Rapid evaluation of catalysts and MAO activators by kinetics: What controls polymer molecular weight and activity in metallocene/MAO catalysts?

Fabio Ghiotto, Chrysoula Pateraki, John R. Severn, Nic Friederichs, Manfred Bochmann

Research output: Contribution to journalArticlepeer-review

34 Citations (Scopus)

Abstract

The influence of methylaluminoxane (MAO) catalyst activators of different concentrations and preparative histories on the performance of 1-hexene polymerisations was investigated by kinetic methods, using rac-Me Si(2-Me-Benz[e]Ind)ZrCl as the standard catalyst precursor. Fast sampling and analysis allow the time dependence of monomer conversion and the growth of the number-average polymer molecular weight to be determined at a sufficiently short timescale to make this a feasible method for routine catalyst evaluation. Differences in productivity, polymer molecular weight and active species count are shown to be primarily a linear function of the trimethylaluminium concentration. The results in toluene and heptane as solvents are compared; the data show that the inferior performance in heptane is due to a substantially lower active species concentration.
Original languageEnglish
Pages (from-to)9040-9048
Number of pages9
JournalDalton Transactions
Volume42
Issue number25
DOIs
Publication statusPublished - 7 Jul 2013

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