Influence of scPLA microsphere on the crystallization behavior of PLLA/PDLA composites

Abstract In this research, stereocomplex poly(lactide acid) (scPLA) microsphere with complete sc-PLA crystal was prepared from poly(L-lactide acid) (PLLA) and poly(D-lactide acid) (PDLA) with different molecular weight using common dimethylacetamide solvent. Size of the scPLA microsphere is closely associated with the molecular weight, which determines the number of crystal nuclei and the mobility of macromolecules chains. Its morphology presented wrinkle surface and porous structure due to the formation of spherocrystal. This scPLA microsphere is an effective heterogeneous nucleating agent to increase the stereocomplex of PLLA/PDLA solution blend. The results of DSC showed that the degree of stereocomplex increased from 49.44% to 91.63% when the content of scPLA microsphere was 7%. The research provides a simple method for producing complete scPLA microspheres, which are expected as renewable additives in PLA-based composites and delivery carriers in biomedical fields.