Production manner of the lactide which designates fermentation lactic acid as the raw materials and production manner null of poly

摘要

PROBLEM TO BE SOLVED: To provide a method for throughout producing lactide from ammonium lactate obtained by lactic acid fermentation, and to provide a method for throughout producing polylactic acid from ammonium lactate obtained by lactic acid fermentation.;SOLUTION: This method for producing the lactide comprises (1) synthesizing a lactic acid ester from ammonium lactate obtained by lactic acid fermentation, (2) polycondensing the lactic acid ester in the presence of a catalyst except monobutyl tin to synthesize the polylactic acid (lactic acid prepolymer) having a weight-average mol.wt. of 15,000, and (3) depolymerizing the polylactic acid to produce the lactide. Further, the method for producing the polylactic acid comprises the ring-opening polymerization of the lactide to obtain the polylactic acid. The method for producing the lactate from the ammonium lactate obtained by the lactic acid fermentation.;COPYRIGHT: (C)2002,JPO