Self-immobilized polyolefin catalysts: A simple and transitional platform for heterogeneous olefin polymerization

The contribution systematically reviews the conceptual proposition, mechanism, catalyst species, applications, existing controversies and future developmental trends of self-immobilized polyolefin catalysts (SIPCs). To avoid the adverse effects in heterogenization of single site catalysts, the concept of self-immobilization was designed in order to not only keep the single site characteristics of catalysts but also improve polyolefin morphology control to reliver reactor fouling. The self-immobilized polyolefin catalysts have extended their territory from earlytransition-metal to late-transition-metal ones, and been applied to produce high value-added polyolefins. Due to the lack of direct evidences, the classic self-immobilization mechanism invokes huge controversies, and the nature of self-immobilization needs to be explored in depth and explained by a more insightful theory. Fortunately, the self-immobilized polyolefin catalysts have been developed into the flexible immobilization modes of more robust product morphology control.