Wide angle X-ray diffraction WAXS

The crystalline structure of polymer composites depends strongly on their thermal history and their manufacturing process. To assess their crystal structure and degree of crystallinity, wide angle X-ray diffraction (WAXS) experiments are frequently performed. Figure 10.11 shows the room temperature diffraction patterns of different PEEK/... 

PVC has a complex particle morphology and a low degree of crystallinity. The crystallinity of PVC increases with increase in syndiotacticity. The level of syndiotacticity rises with fall in the temperature of polymerisation, and in the case of commercial types of PVC-S reaches 54-56%, whereas their crystallinity is only about 10%. The presence of crystalline forms in PVC has been established by studies using e.g. small-angle x-ray scattering, wide-angle X-ray diffraction (WAXS), IR spectroscopy and differential scanning calorimetry (DSC). In PVC, crystallites are formed under conversion conditions of less than 2%. These... 

Wide-angle x-ray diffraction (WAXS) profiles were recorded on a Rigaku RAD-III diffractometer equipped with a pulse-hight discriminator. The intensity was collected by step-scan at 0.02° intervals in 2 6, and the counting time was adjusted to accumulate the peak intensity of about lO counts. The crystallite sizes and... 

VTMS Vinyl trimethoxysilane WAXD Wide-angle X-ray diffraction WAXS Wide-angle X-ray scattering XPS X-ray photoelectron spectroscopy ZnSt Zinc stearate... 

The third group of techniques [wide angle X-ray diffraction (WAXS) and differential scanning calorimetry (DSC)] are those that are able to examine formation of structural order within adsorbed layers of surface treatments on filler surfaces. These are discussed in Section 3.6. 

Classical X-ray diffraction and scattering is carried out in the subarea of wide-angle X-ray scattering (WAXS). The corresponding scattering patterns yield information on the arrangement of polymer-chain segments (e.g., orientation of the amorphous phase, crystalline structure, size of crystals, crystal distortions, WAXS crystallinity). 

Information on the morphology of polymers is revealed by techniques such as powder X-ray diffraction (PXRD), which is often called wide-angle X-ray scattering (WAXS) by polymer scientists, and small-angle X-ray scattering (SAXS). The crystallites exist in a polymer sample below the melting temperature T, an order-disorder transition, above which a viscous melt is formed. 

The evidence from wide angle x-ray scattering (WAXS), differential scanning calorimetry (DSC), and IR spectroscopy (IR) shows that both polymers crystallize separately according to their own unit cell structure. The WAXS diffraction lines of each component are present in the blends no new bands appear (12,13,14). By DSC one observes the melting peaks corresponding to each polymer (Figure 1), and IR shows the typical characteristic crystalline bands of the pure polymers in the blends. The IR spectra of the blend can essentially be accounted for as the sum of the spectra of the components. 

The unique proper way to quantify the amount of /1-modification is based on the X-ray diffraction pattern of a PP sample (Fig. 1). Two peaks stand for the /1-crystalline phase in a wide angle X-ray scattering (WAXS) trace that at 26 = 14.2° representing the (300) plane and that at 29 = 21° accounting the (301) plane. The content of the /i-form is determined by the widely accepted empirical equation of Turner-Jones [86] ... 

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