Catalyst for direct conversion of esters of lactic acid to lactide and the method for producing lactide using the same

Abstract

The present disclosure discloses a catalyst for directly producing a lactide which is a cyclic ester used as a monomer for polylactides, and a method for directly producing a lactide using the catalyst, the method including the transesterification reaction between two molecules of an ester of lactic acid or a mixture containing the ester of lactic acid with a small amount of lactic acid and oligomer of lactic acid under an inert environment in the presence of a titanium-based catalyst or a catalyst mixture containing the titanium-based catalyst so as to produce lactide while simultaneously removing an alcohol (ROH) generated as a by-product. As compared to a conventional commercialized process, since the method for producing a lactide in accordance with the present disclosure is a novel process capable of directly producing the lactide from the ester of lactic acid, energy consumption is low and the lactide can be produced through a simple process showing a high yield while maintaining optical property (D-form or L-form optical isomer).