Olefin Polymerization with Supported Catalysts as an Exercise in Nanotechnology

Research concerning polyolefin synthesis is often focused on the particular catalyst being used, and the importance of the support material is generally not fully appreciated. Only a few common inorganic carriers, such as SiO2 or MgCl2, are typically described in literature, with new developments in support materials rarely found. Acknowledging this lack in fundamental research on support materials, numerous cases in which the catalyst support, particularly organic nanoparticles, plays a critical role in the formation of polyolefins are described. Here, new organic supports for both Ziegler–Natta and metallocene catalysts are described under the same conditions used for inorganic supports. In these cases, similarly high activities can be achieved, while also offering additional features based on designed polymer architectures which inorganic supports cannot provide. These features produce polyolefin fibers and core–shell structures directly from the reactor. Due to the broad synthetic variety, nanoparticles can be optimized for morphology control of the polyolefin products, such as shape and bulk density. The introduction of nucleophilic groups can further improve the binding strength between the catalyst and the support. For the design of new support systems, many of the central concepts found in nanotechnology (e.g., size control, surface properties, or nanoparticle interactions) are extremely important, and it is surprising how much modern nanotechnology has to offer such a mature field as polyolefin synthesis.