Gas phase polymerization of propylene at low reaction rates: a precise look at particle morphology

The relationship between particle morphology and polymerization kinetics at relatively low reaction rates using a Pulse-Flow reactor was investigated. Polymerization in constant pressure was characterized by a special path: an initial peak followed by a rapid decay, then a slow increase in the reaction rate and then a slow decay period. This irregular kinetic profile has been and reproduced many times.From microscopy results of the surface and bulk of the particles and molten particle, it can be concluded that fragmentation of the support is completed at these conditions of reaction. A secondary phenomenon that enhances rate of reaction: cracking.The occurrence of secondary and even tertiary peaks in the kinetic profile would suggest that some changes in the nature of the growing polymer particles, such as cracking, occurs during the reaction