Hydrogen‐Bonding‐Induced Heterogenization of Nickel and Palladium Catalysts for Copolymerization of Ethylene with Polar Monomers
Hu Zhang, Chen Zou, Huipeng Zhao, Zhengguo Cai, Changle Chen
Abstract
Abstract The practical synthesis of polar‐functionalized polyolefins using transition‐metal‐catalyzed copolymerization of olefins with polar monomers is a challenge; the use of heterogeneous catalysts is little explored. Herein, we report the synthesis of heterogeneous naphthoquinone‐based nickel (Ni/SiO 2 ) and palladium (Pd/SiO 2 ) catalysts through hydrogen bonding interactions of the ligands with the silica surface. Ni/SiO 2 exhibits high activities (up to 2.65×10 6 g mol −1 h −1 ) during the copolymerization of ethylene with 5‐hexene‐1‐yl‐acetate, affording high‐molecular‐weight (M n up to 630 000) polar‐functionalized semicrystalline polyethylene (comonomer incorporation up to 2.8 mol %), along with great morphology control. The resulting copolymers possess improved surface properties and great mechanical properties. Pd/SiO 2 can mediate ethylene copolymerization with polar monomers with moderate activity to produce high‐molecular‐weight copolymers with tunable comonomer incorporation.