scholarly journals Migration of mineral oil in elastomers

2021 ◽  
Author(s):  
Tobias Förster ◽  
Artur Blivernitz
Keyword(s):  
Diffusion Coefficients ◽  
Mineral Oil ◽  
Activation Energies ◽  
Concentration Profiles ◽  
Small Reservoir ◽  
Experimental Procedure ◽  
Mineral Oils ◽  
The Absolute ◽  
Suitable Measure

AbstractThis work describes a newly introduced experimental procedure to quantify the diffusion progress of mineral oils locally resolved in NBR. Diffusion of reference oils IRM 901, IRM 902 and IRM 903 in NBR with various acrylonitrile contents was investigated. Classical sorption experiments were performed as a basic characterization and compared to the newly introduced method. Here, elastomer specimens are only being dipped with the bottom in a relatively small reservoir of mineral oil. This provides a determination of locally resolved concentration profiles of mineral oils, and the calculation of diffusion coefficients. These diffusion coefficients follow the same trends like those determined via sorption experiments. Despite differences in the absolute numbers, activation energies of diffusion can be applied as a suitable measure for the compatibility of elastomers and fluids.

scholarly journals Determination of Diffusion Coefficients Using Thermogravimetric Measurements during High Temperature Oxidation

2012 ◽  
Vol 323-325 ◽  
pp. 289-294
Author(s):  
Patrice Berthod ◽  
Lionel Aranda
Keyword(s):  
Diffusion Coefficient ◽  
High Temperature ◽  
Diffusion Coefficients ◽  
High Temperature Oxidation ◽  
Concentration Profiles ◽  
Metallic Elements ◽  
Chromium Diffusion ◽  
Temperature Oxidation ◽  
Iron Based

Thermogravimetry measurements associated to concentration profiles allow determining a diffusion coefficient at high temperature of the most oxidable one among the metallic elements belonging to the chemical composition of an alloy. In this work the employed method is described and applied to chromia-forming alloys essentially based on nickel but also to selected cobalt-based and iron-based alloys. More precisely DCrvalues were estimated for chromium diffusing through the carbide-free zones developed during high temperature oxidation. The effects of the base element, of the chromium carbides density and of the dendritic orientations on the chromium diffusion were evidenced.

Determination of Diffusion Coefficients with Quantitative X-Ray Microanalysis at High - Spatial Resolution

2012 ◽  
Vol 323-325 ◽  
pp. 61-67 ◽  
Author(s):  
Raynald Gauvin ◽  
Nicolas Brodusch ◽  
Pierre Michaud
Keyword(s):  
Diffusion Coefficient ◽  
Diffusion Coefficients ◽  
Beam Energy ◽  
High Spatial Resolution ◽  
Ratio Method ◽  
Concentration Profiles ◽  
X Ray ◽  
Advantages And Disadvantages ◽  
Scanning Electron

This paper present the determination of concentration profiles of an Mg Al diffusion couple that was obtained with a high resolution field emission scanning electron microscope, the Hitachi SU-8000 equipped with a SDD EDS detector. From these concentration profiles, the inter-diffusion coefficient is determined with the Boltzmann-Matano technique. The advantages and disadvantages of working at high and low beam energy for quantitative x-ray microanalysis are highlighted. The f ratio method is used in this work to convert the x-ray intensities into composition.

Chronoamperometric Determination of Diffusion Coefficients for Borohydride Anions in Sodium Hydroxide Solutions

2008 ◽  
Vol 273-276 ◽  
pp. 583-589 ◽  
Author(s):  
Diogo M.F. Santos ◽  
César A.C. Sequeira
Keyword(s):  
Sodium Hydroxide ◽  
Sodium Borohydride ◽  
Diffusion Coefficients ◽  
Activation Energies ◽  
Disc Electrode ◽  
Estimated Parameters ◽  
Borohydride Oxidation

Chronoamperometry is carried out with a Au disc electrode in alkaline sodium borohydride solutions of varying concentrations and temperatures. By selecting conditions for which the borohydride oxidation is controlled by diffusion, it was possible to deduce diffusion coefficients and activation energies for borohydride concentrations ranging from 0.03 M to 0.12 M, and temperatures ranging from 25 to 65 °C. The estimated parameters were compared with other values reported in the open literature.

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