Abstract: The preparation of aluminum complex grease using aluminum isopropoxide as raw material was studied. The effects of the reaction temperature, the reaction sequence of organic acid saponification, the amount of quench oil, the composition of aluminum complex soap and the type of the base oils on the physicochemical properties of the product were investigated. Infrared spectroscopy was used to monitor the synthesis of aluminum complex soap and complex grease. The scale up test was conducted on pilot plant. The materials used are 150BS, where 1/3 is used as quench oil, stearic acid and benzoic acid which react with aluminum isopropoxide at the same time. The optimal reaction conditions are: the molar ratio of stearic acid, benzoic acid and aluminum isopropoxide is 1: 1: 1.2, the maximum refining temperature is controlled at 180-190℃. The preparation process can be well monitored by infrared spectroscopy. The aluminum complex grease prepared has a good performance in mechanical stability, colloidal stability, anti-corrosion and anti-rust, water resistance and abrasion resistance, and meets the US Navy ship grease AA-50433 specification.

Key words: grease, aluminum complex soap, aluminium isopropoxide, infrared spectroscopy