Ceramics-Silikáty 49 (2) 138-141 (2005)

Preparation of g-Alumina from Aluminum Aminoalkoxides

M. M. Amini, S. J. S. Sabounchei, F. Mirnajafi, M. Mirzaee, M. Sharbatdaran

New aluminum aminoalkoxides, Al(OCH₂CH₂OCH₃)₂(OCH₂CH₂NH₂) (1) and Al(OCH₂CH₂OCH₃)(OCH₂CH₂)₂NH (2), were synthesized from aluminum 2-mehoxyethoxide by alcohol exchange method and after characterization by infrared, mass, 1H and 27Al NMR spectroscopes have been used as precursors for the preparation of g-alumina by conventional and hydrothermal hydrolysis. The hydrolysis process revealed that the precursors are significantly less sensitive to hydrolysis than the parent aluminum alkoxides. Thermal analysis indicates that the gel prepared from hydrothermal hydrolysis losses about 65% weight upon heating to 800°C. The X-ray diffraction shows that in the conventional and hydrothermal hydrolysis of (1) and (2) pseudoboehmite phase forms and converts to fine g-alumina by calcination at 800°C. The scanning electron microscopy shows that the alumina prepared by hydrothermal hydrolysis is more uniform than the powder obtained from conventional one. The prepared aluminum aminoalkoxides have good potential for casting monolithic gel by sol-gel process.

Keywords: Aluminum aminoaloxide, g-alumina, Sol-gel, Hydrothermal