Effect of the structure of titanium–magnesium catalysts on the morphology of polyethylene produced

ABSTRACT The structure and formation of polyethylene (PE) particles on supported titanium–magnesium catalysts having different structural characteristics (sizes of microcrystallites, mesopores, and subparticles) were studied for the first time. Scanning electron microscopy was used to identify structural elements of the polymer particles formed over such catalysts and to reveal morphological changes in the growing polymer particles when the yield was increased from approximately 0.2 g PE/g catalyst to approximately 13 kg PE/g catalyst. A relationship was found between structural characteristics of the porous catalyst particles, morphology of the nascent polymer particles, and bulk density of the polymer powder. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 2298–2308 This research finds a relationship between the structural characteristics of porous catalyst particles, the morphology of nascent polymer particles, and the bulk density of polymer powder. Catalyst particles consisting of globular subparticles with high packing density—comprising close‐packed globular microparticles with small mesopores and crystallites—produce PE with high bulk density.