3,6-Dimethyl-1,4-dioxane-2,5-dione (or rac-lactide), is the 50:50 racemic mixture of D- and L-Lactide. Rac-lactide is a lactone derived from lactic acid that has attracted great interest in academia and commercial applications, as it is derived from abundant renewable resources. Rac-lactide can be ready polymerized via ring-opening polymerization, using a variety of metal or organocatalysts, yielding poly(D,L-lactide). While the resulting polymer is generally amorphous, the use of stereospecific catalysts can lead to heterotactic PLA, which exhibits some degree of crystallinity.