Poly WAXS patterns

Poly-P-hydroxybutyrate (PHB) crystallizes in a low temperature modification (LTM), which is transformed into a high temperature modification (HTM) when heated above 320 °C. Both modifications exhibit distinct WAXS patterns, thus a quantitative determination of the two fractions is possible. However, measurements at the HTM are only feasible with S.R., since the molecules quickly decompose at the high temperatures. Figure 23 shows the fraction of the HTM during heating the PHB sample from 280 °C to 340 °C at a rate of 2 °C/min and subsequent cooling to 280 °C at the same rate [49], A reversible transformation is observed. But the transition from the LTM to the HTM occurs at a temperature, which lies about 20 °C higher than the transition in the opposite direction. This indicates, that each modification is formed by its own nucleation process. 

Figure 9.17 WAXS pattern at 25 C A = 154.18 pm (CuKa). Correlation of the WAXS peaks with the components in poly(p-hydroxybenzoic acid-co-ethylene terephthalate) (a) poly(p-hydroxybenzoic acid), a highly crystalline material (b) COP, 18h at 210-220 C and 4 MPa (c) PET, 60 min at 210-220 C and 4 MPa.

Another class of polymers with interesting intersegmental structure and packing properties are the poly(w-alkyl methacrylates) (55,56). Figure 13 gives the waxs pattern of PMMA, PnBMA, PnHMA, PnDMA, and PnLMA. With the exception of PMMA, the waxs spectra for poly( -alkyl methacrylates) show three peaks (arrows 1, 2, and 3 in Fig. 13b). The peak at high q, with an equivalent... 

The drawing performed slightly above the Tg of the reinforcing component (e.g., around 70 °C for poly(ethylene terephthalate) (PET) of the most studied polypropylene (PP)/PET blend) results in a perfect molecular orientation of the two blend partners as can be concluded from the wide-angle X-ray scattering (WAXS) patterns shown in Fig. 6.3. 

All fabrication techniques presented here are based on the use of toner from office laser printers, which is used to print a layout on a transparency film or a wax paper sheet. The transparency film is essentially used as a poly(ethylene terephthalate) (PET) substrate for polyester-toner (PT) microchannels preparation. The wax paper is used as an initial surface onto which the pattern is printed—the patterns are subsequently transferred either to a recordable compact disks (CD-R) or a glass surface. In either case, this transference is carried out with heat and pressure using the type of heat transfer machine that is used for T-shirt transfer machine or, in more sophisticated form, a tool similar to that used for hot embossing. 

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