Introduction of sc-PLA crystals as small nuclei or large sc-PLA spherulites has great influence
on patterning the inter-phase boundaries and reducing the cracks in crystallized PLLA in mixtures with PDLA. Unmelted sc-PLA crystals as nuclei induce cracks in later-crystallized PLLA whereas co-crystallization of PLLA with PDLA to develop simultaneous PLLA and sc-PLA spherulites is effective in altering the inter-phases for minimizing the cracks. PLLA cocrystallized with sc-PLA spherulites tends to be more compact than PLLA spherulites crystallizing on sc-PLA nuclei. In general the sc-PLA spherulites suppress the occurrence of a stressed interphase in PLLA spherulites and the depth of cooling-induced cracks is also decreased.