Wide Angle Experiments

It is suggested that the experiments be run in the following order with the following recommended exposure times  

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If the wide angle and small angle experiments are run simultaneously, the timer is not used. For the wide angle experiment, follow steps 2 to 4 and 6 to 9, timing the exposure by clock. 

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. 

The applications of wide angle light scattering are beyond the scope of this work and too numerous to be summarized here but we would like to call attention to some comprehensive reviews (12, 13), basic treatises ( 5, 6), conference proceedings (14, 13) and finally some representative articles, selected from our own experience, that introduce the basic size distribution information obtainable from wide angle light scattering. 

Wide angle light scattering experiments have been carried out with sufficient accuracy to separately identify dust or extraordinary particles, latex particles and small-molecule scattering. 

Figure 8.13 Wide-angle light scattering experiment and the scattering volume.

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/... 

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