Berlin 2018 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 64: Nanostructures, Nanostructuring and Nanosized Soft Matter II
CPP 64.3: Vortrag
Donnerstag, 15. März 2018, 10:00–10:15, PC 203
Effect of boehmite nanoparticles on mechanical properties and network architecture of epoxy — •Media Ghasem Zadeh Khorasani1, Dorothee Silbernagl1, Paulina Szymoniak1, and Heinz Sturm1, 2 — 1BAM, Berlin, Germany — 2TU Berlin, Germany
Boehmite nanofillers (NP) were found to enhance mechanical properties of epoxy nanocomposites. Understanding the underlying mechanism requires investigations on structure-property relationship. Thus, we study the mechanical properties of anhydride-cured epoxy with boehmite NP (up to 15%wt) using AFM-based methods: force distance curves (FDC) and intermodulation AFM (ImAFM). FDC measurements show increase in stiffness of epoxy in the presence of boehmite but cannot resolve NPs. ImAFM stiffness maps with a resolution of ~10 nm reveal an unexpected increase in stiffness of epoxy matrix which implies structural change in the matrix. To investigate these changes dynamic mechanical analysis (DMA) is performed yielding viscoelastic properties and nanostructure of the cross-linked networks. We observe significant inhomogeneity and uncured residues in the neat epoxy which gradually disappear with increasing concentration of NP. In the case of 15wt% NP, despite of an increase in storage modulus of the glassy state, the rubbery state storage modulus and the crosslinking density decrease drastically. Based on these observations, we propose a new mechanism in which boehmite particles not only interact with epoxy matrix but also contribute to curing process and network structure.