Polyaniline-Supported Zinc Oxide Nanocomposite-Catalyzed Condensation of Lactic Acid to Lactide with High Yield and Optical Purity

In this work, we designed polyaniline-supported zinc oxide nanocomposites, which were easily prepared catalysts and could catalyze the condensation reaction of l-lactic acid to produce l-lactide in good yield (84%) with high optical purity (98.2%). The catalyst was recyclable and reusable, while the reaction has been successfully magnified to 3.6 kg of l-LA scale, affording l-lactide in 81% yield with 98.66% optical purity just by water washing and drying under vacuum, while no meso-lactide was generated.