Miscible Blends Containing a Crystalline Polymer

The miscibility of blends containing at least one crystalline component shows that they exhibit 

The thermal history has a profound influence on the DSC curves of polymer blends containing at least one crystalline component. In order to obtain by DSC experiments, the samples are usually first heated to a temperature between the phase separation temperature and the melting point of the crystalline component and held for several minutes to remove the thermal history. 

By measuring the area under the melting peak of DSC curves, it should be possible to evaluate the heats of fusion (AH,) and crystallization (AH ) in the blend. The fractional crystallinity, was 

The findings that the morphological and stability parameter l/y is almost constant and independent of blend composition and that the T -T lines extrapolate to different equilibrium melting points strongly suggest that the melting point depression can be primarily ascribed to the diluent effect of the non-crystallizable polymer as the two components are miscible in the melt. 

The negative values found for B in the case of PEO-PU blends support the idea that these polymers are miscible in the molten state and the fact that the intercept of the Nishi-Wang plot is close to zero indicates that entropic effects contribute little to B. 

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