Control of morphology in olefinpolymerization catalyzed by nickel diimine complexes encapsulated into polybutadiene based support

Abstract

A commercially available hydroxyl terminated low molecular cis-1,4-polybutadiene was modified by carboxylic functions and used as an effective support in single-site α-olefin polymerization. Dynamic light scattering analysis of support solution in heptane confirmed increased ability to self-assembly of modified polybutadienes in the presence of methylaluminoxane cocatalyst (MAO). α-Diimine nickel and bis(indenyl)zirconium dichloride catalysts activated by trimethylaluminium or MAO cocatalysts were encapsulated into polymer micellar aggregates and used for ethylene and octadec-1-ene polymerization. Furthermore, the effects of cocatalyst type and concentration on the micelle-formation process, activity and morphology of polyethylene (polyoctadec-1-ene) particles were investigated. In the presence of polybutadiene supports, formation of spherical micrometric PE beads was observed during MAO cocatalyzed ethylene polymerization, whereas the activity of polymerization was not decreased.