General comments on miscibility and crystallinity of

3 GENERAL COMMENTS ON MISCIBILITY AND CRYSTALLINITY OF LONGITUDINAL + EP BLENDS 

73PHB and a semiflexible PLC of structure similar to HTHIO but with four flexible units in the spacer, TR-4, 

Part of the reason for the difficulty in making hard and fast rules in these systems is that both nucleation and growth contribute to overall crystallization rate and blending has the potential to be affective either in subtle and possibly independent ways. This is illustrated by the work of Van Ende et al. [164] who found that a semicrystalline polymer formed a miscible blend with a flexible EP and this resulted in increased nucleation density and growth rate whilst the addition of a more rigid PLC of similar chemical structure but only partial miscibility was 

Another important factor in immiscible PLC + EP blends is whether the crystallizing EP phase is crystallizing in the presence of a solid (glassy, crystalline) or flexible (liquid crystalline) PLC phase and this can be assessed by looking at the various crystallization temperatures of PLCs and the EPs (preferably at cooling rates relevant to the processing technique) with which they are blended. This can be 

MacDonald, W.A. (1991) in High Value Polymers, Royal Soc. Chem., London, Spec. Publ., 87, 428. 

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