caa a22 4500 475759710 CHVBK 20180406123547.0 cr unu---uuuuu 170329e20000701xx s 000 0 eng 10.1007/BF02495759 doi (NATIONALLICENCE)springer-10.1007/BF02495759 Highly active three-component catalytic systems based on dialkylzirconocenes, triisobutylaluminum, and perfluorophenyl borates for synthesis of low-molecular-weight polyethylene [Elektronische Daten] [A. Panin, I. Dubnikova, N. Bravaya] The catalytic properties of the zirconium complex with "constrained geometry” Me2SiCp*NBu1ZrX2 (Cp*=C5Me4, X=Cl (1a), Me (1b)) and bridged bis(cyclopentadienyl)zirconocene Me2SiCp2ZrX2 (X=Cl (2a), Me (2b)) during their activation with triisobutylaluminum/perfluorophenyl borates (TIBA/LB(C6F5)4, L=CPh3 (3), Me2HNPh (4)) in ethylene polymerization under a monomer pressure of 2-20 atm were studied by comparison. Both dichloride complexes exhibit moderate activity under the action of the combined TIBA/3 activating agent and give linear high-molecular-weight polyethylene (PE). The interaction of the dimethyl complexes with TIBA/3(4) afford active sites in which the growing polymeric chain is intensely transferred to the monomer, due to which low-molecular-weight PE is formed. The dichloride complexes affected by TIBA/4 also afford low-molecular-weight PE. Analysis of the structure of the polymeric products (1H NMR spectrometry, IR spectroscopy), molecular-weight parameters of the PE samples (gel permeation chromatography (GPC)), and kinetics of polymerization suggested that the active site contains AlBui 3 as a heteronuclear bridged cationic complex. The influence of various basic substrates (the products of chain transfer with the terminal vinyl groups, the dimethylaniline fragment of borate4 or other amine specially introduced into the reaction mixture) on the catalytic properties of the Zr−Al site was revealed. The polymerization rate and molecular-weight parameters of PE as functions of the reaction temperature, ethylene pressure, and modifying additives were studied. Kluwer Academic/Plenum Publishers, 2000 metallocene catalysts nationallicence ethylene polymerization nationallicence ethylene oligomerization nationallicence polymerization kinetics nationallicence active site nationallicence perfluorophenyl borates nationallicence triisobutylaluminum nationallicence polyethylene nationallicence Panin A. Institute of Problems of Chemical Physics, Russian Academy of Sciences, 4 pr. Institutskii, 142432, Chernogolovka, Moscow Region, Russian Federation aut Dubnikova I. Institute of Problems of Chemical Physics, Russian Academy of Sciences, 4 pr. Institutskii, 142432, Chernogolovka, Moscow Region, Russian Federation aut Bravaya N. Institute of Problems of Chemical Physics, Russian Academy of Sciences, 4 pr. Institutskii, 142432, Chernogolovka, Moscow Region, Russian Federation aut Russian Chemical Bulletin Kluwer Academic Publishers-Plenum Publishers 49/7(2000-07-01), 1185-1194 1066-5285 49:7<1185 2000 49 11172 https://doi.org/10.1007/BF02495759 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02495759 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Panin A. Institute of Problems of Chemical Physics, Russian Academy of Sciences, 4 pr. Institutskii, 142432, Chernogolovka, Moscow Region, Russian Federation aut NATIONALLICENCE 700 1- Dubnikova I. Institute of Problems of Chemical Physics, Russian Academy of Sciences, 4 pr. Institutskii, 142432, Chernogolovka, Moscow Region, Russian Federation aut NATIONALLICENCE 700 1- Bravaya N. Institute of Problems of Chemical Physics, Russian Academy of Sciences, 4 pr. Institutskii, 142432, Chernogolovka, Moscow Region, Russian Federation aut NATIONALLICENCE 773 0- Russian Chemical Bulletin Kluwer Academic Publishers-Plenum Publishers 49/7(2000-07-01), 1185-1194 1066-5285 49:7<1185 2000 49 11172 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer