The Effect of Magnesium Particles Size and Reaction Conditions on Morphology of the Synthesized Magnesium Ethoxide

Research subject: 

Magnesium ethoxide is a metal alkoxide used as a support for preparation of Ziegler-Natta catalyst. This important material which is used in HDPE production plants is not produced in Iran. It forms a complex with the catalyst that results in increase of the number of the reacting transition metal atoms inside it. Therefore the catalyst activity increases. The chemical reaction between magnesium and ethanol, in presence of iodine, results in magnesium ethoxide production.

Research approach: 

In this work, by performing analyses such as thermal gravimetric analysis (TGA), BET and scanning electron microscopy (SEM), the effects of reaction conditions such as iodine/magnesium, ethanol/magnesium, temperature and mixer speed on morphology and characteristics of magnesium ethoxide were investigated.

By using Iodine, proper morphology of product was obtained. The mixer rotation speed didnchr('39')t affect the reaction time. The particle size of the product was dependent on the magnesium amount and particle size and mixer speed. Increasing the rotation speed of the mixer at high amount of magnesium (low ethanol/magnesium) led to more collision of the particles and therefore finer product particles. Reaction at temperatures as low as 60 ₒC led to formation of fine particles with undesirable flake-like morphology. Magnesium with two average particle sizes (420 and 840μm) was used. It was shown that synthesis with magnesium of 840 μm(FW40) led to a sample similar to the commercial one with appropriate specific surface area. Lowering the temperature from 110 to 100 ₒC and reflux of ethanol at boiling point resulted in higher specific surface area.