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Physical and chemical properties on the aging inhibition mechanism of hydrous alumium oxide were studied by means of dehydration velocity, activation energy, DTA, TGA, IR spectra, X-ray diffraction and TMA, During aging, changes may occur in the hydrous aluminum oxide structure which results in a loss of acid reactivity and in crystal formation to the hydrated hydrous alumina. The results obtained from the X-ray diffraction pattern and DTA, TGA thermogram studies showed that the aging product stabilized with either sobitol or mannitol was hydrous aluminum oxide (Al2O3.xH2O) but the aging product not stabilized was hydrated hydrous aluminum oxide(Al2O3.xH2O.yH2O). The activation energy of dehydration of the hydrous almina was about 17Kcal. mol.-1 deg.-1 which was observed a little less than that of 22Kcal. mol.-1 deg.-1 of the hydrated hydrous alumina. By stabilizing with either sorbitol or mannitol, the inhibition mechanism in the aging process from the hydrous aluminum oxide to hydrated hydrous aluminum oxide is assumed to prevent the formation of the hydrated hydrous aluminum oxide and the aging process is thought of as analogous to the polymorphic transformations which occur as a system converts to its most stable state.
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