An outlook on progress in polypropylene-based polymer technology

Developments in the Ziegler--Natta initiator system and the evolution of process plants are described in detail. These developments are said to have led to a breakthrough in the production of both polypropylene homopolymers and random and impact copolymers. Due to the advantages in terms of product quality, process flexibility and operating economies, the Spheripol process--introduced in 1983--is viewed as the most successful technology ever developed. Present developments resulting form the Himont technology are forecast to draw further advantages from the ability to copolymerize different monomers and to control particle morphology, specific surface area and porosity.