HIGHLY PUREIFED POLYACTIC ACID, OR A DERIVATIVE THEREOF, A SALT OF THE SAME, AND PURIFICATION METHOD THEREOF

摘要

PURPOSE: Highly pure polyactic acid, a derivative thereof, and a purification method thereof are provided to obtain the polyactic acid and its derivative with an improved molecular weight amount and a low lactide content. CONSTITUTION: A purification method of Highly pure polyactic acid and its derivative comprises the following steps: dissolving the polyactic acid and its derivative to a water-miscible organic solvent with the water miscibility; adding an alkali metallic salt solution or water with the solution and mixing; collecting an organic solvent layer by removing water from the mixed solution by a layer separation; and collecting a polymer by removing an organic solvent from the organic solvent layer. The organic solvent is either acetone or acetonitrile.