An Experimental Investigation of the Impact of Gas Phase Prepolymerization of Propylene. Issue 3 (4th March 2020)

• Record Type: Journal Article
• Authors: Yu, Yue; McKenna, Timothy F. L.
• Is Part Of: Macromolecular reaction engineering. Volume 14:Issue 3(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-03-04
• Subjects: effect of mineral oil -- gas phase -- number of active sites -- polypropylene -- prepolymerization; Polymers -- Periodicals; Polymerization -- Periodicals; Reaction mechanisms (Chemistry) -- Periodicals; Electronic journals; 547.705
• DOI: 10.1002/mren.201900052
• Languages: English
• ISSNs: 1862-832X

Abstract

Abstract: A systematic investigation is carried out on the gas phase of propylene during the initial instants of polymerization. The results confirm the positive impact of small amounts of mineral oil on the initial reaction rate and morphology. It is shown that polymerizing under conditions of mild temperature and pressure alone are not enough to achieve the same result. It is found that the presence of mineral oil, and low temperature of polymerization can be used to control the morphology of polymer particles and to obtain high activity in the main reaction. If enough oil is used, moderate to high temperatures of prepolymerization are acceptable in terms of controlling morphology but can compromise the activity of the main polymerization. It is also observed that the way in which the oil is introduced has an impact on the kinetics and particle morphology. Separate addition of oil from the precatalyst gives rise to relatively flat kinetics during prepolymerization and highest rate during main polymerization. To account for the activity enhancement, a selective quench‐labeling study employing methyl propargyl ether shows that the presence of mineral oil appears to increase the fraction of active titanium by a factor of almost 2. Abstract : A systematic investigation of the gas phase prepolymerization of propylene shows that the addition of small amounts of mineral significantly improves the kinetics of the full polymerization stage, as well as the morphology of the prepolymer and polymer particles.