- Rational design of nickel catalysts containing N-acylated imidazolin-2-imine ligand for ethylene copolymerization with polar monomer
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By taking advantage of electronic influence of ligand design, the novel neutral nickel complexes bearing strong electron-donating N-acylated imidazolin-2-imine ligand were synthesized and characterized. The nickel catalysts conducted ethylene polymerization with high activity and good thermal stability, affording semicrystalline polyethylene with short chain branches (32–46/1000 C atoms). The complex Ni2 bearing adamantyl substituent on the imidazoline ligand showed higher activity than phenyl substituted complex Ni1, and highest activity was observed at 60 °C (up to ~106 g?mol?1?h?1). Most importantly, the catalysts were also effective for the copolymerization of ethylene and 5-hexenyl acetate with moderate activity (~105 g?mol?1?h?1). The microstructure analyses by the 13C NMR spectroscopy indicated that the 5-hexenyl acetate was successfully incorporated into the polyethylene main chain with reasonable comonomer content.
- Li, Yanqing,Cheng, Hailong,Xiao, Ru,Cai, Zhengguo
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p. 117 - 123
(2020/02/04)
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- Keto-imidazoline-2-imine ligand [N,O] bidentate nickel and palladium complex as well as preparation method and application thereof
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The invention relates to a keto-imidazoline-2-imine [N,O] bidentate nickel and palladium complex as well as a preparation method and application thereof. The preparation method comprises the followingsteps: reacting a keto-imidazoline-2-imine ligand with a hydrogen withdrawing reagent and a metal precursor in sequence to prepare a keto-imidazoline-2-imine [N,O] bidentate nickel and palladium complex; and the structural formula of the prepared complex is one of formulas shown in the specification. The complex and a cocatalyst form a catalyst composition, the complex or the catalyst compositionis used for catalyzing homopolymerization or copolymerization of olefin monomers, and the specific process is as follows: under the protection of nitrogen, firstly dissolving the complex or the catalyst composition in a solvent, then adding an olefin monomer, and conducting reacting for a period of time at a certain temperature and under a certain pressure to prepare the olefin polymer. The complex and the catalyst composition provided by the invention have relatively high catalytic activity, high tolerance to polar monomers and relatively low application cost.
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Paragraph 0082; 0087; 0094; 0099; 0106; 0111; 0118; 0123
(2019/11/13)
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