IMAGING PLATES AS AN INTEGRATING AREA DETECTOR FOR X-RAY SCATTERING AND DIFFRACTION OF POLYMERS. M. Dosiäre, C. Dammer, Universite de Mons-Hainaut, Laboratoire de Physicochimie des Polymäres, place du Parc, 20, B - 7000 - Mons, Belgium

Imaging plate (IP) initially developped for diagnostic radiography by Fuji Photo Co., Ltd.(1), has been used as a two-dimensional integrating X-ray detector(2). The image plate has a high quantum efficiency, a wide dynamic range of 4 to 5 digits and no counting rate limitation. Fuji plates have been substituted to X-ray films in a pinhole collimation camera allowing to record simultaneously wide and small angle patterns of polymers with conventional X-ray generators (sealed tube and rotating anode) available in a laboratory. The two large advantages of imaging plate with respect to the X-ray film is the availability of the intensity in the same time as the position of the diffracted spots and its quickness. The image plate is a 120 mm edge size square ; the pixel size is 50 Êm. The Fujix BAS 3000 device was used to read-out the image. Use-friendly computing programmes have been developped in C++ language in Windows environment for polymer physics. For isotropic polymer samples, the signal to noise ratio has been substancially increased by integrating the diffraction circles.A routine allows to determine with a precision of 1 pixel the center of the X-ray pattern. The experiment X-ray data are corrected for absorption of the sample, polarization, Lorentz factor,...

The following programmes concerning polymers has been developped and are available with reference samples (PE,PP,PEO,PEEK,...) to determine: a) the dhkl spacings and to calculate the unit cell parameters or their modification resulting from thermal dilatation, compression...; b) the degree of crystallinity from wide angle X-ray diffraction pattern; c) the orientation function of oriented samples (spherulite, stretched or rolled samples); d) the long spacing from SAXS patterns; e) the orientation of the chain axis with respect to the limiting faces of lamellar crystals in oriented samples; f) the integrated SAXS intensity (invariant); g) the correlation fucntion from SAXS intensity data. Demonstrations of these friendly use programmes will be presented.

References

1. M. Sonoda, M. Takano, J. Miyahara, H. Kato, Radiology, 148, 833 (1983).

2. Y. Amemiya, Y. Satow, T. Matsuschita, J. Chikawa, K. Wakabayashi, J. Miyahara, Topics in Current Chemistry, 147, 121 - 144 (1988)