Groups 3 and 4 single-site catalysts for olefin-polar monomer copolymerization

Abstract

Introducing functional polar groups into polyolefins can significantly improve the material properties, but there are still challenges in achieving this goal, with the core difficulty being that polar groups are prone to interact with metal active species, affecting the efficiency of the copolymerization. With the rapid advancement in catalyst, a variety of copolymerization strategies are developed aimed at producing more versatile polyolefin materials. Although early transition metal catalysts play an indispensable role in the traditional polyolefin industry, their inherent strong oxophilicity becomes a significant constraint in copolymerization involving polar olefins, limiting their application scope. This review summarizes the progress made in recent years in the efficient copolymerization of non-polar olefins with polar comonomers catalyzed by groups 3 and 4 single-site catalysts. We classify the catalysts into four categories, Sc-, Ti-, Zr-, Hf-, based on the type of metal centers, and provide insights into the influence of catalyst structures and the type of comonomers on the copolymerization behavior. The introduction of polar monomers fundamentally improves the comprehensive performance of the products, greatly broadens the application scope of polyolefin materials, and meets the growing market demand for multifunctional and high-performance materials.