| 초록 |
Polymers composed of a pre-defined number of repeating units can be synthesized to have a precisely-defined stereochemical purity, which could furnish unprecedented platforms to explore their crystallization. Herein, we fabricate discrete poly(D-lactic acid) (DLA) with a stereochemical sequence using the cross-convergent method and investigate their crystal structures. Enantiomerically pure block copolymers formed irregular leaf-like crystallites. In contrast, BCPs with modulated stereochemistry form diamond-shaped crystallites. Chain folding of DLA40 could generate a terminal segment containing eight residues that might tamper with the crystallization of PLA segments comprising 32-repeating units. The effect of the degree of stereocomplexation on crystallization-driven self-assembly was also investigated. Depending on the degree of stereocomplexation, the stereocomplex between BCPs containing stereochemical sequences formed rod-shaped or triangular crystallites. |
