Simultaneous measurements of small- and wide-angle X-ray scattering during low speed spinning of poly(propylene) using synchrotron radiation

Simultaneous measurements of small- and wide-angle X-ray scattering (SAXS and WAXD) were performed during the melt spinning of isotactic poly(propylene). The extruder assembly was mounted on a platform, which could be moved horizontally and vertically allowing variations of the measuring point between distances of 28 and 90 cm from the spinneret. The SAXS and WAXD pattern were taken simultaneously with two two-dimensional detectors. Additionally, the fiber diameter profile was measured. The development of the crystallization and the orientation of the crystallites were studied as a function of the distance from the spinneret, The wide-angle data revealed that highly oriented crystals grow out of an apparently unoriented amorphous matrix. Moreover, the orientation of the crystallites was found to be constant along the spin line. Both crystalline WAXD and SAXS peaks were found to occur at the same distance from the spinneret within the resolution of the apparatus. A comparison of WAXD and SAXS shows that the crystallization and the formation of a superstructure follow the same kinetics. (C) 1999 Elsevier Science Ltd. All rights reserved.