Interlamellar amorphous regions

Overall, the data were taken to indicate that the PCL blocks tended to be incorporated into the crystalline lamellae in a manner similar to the PCL homopolymer. The polybutadiene blocks were thus located in the interlamellar amorphous regions and contributed to the ring-banding. It is not clear if the polybutadiene block was uniformly distributed in the amorphous regions but in the preferred model there was some segregation of PB and PCL within the amorphous regions. 

Figure 26 Schematic illustration of the two possible models of the lamellar stack of semirigid chain polymers. Left, stacks with thin crystals and thicker interlamellar amorphous regions. Right stacks with thicker crystals and thinner interlamellar amorphous regions. The ambiguity of the microstructural model Is due to the Babinet principle, which makes the scattering from the two structures indistinguishable.

Figure 1.8 Semiorystalline polymer (PE) with arrangement of crystalline lamellae (clearly visible as bright bands in edge-on position) and interlamellar amorphous regions and lamellae interfaces (dark), and gray bands represent lamellae in a tilted or flat-on position (chemically stained UDS, TEM)...

At the initial stages of deformation, these processes are mainly controlled by the amorphous phase. Occasionally, microvoid formation between lamellae (in the interlamellar, amorphous regions see Fig. 2.17) supports ductile processes. 

The PEO/EMAA and PEO/SHS blends exhibit volume-filling spherulites for all compositions examined in this part of the study (i.e., 20%). These observations, in concert with SAXS results, indicate at least partial exclusion of the diluent into regions between lamellar stacks at these compositions. The distribution of the second polymer between the interlamellar and interfibrillar regions can be estimated using measured bulk crystallinities and correlation function parameters as follows. The volume fraction of lamellar stacks is determined from the bulk and linear crystallinities (v, average electron density difference between crystalline and interlamellar amorphous regions can be determined using eqn. 2. 

In an earlier paper by Galeski, Argon and Cohen [39] the following scenario of crystalline polymer deformation imder uniaxial tension was outlined the packets of lamellae in the 45° fans of spherulites experience resolved shear stress that promotes chain slip in the lamellae and shear in the interlamellar amorphous regions (see Figure 1.1). 

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