Scalable Nickel Catalysts for Carbonylative Terpolymerization of Ethylene/α-Olefin with High Efficiency

The carbonylative polymerization of olefin yields aliphatic polyketones, which are used as engineering plastics in the market due to their excellent mechanical strength, chemical resistance, and surface and barrier properties. However, the usage of precious palladium catalysts has restricted their extensive application as commodity materials. Herein, we present a series of phosphine-sulfonate Ni catalysts with a wide spectrum of electronic and steric substituents on the phosphorus moiety for the carbonylative polymerization of ethylene. Such efficient nickel-catalyzed copolymerization shows the on-demand transformation of ethylene/CO gas to polyketones with quantitative yield and product specificity. A remarkable productivity of up to 20 kg PK (g Ni)^-1 was obtained during ethylene/propylene/CO terpolymerization, and the polymerization productivity is independent of the type and feeding amount of α-olefin. The resulting terpolymers show comparable crystallinity, thermal stability, and tensile properties with commercial POKETONE products from Hyosung. The nickel catalyst also features the advantages of using cheap raw material sources and simple synthetic procedures that can be scaled up easily, which enables it to be a promising candidate for industrial application.