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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 40: Nanoparticles and Composite Materials I

CPP 40.7: Vortrag

Donnerstag, 25. März 2010, 11:15–11:30, H48

Influence of the nanoparticles on the structural relaxations in epoxy nanocomposites as seen by rheological spectroscopy — •Matthieu Thomassey, Jörg Baller, Jan Kristian Krüger, and Roland Sanctuary — Université du Luxembourg, Laboratory of Physics of Condensed Matter and Advanced Materials (LPM), 162a Avenue de la Faïencerie L-1511 Luxembourg

Due to their large surfaces nanoparticles are well known to have a dramatic influence on the glass transition behavior of nanocomposites made of oligomer matrices and inorganic fillers. Generally one distinguishes between topological and surface induced effects of the nanoparticles. By changing the concentration of the filler particles, topological constraints are expected to have an influence on the glass transition of the composite. By modifying the state of their surfaces the interaction between the oligomer molecules and the nanoparticles and hence the mechanisms leading to the glass transition are also altered. This paper presents a rheological study of an epoxy resin (DGEBA) filled either with alumina particles with a hydrophilic surface or silica with a hydrophobic surface. Topological and surface-induced effects of the nanoparticles on the glass transition behavior of the composite are elucidated. Rheological spectroscopy is used to study the temperature and frequency dependencies of the shear moduli for the two types of nanocomposites. Special attention is paid to an abnormal behavior of the real and imaginary parts of the shear modulus.