Wide-angle X-ray diffraction WAXD

Figure 5. Room-temperature, wide-angle X-ray diffraction (WAXD) pictures of stretch-oriented samples of PDHS (left) and PDPS (right).

The crystalline lamellar thickness Dc obtained by StrobPs method is initially 1.4 nm and grows to about 2.0 nm, which is roughly equal to the crystallite size in the chain direction of 2.8 nm estimated from the wide-angle X-ray diffraction (WAXD) [7]. Interestingly, the persistence length /p = 1.45 nm just before crystallization measured by SANS (also see Fig. 11) [9,10] is almost equal to the crystal thickness. 

Wide angle X-ray diffraction, WAXD, studies on the PHAs from octanoic acid (PHA-OCT), nonanoic acid (PHA-NON), and decanoic acid (PHA-DEC) showed that these polymers had the same features as synthetic comb-like polymers [54]. PHA-OCT is the most crystalline (AHm = 8.3 cal/g) and PHA-HEX (the PHA from hexanoic acid) is amorphous, while PHA-HEP (the PHA from hep-tanoic acid) has a very low degree of crystallinity (AHm= 1.3 cal/g). The degrees of crystallinity of PHA-OCT and PHA-NON were determined to be 20 and 30%,... 

Nevertheless, we have often faced the problem that the nanocomposite shows fine and homogeneous distribution of the nanoparticles in the polymer matrix (e.g., poly (L-lactide)) without a clear peak shift of the mean interlayer spacing of the (001) plane, as revealed by wide-angle X-ray diffraction (WAXD) analysis [14], Furthermore we... 

Figure 11.16 shows the wide-angle x-ray diffraction (WAXD) pattern of an oriented PTT and indices of some of the reflections. Although PTT has a 002 reflection, the intensity is weak. It is also not a true meridianal reflection, being offset from the meridian by about 3°. The offset reflections are so close to each other that they overlap and appear as one meridianal reflection [39], and could not... 

The structural anisotropy in crystalline or structurally ordered BPDA-PFMB films was studied in this laboratory with wide-angle X-ray diffraction (WAXD) methods. In brief, WAXD experiments were designed to examine both the reflection and transmission modes of thin-fihn samples. In addition, uniaxially oriented polyimide fiber WAXD patterns were obtained to aid in the identification of the film structure. The film WAXD pattern obtained from the reflection mode corresponded well to the fiber pattern scanned along the equatorial direction (Figure 16.3), " which indicates that the reflection mode pattern represents the (hkQ) diffractions. On the other hand, as shown in Figure 16.4, the (001) diffractions were predominant in the film WAXD pattern obtained via the transmission mode. This pattern corresponded to the fiber pattern scanned along the meridian direction. These experimental observations clearly indicate that the c-axes of the crystals are preferentially oriented parallel to the film surface however, within the film, they are randomly oriented. 4.2 5 j( should be pointed out that the WAXD experiments are only sensitive to crystalline or ordered structures in polyimide films. They do not provide any information on the amorphous regions. 

Our wide-angle x-ray diffraction (WAXD) measurements have shown that stretching pure Epcar 847 induces considerable orientation and crystallinity—just as is the case with natural rubber. The blend of Epcar 847 with 50 phr LDPE also undergoes stress-induced crystallization. However, quantitative or qualitative differences in amounts of... 

The above disadvantage of the lack of spatial information can be overcome by a combination of NMR data and other techniques. From the aH pulse NMR, the fraction and the molecular mobility of different molecular environment can be obtained as free induction decays (FIDs) within a short time, which is suitable for a practical, better understanding of the morphology-property relationship. Wide angle X-ray diffraction (WAXD) and small angle X-ray diffraction (SAXD) as well as electron microscopy provide direct information between the nano- and micrometre scale. A combination of NMR data with those from X-ray diffraction and electron microscopy should be able to analyse the structure from the atomic level to the macro scale. In this review, the morphology-property relationship, the dynamics of morphological transition, the kinetics of crystallisation, etc. analysed by a combination of NMR and other tools are introduced. 

To obtain an insight into the effect of the draw ratio on the molecular orientation of the Vectra phase, wide angle x-ray diffraction, WAXD, was utilized and the results for the Ultem/Vectra 70/30 sheet drawn in the first zone are shown in Figure 11. For the sample with the lowest draw ratio, a sharp Debye ring corresponding to a d-spacing of 0.46 nm is observed. This observation is in agreement with previous data on Vectra reported in the literature (10). As the draw ratio increases, the azimuthal dependence of the... 

Figure 2.28 Diffraction geometry of wide angle X-ray diffraction. (WAXD)...

X-ray diffraction tests are based on the fact that incident X-ray radiation is diffracted at certain angles by regularly spaced inclusions. The two main techniques used in reactive polymer systems are wide-angle X-ray diffraction (WAXD) and small-angle x-ray... 

Results. The small angle x-ray scans frcm hydrolysed polymer are fairly complex and the results are consistent with the existence of three distinct phases (3, 4). Only part of this information, however, is directly related to ionic clustering and to better distinguish features in the SAXS associated with ionic clustering it is appropriate to first examine some experimental results from a wide angle x-ray diffraction (WAXD) experiments. 

The crystallinity of the polyimide films was examined by wide angle X-ray diffractions (WAXD). All polyimides exhibited amorphous patterns and broad dispersive peaks of diffraction around at 16 °(20), as shown in Figure 3. This observation is quite reasonable because the presence of polyalicyclic (bicyclic) structure decrease the intermolecular force between the polymer chains with a consequent decrease in crystallinity. 

Datta and Birley (61) first reported on the crystallization behavior of HDPE/LLDPE blends using DSC and wide-angle X-ray diffraction (WAXD). In the DSC measurements, the blends revealed only one endothermic peak for both fast and slow cooling conditions, indicating that the blend components were cocrystallized. The X-ray... 

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