Preparation method of high-steric-structure composite crystal polylactic acid foam material

The invention discloses a preparation method of a high-steric-structure composite crystal polylactic acid foam material, and belongs to the technical field of high polymer material processing. The preparation method specifically comprises the following steps: carrying out melt blending on the poly-L-lactic acid, the poly-D-lactic acid and the bio-based nucleating agent to obtain a blend; s2, drying the blend obtained in the step S1, and performing compression molding to obtain a foam matrix; placing the foam matrix obtained in the step S2 in a high-pressure kettle for CO2 saturation treatment, then taking out the foam matrix, placing the foam matrix in high-temperature liquid for soaking treatment, and performing water-cooling shaping to obtain the high-steric-structure composite crystal polylactic acid foam material. According to the invention, effective construction of the single high-stereocomplex crystal content in the polylactic acid foam material is realized through one-pot melt blending and kettle pres