The effects of crystallization temperature of PBS (TIC,PBS) on the fractional crystallization, phase segregation, and crystalline morphology of PEO in their miscible crystalline/crystalline blends are investigated. The crystallization kinetics and phase segregation of PEO are considerably influenced by TIC,PBS. A higher TIC,PBS results in the crystallization of PEO at an extremely large degree of supercooling and may facilitate the segregation of PEO within the interlamellar regions of PBS. At a high TIC,PBS (e.g., 95 8C), the long period, thickness of amorphous and crystalline layers of PBS increase upon blending with PEO. The TIC,PBS dependence of phase segregation of the PEO component is discussed from a thermodynamic as well as a kinetic perspective.