Synthesis Technology of Poly(D,L-lactide) by Ring-Opening Polymerization

D,L-Lactic acid as raw meterial,in the preparation of lactide,with 2 %(based on total mass of reactants) ZnO/Sn(Oct)2,meanwhile distilling lactide,yield of lactide reached 39.2 %.Polylactic acid was prepared through the lactide ring-opening polymerization,under the condition of reaction temperature 160 ℃,and the molecular weight of prepared PLA reached 8.9×104.The purity of lactide and the structure of polylactide were characterized by computer-melting point and infrared spectroscopy(IR) respectively.