Abstract:
Rheological set-ups with in situ analytical sensors, combine information on
the flow and deformation behavior of soft matter, with simultaneous insights
into structural and dynamic features. Furthermore, they permit the study of
soft matter under well-defined flow conditions. Herein are presented hyphenations of rheology and nuclear magnetic resonance (NMR), small angle X-ray
scattering (SAXS), and optical microscopy. They are employed to unravel
relationships between the molecular dynamics, morphology, and rheology of
crystallizing polymers. The results confirm a physical gelation process during
polymer crystallization, mediated by the interaction of growing superstructures at volume fractions of 10–15%. The buildup of row-nucleated structures
during flow-induced crystallization is found to reduce the time of gelation as
detected by the rheological response. These investigations help to clarify the
crystallization mechanism, structure–property relationships, and the hardening behavior of crystallizing polymers.
