Author/Authors :
Luruli، نويسنده , , Nyambeni and Heinz، نويسنده , , Lars-Christian and Grumel، نويسنده , , Valérie and Brüll، نويسنده , , Robert and Pasch، نويسنده , , Harald and Raubenheimer، نويسنده , , Helgard G. Raubenheimer، نويسنده ,
Abstract :
Ethylene/1-pentene copolymers were synthesized using Cp2ZrCl2(1)/MAO and [(CO)5WC(Me)OZr(Cp)2Cl](2)/MAO catalyst systems. The copolymers were characterized by SEC, DSC, FTIR and 13C NMR spectroscopy. The copolymers synthesized with [(CO)5WC(Me)OZr(Cp)2Cl](2)/MAO had higher average molecular weights and broader polydispersities compared to those produced with Cp2ZrCl2(1)/MAO. The chemical heterogeneity was investigated by SEC-FTIR and fractionation techniques. All copolymers showed a higher incorporation of the 1-pentene in the low molecular weight fraction as revealed by SEC-FTIR. Crystallization analysis fractionation (CRYSTAF) showed a broad chemical composition distribution (CCD) for all the copolymers synthesized with these two catalyst systems. Selected copolymers were also analyzed using an automated preparative molecular weight fractionation.
Keywords :
Ethylene/1-pentene copolymers , Short chain branching distribution (SCBD) , Automated preparative molecular weight fractionation (PMWF)
