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.

Automated summary

A catalyst composed of polyaniline-supported zinc oxide nanocomposites was successfully designed to catalyze the condensation reaction of L-lactic acid with high yield and optical purity. This recyclable and reusable catalyst allowed for the successful scale-up of production to 3.6 kg of L-LA, producing L-lactide with high optical purity through a simple water washing and vacuum drying process, without the generation of meso-lactide.