X-RAY-CAMERA FOR HIGH-ANGLE AND SMALL-ANGLE X-RAY-DIFFRACTION STUDIES OF THE DRAWING AND ANNEALING OF POLYMERS AT DARESBURY SYNCHROTRON RADIATION SOURCE

A purpose-designed x-ray fiber diffraction camera has been constructed in the Keele University Physics Department to be used at the SERC Daresbury Laboratory Synchrotron Radiation Source. The camera allows time-resolved studies of the change in both the high- and low-angle diffraction patterns during drawing and annealing of polymer films to be recorded. Drawing of the films is achieved by two opposed stepper motors which allow films to be drawn uniaxially in both directions. The temperature of the sample environment can be controlled to within 1-degrees-C by a radio spares proportional, integral, and derivative (PID) controller. Diffraction patterns can be recorded on the Enraf-Nonius TV FAST detector or on photographic film. Exposure times using the FAST detector are typically 5 s, representing a gain of approximately a factor of 5 over photographic film. The FAST detector has a further advantage over photographic film in that essentially an unlimited number of diffraction patterns can be recorded end-to-end while a structural transition is being followed. A video camera is incorporated to allow the variation in the gross appearance of the specimen to be recorded during drawing and annealing and to be related to the variation in the diffraction pattern. The application of the camera in the study of drawing and annealing of poly (aryl-ether-ether-ketone) (PEEK) is described.