Recent developments in olefin polymerizations with transition metal catalysts

Discovery of effective homogeneous transition metal catalysts for olefin polymerization must be one of the most dramatic technologies for polymer synthesis in the 1980s. Especially, development of group 4-metallocene catalysts not only improved the property of manufactured polyolefins but also made us possible to synthesize new type polyolefins. A large number of studies have also been made on structure and property of the resultant polyolefins with the advance of catalyst technology. Over the past few years, trend in catalyst development has moved from modification of group 4-metallocene catalysts to search for new generation catalysts, such as non-metallocene catalysts and late transition-metal catalysts. Some of the new catalysts can proceed specific polymerizations, which are not achieved with existent olefin polymerization catalysts. Although, there are some subjects for the manufacturing of new catalysts and polyolefins, the technologies are progressing rapidly. In this review, we highlight not only the development of polymerization catalysts but also the polyolefins obtained with the new catalysts in the last decade.