抄録
The hydrolysis of benzene solutions containing aluminium isopropoxide which is chosen as a representative compound of aluminium alkoxide in contact with water has been examined under different conditions. The precipitates were checked by X-ray diffraction study, infrared spectroscopy and thermal analysis (TG and DTA). It was found that the freshly precipitated gelatinous aluminium hydroxide exists in an amorphous type and goes to pseudoboehmite by ageing in settling, and then proceeds to bayerite. The amount of pseudoboehmite increased with increasing the concentration of aluminium isopropoxide in benzene solution contacted with water and the preparation temperature. In addition, the composition of the precipitate was not much influenced by the initial pH value of water added to benzene solution of aluminium isopropoxide. When the mixture of benzene solution containing aluminium isopropoxide and water was aged in agitation, the formation of hydrargillite was accompanied with that of bayerite. Consequently it is inferred that the crystallization of gelatinous aluminium hydroxide prepared by the hydrolysis of aluminium isopropoxide proceeds in the following sequence :freshly precipitated amorphous aluminium hydroxide → pseudoboehmite →bayerrite→hydrargillite
