Dresden 2014 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 37: Poster Session 2
CPP 37.67: Poster
Mittwoch, 2. April 2014, 15:00–19:00, P3
Kinetics of nucleation and crystallization of poly(e-caprolactone) * multiwalled carbon nanotube composites — •Evgeny Zhuravlev1, Andreas Wurm1, Petra Pötschke2, and Christoph Schick1 — 1University of Rostock, Institute of Physics, Rostock, Germany — 2Leibniz Institute of Polymer Research Dresden, Dresden, Germany
The nucleation efficiency of multi-wall carbon nano-tubes (MWCNT) in poly(e-caprolactone) (PCL), as an example, was tested for a wide range of temperatures and cooling rates and compared to the efficiency of homogeneously formed nuclei. The temperature range below the maximum of crystallization rate is generally not accessible for non-isothermal cooling experiments because the sample becomes amorphous at the needed cooling rates. Isothermal experiments after fast quenches extend the temperature range down to and below the glass transition. The employed differential fast scanning calorimeter (DFSC) allows cooling at rates up to 100,000 K/s and precise control of isothermal conditions in the time range from 10^-4 to 10^4 s. Heterogeneous crystal nucleation dominates at low supercooling, revealing a significant dependence of crystallization rate on MWCNT concentration. No saturation of the nucleation activity at a MWCNT loading of 0.2 to 0.5 wt% was observed. At high supercooling, where homogeneous nucleation is prevalent, the addition of MWCNT does not enhance neither reduce the crystallization rate. At the temperature of maximum homogeneous nucleation rate, formation of homogeneous nuclei always dominates crystallization.