Ethylene/1 -Pentene copolymers synthesized using the Metaloxycarbene complex catalyst system [(CO)5W=C(Me)OZr(Cp)2Cl]/MAO
Ethylene/1-pentene copolymers were prepared using a [(CO)5W= C(Me)OZr(Cp)2Cl] (1)/MAO catalyst system. 1-Pentene incorporation in the copolymer was monitored using 13C-NMR spectroscopic methods. The weight average molecular weights (Mw) 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.