Recent Technical Advances in Polypropylene

Abstract

The Spherizone process technology, which is based on a multizone circulating reactor (MZCR), represents a significant innovation in polypropylene (PP) production. In comparison to traditional multi-step technologies, the MZCR provides a step change in the polymer homogeneity of the final product, obtained by continuously circulating the growing polymeric granules between two interrelated zones where different gas-phase compositions are realized. In addition to traditional Z-N catalysts, metallocene catalysts are also being introduced in PP manufacture: single-site catalysts allow differentiated products with outstanding property combinations. Due to its versatility and sustainability, PP continues to be utilized in a large range of applications. Innovative polymer structures featuring diverse comonomers exhibit improved properties (i.e., stiffness-impact balance, aesthetics, transparency, processability), which reinforce the capability of PP to replace traditional materials such as wood, paper, glass, and metals, as well as standard polymer products.