Regensburg 2019 – wissenschaftliches Programm
CPP 10.2: Vortrag
Montag, 1. April 2019, 15:15–15:30, H13
Combining Infrared Micro-Spectroscopy and Fast Scanning Chip Calorimetry to unravel homogeneous nucleation and crystallization in poly(amide-6-6) — Wilhelm Kossack1, Evgeny Zhuravlev2, Rustem Andrianov3, Christoph Schick2,3, and •Friedrich Kremer1 — 1University Leipzig, molecular physics, Linnestr. 5, Leipzig, Germany — 2Institute of Physics and Competence Centre CALOR°, University of Rostock, Albert-Einstein-Str. 23-24, 18051 Rostock, Germany — 3Institute of Chemistry, Kazan Federal University, 18 Kremlyovskaya Street, Kazan 420008, Russian Federation
A combination of Infrared micro-spectroscopy and Fast Scanning calorimetry is used for a simultaneous measurement of moiety specific IR-absorption and heat capacity in the super-cooled amorphous melt of poly(amide-6-6). The temporal evolution of both quantities is recorded depending on temperature and time to unravel the microscopic, moiety-specific mechanism of homogeneous nucleation. The IR results reveal a continuous increase of bands related to the crystalline phase on expense of the amorphous phase. In agreement with classical nucleation theory, first experiments do not reveal a moiety-specific interaction during homogeneous nucleation. Furthermore both, IR-signature and calorimetric crystallinity and nuclei densities follow similar kinetics. In summary, no evidence is found that homogeneous nuclei and early crystals differ qualitatively on the level of a unit cell from well grown lamellae. Based on these experiments an experimentally based estimate of the size of homogeneous nuclei is possible.