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A supported TiCl4/MgCl2 catalyst without internal electron donor (O-cat) was prepared firstly. Then it was modified by 2,6-diisopropylphenol to make a novel modified catalyst (M-cat). These two catalysts were used to catalyze ethylene/1-hexene copolymerization and 1-hexene homopolymerization. The influence of cocatalyst and hydrogen on the catalytic behavior of these two catalysts was investigated. In ethylene/1-hexene copolymerization, the introduction of 2,6-iPr2C6H3O-groups did not deactivate the supported TiCl4/MgCl2 catalyst. Although the 1-hexene incorporation in ethylene/1-hexene copolymer prepared by M-cat was lower than that prepared by O-cat, the composition distribution of the former was narrower than that of the latter. Methylaluminoxane (MAO) was a more effective activator for M-cat than triisobutyl-aluminium (TIBA). MAO led to higher yield and more uniform chain structure. In 1-hexene homopolymerization, the presence of 2,6-iPr2C6H3O-groups lowered the propagation rate constants. Two types of active centers with a chemically bonded 2,6-iPr2C6H3O-group were proposed to explain the observed phenomena in M-cat.
A supported TiCl4 / MgCl2 catalyst without internal electron donor (O-cat) was prepared first. Then it was modified by 2,6- diisopropylphenol to make a novel modified catalyst (M-cat). These two catalysts were used to catalyze ethylene / The influence of cocatalyst and hydrogen on the catalytic behavior of these two catalysts was investigated. In ethylene / 1-hexene copolymerization, the introduction of 2,6-iPr2C6H3O-groups did not deactivate the supported TiCl4 / MgCl2 catalyst. Although the 1-hexene incorporation in ethylene / 1-hexene copolymer prepared by M-cat was lower than that prepared by O-cat, the composition distribution of the former was narrower than that of the latter. Methylaluminoxane (MAO ) was a more effective activator for M-cat than triisobutyl-aluminum (TIBA). MA 1 led to higher yield and more uniform chain structure. In 1-hexene homopolymerization, the presence of 2,6-iPr 2 C 6 H 3 O-groups lowered the propagation rate co nstants. Two types of active centers with a chemically bonded 2,6-iPr2C6H3O-group were proposed to explain the observed phenomena in M-cat.