PHB-specific FT-IR image

Figure22.16 Visual image (left), PLA-specific FT-IR image (center) and PHB-specific FT-IR image (right) of the PHB/PLA (50/50wt%) blend film at 175°C.

Figure 22.19 Visual image (a), PHB-specific FT-IR image (b) and PCL-specific FT-IR image (c) of a PHB/PCL (50/50wt%) blend.

Figure 55 F-IR imaging of 260 urn x 260 im area of PHB/PLA biend fiims. (a) FT-iR spectrum of a PHB/PLA (50 50 wt.%) blend film (b) visible image (ieft), PLA-specific F-iR image (centre), and PHB-specific F-IR image (right) of a PHB/PLA (50 50 wt.%) blend film (c) visible image (left), PLA-specific F-IR image (centre), and PHB-specific FT-iR image (right) of a PHB/PLA (30 70 wt.%) blend film.

The FT-IR transmission spectra of the individual blend components PHB and PLA and of a PHB/PLA (50 50wt%) blend film are shown in Figure 9.21a and b, respectively. In Figure 9.21a, only a limited number of absorption bands are detectable which are specific for the individual blend components PHB and PLA. For FT-IR imaging, primarily the nonoverlapped left and right wings of the intense... 

At 175 °C neither in the visible nor in the FT-IR images of the PLA- and PHB-specific regions can the structures of phase separation be detected, which confirms that both phases of the PHB/PLA polymer blend are molten and that a more-or-less homogenous liquid phase remains. 

In order to develop the FT-IR contour plots, the PHB-specific (981 cm ) and PCL-spedfic (1473 cm ) absorption bands were integrated for all pixel spectra. The visible and FT-IR images of the PHB/PCL 50/50wt% polymer blend, mapped for a 260 pm x 260 pm area, are shown in Figure 22.19. 

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