METHODS FOR PRODUCING LACTIDE WITH RECYCLE OF MESO-LACTIDE

摘要

An S, S- and R,R-lactide stream suitable for polymerization is prepared by producing a low molecular weight poly(lactic acid), depolymerizing the low molecular weight poly(lactic acid) to form a mixture of S, S-, R,R- and meso- lactide, and separating meso-lactide from this mixture to form an S, S- and R,R- lactide stream. Meso-lactide is recycled into the process, and shifts the mole fractions of the lactides in the lactide mixture that is produced.