Nano polymerization catalysts: Further insights into nanoparticle-facilitated polymerization of olefins

Abstract

Based on recent developments on the use of Schiff-base functionalized nickel nanoparticles as pre-catalysts in the polymerization of norbornene, the potential of these nano-systems was further explored using other olefins, both aromatic and aliphatic olefins. Herein, Schiff-base functionalized NiCl2 nanoparticles were further evaluated as potential coordination polymerization catalysts for styrene employing modified methylaluminoxane (MMAO) as a co-catalyst. Furthermore, the first attempted co-polymerization of styrene with α-linear olefins (C5-C9) using nanoparticle-assisted transformation is reported. It was found that the nano-catalysts were capable of the coordination polymerization and co-oligomerization of styrene and gave relatively monodispersed medium molecular weight polymers and short chained co-oligomers with activities comparable to the complex analogs. It was further shown that the activity of the nano-catalysts as well as the Mw and PDI of the polymers/oligomers, were not dependent on the Schiff-base ligand used as capping agent nor its concentration. The nano-catalysts were also shown to exhibit stereocontrol, giving isotactic-rich atactic homo- and co-polymers.