Synthesis and Characterization of New Olefinic Block Copolymers

Olefinic multi-block copolymers are synthesized by simultaneous using of two catalysts with significantly different comonomer selectivity in copolymerization of ethylene and α-olefins, in presence of a chain shuttling agent (CSA). We have utilized two catalysts with different comonomer affinities; rac-[ethylenebis(indenyl)] zirconium(IV) dichloride and 2,6-diacetyl pyridine bis(isopropylanil) iron (II) dichloride (which have proved the ability of catalyze chain growth on zinc) in copolymerization of ethylene and 1-hexene in presence of different concentration of diethylzinc (DEZ) as a new system for production of OBC. While the former catalyst has high comonomer affinity, the latter is expected to incorporate negligible comonomer units, giving rise to production of successive amorphous and crystalline blocks along the chain. In this work, activity and thermal properties of resulted copolymers were studied