AbstractIn this paper, the synthesis of different catalytic systems based on the reduction of TiCl4by Grignard compounds has been systematically studied. The catalysts exhibited the highest activities when used in the copolymerization of ethylene withn‐hexene. The profile of the kinetic curves also changed when the comonomer was present during polymerization. By thermal analysis and scanning electron microscopy techniques, it could be found that the incorporation of the comonomer to the polymer chain brings about a decrease in the polymer crystallinities and an increase in the porosities of the growing particles. Due to that, the diffusion of the monomer to the catalytic active centers takes place more easily, consequently increasing the polymerization rate. In addition, catalysts control better the morphology (size and shape) of the nascent polymer particles when used for copolymerizatio
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