Abstract: Anhydrous AlCl₃ is one of the primary catalysts used by domestic enterprises in the production of poly-α-olefin (PAO) base oils. However, the direct synthesis process of PAO suffers from issues such as low yield, intense exothermic reactions, and wastewater generation. To address these problems, anhydrous AlCl₃ was added in batches to α-olefins under solvent-free conditions at a constant reaction temperature. The products were characterized using infrared spectroscopy, nuclear magnetic resonance hydrogen spectroscopy, gel permeation chromatography, and gas chromatography. The results showed that the PAO exhibited a coefficient of variation of less than 2.2% for kinematic viscosity at 40 °C, a yield exceeding 98%, a flash point above 280 °C, and a dispersity index below 1.6. Additionally, the PAO product contained no dimers, consisting primarily of tetramers and higher oligomers. Furthermore, a KOH-C₂H₅OH solution was used to neutralize the crude PAO, achieving a chloride ion (Cl^-) removal rate of over 80%, reducing the Cl^- mass fraction to below 255 μg/g, and lowering the acid value to 0.01 mgKOH/g. The entire treatment process was carried out under anhydrous conditions, resulting in no direct environmental wastewater issues.

Key words: poly-ɑ-olefin, anhydrous AlCl₃, poly-ɑ-olefin base oil, solvent-free, dechlorination