Spherulites in blends

Nojima et al. [160] examined the nature of spherulites in blends of PCL with 8-caprolactone-butadiene diblock copolymers. Blends were prepared by solventcasting mixtures of the components, using a series of block copolymers and PCL samples. Optical microscopy showed that all blends investigated, and cast at... 

At very low crystallization temperatures (Fc < 75°C), the growth of iPB crystals in the blends proceeds simultaneously with the crystallization of iPP. The presence of iPB crystals may induce additional nucleation of iPP at the interface between the two polymers thus, two populations of spherulites can appear in the blends small iPB spherulites nucleated inside the iPB-rich phase and iPP spherulites nucleated at the interfaces. As a consequence of the above phenomena, the size of iPP spherulites in blends decreases at large undercooling, while it increases at low undercoolings, as compared with plain iPP crystallized at the same Fc [60]. 

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