Abstract
New non-metallocene, bi-nickel center catalysts were prepared by Schiff base condensation of 2,3-butanedione with 2,6-di-isopropylaniline and subsequent metathesis reaction with (DME)NiBr(2), and tested for ethylene polymerization reaction at different conditions. Catalyst productivities were found to be high, 45 x 10(3) kg/mmol Ni per h. The molecular weight of the product, i.e., polyethylene, varied from 4831 (a paste-like material) to 968 754. The polydispersity (M(w)/M(n)) of the synthesized polyethylene varied from 2.16 to 8.06. Structurally, the results indicated that, when the end-group density decreased, M(w) increased with broadening of M(w) distribution and crystallinity of PE samples increased when the end-group density decreased. (C) Koninklijke Brill NV, Leiden, 2010