Are carbodiimide-quenched polyethylene distributions representative of bulk polymer samples? Analysis of metallocene-catalyzed ethylene polymerization by ESI-MS, MALDI, GPC and NMR.
Polyethylene molecular weight distributions observed by ESI-MS following the quench of a Cp(2)ZrCl(2)/MAO-catalyzed ethylene polymerization with N,N'-dicyclohexylcarbodiimide do not agree with GPC or NMR analysis of methanol-d(1) quenched samples; factors contributing to the discrepant results include high sample polydispersities, polymer insolubility, and the incomplete quench of metal-polymer species. Kinetic analyses of molecular weight distributions obtained by ESI-MS are not representative of the predominate monomer-consuming pathways.
Moscato
Beth
B
Dept. of Chemistry, UW-Madison, 1101 University, Madison, WI, USA.
Landis
Clark
C