Crystallizable matrix

Blends with a Crystallizable Matrix and an Amorphous Dispersed Phase... 

Since in immiscible blends the phases are physically separated, the same heterogeneities that nucleate the homopolymer at T may nucleate the crystallizable matrix. As a result, the crystalhzation temperature, T, of the blend during coohng from the melt will in general not differ that much from the T of the pure component. 

Although most principles for the crystallization of homopolymers remain valid for immiscible blends with a crystallizable matrix, the crystallization behavior can be altered by two phenomena, inherently correlated with immiscible two-phase systems, namely migration of impurities during melt-mixing and the nucleating activity of the interface between two phases. 

In the case of immiscible blends with a crystallizable matrix, the spherulite growth can be disturbed to a certain degree by the presence of an amorphous phase component, dispersed in the crystallizable melt. 

Several factors determine the amount of energy required by the growth front to be overcome in order to allow the crystallizable matrix to form spherulites... 

The addition of a second non-crystallizable component to a crystallizable matrix can cause drastic variations of important morphological and structural parameters of the semicrystalline phase, such as the shape, size, regularity of sphemlites and intersphemlitic boundary regions, lateral dimensions of the lamellae, etc. These factors may greatly influence the mechanical behavior and, in particular, the fracture mechanisms, and thus are of great importance, especially when the toughening of semicrystalline polymer blends is considered. 

Table 3.21. Examples of the spheruhte growth rate, G, of the crystallizable matrix in crystaUine/amorphous polymer blends... 

Blends with a crystallizable matrix and an amorphous dispersed phase... 

Hm is the molecular mass of the repetitive unit of the macromolecular chain of the crystallizable matrix... 

The addition of a second noncrystallizable component to a crystallizable matrix can cause drastic variations of important morphological and stmcmral parameters of the... 

Table 3.22 Global crystallization kinetics of the crystallizable matrix in some crystalline/...

Blends of Crystallizable Matrix and Amorphous Dispersed Phase. 291... 

Polymer Blends Containing Crystallizable Matrix and Dispersed Phases.296... 

BLENDS OF CRYSTALLIZABLE MATRIX AND AMORPHOUS DISPERSED PHASE... 

However, in the case of immiscible blends with a crystallizable matrix, the spherulite growth can be disturbed to a certain degree by the presence of an amorphous dispersed phase and intentional seeding (nanofillers) localized in the crystallizable matrix or at the interface. In the presence of molten or glassy dispersed phase, along the path of crystallization growth front can markedly disturb the... 

For nanostructured materials that improved compatibility, it is expected that this can lead to a serious shift in the crystaUization temperature toward lower temperatures. Thereby leading ultimately to a more pronounced fractionated crystallization or even resulting in a homogeneous aystallization. Just as discussed for crystallizable matrix, the crystallizable dispersed phase may crystallize in the presence of either melt or glassy amorphous matrix. 

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