Fringed-micellar crystallite junctions

Fig. 24. Schematic representation of a network structure formed by copolymer molecules consisting of non-crystalline sections and sections which crystallize to form fringed-micellar crystallite junctions.

Keller et al. [86, 89,90] proposed the existence of two families of X-ray effects in stretched commercial poly(vinyl chloride) A-crystals with an orientation of the a-axis (i.e. in the direction of the polymer backbone) in the stretch direction and B-crystals with an orientation of the c-axis (i.e. perpendicular to the polymer backbone) in the stretch direction. The B-crystals are smaller and are supposed to form the network junctions (crosslinks) of fringed micellar crystallites, whereas the large A-crystals are supposed to be well developed... 

To And the number of statistical units taking part in a junction, let us consider a simple model junction that binds k chains with f sequential units per chain (Figure 8.1(a)). This model is suitable for the descripAon of thermoreversible gels with junctions formed by fringed-micellar crystallites, but Ands applicaAon to other important types of junctions. 

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