Ring-banded spherulites have never been formed directly from the glassy state of poly(L-lactide) (PLLA), particularly in case of its copolymers containing some stereodefective D-lactic units, which kinetically hinder the crystallization. By utilizing compressed CO2, banded spherulites have been directly obtained by treating the glassy PLLA containing 4-6% D-isomer. Specifically, ring-banded spherulites with regular rings, consisting of periodically parallel-aligned lamellar crystals twist in the left-handed sense, were exclusively formed in CO2 of high pressures (8 - 16 MPa) and low temperatures below the normal glass transition temperature (T-g). Owing to the relatively high D-isomer content, PLLA possessed the adequate resistance to crystal nucleation during melt-quenching, which is inherently favorable for obtaining a fully glassy sample with negligible crystal nuclei and plays a significant role in promoting the formation of banded spherulites. The formation of banded spherulites in PLLA from the glassy state is plausibly attributed to a synergistic effect of the specific molecular structure and the suitable CO2 atmosphere (i.e., low temperatures and high pressures). The unbalanced stress at opposite fold-surfaces responsible for the lamellar twisting was intensified by the D-isomer and released by the compressed CO2, which eventually resulted in cooperatively twisted lamellae for constituting the ring-banded spherulites. (C) 2016 Elsevier Ltd. All rights reserved.