Filters

2016 - 20192

More filters

2021 - 20232
Reset filters

Settings

Author: Pötschke, Petra × End date: 2023 × Start date: 2020 × End date: 2019 × Start date: 2010 × Has files: Yes × Subject: Electrical conductivity × Subject: Thermal conductivity ×

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Electrical and thermal conductivity of polypropylene filled with combinations of carbon fillers
    (Melville, NY : AIP, 2016) Krause, Beate; Pötschke, Petra
    The thermal and electrical conductivity of polymer composites filled with a low content up to 7.5 vol% of different carbon fillers (carbon nanotubes, carbon fibers, graphite nanoplates) were investigated. It was found that the combination of two or three carbon fillers leads to an increase of thermal conductivity up to 193% which is higher than the sum of the effects of both fillers.
  • Thumbnail Image
    Item
    Characterization of highly filled PP/graphite composites for adhesive joining in fuel cell applications
    (Basel : MDPI, 2019) Rzeczkowski, Piotr; Krause, Beate; Pötschke, Petra
    In order to evaluate the suitability of graphite composite materials for use as bipolar plates in fuel cells, polypropylene (PP) was melt compounded with expanded graphite as conductive filler to form composites with different filler contents of 10–80 wt %. Electrical resistivity, thermal conductivity, and mechanical properties were measured and evaluated as a function of filler content. The electrical and thermal conductivities increased with filler content. Tensile and flexural strengths decreased with the incorporation of expanded graphite in PP. With higher graphite contents, however, both strength values remained more or less unchanged and were below the values of pure PP. Young’s-modulus and flexural modulus increased almost linearly with increasing filler content. The results of the thermogravimetric analysis confirmed the actual filler content in the composite materials. In order to evaluate the wettability and suitability for adhesive joining of graphite composites, contact angle measurements were conducted and surface tensions of composite surfaces were calculated. The results showed a significant increase in the surface tension of graphite composites with increasing filler content. Furthermore, graphite composites were adhesively joined and the strength of the joints was evaluated in the lap-shear test. Increasing filler content in the substrate material resulted in higher tensile lap-shear strength. Additionally, the influence of surface treatment (plasma and chemical) on surface tension and tensile lap-shear strength was investigated. The surface treatment led to a significant improvement of both properties.