Synthesis and Characterization of Alternating Lactic and Glycolic Acid Alternating Copolymer

With chloroacetic acid and DL -lactic acid as raw materials, alternating lactic and glycolic acid copolymer ( DL -PLGA) was synthesized by means of esterification, ring-closure and ring-opening polymerization, and the product structure was characterized by IR spectra and 13 CNMR spectra. The results showed when the reaction time was 5～6 h and at reaction temperature of 105 ℃, a higher yield of o -chloroacetyl- DL -lactic acid could be obtained; and when Na2CO3 was used as catalyst and the process conditions were changed, the methylglycoide yields of the monomer could come up to 50%. And when the mass ratio of the monomer to catalyst was 1 000, and polymerized at 140 ℃, the M n could be more than 10 000 g/mol.