摘要
The seminal report ofα-diimine palladium and nickel catalysts in 1995 represented a major breakthrough in the preparation of functionalized polyolefin materials.Owing to the high abundance and low cost of nickel,nickel-based catalysts have great application prospects in the industrialization process of olefin coordination polymerization.In this work,various N-aryl substituents with different electronic effects were synthesized and introduced intoα-diimine ligands.The aspreparedα-diimine nickel catalysts showed high polymerization activity(0.9×10^(7)–3.0×10^(7)g·mol^(−1)·h^(−1))in ethylene polymerization,generating polyethylene products with adjustable molecular weights(Mn values:7.4×10^(4)–146.9×10^(4)g·mol^(−1))and branching densities(31/1000 C–68/1000 C).The resulting polyethylene products showed excellent mechanical properties,with high tensile strength(up to 25.0 MPa)and high strain at break values(up to 3890%).The copolymerization of ethylene and polar monomers can also be achieved by these nicekel complexes,ultimately preparing functionalized polyolefins.
1995年,α-二亚胺钯和镍催化剂的开创性报道是制备功能化聚烯烃的重大突破。由于金属镍在自然界中具有较高的丰度和低廉的价格,因此镍系催化剂在烯烃配位聚合的工业化过程中显示出巨大的应用前景。本工作合成了各种具有不同电子效应的N-芳基取代基,并将其引入到α-二亚胺配体中。所制备的α-二亚胺镍催化剂在乙烯聚合中表现出较高的聚合活性(0.9×10^(7)–3.0×10^(7)g·mol^(−1)·h^(−1)),生成分子量(Mn:7.4×10^(4)–146.9×10^(4)g·mol^(−1))和支化度可调(31/1000 C–68/1000 C)的聚乙烯产品。所制聚乙烯产品显示出优异的机械性能,具有高拉伸强度(最高可达25.0 MPa)和高断裂应变值(最高可达3890%)。这些α-二亚胺镍催化剂还可以实现乙烯和极性单体的共聚,最终实现官能化聚烯烃材料的制备。
基金
supported by the National Key R&D Program of China(2021YFA1501700)
Fundamental Research Funds for the Central Universities(WK9990000142).
