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2021
Report
Title
Elastische Kleb- und Vergusssysteme zur Ableitung elektrostatischer Ladungen
Title Supplement
Herstellung und Charakterisierung elektrisch leitfähiger Polyurethan- und Silikonsysteme mit Nanokohlenstoffen; Abschlussbericht zum IGF-Projekt
Abstract
The aim of the project was to produce elastic, electrically conductive polymer systems based on polyurethanes and silicones by adding nanocarbons. After a material pre-selection, polymer composites based on three commercial silicones (Novasil S44, Novasil S822, Sylgard 184) and two commercial polyurethanes (WEVO-PUR PD52, WEVOPUR 895) as well as three nanocarbon-based fillers (Carbon Black ENSACO 250 G, Single-Walled Carbon Nanotubes Tuball, Multi-Walled Carbon Nanotubes NC7000) were produced and characterized. The dispersion processes considered were the dual asymmetric centrifuge (DAZ) and the three-roll mill. With filling degrees up to 0.5 wt.%, the electrical volume resistivity of the composites could be reduced by up to 16 orders of magnitude, so that the composites could be classified as electrically conductive. This condition has proven to be stable in climate change tests over 1.000 hours. Consequently, composites suitable for ESD applications can be produced. Furthermore, the application for contacting resistance heating elements for passenger cars was tested in a demonstrator. The achievable properties depended strongly on the dispersion quality achieved. It was higher with the three-roll mill compared to DAZ, following a higher sedimentation stability of these resins. The viscosity was greatly increased by the addition of the nanotubes, especially for low-viscosity potting systems, but can probably be reduced again by processing additives. However, the latter was not the subject of the research project. Stress at break and elongation at break were only slightly to strongly influenced, depending on the system. No systematic influence on adhesion could be determined in the area under consideration. The surface energy tends to be reduced by nanotubes for polyurethanes and increased for silicones.
Author(s)