Formation of Porous Spherulites of Poly(L-lactide) Grown from Solutions

Poly(L-lacide) (PLLA) was crystallized from 5.0 wt % solutions of diethyl phthalate (DEP), glycerol tri-n-propionate (TP), N,N-dimethylformamide (DMF), and dimethyl sulfoxide (DMSO). From DEP and TP solutions, very porous flower-like spherulites consisting of assembled petals are formed, and each petal may include stacked lamellae. From DMF and DMSO solutions, on the other hand, less porous crystalline aggregates are formed, but they can be converted to crystallites with porous surface by etching treatment.