“Chain‐End‐Controlled Isotactic” and “Stereoblock‐Isotactic” Polypropylene: Where Is the Difference?

Abstract This communication describes the microstructure of “stereoblock‐isotactic” polypropylene obtained with sterically hindered “oscillating” metallocene catalysts, points out in which respects it differs from that of “chain‐end‐controlled isotactic” polypropylene, and explains why the two definitions cannot be used as synonymous (as is commonly found in the literature).