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Now showing 1 - 3 of 3
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    Carboxylated nitrile butadiene rubber/hybrid filler composites
    (São Carlos : Universidade Federal de São Carlos, 2012) Mousa, A.; Heinrich, G.; Simon, F.; Wagenknecht, U.; Stöckelhuber, K.-W.; Dweiri, R.
    The surface properties of the OSW and NLS are measured with the dynamic contact-angle technique. The x-ray photoelectron spectroscopy (XPS) of the OSW reveals that the OSW possesses various reactive functional groups namely hydroxyl groups (OH). Hybrid filler from NLS and OSW were incorporated into carboxylated nitrile rubber (XNBR) to produce XNBR hybrid composites. The reaction of OH groups from the OSW with COOH of the XNBR is checked by attenuated total reflectance spectra (ATR-IR) of the composites. The degree of curing ΔM (maximum torque-minimum torque) as a function of hybrid filler as derived from moving die rheometer (MDR) is reported. The stress-strain behavior of the hybrid composites as well as the dynamic mechanical thermal analysis (DMTA) is studied. Bonding quality and dispersion of the hybrid filler with and in XNBR are examined using scanning-transmission electron microscopy (STEM in SEM).
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    Topographical anisotropy and wetting of ground stainless steel surfaces
    (Basel : MDPI AG, 2012) Calvimontes, A.; Mauermann, M.; Bellmann, C.
    Microscopic and physico-chemical methods were used for a comprehensive surface characterization of different mechanically modified stainless steel surfaces. The surfaces were analyzed using high-resolution confocal microscopy, resulting in detailed information about the topographic properties. In addition, static water contact angle measurements were carried out to characterize the surface heterogeneity of the samples. The effect of morphological anisotropy on water contact angle anisotropy was investigated. The correlation between topography and wetting was studied by means of a model of wetting proposed in the present work, that allows quantifying the air volume of the interface water drop-stainless steel surface.
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    Volumetrical characterization of sheet molding compounds
    (Basel : MDPI, 2010) Calvimontes, A.; Grund, K.; Müller, A.
    For a comprehensive study of Sheet Molding Compound (SMC) surfaces, topographical data obtained by chromatic confocal imaging were submitted systematically for the development of a profile model to understand the formation of cavities on the surface. In order to qualify SMC surfaces and to predict their coatability, a characterization of cavities is applied. To quantify the effect of surface modification treatments, a new parameter (Surface Relative Smooth) is presented, applied and probed. The parameter proposed can be used for any surface modification of any solid material. © 2010 by the authors.