ausblenden:
Schlagwörter:
copolymerization; kinetics; metallocene catalysts; NMR; polar norbornene derivatives
Zusammenfassung:
Full Paper: Ethene copolymerizations were carried out with triisobutylaluminum (TTBA)-protected norbornenemethanol and norbornenecarboxylic acid, respectively, using homogeneous metallocene/MAO catalyst systems. Moreover, ethene terpolymerizations with both polar norbornene derivatives were investigated for the first time, The metallocenes utilized, such as iPr[CpInd]ZrCl2, iPR[(3-iPr-Cp)Ind]ZrCl2, and iPr[(3- tert-But-Cp)Ind]ZrCl2 contain ligand frameworks of various sterical demands. The incorporation of polar monomers into the polymer chain was determined by NMR spectroscopic investigations. Kinetic and analytical results of the polymerization experiments revealed increasing activities and a decreasing comonomer incorporation into the polymer chain with an increasing sterical demand of the metallocene ligand. Additionally, the TIBA-protected norbornenecarboxylic acid shows a lower incorporation rate into the copolymer chain in comparison with the TIBA-protected norbornenemethanol.
