Comparison of gas‐ and liquid‐phase polymerization of propylene with heterogeneous metallocene catalyst

Abstract

ABSTRACT:Sorption measurements are executed to study the sorption behavior of propylene in a semicrystalline polymer. Decreasing values for the Flory-Huggins interaction parameter with increasing temperature are obtained. Large deviations are found, especially at higher temperatures, compared to data from the literature. Propylene is polymerized in liquid and gaseous propylenes with Me 2 Si[Ind] 2 ZrCl 2 /MAO/ SiO 2 as the metallocene catalyst. Lower relative reaction rates are found in the gas phase compared to the experiments in the liquid phase. The activation energies from the experiments in both phases are on the same order of magnitude. However, the literature versus experimental sorption data has a large effect on the determined kinetic parameters.

Ethylene Polymerization Kinetics with a Heterogeneous Metallocene Catalyst – Comparison of Gas and Slurry Phases

“…This forced circulation improved the heat transfer from the polymerizing particles to the cooled reactor wall. [8] The stirrer speed could be varied up to 2 000 rpm. The reaction temperature was measured above the helical stirrer, in contact with the circulating powder.…”

Comparison of Gas and Liquid Propylene Polymerization Technique – Hydrogen Effect on Thermal, Rheological, and Morphological Properties of PP

“…Experimentally, the reaction rate of the LP polymerization, was measured by means of a calorimetric method, which is described by Samson et al13,14 and Pater et al15,16 in more detail. For gas phase polymerization, the reaction rate can be estimated by continuously measuring the pressure inside the reactor and neglecting no sorption of the monomer in the amorphous part of the polymer 17,18…”

“…In the past, many endeavors have been made to achieve a continuous improvement in reactor operability and better control of the polymer properties. In particular, a lot of kinetic and morphological analyses form the basis of these endeavors, which is supported by numerous publications 4–31. Furthermore, there are many articles discussing the final properties of plastic parts influenced by structural changes and processing conditions 32–36.…”

Comparison of catalytic ethylene polymerization in slurry and gas phase

“…A helical stirrer is used to achieve better mixing of components and better heat transfer through the cooling jacket [49]. The stirrer speed can be varied up to 2000 rpm.…”