多孔材料负载烯烃配位聚合催化剂的研究进展

Progress of Catalysts Supported on Nanoporous Materials for Olefin Coordination Polymerization

综述了将均相烯烃配位聚合催化剂(即Ziegler-Natta催化剂、茂金属催化剂和后过渡金属催化剂)负载于具有不同孔结构与孔径的多孔材料(如SiO2、分子筛等)上进行烯烃聚合的研究进展,分析了载体和催化剂组成对配位聚合活性及聚合物性能的影响。多孔材料不但具有承载活性组分、改善其分散性的作用,并且其纳米空间对聚合过程中单体的扩散起到限制作用,使单体的插入方式和链增长过程与自由空间不同,因此改变了聚合反应活性和聚合物的相对分子质量及其分布、熔点和等规度等性质。

This paper focuses on the development of Ziegler-Natta catalysts, metallocene catalysts and late transition metal catalysts supported on nanoporous materials such as SiO2 and molecular sieves, which were used in olefin coordination polymerization. The influences of the various supports as well as the catalyst composition on the coordination polymerization and the polymer properties were analyzed. The nanoporous materials with different pore structures not only play the role of supports which carry the metallic active sites and change their dispersity, but also influence the olefin polymerization kinetics, the obtained polymer textual parameters and polymer properties due to the different monomer diffusion in the nanopore space and thereby different monomer insertion and chain growth manner. The close relationship between the confined space provided by nanoporous supports, the catalyst activity and the polymer properties such as molecular weight, melting point, polydispersity index, stereoregularity, comonomer content and improved morphology was described in detail.