Hydrogen‐Bonding‐Induced Heterogenization of Nickel and Palladium Catalysts for Copolymerization of Ethylene with Polar Monomers

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/SiO2) and palladium (Pd/SiO2) catalysts through hydrogen bonding interactions of the ligands with the silica surface. Ni/SiO2 exhibits high activities (up to 2.65×106 g mol−1 h−1) during the copolymerization of ethylene with 5‐hexene‐1‐yl‐acetate, affording high‐molecular‐weight (Mn 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/SiO2 can mediate ethylene copolymerization with polar monomers with moderate activity to produce high‐molecular‐weight copolymers with tunable comonomer incorporation. An alternative heterogenization approach that uses hydrogen‐bonding‐induced interactions of a solid support with metal complexes was developed. The resulting heterogeneous nickel and palladium catalysts showed superior properties in ethylene polymerization and copolymerization with great product morphology control.