SMALL-ANGLE X-RAY STUDY OF MICRODOMAINS IN RIGID PVC

PVC samples prepared under various conditions have been examined by small-angle X-ray scattering (SAXS) in the region greater than 5 milliradians. The intensity of the scatter is consistent with a two phase structure of crystallites in an amorphous matrix. The scatter profile from the original powder and from mouldings that have not been annealed fits a Debye exponential correlation function. This suggests nodular crystallites of wide size distribution with typical diameters of 3 nm. Mouldings that have been annealed give scattering profiles with a broad peak, whose maximum corresponds to an equivalent Bragg period of about 10 nm. Probably after annealing the nodular crystallites have become more uniform in size and are arranged more regularly. © 1979.