Tailor-Made Thermoplastic Elastomeric Stereoblock Polypropylenes by Modulation of Monomer Pressure

Isotactic-stereoirregular stereoblock polypropylenes are produced using the bis(p-tolylamidinate)zirconium catalyst by rapid changes of the monomer pressure during the polymerization. It was shown that the stereoirregular blocks lengths depend linearly on the low pressure duration in a cycle, which in turn affect the physicomechanical properties of the polymers. This ability to tune the microstructure of the polymer by pressure, an easily controlled process parameter, enables the preparation of unique materials, which are inaccessible by other polymerization methods.