| Abstract |
Polyolefins account for two thirds by weight of the global synthetic polymers. There are more than 300
grades of commercial polyolefins, whose properties depend on their microstructures being varied
according to the type of catalyst used in the production process and ultimately on the final method
of manufacture. Despite having catalytic activities not higher than those of common catalysts,
vanadium-based catalysts display several advantages, such as ethylene polymerization for ultra-high
molecular weight polyethylene, better copolymerization of alpha-olefins with ethylene which affords
higher comonomer incorporation, producing good syndiotactic polypropylene, as well as producing
synthetic rubbers by copolymerizing either ethylene-propylene or ethylene-propylene-diene. The latter
materials, in particular, are known for their excellent applications with ozone, UV, heat and waterresistance,
for the automotive industry and seal gaskets for shield tunnels and even in heat shielding
materials for solid rocket motors. To tailor polyolefins in order to design their microstructures, there
are more and more studies on post-metallocene vanadium(III-V) catalysts employing various N-, O-,
N,O- and even P-ligands. Herein we summarize important developments of the vanadium complex
catalysts within a decade. |
