Ethylene polymerisation with hafnocene difencholate/MAO system: a comparison with other hafnocenes

• Published in: Journal of molecular catalysis. A, Chemical Chemical, 2005-01, Vol.229 (1), p.59-65
• Main Authors: Grafov, Andrei V., Lopes, Daniela E.B., Grafova, Iryna A., Dias, Marcos L., Marques, Maria F.V.
• Format: Article
• Language: English
• Subjects: Alicyclic alcoholato-ligand; Applied sciences; Catalytic behaviour; Exact sciences and technology; Metallocenes; NMR spectra; Organic polymers; Physicochemistry of polymers; Polymerization; Preparation, kinetics, thermodynamics, mechanism and catalysts
• ISSN: 1381-1169; 1873-314X
• DOI: 10.1016/j.molcata.2004.11.007

NMR spectra of new catalyst Cp 2Hf(OFl) 2 (where OFl = OC 10H 17 is a deprotonated moiety of fenchyl alcohol, endo-1,3,3-trimethylbicyclo[2.2.1]heptan-2-ol) and its catalytic behaviour in homogeneous ethylene polymerisation activated by MAO are discussed in comparison with known (Cp 2HfCl 2/MAO) and previously studied (Cp 2Hf(OMAd) 2/MAO, where OMAd is a deprotonated moiety of 2-methyl-2adamantanol) systems. The influence of σ-bonded bridged alicyclic alcoholato-ligand on polymerisation process and final polymer properties is shown. The dependencies of the catalytic activity of these systems and those of M w of the polyethylene obtained versus independent and dependent variables of the polymerisation process are compared and discussed. Catalytic behaviour of Cp 2Hf(OC 10H 17) 2 in homogenous ethylene polymerisation activated by MAO is discussed in comparison with Cp 2HfCl 2/MAO and Cp 2Hf(OC 11H 17) 2/MAO systems. The influence of σ-bonded bridged alicyclic alcoholato-ligand on polymerisation process and polymer properties is shown. Dependence of the catalytic activity and the M w of the polyethylene obtained on independent and dependent variables of the process are compared and discussed. ▪