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Ethylene/1‐pentene copolymers synthesized using the metaloxycarbene complex catalyst system [(CO) 5 W=C(Me)OZr(Cp) 2 Cl]/MAO

2004; Wiley; Volume: 42; Issue: 20 Linguagem: Inglês

10.1002/pola.20314

1099-0518

Nyambeni Luruli, Valérie Grumel, Robert Brüll, A. Du Toit, Harald Pasch, Albert J. van Reenen, H.G. Raubenheimer,

Polymer crystallization and properties

Abstract Ethylene/1‐pentene copolymers were prepared using a [(CO) 5 W= C(Me)OZr(Cp) 2 Cl] (1)/MAO catalyst system. 1‐Pentene incorporation in the copolymer was monitored using 13 C‐NMR spectroscopic methods. The weight average molecular weights ( M w ) of the copolymers were between 142,000 and 629,000 g/mol, with polydispersity indexes (PDIs) ranging from ≈ 2 to 90, as analyzed by size exclusion chromatography (SEC). Melting and crystallization temperatures, determined using differential scanning calorimetry (DSC) and crystallization analysis fractionation (CRYSTAF), decreased linearly as the amount of 1‐pentene in the copolymer increased. SEC‐FTIR revealed that the 1‐pentene is predominantly incorporated in the low molecular weight fraction. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5121–5133, 2004