TIT# SAXS observations of the crystallization of polyolefines from the melt
AUT# Almendarez Camarillo, Armando; Stribeck, Norbert;
SOU# Fibr. Text. EE (2005), in print
LOC# xv093
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ABS# In-situ experiments on the nanostructure evolution during the oriented
     crystallization of polyolefines (polyethylene (PE), polypropylene (PP))
     from a highly oriented melt have been carried out by means of synchrotron
     radiation and small-angle X-ray scattering (SAXS). The general options of
     data analysis are demonstrated using good data recorded in a study of PE.
     Mainly we report on the oriented crystallization of PP from the melt. We
     report the conditions, under which oriented crystallization is observed.
     While in our studies of PE we generally observed two-point diagrams, there
     are processing conditions for PP under which a peculiar four-point
     diagram is observed with the first two reflections on the meridian and
     the last two on the equator. On the other hand, a similarity is observed.
     Under isothermal crystallization conditions only during the first minutes
     extended crystalline lamellae are formed, whereas the crystallites formed
     later remain small. The orientation memory of PP is found to strongly
     depend on the melt temperature. Its dependence on melt annealing time is
     low. Because of instrumental problems at beam line BW4, HASYLAB Hamburg
     our data are too noisy to be used for a quantitative analysis by application
     of the multidimensional chord distribution function (CDF) method.