene-propylene (EPM) and ethylene-propylene-diene (EPDM) copolymers. We present the results on ethylene/propylene copolymerization and terpolymerization of ethylene/propylene/5-ethylidene-2-norbornene with different metallocenes activated by (2,6- t Bu 2 PhO-)Al i Bu 2 . Metallocenes employed are EtInd 2 TiMe 2 , rac -EtInd 2 ZrMe 2 , rac -EtInd 2 HfMe 2 , rac -Et(2-MeInd) 2 ZrMe 2 , rac -Me 2 Si(2-MeInd) 2 ZrMe 2 . The data encompasses catalytic performance of the systems and copolymers properties: composition, molecular weight, thermo-physical, and mechanical characteristics. The highest copolymerization activities were observed for zirconocenes, the lowest — for rac -EtInd 2 HfMe 2 . On the other hand, rac -EtInd 2 HfMe 2 shows the best incorporation of both propylene and 5-ethylidene-2-norbornene, yielding polymers with high molecular weights, low crystallinities and melting points. This catalyst system demonstrated the possibility of producing terpolymers with propylene content up to 39 wt % and 5-ethylidene-2-norbornene up to 18 wt %. Copolymers of ethylene with propylene with the highest tensile strength and elongation at break are obtained on rac -Me 2 Si(2-MeInd) 2 ZrMe 2 , while terpolymer with good elastic properties is formed on rac -EtInd 2 ZrMe 2 and rac -EtInd 2 HfMe 2 . Copolymers with the best relaxation properties were synthesized on rac -EtInd 2 HfMe 2 . • Catalyst systems: different metallocenes with iso-butylaluminum aryloxide as а non-traditional activator. • Ethylene/Propylene (E/P) copolymerization and E/P/5-Ethyledene-2-norbornene (ENB) terpolymerization. • E/P and E/P/ENB copolymer elastomeric characteristics, stress-strain tests.