In this work, the miscibility effect on the localization of poly(butylene succinate) (PBSU) during the crystallization of PVDF in their blend has been investigated. After annealed at 200 °C and 240 °C, homogeneous and phase‐separated structures can be obtained respectively, which was followed by isothermal crystallization at 141 °C. In the case of 200°C, PBSU tends to enrich in inner‐spherulitic regions because of the excellent miscibility of the blend and the higher growth rate of PVDF crystals. When the specimen was annealed at 240 °C, phase separation produces PVDF and PBSU domains. Upon cooling to 141 °C, one part of PBSU is miscible with , while the other part of it remains as phase‐separated domains due to the high viscosity and slow relaxation of them. The former accounts for the distribution of PBSU in inner‐spherulitic regions. In the latter, however, phase‐separated structures depress the diffusion of PVDF during its crystallization, leading to the lower magnitude of growth rate of spherulites. Both of them contribute to the localization of PBSU in inter‐spherulitic regions. The distribution of PBSU among PVDF spherulites has been validated by long periods, pore size, and mechanical performance of the porous PVDF membranes.

中文翻译：

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PVDF / PBSU共混物中PVDF结晶过程中PBSU的球内/球内定位

在这项工作中，已经研究了PVDF在其共混物中结晶过程中对聚丁二酸丁二酯（PBSU）的局部混溶性影响。在200°C和240°C退火后，可以分别获得均质和相分离的结构，然后在141°C等温结晶。在200°C的情况下，PBSU倾向于富集内球晶区域，这是因为共混物的优异混溶性和PVDF晶体的较高生长速率。当样品在240°C退火时，相分离产生PVDF和PBSU域。冷却至141°C后，PBSU的一部分可与混溶，而另一部分则由于其高粘度和缓慢松弛而保留为相分离的畴。前者解释了PBSU在球内区域的分布。然而，在后者中，相分离的结构抑制了PVDF结晶过程中的扩散，从而导致球晶生长速率降低。它们都有助于PBSU在球间区域的定位。PBSU在PVDF球晶中的分布已通过多孔PVDF膜的长周期，孔径和机械性能进行了验证。