Berlin 2008 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 37: Molecular Dynamics

CPP 37.8: Vortrag

Freitag, 29. Februar 2008, 12:15–12:30, C 230

Morphological Differences in Semi-crystalline Polymers: Its Implications on Local Dynamics and Chain Diffusion — •Robert Graf¹, Yefeng Yao¹, Sanjay Rastogi², and Hans Wolfgang Spiess¹ — ¹Max-Planck-Institut für Polymerforschung, 55128 Mainz, Deutschland — ²Eindhoven University of Technology, 5600MB Eindhoven, The Netherlands

Morphological differences in semi-crystalline polymers due to different crystallization conditions have strong implications on the chain motion. Using a broad variety of solid state NMR techniques probing the molecular dynamics on different time and length scales, the local dynamics in the non-crystalline regions of solution crystallized linear polyethylene was found to be is lower than in a melt crystallized sample under the same conditions, but the opposite is observed for chain diffusion between non-crystalline and crystalline regions. The activation enthalpy for chain diffusion, however, is the same, indicating that entropic differences in the non-crystalline regions strongly influence the chain diffusion of the same polymer in different morphologies.

Reference:

Y-F. Yao, R. Graf, H.W. Spiess,D.R. Lippits, S. Rastogi, Phys. Rev. E, in press.