Ethylene-norbornene copolymers were synthesized with a homogeneous catalyst system based on bis(imino) pyridine iron with the addition of diethyl zinc (DEZ) as alkyd transfer agent to promote immortal copolymerization. The addition of DEZ did not influence the catalytic activity in copolymerization with 7. 5 mmol of norbornene (NB). but in the reactions with 70 mmol. https://www.freaknleather.com/product-category/welding-table-tools/