High molecular weight polypropene elastomers via "dual-side" zirconocene dichlorides

A series of asymmetric ansa-zirconocene dichlorides were investigated in propene polymerization reactions with respect to monomer concentration and polymerization temperature. The two different coordination sides of these "dual-side" catalysts allow a precise control of the total amount of randomly distributed isolated stereoerrors along the isotactic polymer chains leading to bulk properties which can be adjusted from flexible, semicrystalline to excellent thermoplastic elastic. The obtained homopolypropenes have a great potential to come into competition with commercialized copolymers for possible industrial applications.