Aqueous Catalytic Olefin Polymerization With Nickel and Palladium Catalysts

Polyolefins are extensively used in modern society, with hydrocarbon organic compounds traditionally serving as solvents for their preparation. Water, as a reaction medium, offers significant advantages, including non-flammability, non-toxicity, high specific heat capacity, and strong polarity. A promising avenue of research involves replacing organic media with water in polymerization reactions, which could yield considerable economic benefits. Among the various transition metal catalysts used to synthesize polyolefins, late-transition metal catalysts, such as Ni(II) and Pd(II) catalysts, demonstrate enhanced tolerance to polar groups, making them particularly suitable for aqueous polymerization of olefins. This review focuses on the Ni(II) and Pd(II) catalysts utilized for the aqueous catalytic polymerization of olefins, as well as various types of polyolefins fabricated. Key aspects encompass designs of catalysts, polymerization systems, monomers, and material microstructures. The preparation of ultra-high molecular weight polyethylene (UHMWPE) nanocrystals and the modulation of polymer morphology are highlighted. The possible development trend of aqueous catalytic polymerization is envisioned to achieve the development concept of environmental protection and the needs of industrial production.