A Submicron Spherical Polypropylene Prepared by Heterogeneous Ziegler–Natta Catalyst

A novel type of spherical nano Ziegler-Natta catalyst was prepared by loading TiCl4 on nanosized magnesium chloride support for propylene polymerization to form nanosized spherical polypropylene (PP) particles. Polyvinylpyrrolidone (PVP), a common macromolecular surfactant, was used to ensure sphericity and inhibit aggregation of the nanosized particles. The morphology of the support (60 nm), catalyst (80 nm), and PP particles (500 nm) were spherical, and the size distribution is uniform which is confirmed by scanning electron microscopy (SEM) and transmission electron microscope (TEM), respectively. The laser granulometer results showed that the size of the prepared PP particles was in the range of 10-110 urn, and the average diameter was 36 um, which had potential application in 3D printing. In addition, the obtained polypropylene had low bulk density (0.170 g/mL).