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Solution Al-27 NMR at 750 MHz (H1) of Methylaluminoxanes


EMSL Project ID
2601

Abstract

We request three 12-hour shifts spaced throughout the period of October 2002 to April 2003 on the 750 MHz (H1) NMR. Solution-state Al-27 NMR are to be obtained by remote operation, with variable temperature in the range of +20 C to +120 C. In each shift, 2 to 4 samples are to be studied. The sample, methylaluminoxane (MAO), is pyrophoric. Flame sealed quartz NMR tubes (medium wall thickness) will be preparedin Baton Rouge, LA and ground shipped to EMSL. We wish to operate the NMR remotely from Baton Rouge. This project is funded by an NSF GOALI grant. We propose a study of methylaluminoxane (MAO) structures via Al-27 NMR. MAO is a key component of new-generation Ziegler-Natta catalysts for propene polymerization. Polypropylene is very large business: global capacity is 29.6 million metric tonnes/yr and polypropylene is the fastest growing segment of the polymer industry. In spite of its importance, most of the structural features of MAO remain undetermined. Structural determination is not just an academic curiosity, MAOs with virtually the same composition can have dramatically different catalyst performance for reasons which remain unknown. MAO may consist of 5-10 complexes in slow exchange at room temperature. (see more decscription in attachment)

Project Details

Project type
Capability Research
Start Date
2002-10-01
End Date
2003-04-17
Status
Closed

Team

Principal Investigator

Leslie Butler
Institution
Louisiana State University

Team Members

Walter Treleaven
Institution
Louisiana State University

Jan Eilertsen
Institution
Louisiana State University