(633a) Controllable Preparation of Uniform Magnesium Ethoxide Particles: The Effects of N-Hexane and Silicone Oil and Their Synergic Effect

Magnesium ethoxide (Mg(OEt)₂) is an important organometallic material, widely used in ceramics, catalyst, pesticides, etc., especially as the carrier for Ziegler-Natta catalysts for the synthesis of polyethylene and polypropylene. The synthesis process of magnesium ethoxide using magnesium powder, ethanol and iodine, involves the complicated solid-liquid reactions as well as particle evolution mechanisms including nucleation, growth, and agglomeration. The control of particle morphology and the agglomeration process is the difficulty in the preparation of magnesium ethoxide particles. In particular, it is still lack of relevant regularity research and understanding towards magnesium ethoxide particles with low size and well dispersity.

In this study, n-hexane and low viscosity silicone oil were innovatively added to regulate and control the nucleation process. Regularity study of the growth of magnesium ethoxide revealed that: 1) n-hexane could lead to the explosive nucleation and compact the particles; 2) low viscosity silicone oil as the inert component played an effective role in dispersing the reaction system to reduce agglomeration between particles. Through the effective control based on the synergistic effect of n-hexane and low viscosity silicone oil, it achieves flexible control of particle size, bulk density and dispersibility of magnesium ethoxide particles. The D50 of particles was controlled from 5 to 30 μm, the RSF (relative span factors) was under 1.0, and bulk density ranged from 0.2-0.7 g/cm^-3. The addition of n-hexane and low viscosity silicone oil improved the flexibility of preparation, and these strategies provided useful guidance for the customized preparation of micron-sized magnesium ethoxide particles serving the large-scale industrial applications.