Dispersity

Molar mass distribution

Organic chemistry

Polymer chemistry

Nickel

Low-density polyethylene

Nuclear chemistry

Catalysis

Composite material

Chemistry

Schiff base

Metallurgy

Materials science

Ethylene

Polyethylene

Polymerization

Crystallinity

Polymer

Designed Monomers & Polymers

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)NiBr2, and tested for ethylene polymerization reaction at different conditions. Catalyst productivities were found to be high, 45 × 103 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.

Characterization of Polyethylene Synthesized by Bi-Nickel Catalysts