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Aging of polymeric materials by stray‐field NMR relaxometry with the NMR‐MOUSE
The sensitivity of NMR relaxation to molecular motion is explored to study the aging of polymer materials and paint binder in master paintings. Polymeric materials are formulated from macromolecules with a distribution of molecular weights and low molecular weight additives. Their physical and chemical properties change with time due to exposure to temperature, mechanical stress, …
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Estimation of Self-Diffusion Coefficients of Small Penetrants in Semicrystalline Polymers Using Single-Sided NMR
A simple and fast way to measure proton self‐diffusion coefficients of small penetrant molecules in semicrystalline polymers is introduced. The approach takes advantage of the strong static gradient of a mobile single‐sided NMR sensor and it is demonstrated on PE samples with varying degrees of crystallinity fully saturated in either toluene or n‐hexane. The self‐diffusion …
Optimierung der Umhüllung von Stahlrohren
Das Verständnis der Korrosions- bzw. Alterungsvorgänge in teilkristallinen Polymeren wie beispielsweise Polyethylen oder Polypropylen und deren Einfluss auf das Bruchverhalten ist eine wesentliche Voraussetzung zur Optimierung von Umhüllungssystemen für Stahlrohre. Die in der Praxis beobachteten Effekte und Ursachen der Spannungsrissbildung werden derzeit anhand von Erkenntnissen aus Zugversuchen diskutiert. Für die Beantwortung der damit verbundenen Fragestellung, …
Aging of polyethylene: Non-destructive testing with mobile magnetic resonance
Magnetic Resonance (NMR: Nuclear Magnetic Resonance) is known in medical imaging as a diagnostic tool and in chemistry as a spectroscopic method for molecular structural analysis. In both cases, the object of interest is investigated with radio-frequency waves in the center of strong super-conducting magnets. High and homogeneous magnetic fields simplify the measurement process, but …
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Investigation of silicone breast implants with the NMR-MOUSE
Silicone breast implants are used for breast augmentation and breast reconstruction. The issues of concern associated with such implants are: (a) the quality control of each implant before implantation, and (b) the detection of implant bleeding after implantation. We have studied the use of the Nuclear Magnetic Resonance–MObile Universal Surface Explorer (NMR-MOUSE) for the nondestructive …
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NMR mobil: Wie altert Polyethylen?
Die NMR‐Mouse für die zerstörungsfreie NMR‐Analytik läuft mit einem Spektrometer von der Größe eines Notebooks. Sie untersucht Rohre und Benzintanks aus Kunststoff, Autoreifen und Schläuche, Gemälde alter Meister, lebende Haut und Mumien. Auch Tomogramme und NMR‐Spektren von Flüssigkeiten lassen sich in Auflagetechnik messen. Blümich, NMR mobil: Wie altert Polyethylen? Nachrichten aus der Chemie 55 (2007) …
Analysis of Polymer Materials by Surface NMR via the NMR MOUSE
Applications are discussed of a novel NMR device, the NMR MOUSE (mobileuniversalsurfaceexplorer), for characterization of polymers. Different properties of elastomers can be related to an effective transverse relaxation parameterT2eff. Effects of multiecho sequences influence the decay curve and can be described in terms ofB0inhomogeneity and spin-lock effects. Furthermore, the signal-to-noise ratio (S/N) can be improved …
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