Evaluation of Bis(imino)pyridine Iron Catalyst on Heterogeneous Ethylene Polymerization

Abstract

This work deals with synthesis, characterization and evaluation of post-metallocene complexes based on silica-supported bis(imino)pyridine iron, containing amino groups in ethylene polymerizations. The reaction of these complexes and methylaluminoxane generated active species in heterogeneous ethylene polymerization. The absence of substituents at the orthoposition of the phenyl rings near the metal site was not compensated by the steric hindrance of the silica surface, negatively affecting the catalytic activity and the molar mass of the produced polymer. The catalyst C1, with the most bulkier ligand, presented the best performance, showing high catalytic activity not only in homogeneous system, but also in supported systems due to the chemical bond between the functionalized complex and the support surface, which led to polyethylene particles with good morphology, spherical tendency, filled pores and the decrease in bulk density compared to the particles produced through homogeneous catalyst.

Disentangled UHMWPE@silica powders for potential use in power bed fusion based additive manufacturing

“…The choice of ligand allows to tune the complex in combination with an activator from an ethylene oligomerization catalyst to a system generating high molecular weight polyethylene. The catalyst system can readily be supported on silica and other carriers keeping its high activity, and is still subject of recent developments [42][43][44][45][46][47][48]. The family of iron catalysts would allow to choose a combination for the preparation of a blend of polyethylenes, as they have various modes of polyethylene formation.…”