The invention belongs to the technical field of
organic synthesis, and particularly discloses a method for synthesizing
polylactic acid by adopting a large-channel
continuous flow microreactor, and the method comprises the following steps of: dissolving
lactide in an
organic solvent, then injecting a
lactide solution and a non-
metal organic catalyst into the large-channel
continuous flow microreactor, and carrying out
polymerization reaction to synthesize the
polylactic acid. According to the method, the non-
metal organic catalyst is combined with the
continuous flow microreactor, so that the continuous material ratio, the
reaction temperature and the reaction time can be precisely controlled, the reaction realizes
rapid mixing and
mass transfer, and the obtained product is good in reproducibility, stable in quality, high in
monomer conversion rate, high in
polymerization degree and low in molecular
weight distribution index, and can be controlled to meet the high requirement of 1.1-1.3, the yellow index is low, expanded production in industrial reaction is facilitated, and the problems of high synthesis
reaction temperature, many side reactions, long
residence time, low production efficiency and the like of
polylactic acid in the prior art can be effectively solved.